Quick Search

Search Results

The database contains publications from Structural-Safety and CROSS International partners.

The search engine looks at document titles, a keyword associated with documents, and the text of Word documents. Entering a single word into the keyword facility will find all documents containing that word.

After receipt, reports are categorised using a general construction taxonomy. This is available on request and anyone wishing to make more detailed searches should contact structures@structural-safety.org for advice.

Found 206 document/s:
Search Term: temporary works


16 Deep excavation

On a construction site by a busy main road a reporter saw a deep excavation with no internal temporary works.

View Report  


20 Steel Portal Frame Erection

A project involved the construction of a large span steel framed portal frame building in which longitudinal stability was provided by triangulated vertical side bracings and triangulated bracings in the plane of the rafters.

View Report  


25 Steelwork connection design

A reporter was asked to design connections for a multi-storey building for which the frame had been designed by another engineer. The result was a near collapse situation.

View Report  


26 Scottish tenements

Tenements appear massive and solid but many are not particularly robust, and are quite vulnerable to accidental damage.

View Report  


27 Pre-cast concrete demolition

During the demolition of a tower block, a column collapsed unexpectedly.

View Report  


32 Masonry support prop adaptor

The use of a steel bracket on top of a prop, giving an eccentricity of about 200 mm would not seem to be such a good idea.

View Report  


33 Building Regulations checking

A reporter’s firm has been carrying out Building Regulations checks for 25 years, but it is only in the last six or seven years (say 2000-2006) that concerns have arisen, some of which are described below.

View Report  


53 Scaffolds and traffic protection

A reporter who is a Local Authority Structural Engineer is often consulted about, and sometimes has to arrange for, scaffolds to be erected on the Public Highway, or at least within close proximity of vehicular traffic. What amazes him is the lack of consideration shown both in British Standards and industry guidance regarding the risk of impact of vehicles with scaffolds and thereby putting at risk those working on a scaffold and those in the vicinity should a collapse or partial collapse occur.

View Report  


62 Timber truss

The reporter has been dealing with an application where the engineer involved discovered proprietary timber girder trusses 400mm deep and spanning 7.5m @ 1.2m centres with glued joints. Some of these joints have come loose.

View Report  


72 Underpinning

This reporter (who was the ‘Designer’) attended site to meet a Party Wall Surveyor and the Structural Engineer, acting for the adjoining owner, for a building on one edge of the site. The groundworks contractor had proceeded with underpinning to that adjoining property in advance of the contract being signed but, more alarmingly, had completely ignored the specified 5-bay sequence and timing of the works shown on the reporter’s drawings.

View Report  


73 Scaffold protection

The bridge in question comprises of two main edge lattice through-girders with troughing between the bottom flanges. The temporary scaffold is suspended from the bottom flanges, on proprietary girder couplers, to provide a crash deck below to give full access to underside, together with a temporary roofed shelter surrounding the main girder above road level on one side at a time to allow single lane traffic, controlled by traffic lights, to run over.

View Report  


87 Long term risks for ground anchors

Two reporters have been involved in several projects or potential projects where riverside sites have been considered for redevelopment. In each case, the river wall forms part of the strategic flood defences for the area and typically comprises of driven steel sheet piling held back by tensioned ground anchors up to 30m (or more) in length and raked at angles between 25° and 50° to the horizontal.

View Report  


96 Demolition risks

This is about the collapse of a ‘flat slab’ building that occurred overseas whilst the top floor of the building was being demolished onto the next floor down. He says that this process was being undertaken by three tracked vehicles operating on the floor. The collapse was a classic "pancaking" of the slabs as they effectively slid down the supporting concrete columns. Several employees were killed in the accident and a number of serious defects were identified.

View Report  


99 Collapse of a wall during construction

An internal corridor wall collapsed in a school under construction. The wall, when checked, was not to be unstable in all stages of its construction even when built up to the head, until the external envelope was substantially complete.

View Report  


112 Inadequate foundation reinforcement

The photograph is of ground beams for a multi-storey development where the subcontractors carrying out the ground works failed to provide sufficient continuity reinforcement.

View Report  


113 Blind bolt query

Further to report No 071 published in the newsletter No 6 (April 2008) regarding ‘blind bolts’ a query was received as to how to include an appropriate clause in a specification for structural works

View Report  


125 Advice wanted by amateur builder

I am removing a supporting wall between the old exterior of the house and the new 'lean-to' extension. Because the 4-metre lintel will be fitted into the ceiling cavity I can't needle it but will be using 4 strongboys on the outside and 3 acros supporting the ceiling on the inside. I will also have a couple of temporary acros to use directly under the wall. The wall is a concrete block cavity wall.

View Report  


128 House collapse

This is a case of collapse caused by a builder carrying out underpinning works.

View Report  


133 Wind loads during construction

During construction the structure and associated temporary works are subjected to wind loading. This load case is typically short term and BS 6399 Part 2 allows for a reduction in wind speed where the load is of a temporary nature. What is not made clear in the code, but is in the supporting documentation, is that this reduction is based on the expectation that in times of high wind load the structure will not be in use, and therefore the consequence of failure is not severe.

View Report  


136 Public art structures

Engineers have noticed a trend for more works of “Public Art” being placed near to highways and in cities. The works may be large and warrant a significant engineering input but may be driven forward by persons without sufficient appreciation of the technical issues involved. Three examples are given.

View Report  


142 Temporary bridge jacking

Transport for London (London Rail) reported publically on an incident concerning temporary bridge jacking and permission to reproduce an extract is gratefully acknowledged by CROSS. In early May 2008 Bridge GE19 was successfully moved into position above Network Rail tracks just outside Liverpool Street station, and a few weeks later the bridge was in the process of being 'jacked down' into its final resting place. After work had finished for the day the temporary supports for the bridge failed at the east end. This failure resulted in the bridge dropping approximately 200mm off the temporary support plates onto the permanent bearings.

View Report  


146 Temporary works propping

A self-employed structural engineer was working for a consulting firm on a design and build contract refurbishing a large office building which was anything from 50-80 years old. The structure consisted of hollow pot floors with concrete encased steel columns. During previous works a plant room had been added to the roof and no remedial work undertaken, so after a load assessment it was decided that a column needed strengthening over one storey. The work involved the installation of a stressed prop to provide temporary support to the structure.

View Report  


147 Post-tensioned pre-cast concrete tank failure

A utility company suffered a sudden and catastrophic failure of a concrete tank at a sewage treatment works. The tank was constructed from pre-cast concrete panels which were pre-stressed with circumferential un-bonded cables in grease filled sheaths.

View Report  


150 Collapse of tank falsework

The issue relates to the collapse of falsework erected to construct an in situ, reinforced concrete, circular water retaining structure about 20m diameter by 15m high – a typical digester tank on a sewage treatment works. The company (now no longer in existence) that emplyed the reporter was the design and build contractor for a number of tanks on the site.

View Report  


151 Divided design responsibilities

Having sized the lintels (to support 5m height of blockwork) the firm were then asked by the contractor to confirm the overall stability of the walls. It transpired that the brickwork sub-contractor had taken on a "works package" from the management contractor. The sub contractor had apparently assumed design responsibility for their portion of works such that; wind posts had been sized and located by the wind post company and lintels were to be sized by the lintel company’s advisors (the reporter’s firm). "Overall" responsibility appears to have been apportioned out to individual parties rather than having one structural consultant onboard to pull all the various aspects together.

View Report  


153 Dangerous arches

Several arches of an undercroft style structure in a conservation area were demolished, apparently without consent, leaving one standing which was used as a garage below and giving vehicular access to a multi-occupancy house above. The arches carried a road and, according to the reporter, the situation was very dangerous.

View Report  


155 Bridge failure report and CDM

A report was developed for CDM co-ordinators based on the findings of the TfL report into a bridge incident (28/5/08) over the rail tracks outside Liverpool Street Station London (see CROSS Newsletter No 14). The conclusions, in the report, were used to illustrate advice and guidance that the CDM Co-ordinator (under Construction (Design and Management) Regulations 2007) for both client and design team.

View Report  


157 More about public art

I felt (says a reporter) that I had to write concerning the issue of Public Art (CROSS Newsletter No 14 report 136), having had a lot of interaction with a Council when I was Head of Building Control.

View Report  


169 Dangerous modification to a column

A reporter was requested to visit a warehouse to inspect work carried out to a column that was constantly being hit by a fork truck. The Client had commissioned a 'design & build' contractor to remove the lower section of the column and support the higher section out of the path of the forklift with a cantilever.

View Report  


171 Concerns on stability require prompt action

A reporter was concerned about overall building stability during an extension and conversion project. All old internal walls and floors had either been removed or were being removed and external walls were in a precarious condition.

View Report  


175 Unsuitable underpinning

When reviewing a consulting engineers proposal to underpin a party wall, the reporter noticed that there was insufficient vertical load to maintain stability under lateral load from the retained height of soil.

View Report  


176 Lifting large double glazing unit

Inadequate instructions were provided by a double glazing pane supplier on how to lift and move their product, supplied on a flatbed truck, off the truck and onto the works.

View Report  


189 Retaining wall concerns and the stance of a local authority

A reporter was asked by a Client to assess a retaining wall built on their boundary by a neighbour who had erected a new dwelling. Of reinforced concrete block work construction the wall is about 2.75m high at its highest point and retained the Client’s land. From a visual inspection the wall appeared sound. However, a review of the calculations and a typical section, gave serious concern for its strength.

View Report  


204 Split responsibilities on temporary bracing of steelwork

A project is supported by numerous steel columns which start at ground floor level. Because of various site constraints, several columns are kinked at upper floor levels; the resulting horizontal forces are taken back to a substantial concrete core through the floor beams or slabs. The second floor slab is post tensioned concrete and the contractor decided to erect the steel first and install the second floor slab later, when the steelwork and concrete subcontractors would not interfere with each other.

View Report  


205 Role of approved inspectors

A reporter’s firm is involved in a partially built project, worth £6m, where there is defective work and the builder has gone into liquidation. The project is 2-3 storey building in the health care sector and has load-bearing masonry walls and floors spans of up to 9m. The reporter and the client have sought the information that they would normally expect be lodged with the Approved Inspector concerning the structural design.

View Report  


209 Risk in notching timber studs

During the construction of a block for student accommodation a reporter found a couple of locations on an external 4th floor wall where the load-bearing studs had been notched well past permissible depths.

View Report  


212 Do Building Regulations apply to repairing a collapsed building?

The building in question is mid 19th century mill with cast iron frames spanning 8.0m at 3.3m centres and jack arch floors. It has three storeys and a roof and is 24m wide by 67m long and was subject to a fire which resulted in the sudden collapse of part of the interior structure.

View Report  


215 Permanent formwork to slabs

The advantage of permanent formwork to slabs is that it can remove the need for temporary falsework and formwork. However, designers of structural frames usually leave the specification of the sheeting to the contractor and do not specify what propping is required when the concrete is placed. In turn, the people responsible for procurement within the contractor go out for quotes to specialist suppliers of the sheeting. The suppliers typically do not know the deflections of the steel frame under dead load so assume zero deflection and specify sheets over one, two or three spans.

View Report  


219 Deficiencies on access scaffold

Investigation by a reporter’s firm into an access scaffold on a refurbishment contract on a city centre site brought to light a number of deficiencies which rendered the scaffold outwith its design parameters.

View Report  


228 Hoarding blown onto child (news)

A two-year-old child escaped with minor injuries injury after a 2.4 m high, 17m wide, shop hoarding collapsed on him as it was blown over. The main contractor and the hoarding sub-contractor pleaded guilty to breaching the Construction (Design and Management) regulations 2007.

View Report  


230 Defective imported scaffold ties

On a contract where multi lift access scaffolds had been installed for a period of up to 18 months in an exposed coastal location, it was found by a reporter on one of the regular inspections that some of the scaffold ties had failed.

View Report  


241 Lack of control on site when underpinning

The concern is in relation to the sequencing of construction and the lack of control on site from competent persons. The reporter says that a Victorian building with four storeys and a basement was being converted to a small hotel. As part of this work the basement level was being lowered by approximately 1m.

View Report  


255 Use of water filled containers to anchor temporary structures

The reporter is a local authority Environmental Health Officer who is responsible for licensing the safety aspects at a local festival. As part of the structure of the main stage, water filled plastic containers are used as anchors/ballast. He says that he has concerns over the suitability of these as he believes they could become crushed quickly and not provide the weight that is intended.

View Report  


256 Adequacy of termination connectors for tensile bars

The following report is intended to raise concern regarding the structural adequacy, quality control and inspection techniques used in the manufacture of proprietary bar systems, in particular the cast end terminations of the bar systems.

View Report  


257 Foundation base plates for tower cranes

On two different contracts it was observed that the foundation base plates for tower cranes have suffered from low compaction of the concrete on which they rest.

View Report  


258 Collapse of a hollow core unit

This refers to the collapse of one modest span PC hollow core concrete unit and the excessive deflection of others on a building which was under construction. The collapse occurred when the only load was self-weight and fortunately the falling debris missed workers below and there were no injuries.

View Report  


262 Asymmetric bridge design and construction – a near miss

During the construction stage of an arch footbridge, says a reporter, a design error was identified that had been indirectly revealed by an associated error in construction. It is reported that effective correction of these errors was expensive but resolved the potential performance safety issues.

View Report  


263 Concern about faulty self-certification of new installation

A reporter’s client had work done in a domestic property by a specialist contractor who was registered under a self-certification Competent Person’s Scheme (CPS) but the work was faulty. The scheme was intended to ensure that installations complied with Building Regulations. The regulatory body for the scheme was unwilling to arrange remedial works and it took more than a year (and two re-installations) before an adequate job was done.

View Report  


276 Licensing of temporary structures

Temporary structures, such as stages, marquees, lighting towers, video screens and the like are erected at a huge number of events in the UK each year. I have, says a reporter, inspected many such structures and have concerns that the systems in place for ensuring their stability are not working. Because of the number of people in close proximity, he continues, the failure of such a structure could have very serious consequences.

View Report  


278 Hoarding incident

A reporter says that under high, but not severe, wind loads a portion of timber hoarding failed and struck site personnel.

View Report  


297 New basements beneath existing properties

A reporter is concerned about the construction of some basements in London. He has reviewed two projects covering basement works in relation to Building Regulation checks on the structural aspects.

View Report  


298 Props to large excavations

A correspondent is concerned about the design of propping to large excavations and particularly about the design of the connections for a raking prop to a horizontal waler.

View Report  


298 Props to large excavations

A correspondent is concerned about the design of propping to large excavations and particularly about the design of the connections for a raking prop to a horizontal waler.

View Report  


302 Example of small temporary stage structure

This is an example of a small stage that is potentially unstable.

View Report  


312 Look-alike construction equipment

A reporter wonders if the risks brought to the industry by look-alike temporary works equipment is something that had been reported to CROSS?

View Report  


317 Chain hoist problem

A number of brand new proprietary hoists were being used during the progressive demolition of a gas holder says a reporter. One, a 20 tonne hand chain block was left under load over a weekend and afterwards one strand of the 6 strands of chain was found to be broken.

View Report  


324 Lack of experience on steel column erection

Geometric constraints required that some column baseplates used a 2-bolt solution with the bolts located between the flanges of the UC sections. Notes on the drawings identified a temporary stability issue and said that the columns required propping until fully grouted. Several requests were made to the contractor to provide a method statement for erection but this was not provided and the reporter only noticed via a project webcam that the works had started.

View Report  


327 Erecting reinforcement cages

A reporter asks about best practice guidance for the installation of pre-assembled reinforcement cages, as he can find very little guidance on the web.

View Report  


332 Stud failure

This concerns the failure of a stud during construction works on a new bridge associated with major road improvements. The form of the bridge is of steel girders with a reinforced concrete deck and parapets. In order to pour the deck and parapets, cantilevered formwork was installed. As one of the support rods was being tightened to take the load of a table unit, a stud which attached the forged beam bracket to the steel girder failed.

View Report  


333 Falsework support to a bridge – a near miss

This report follows the near collapse of a birdcage scaffold falsework structure during an 800 cubic metre concrete pour on a motorway bridge.

View Report  


337 Falsework collapse during slab pour in SE Asia

There was a partial collapse of falsework on a project in Southeast Asia. He says that during a pause in a slab pour of a post tensioned slab with band beams, a collapse of the supporting falsework occurred across an area of approximately 300 m2. A forensic investigation led to the discovery of a multitude of errors with regards to falsework design and construction.

View Report  


343 Inadequate steel beam splice

As part of a project a reporter provided the design for a steel beam. The client sourced this from a fabricator and it came with a mid-span splice.

View Report  


346 Viaduct survey concerns

A small four span brickwork railway viaduct has been degrading for some time and a reporter, who was not associated with the structure, noted that cracks had worsened over recent years.

View Report  


357 Wall reinforcement cages collapse

A contractor says that he has experienced two cases of wall reinforcement cages collapsing.

View Report  


359 Boom MEPW falls through precast planks

A high injury potential near-miss (near hit) incident occurred when a boom MEPW fell through such a floor at a point where there was a notched precast plank. The plank failed because of installation and quality errors which could potentially have resulted in the MEWP and operator falling through multiple floors of the structure.

View Report  


361 Basement party walls

The client's Consulting Engineer had designed a new basement but, when queried by the Consulting Engineer for the main contractor, was unable to provide survey information for the adjoining property.

View Report  


368 Potentially dangerous excavation

A reporter has submitted this photograph of a potentially dangerous excavation.

View Report  


374 Rebar cage temporary stability

The reporter says that on two occasions in, on different sites, 6m high rebar cages collapsed under wind loads.

View Report  


385 Failure of existing basement wall

A basement retaining wall failed when a new basement was formed by excavating 1.8m.

View Report  


395 Partial roof collapse at shopping centre

There was a recent partial roof collapse at a Shopping Centre which was, says the reporter, built in the early 1970s in a form which may have been used extensively throughout the UK during this period and possibly beyond.

View Report  


407 Unsafe timber scaffolding

A rickety temporary scaffold had been constructed from 4”x2” (100mm x 50mm) timber and scaffold boards apparently nailed together, says a reporter.

View Report  


420 Contractor varies structural design intention

This report concerns two steel beams to support first floor masonry in a two storey house. The wall was of solid construction and supported the first floor and roof structure.

View Report  


423 Temporary works design for basements

A reporter had an inquiry from a Contractor who, after appointment, discovered that there was a serious lack of temporary works design information (surveys/loads/wall thicknesses, sequencing, in principle method statement regarding the party walls).

View Report  


429 Failure of epoxy resin bonded anchors in concrete

A reporter expresses concern about adhesive bonded anchors made by injecting epoxy resin into drilled holes to fix threaded bars at a pre-determined design depth. During a lifting operation for a section of the guide-wall, the anchors failed progressively when the crane lifted the section 500mm off the ground. The anchors detached from the resin and came out of the holes.

View Report  


430 Failure of anchor bolts holding suspended scaffold

During the removal of a suspended scaffold it was found that a number of the screw bolt anchors had failed.

View Report  


433 Failure of pre-cast concrete 'L' shaped retaining wall

A recent incident occurred on a site, where a temporary pre-cast retaining wall failed leading to a pile of clay approximately 3m high spilling through the wall.

View Report  


435 Balcony strengths of blocks of flats - further experiences

A reporter's firm have been undertaking structural assessments of cantilevered reinforced concrete walkways, which in the majority of cases have been found to be under strength.

View Report  


442 Apollo Theatre London ceiling collapse (news)

In January 2014 Westminster City Council circulated some interim guidance regarding the management of suspended ceilings. The investigation of the partial collapse of the suspended ceiling at the Apollo Theatre in Shaftesbury Avenue London is still in progress and the Council now have a better understanding of the failure mode of the ceiling. A key element of the interim advice is for theatres to understand the form of construction of their individual ceilings and how the constituent parts are joined together and ultimately supported from the main structure. Some of the relevant information about the Apollo Theatre ceiling is given in this report.

View Report  


443 Post-fixed RC anchors - erroneous assumptions leading to unsafe design

Consultants on a recently finished project have reported that a number of steel to RC moment resisting connections were required. During construction the reporter became concerned and realised that several of the proposed fixings did not have the minimum concrete edge distance required and when these fixings were disregarded the software calculated that the design had only a small fraction of the required capacity.

View Report  


458 Alteration to historic column bases

On this small project, says a reporter, a Structural Engineer was commissioned by a contractor to recommend required works for the improvement of first floor living quarters over a shop. The fragile building was over 100 years old with the first floor projected over a pavement and supported by timber columns which were on sandstone stub columns projecting above pavement line.

View Report  


476 Cantilevered brickwork - fatal collapse during construction

A blade of 270mm cavity brickwork in a temporary condition fell and killed a bricklayer after sixteen scaffold planks were leant against the wall on the side remote from the bricklayer.

View Report  


482 Unbraced temporary props

An alarming photograph has been sent by a contributor.

View Report  


488 Fire risk in timber framed structures

The Health & Safety Executive (HSE) has written an ‘open letter’ to the timber-frame frame industry about fire risk during construction. The HSE said “it has acted in the wake of serious incidents where fires involving timber frame structures under construction have affected neighbouring buildings”. Last month, fire ripped through a partially-built laboratory at the University of Nottingham, where the frame was constructed mainly from glue laminated (glulam) beams.

View Report  


500 Partly demolished site

Existing buildings on a city centre site were partly demolished to make way for a new development but the work was delayed and ownership changed.

View Report  


506 Wind problem in city centre

A reporter is dealing with temporary works for sub-contractors working in and around the centre of a major city. He has experienced a spate of wind related incidents where structures which have been designed in accordance with normal practice using current codes have suffered damage and he feels that there is an issue which needs to be investigated and discussed so that Engineers dealing with structures in the vicinity of tall buildings and groups of tall buildings are fully informed.

View Report  


507 Independence of Approved Inspectors

Owners, who provided this report, contracted a house extension company who claimed to handle all aspects of the house extension. Their contractual obligations included obtaining building control approval for plan/design and bringing the project to completion. A series of defects then started surfacing after the completion of the project.

View Report  


522 Failure of Stainless Steel Tie Bars

In 2002 the footways of an important estuary bridge were widened says a report from the owner. The works replaced the cantilevered footways of the structure with footways supported on steel girders which in turn were supported on steel columns. The strengthened footways and the original structure are connected through a keyed concrete joint and pairs of 32mm diameter stainless steel tie bars.

View Report  


522 Failure of stainless steel tie bars

A principal inspection of a bridge found that numerous ties connecting the original bridge to strengthened footways had failed.

View Report  


524 Spalling concrete falling from motorway bridge

An incident occurred at a motorway overbridge resulting in a piece of spalling concrete falling onto the carriageway and striking a vehicle. This resulted in minor injuries to the driver. It is understood that the concrete which fell was no greater than 50 - 60mm in size and had spalled from an area of previously repaired concrete.

View Report  


529 Risks from off-site manufacture and hybrid construction

A reporter was recently investigating a ‘near miss’ involving concrete construction in which pre-cast and in-situ concrete were used in combination. This type of construction offers efficiencies and, as in this instance, can reduce the number of man-hours worked at height. It is growing in popularity. It does however bring its own risks, and these need to be understood. The works under investigation comprised a circular shaft 20m in diameter and 20m deep, which required an L-shaped shelf or balcony some 5m from the top.

View Report  


530 Incentivising Safe Behaviour Through Standard Agendas

A reporter was investigating a ‘near miss’ involving concrete construction in which pre-cast and in-situ concrete were used in combination. This type of construction offers efficiencies and, as in this instance, can reduce the number of man-hours worked at height. It does however bring its own risks, and these need to be understood.

View Report  


532 Stored glazing panels

A reporter has been undertaking facade inspections for insurers across many buildings in the UK and the same issue keeps appearing on every site; glazing is not individually tied back to storage frames or to a secure place when being stored.

View Report  


538 Failure to check designs produced by software

A reporter works as a Building Control Officer and recently checked some block work wall calculations for a new office building that had been undertaken using proprietary design software. He noticed a regular error appearing that returned a value of zero for the effective plan area when performing the check for the minimum area required.

View Report  


559 Concrete encasement fall from bridge girder - No.1

Overnight, sections of concrete from the bottom flange of a single encased girder became detached and fell onto an operational line which is adjacent to two platforms.

View Report  


564 Defects found in previously repaired bridge

When carrying out strengthening work on a bridge, there was concern that by removing the non-structural encasement, alternative load paths had been removed.

View Report  


565 Pre-slung rebar loads

A contractor issued a safety alert about pre-slung loads of rebar which has resulted in loads being 'out of balance' when unloaded and bundles not being correctly chocked allowing bars to slip out of the load.

View Report  


567 Fall of old rail section from restaurant ceiling

A report was received from a tenant business manager of a fall of metal from the soffit onto a table in a restaurant/bar.

View Report  


572 Embankment slip

Vertical movement was observed on the safety critical surface at the top of an 8m high embankment. This occurred over a distance of some 25m directly above a length of rockfill shear key being installed at the embankment toe. Had there been a failure of the embankment the consequences could have been severe.

View Report  


574 Responsibilities for hybrid concrete construction

There was a report about a problem during the construction of a hybrid concrete over-bridge. A substantial pre-cast element, weighing over 10t, had been placed in position and used as part of the shuttering for an insitu pour. During the pour the element was pushed out of alignment by the pressure of wet concrete and there was a substantial spillage onto an operating area below.

View Report  


575 Scaffold overturn

A 5m high scaffold screened with fabric overturned when airflow was introduced to a building.

View Report  


576 Worker trapped in excavation

An operative received serious injuries when the excavation they were in collapsed.

View Report  


577 Bridge wing wall collapse

The masonry wing wall of a bridge fell as a single section and came to rest against an adjacent pile. Although the roles and responsibilities placed on individuals on site was clear, there was a lack of direction on who held ultimate responsibility for identifying the need for temporary works.

View Report  


580 Alteration of calculations on a loft conversation that was already built

A reporter says he was pressurised to change retrospectively calculations and drawings following completion of works at a domestic property.

View Report  


587 Plasterwork ceiling partial collapse at railway station

One morning, a railway employee opened the station as normal and saw a section of the cornice, plasterboard roof and lighting on the floor.

View Report  


589 PV panels and structural adequacy of roofs

In total over a period of a few years a reporter's firm of consulting engineers assessed approximately 25,000 domestic roofs on the basis of existing roof information provided by the installer and of those between 15 and 20% were structurally inadequate.

View Report  


596 Sudden hole in piling mat - No.2

This is further information about Report 566 Sudden Hole in Piling Mat which was published in the April 2016 Newsletter. The report at that stage was not conclusive about the cause of the hole and does not reflect the conclusions of later investigation. The report has therefore been updated.

View Report  


597 Inadequate structural design at a school

On review of a design for a school extension, a reporter noted several major issues including an almost total lack of vertical bracing throughout the extension.

View Report  


603 Changes in temporary works scheme

A multi-storey above-ground structure was designed so that the superstructure rested on a basement liner wall, which in turn was dowelled into the secant piled retaining wall. The temporary works designer placed raking props and whaling beams against the secant wall in the temporary case, which prevented completion of the liner wall.

View Report  


612 Number of near misses and the regulatory regime

A reporter is concerned about the number of investigations on which he is working, or of which he is aware, but most cannot be reported to CROSS because of legal or insurance constraints. He sees an increasing number of actual failures, including collapses, and an increasing number of near misses.

View Report  


626 Partial failure of PC tank unit on installation

The use of precast concrete units to construct water retaining structures is becoming more common but their safe installation is not as straightforward as may be suggested.

View Report  


635 Incomplete casting of composite brick/concrete parapets

A reporter states that during a parapet raising scheme over a mainline railway, a void up to 300mm deep was identified below existing coping bed level.

View Report  


644 Inadequate end bearings for transfer beams

Whilst advising a steel fabricator on tendering for a transfer structure steel frame, a reporter's firm noticed a serious design error.

View Report  


652 Designer competency and missing rebar

A reporter says that on a major highway project it was noticed that the contractor was casting a pad foundation. However, there was no reinforcement in the base. The contractor stated that this was an innovative design which allowed for fast-track construction.

View Report  


653 Collapse of outfall structure to watercourse

An outfall conveying surface water drainage to a watercourse collapsed due to its not having been properly constructed.

View Report  


664 Steel canopy collapse during building completion works

During the construction of a new school, a long span steel truss failed, resulting in the collapse of a canopy.

View Report  


665 Lack of masonry wall ties

A reporter states that they have come across the presence of serious defects in masonry construction in the past and have no doubt that many other engineers have had similar experiences.

View Report  


672 Unacceptable quality of construction and lack of supervision on a block of flats

The project involves new buildings for residential flats over a single storey basement. He attended site a number of times in the early stages of construction and found issues including: - poor document control, - using superseded drawings on site, - incorrect/failure to install temporary works required to prop the perimeter piled wall, - omission of designed steel reinforcement, and undermining of adjacent structures.

View Report  


675 Collapse of unsupported trench

A worker was trapped within a partially collapsed excavation which was unsupported and not suitably benched.

View Report  


692 Collapse of lifting tackle connected by threaded bar

No one was struck or injured when a set of 3T chain blocks and a 1m length of 20mm diameter threaded bar fell from a height of 5m, according to a reporter.

View Report  


694 Dangerous balcony construction

During an investigation of a balcony construction, a reporter discovered serious inadequacies related to total lack of co-ordination between sub-contract work packages coupled with lack of appropriate supervision.

View Report  


697 Serious safety failings during construction of high level lattice girder walkways

A reporter discusses extremely serious safety failings with the construction of two new high level lattice girder walkways in the fly tower of a theatre.

View Report  


700 Incorrect scaffold installation

During the pre-sheeting inspection of a designed scaffold, the temporary works coordinator observed that tension connections on standards were either omitted or had incorrect pins/bolts used.

View Report  


701 Designed scaffold built incorrectly

A TWC found that scaffolding was not built in accordance with the approved design drawings and a number of unauthorised modifications were made.

View Report  


702 Scaffold lifting beams incorrectly installed

During inspection of scaffolding prior to loading, it was observed that there were lifting beams with end stops and ultimate stop cross bolts incorrectly installed.

View Report  


705 Use of untreated billet connections in precast concrete structures

Whilst completing a third-party design appraisal, a correspondent found that solid steel billets intended to form the primary shear transfer mechanism between concrete beams and columns were insufficient for this purpose.

View Report  


706 General fire safety in residential blocks

A reporter discusses fire safety issues discovered during investigations of building defects in residential blocks.

View Report  


730 Collapsed scaffolding

Following modest levels of snow fall in the winter, scaffolding erected in order to support a temporary roof collapsed inwards, says a reporter.

View Report  


757 Lack of method statements on domestic projects

A reporter has observed that where an opening is being formed on domestic properties for, say a rear extension, that the builders tend to remove the masonry and follow up with the temporary propping.

View Report  


766 Shutter failure during concrete wall pour

Resin fixed ties for a shutter failed during a concrete wall pour.

View Report  


776 Split responsibility for collapsed boundary wall adjacent to railway

A train driver reported striking debris from a collapsed wall in an urban location.

View Report  


778 Casting, transporting and installing precast concrete kerbs

The construction consisted of precast concrete robust kerbs to contain the permanent way for railway lines.

View Report  


781 Quality of design and construction of a major bridge structure

This report concerns the design and installation of the bridge bearing zones on a new precast prestressed reinforced concrete viaduct.

View Report  


789 Temporary stability of steel frame building

This event concerns the temporary stability of a 4-storey steel frame structure with precast concrete planks and a structural topping.

View Report  


796 Bridge bearing design and installation – more

A reporter says that the issue of successful co-ordination between designers, contractors and specialist bearing suppliers is one they have experienced.

View Report  


AUS-1 Set-up of temporary works

A correspondent was called onto site after the formwork for a slab collapsed during construction.

View Report  


800 Retaining wall excavation collapse

A 6m deep excavation formed for constructing a retaining wall collapsed due to insufficient propping.

View Report  


802 Fixing brackets for glazing systems

A reporter's organisation has been alerted to several cases of broken glass panels in a canopy at a transportation facility.

View Report  


AUS-8 Poor quality of structural design on high-rise buildings

The correspondent has been very concerned about the quality of structural engineering on some projects in recent years, particularly for certain high-rise buildings.

View Report  


852 Rotting of cross-laminated timber (CLT) roof panels

The reporter was asked to check the roof of a building which had been leaking for a few years but was still occupied.

View Report  


870 Principal Designers’ obligations for temporary works

A correspondent believes that the new BS 5975:2019 standard places some onerous duties on the Principal Designer.

View Report  


AUS-11 Design and erection of prefabricated (precast) concrete

A correspondent considers that there should always be an experienced temporary works designer for prefabricated concrete structures as many structural engineers do not consider the erection methodology when designing such structures.

View Report  


882 Post-tensioned slab failure

Lessons learned after the end of a slab burst during a cable tensioning operation are shared by a reporter.

View Report  


885 Disproportionate collapse assessment of Large Panel System (LPS) buildings

A reporter has become concerned by the approach being taken by some engineers to assess the risk of disproportionate collapse due to fire in LPS buildings.

View Report  


886 Unconservative design of flat slab

A reporter discusses how a design/modelling problem caused an under-designed RC slab to be constructed.

View Report  


902 Unauthorised structural alterations to accommodate drainpipes

A reporter became aware of cases where main structural steel sections were ‘butchered’ to accommodate drainpipes.

View Report  


908 Failure of RAAC planks in schools

Further issues with defective RAAC planks in flat roofs are highlighted in this report.

View Report  


915 Crane outrigger loads underestimated due to misuse of software

The crane boom was not in the worst-case position when crane outrigger loads were calculated for a particular lift.

View Report  


926 Emergency motorway lane closure during concrete repairs

Confusion during concrete repair works led to an unplanned emergency lane closure of a bridge carrying a motorway.

View Report  


5003 Concrete system buildings - need for periodic inspection

SCOSS ALERT (2001) Precast concrete systems were quite widely used in the 1950s to 1970s for the construction of schools, offices and other buildings. Concrete components were mainly reinforced or pretensioned but post-tensioned construction of roof and floor structures was adopted in some systems, eg Intergrid and Laingspan, particularly where larger spans were required in, for example, assembly halls.

View Report  


5007 Installation of timber joist hangers

SCOSS ALERT (2006) The use of joist hangers to support timber floor joists, particularly in new housing schemes, has increased in recent years. The revised Part L of the Building Regulations has also led to designers specifying joist hangers, rather than building timber joists into supporting walls. The use of joist hangers on site is, therefore, a common occurrence.

View Report  


5010 The collapse of the Nicoll Highway

SCOSS FAILURE DATA SHEET (2004) The collapse occurred as a consequence of the failure of a deep excavation adjacent to Nicoll Highway. The excavation was for the Mass Transit’s new Circle line; it was the deepest ever cut and cover construction in Singapore and consisted of braced diaphragm walls with an excavation depth of around 33m. The bracing involved 10 levels of conventional steel struts with waling beams, and two additional jet grout struts (one of which was sacrificial). The steel struts were supported by piled king posts at mid span. The failure was initiated at the strut/waler joint at level 9, located just above the sacrificial jet grout strut, which was being excavated. Level 10 struts were not effective at the time of failure

View Report  


5011 The collapse of NATM tunnels at Heathrow airport

SCOSS FAILURE DATA SHEET (2004) In October 1994 a section of tunnel being constructed at Heathrow Airport collapsed; although there were no injuries, many people were put at risk and the consequential cost was significant. A number of the lessons arising from this collapse can be applied to engineering projects generally.

View Report  


5050 Falsework: full circle?

SCOSS TOPIC PAPER (2002) The late 1960s and early 1970s was a time of great activity and innovation in the construction industry, following the austerity years of the Second World War and the 1950s. Boundaries were being pushed out in all directions- in respect of design, materials and scale of projects. This brought about some great achievements, but also a number of serious repercussions.

View Report  


5053 Erection of steelwork: learning from experience (1)

SCOSS TOPIC PAPER (2004) A recently quoted prosecution (2004) arose from the death of an operative during steelwork erection. The background to this case has led SCOSS to conclude that there remain some generic lessons to be learnt in respect of the erection of steel structures generally, and with regard to wind loads specifically.

View Report  


5055 A risk managed framework for ensuring robustness

SCOSS TOPIC PAPER (2006) This paper describes an holistic approach to the process of ensuring robustness, utilising appropriate people, processes and products. It emphasises the need for a team approach having regard to all the stages in the structures life, and all the parties involved. It is placed on the SCOSS website for information and discussion. It does not deal with the technical detail or options to assuring robustness.

View Report  


5057 Risk issues associated with large TV/video screens at public events

SCOSS TOPIC PAPER (2008) The IStructE task group on ‘Temporary Demountable Structures: Guidance on Procurement, Design and Use’ requested SCOSS to review the issues associated with inter-module fixings as used on outdoor TV/video screens.In the course of this work it became apparent to the Committee that there were some broader concerns relating to the whole procurement process. Hence this report extends to cover the wider picture. It also applies to screens used at indoor events, as appropriate.

View Report  


5058 The assumptions behind the Eurocodes

SCOSS TOPIC PAPER (2009) All design codes of practice are constructed around a number of assumptions and limitations; these relate to the competency of those using the code, the analysis and design process and the material itself. In the traditional ‘BS’ codes of practice these assumptions generally featured in the Foreword or Introduction e.g. BS5950, Clause 1.0. This note considers the implications of the equivalent assumptions relating to the structural Eurocodes which are given in BS EN1990.

View Report  


5059 Independent review through peer assist

SCOSS TOPIC PAPER (2009) This form presents aspects to be considered in any appointment. It should be tailored and reviewed to suit particular circumstances.

View Report  


5062 Role of legislation

Extract from 11th SCOSS report 1997 Some changes have occurred in recent years which will help to restore good communications and also to foster a safety culture in the construction industry. Important new legislation has come into effect, including the Management of Health and Safety at Work Regulations 1992 (2), the Construction (Design and Management) Regulations 1994 (3) (CDM Regulations) and the Con­struction (Health, Safety and Welfare) Regulations(4) (CHSW Regulations). The CHSW Regulations consolidate, modernise and simplify older health and safety regulations, and introduce some new provisions arising from the implementation of an EC Directive on construction.

View Report  


5069 Assessment of safety and risk at the design stage

Extract from 11th SCOSS report 1997 The Construction (Design and Management) Regulations 1994(50) came into force on 1 March 1995. These Regulations require the consideration of hazards and risks arising during design, construction, cleaning and demolition processes(51). The requirements are compatible with the suggestion, made in the Tenth SCOSS Report, for assessment of hazard and risk to be an explicit procedure at the design stage of permanent works.

View Report  


5071 Design and build

Extract from 11th SCOSS report 1997 SCOSS has considered whether some forms of design and build contract might introduce safety loopholes not normally experienced with more traditional forms of contract.

View Report  


5072 Temporary stands and stage structures

Extract from 11th SCOSS report 1997 The Institution of Structural Engineers published guidance on procurement, design and use of temporary demountable structures in 1995(61). This was intended to supersede the existing general guidance on temporary demountable structures(62,63). It was prepared by a Task Group which took account of recommendations in the Ninth and Tenth SCOSS Reports. These arose from examination of the safety of these types of structure and of reported collapses and disturbing sway movements.

View Report  


5081 Pin connections in bridges and building structures

Extract from 11th SCOSS report 1997 Pin connections have, for many years, been a structural feature sometimes used to implement the concept of steel bridges. Such connections are being used increasingly today in building structures particularly in roof structures, e.g. sports stadia. Articulating structures using pins are also common, e.g. link spans to berthed ships. Arrangements of rods, cables and turnbuckles to support building elements are often a feature of modern architecture and use a similar concept of pin connection. These arrangements however, may have no articulation function and no rotation may be required at connections.

View Report  


5083 Air-supported and fabric structures

Extract from 11th SCOSS report 1997 The construction of air-supported structures is a very small industry in the United Kingdom. They are subject to control under Building Regulations in Scotland and Northern Ireland. However, in England and in Wales, local authority policies differ over whether or not they should be regarded as a form of temporary structure. This variation in their treatment can lead to confusion and a coherent policy is desirable.

View Report  


5106 Demolition and structural alteration

Extract from 12th SCOSS report 1999 Instances of unplanned collapses during alteration and demolition work continue to occur from time to time. Demolition and structural alterations are much easier, safer and less costly if accurate structural records and drawings are available. SCOSS has been pleased to note that some of those commissioning works appear to be recognising their responsibilities for providing accurate information as a requirement of the CDM Regulations. In due course, CDM health and safety files should form a good basis for developing operational manuals including detailed structural information.

View Report  


5107 Thaumasite sulphate attack in structural concrete (1)

Extract from 12th SCOSS report 1999 The presence of thaumasite sulphate attack in concrete in the foundations of some bridges over the M5 motorway became known in early 1998. This phenomenon had not been previously identified in major structures in the UK although it was known to cement technologists over 25 years ago.

View Report  


5115 Checking and certification

Extract from 13th SCOSS report 2001 Certification of design or other structural engineering work is a formal step included in many engineering projects to provide additional assurance that defined requirements are met. Certification may be by the project engineer within the design organisation, commonly termed self-certification, as part of the organisation's quality management system. It may also be by a separate group employed by the organisation originating the work. This is also sometimes referred to as self-certification. Alternatively an independent third party certifier may be employed by the client.

View Report  


5116 Application of risk assessment methods

Extract from 13th SCOSS report 2001 Evolution from prescriptive codes-based approaches towards a more systematic and rigorous approach to preventing failures in engineering systems began following experience and inquiries into catastrophic failures in the nuclear, chemical process, offshore oil and railway industries and the increasing understanding of the human contribution to accidents. The emphasis in these industries has turned more to a 'goal-setting' approach in which hazards are identified and assessed and then measures determined to control the risks arising.

View Report  


5123 Risk management of structures

Extract from 14th SCOSS report 2003 Although the need to avoid, mitigate and control structural risk at the time of design, over the lifespan of a structure, has been a requirement for many years, it is often not well done. We only have to look around at the UK’s infrastructure to see examples of deterioration or misuse, and cause for concern. SCOSS has commented and raised such concerns on various aspects of this subject on previous occasions.

View Report  


5127 Alerts and other matters

Extract from 14th SCOSS report 2003 The Committee has issued a number of Alerts and other advice since the publication of Report 13 in May 2001. Alerts are issued when there is a subject that the Committee believes requires more immediate attention than would be achieved via an occasional publication such as the Bulletin or Biennial Report. The full text of all the Alerts and other commentaries may be found on the web site.

View Report  


5131 Designers' responsibilities

Extract from 15th SCOSS report 2005 The Committee has noted the uncertainty and concern expressed in various technical articles in respect of designer responsibilities under the CDM Regulations. These articles have appeared in NCE. The Committee considers that uncertainty as to what is required of designers is a serious impediment to progressing productive dialogue between all parties involved in construction. The Committee sees an opportunity, if not an obligation, in the fact that ISE, ICE and HSE are the sponsors of SCOSS, to bring greater clarity to the issues generally, and specifically to bring clarity to the issue of designer duties.

View Report  


5139 Lessons from failure: reflecting on the work of SCOSS over the last 30 years

Extract from 16th SCOSS report 2007 Structural failure continues to be a matter of great concern: within the last two years we have witnessed the collapse of the Gerrards Cross tunnel, the Milton Keynes scaffolding, the Montreal highway bridge and a number of construction cranes. The Buncefield explosion and fire at Hemel Hempstead in December of 2005, although not a ‘structural engineering failure’ in the first instance, does nonetheless raise a number of lessons for us all. How is it that, with an abundance of experience, quality codes of practice, and the lessons of previous failures to draw upon, these events continue?

View Report  


5140 Confidential reporting on structural safety

Extract from 16th SCOSS report 2007 CROSS was launched by SCOSS in June 2005 [1] after a long gestation period. This scheme is unique to the construction industry, but not so generally, as other industries had seen the benefit of such reporting some time before. CROSS is designed around the principles adopted for the UK Confidential Human Factors Incident Reporting Programme (CHIRP) which operates for the aircraft industry, and which has been running for 20 years and now receives around 250 reports annually. In all such programmes complete confidentiality is maintained. Indeed the NASA supported Aviation Safety Reporting System (ASRS) has had over 700,000 reports in 30 years without confidentiality ever having been breached.

View Report  


5141 Independent review of structures

Extract from 16th SCOSS report 2007 SCOSS has been considering how best to promote the public safety requirements inherent in large or complex projects where a typical numerical check against design code may not be sufficient and where a different approach can bring broader benefit to the project. One way in which this can be achieved is by introducing the concept of an independent review. The independent review is not a further layer of bureaucracy; it is designed to be useful to all parties and to assist in reducing risks and adding value to the project at affordable cost to the client. It is already accepted in specific sectors as a client-sponsored safeguard which recognises that the wider benefits greatly outweigh the additional cost.

View Report  


5143 Robustness: disproportionate collapse

Extract from 16th SCOSS report 2007 The Committee has reviewed this topic on a number of occasions over the period since the last Report. It is a wide and complex subject, but one that is fundamental to the establishment of safe structures. In recognition of this situation, SCOSS sponsored a workshop in October 2006, to allow discussion amongst interested parties. These included the material sectors, Building Control, checking engineers, Department of Communities and Local Government (DCLG - responsible for the building regulations), and specific interested individuals. From this, four threads of concern have been identified as outlined below.

View Report  


5144 Temporary structures (entertainment events industry)

Extract from 16th SCOSS report 2007 The ‘events’ industry has seen a significant increase in the size and sophistication of its temporary structures over recent years. Large and complex stages and overhead lighting gantries are commonplace. To these must now be added TV/video screens- the increasing size reflecting the rapid advancements in visual data technology. It is not untypical for such screens to be of the order of 9m x 6m and some 11m high overall.

View Report  


6006 Saddlespan tent alert from SCOSS

The use of sophisticated temporary structures is becoming more common at public events such as music festivals. One such type of stage structure is the ‘saddle span’ type tent. In this note, ‘sophisticated’ refers to the critical nature of the structural installation in relation to the manufacturers design, and also the operational management on site, in order to ensure its stability against adverse conditions.

View Report  


6010 Temporary stage structures - Alert

This Alert is aimed at those who may commission or procure or licence temporary stages and other temporary structures, for example large outdoor TV screens, which offer potential risks to the public.

View Report  


Constructing Health and Safety 2014

The topic of this conference is Improving Welfare, Standards and Practice and the event will be held at ICE London on 25 September 2014. Go the full report below for a link to full details. ICE is s sponsor of Structural-Safety.

View Report  


Hoardings - Temporary Works Forum

Download PDF Version Download PDF Version  


Newsletter No 3 - July 2006

In the 12 months since CROSS was launched reports have been received on: Building Control Issues, Collapses, Construction, Design, Engineers on Site, Materials, Near Misses, and Temporary Works. In this Newsletter reports are all related to existing structures. The Newsletters in which these are published have a potential readership of over 50,000 engineers and others in the construction industry not only in the UK but worldwide. Every reader will have had experiences that they use in their own work to avoid future problems. If your reading of a Newsletter triggers recollection of a similar experience that you feel should be taken up then please make a report to CROSS. The goal is to provide an effective avenue for identifying real concerns (which are often not raised through other routes) in order to promote a culture of learning and influence action by Government, Institutions and other bodies. In time, the scheme will also become an important resource of knowledge for the construction community. New buildings represent only a small proportion of the total building stock. As a national resource the number and value of old buildings is much greater and they need protection, maintenance and improvement. These matters are assuming more importance as energy efficiency, water savings, and other sustainability issues are increasingly relevant. Accordingly this Newsletter addresses concerns found with some older buildings, and the potential problems with conversions and alterations. Other reports received in the last three months will be held over for future Newsletters. Reports from contributors have identifying features removed and may be edited to give more clarity and may be shortened, but the views expressed remain those of the authors. Comments given at the end of each report are those from the SCOSS sub group of representatives from the industry. Material from the reports will be used by SCOSS to detect trends so that appropriate action can be taken and advice given.

View Newsletter   Download PDF Version Download PDF Version   Download Word Version Download Word Version  


Newsletter No 8 - October 2007

There have been several encouraging moves about the development of CROSS. At a recent meeting the current Presidents, and the immediately to follow Presidents, of the Institution of Structural Engineers and the Institution of Civil Engineers, were updated on the scheme and gave valuable input and encouragement. A major insurer of consulting engineers has recommended to its clients that use be made of the CROSS system to report concerns so that others may have the benefit of learning from these. The Core Cities Group representing the chief Building Control Officers from major cities in the UK are to support the scheme. In this issue there are concerns about structures where there may be hidden degradation; firstly in walkable ceilings, and secondly with ground anchors. By publicising potential problems awareness will be raised to the benefit of users and the public. It is very welcome to see three reports from contractors; two about temporary conditions and one about steelwork delivered to site. There is also a concern published here that risks from earthquakes, and indeed other extreme events, are not understood by the purchasers of holiday or retirement homes overseas. The success of a confidential reporting scheme cannot be measured in terms of the number of incidents that are prevented because this is not known, but it can be assessed by the number and quality of reports received and the outcomes from feedback. As a result of earlier reports to CROSS the manufacturers and distributors of a product are amending their advice to users. The supplier of another product is in discussion with SCOSS. Evidence from reports on temporary works collapses during alterations are being considered by the Health & Safety Executive in the formulation of new guidelines, and the concerns raised in Newsletter No 7 about Local Authority issues have been passed to the Department of Communities and Local Government. To encourage more reporting a form has been added to the end of the Newsletter.

View Newsletter   Download PDF Version Download PDF Version   Download Word Version Download Word Version  


Newsletter No 17 - January 2010

The new website is working well and reports are coming in through the new on-line system. More reports on all topics are welcome both to add to the database and to publish in Newsletters. Published concerns can generate others in similar veins and when there is a trend then steps can be taken to give practical advice which will reduce risk and improve safety. There have been a number of CROSS reports about fixing failures which has resulted in the Construction Fixings Association promoting a new BS Code of Practice for the use of anchors in safety critical applications. The drafting is due to commence shortly. In addition, the fixings industry, in conjunction with SCOSS, is drafting a guide to ceiling fixings. This is a success story: thanks to those who contributed towards this by submitting reports The recent winter weather in parts of the UK has resulted in roof failures due to the dead weight of snow. Some of these have been highlighted in the press but more evidence is needed to learn how buildings are performing in unusual, but perhaps not exceptional conditions. In this issue there is a good selection of reports on concerns from which lessons can be learned: the failure of blind bolts on an offshore platform resulted in the collapse of an important piece of equipment, hydrogen generated from a foamed concrete mix exploded, there is another case of a temporary works problem but this was spotted in time by an alert engineer, partial demolition of some brickwork arches led to a potentially dangerous situation, the importance of taking prompt action on stability is described, and there are two more ceiling failures – this time associated with dynamic loading. If you have similar examples please send in a report.

View Newsletter   Download PDF Version Download PDF Version   Download Word Version Download Word Version  


Newsletter No 28 - October 2012

Half of the reports to CROSS are about problems during construction and in this Newsletter are examples of issues where temporary works have been involved. The common thread in these reports is that something goes wrong on site; due to communication issues, or quality assurance in the supply of components, or simply a lack of appreciation of the importance of stability. In none of the cases here were there injuries but if circumstances had been slightly different the results would not have be reported to CROSS, but could have been examined in the courts with possibly dire consequences for some of those involved. The importance of the subject has gained increasing recognition as demonstrated by the formation of UK Temporary Works Forum. The TWf aims to encourage discussion of matters related to Temporary Works and the group is open to anyone, individual or corporate, working within the industry and sharing this intent. There is always a need for more reports and if you see value or gain anything by reading these Newsletters then please reciprocate by sending in your own experiences. The objective is to identify the precursors of failure and learn from them. The CROSS programme depends on receiving reports and individuals and firms are encouraged to participate by sending concerns in confidence to structural-safety.

View Newsletter   Download PDF Version Download PDF Version  


Newsletter No 30 - April 2013

This issue concentrates on competency and on issues identified on site. Statistics are collected from reports and one category is the stage of a project when a concern is identified. As shown in the pie chart almost a half of all events, 44%, are related to construction (34%) and temporary works (10%), with design accounting for 13%, and normal operations i.e. building or structure in use, 34%. Maintenance operations amount to 5% of the total and there are a few other minor categories. Lack of competency is reported to be a major reason for most of the safety-critical matters described below. It is very satisfactory to note that there is now a backlog of reports awaiting publication and in order to control this some reports will in future be added directly to the data base after anonymising rather than being included in Newsletters. Reporters will be told if this is to happen and lists will be given in Newsletters. All reports, together with expert comment from our panel of volunteers, are on the data base which is freely searchable. The growth of the CROSS programme depends on receiving reports and individuals and firms are encouraged to participate by sending concerns in confidence to structural-safety.

View Newsletter   Download PDF Version Download PDF Version  


Newsletter No 39 - July 2015

In December 2013 part of the fibrous plaster ceiling of the Apollo Theatre in London fell and 88 people were injured. A 12-month investigation by Westminster City Council concluded that the collapse happened because of the age of the structure and there had been “no breach of the current laws”. A new report has been received regarding a similar type of structure in a public building in another part of the country where the fabric suspension ties were found to be completely decayed. Failure was only prevented by the shape of the plasterwork. Probably a near miss. Publicity has been given to this problem in theatres but not to the possible risk to other buildings with old and ornate heavy ceilings. The new report is published here and Structural-Safety will be giving consideration as to how the matter can become more widely known. Other subjects include temporary works design for basements, another case of fixings failures, questions about plastic rebar spacers, rotten rafters, Building Regulations and Approved Inspectors, policing of CE markings, and construction which differs from design drawings. These are all topics which contribute to the improvement of structural safety and the reporters are to be thanked for enabling them to be shared with others. Our panel of experts is, as ever, to be thanked for providing the comments. There are many other situations where external events have precipitated structural failure around the world in recent months such as the earthquake in Nepal and extreme heat in India and Pakistan. Engineers can help to ameliorate the effects of such catastrophes if given the resources and the more we learn the more effective we can become. The success of the CROSS programme depends on receiving reports, and individuals and firms are encouraged to participate by sending concerns in confidence to Structural-Safety.

View Newsletter   Download PDF Version Download PDF Version   Download Word Version Download Word Version  


Newsletter No 41- January 2016

A report last year was about high local winds in a city centre causing damage to temporary works. This generated interest in the SCOSS Committee so an Alert: Wind Adjacent to Tall Buildings was published in December 2015. Although the Alert was prompted by concerns regarding the design of temporary structures, it is noted that wind around tall buildings can lead to unpleasant, and sometimes dangerous, conditions for pedestrians. Aggregating a number of reports, whether they are on matters sent confidentially to CROSS or from other material, to produce a SCOSS Alert is part of the Structural-Safety system. Ian Fleming wrote: “Mr Bond, they have a saying in Chicago: 'Once is happenstance. Twice is coincidence. The third time it's enemy action'.” At Structural-Safety the third time means that an Alert may be needed. The first report in this edition is about a near miss involving pre- cast and in-situ concrete from which a number of lessons can be learned. After the next article on wind problems there is a case about defects during construction and the relationship between an engineer and a client. Then comes an example of the problems that can arise at the interface between steelwork and concrete encasement. Moving on to demolition a reporter voices concerns about flat slab structures when unexpected shear failure adjacent of a column can precipitate general failure. Another has concerns on the way in which a mansafe system was designed without recognition of structural principles and which was found during a third party review. Finally a building control officer found a bug in a proprietary software programme. The success of the CROSS programme depends on receiving reports, and individuals and firms are encouraged to participate by sending concerns in confidence to Structural- Safety.

View Newsletter   Download PDF Version Download PDF Version   Download Word Version Download Word Version  


Newsletter No 45 - January 2017

Relationships with the Temporary Works Forum have been strengthened as a result of Structural-Safety becoming an Invited member. This category is exercised at the discretion of the Directors and is awarded to an individual or organisation (not currently a Member) which, in the Directors’ view, deserves special recognition in some way for its contribution to temporary works. We look forward to sharing information on improving safety in this area. New contacts have been made with CABE, the Chartered Association of Building Engineers, who have become a supporter, and many of whose members become involved with the safety of buildings during construction. On an international front a meeting has been held with AQC, Agence Qualité Construction, based in Paris on future co-operation. Mathew Syeed of the Times recently interviewed Captain Chesley Sullenberger, the pilot who landed an Airbus A320 on the Hudson River in 2009, saving the lives of 155 crew and passengers after an engine failure. He talked about how the impressive safety record in aviation is based upon constant learning from accidents and near-miss events, a method, he said, which other industries would do well to follow. He also talked about how he had trained his brain to think calmly under stress, even as his blood pressure shot up and perception narrowed. Most striking, however, was his sense of duty. He walked the plane twice, even as it was filling with water, to ensure everyone had got out, and refused to do TV interviews, despite feverish media interest, until everyone had been accounted for. “My primary responsibility was to those under my care,” he said. “That was my focus from the moment we landed to the moment I could be sure everyone was safe.” Aviation safety was the model for establishing CROSS and it is heartening to be reminded of how methods of constantly learning from others can, in a very practical way, help to save lives. CROSS is also interested in damage caused to buildings, and building related infrastructure, by weather events. These can be sudden actions such as tornadoes or lightning strikes, or longer term events such as floods. The aim is to gather information that can be used to assess the capability of our buildings to withstand the weather patterns that may be becoming more common. This study is not concerned with the reasons for climate change but only whether the consequences might lead to changes in regulations and practices. Reports can be made here. Indeed the success of the CROSS programme depends on receiving reports, and individuals and firms are encouraged to participate by sending concerns in confidence to Structural-Safety.

View Newsletter   Download PDF Version Download PDF Version   Download Word Version Download Word Version  


Newsletter No 46 - April 2017

Two Alerts have been issued by SCOSS recently: Structural stability/integrity of steel frame buildings in their temporary and permanent condition, and Inquiry into the construction of Edinburgh Schools. Both highlight problems with the quality of construction and the lack of supervision on site. Six of the seven reports in this issue relate to quality issues and it has been a common theme in CROSS reports. The trend is disturbing and it is only by chance, good luck and timing, that there were not multiple casualties. If there had been large scale fatalities, then public outcries and government intervention would have meant that instead of these events being near misses they would have become weapons with which to attack the construction industry. A much better attitude to safety must be cultivated by clients, designers, constructors and supervisors to protect themselves and the public. The urgent need to restore Resident Engineers and Clerks of Works to sites must be recognised. These and other critical recommendations are given in Report of the Independent Inquiry into the Construction of Edinburgh Schools which makes for sobering, but essential, reading for all involved in the safety of buildings. The success of the CROSS programme depends on receiving reports, and individuals and firms are encouraged to participate by sending concerns in confidence to Structural-Safety.

View Newsletter   Download PDF Version Download PDF Version   Download Word Version Download Word Version  


CROSS-AUS Newsletter 2 - July 2019

Several events in recent years have raised serious concerns about safety in the construction industry resulting in calls for significant changes in how the industry operates. The Shergold & Weir Building Confidence report submitted to the Building Ministers’ Forum (BMF) in February 2018 raised concerns about the effectiveness of compliance and enforcement systems for the building and construction industry across Australia. And in March 2019 the BMF published its Implementation Plan for the recommendations in that report. In February 2019 the NSW Government published the Opal Tower Investigation Final Report that raised concerns around the effectiveness of the regulatory environment in which we operate and made several recommendations to raise the standards of building design and construction. Similar issues have been subject to detailed investigation in the UK, concluding that there are systemic issues in the construction industry that must be addressed. For details go to: • Building a Safer Future by Dame Judith Hackitt and SCOSS Alert of July 2018 • Report of the Independent Inquiry into the Construction of Edinburgh Schools and SCOSS Alert of February 2017 Previous reports have raised similar issues e.g. Independent Review of the Building Professionals Act 2005 by Michael Lambert in 2015 with its focus on the effectiveness of the building regulation and certification system in NSW; the 2013 Engineers Australia Report on Defect Free Construction in NSW; and the 2005 report by the Queensland Division of Engineers Australia: Getting it Right First Time noted that poor documentation was contributing an additional 10-15% to project costs in Australia. There is a common theme in these documents that the construction industry needs to “lift its game” and we as Structural Engineers must play our part in addressing these concerns. CROSS-AUS provides a conduit whereby we can contribute towards improving quality and safety performance by sharing lessons learned and disseminating advice on good practice. The reports in this newsletter cover a range of issues including some of the concerns raised in the above documents particularly related to competency, communications, documentation, application of Australian Standards, site inspections, quality control, and the influence of parties other than engineers (AUS-8, AUS-3, AUS-7, AUS-2). Unfortunately issues around temporary works (AUS-1) and excavation hazards (AUS-6) remain all too frequent. We encourage you to give us feedback on any of these matters or to submit a report on any safety issues or matters of concern that you may have.

View Newsletter   Download PDF Version Download PDF Version  


CROSS-AUS Newsletter 3 - February 2020

Welcome to our 3rd Newsletter and an especial welcome to our growing list of subscribers. The NSW Government’s proposed Design and Building Practitioners Bill 2019 in response to the Shergold Weir Building Confidence Report is currently with the Legislative Assembly. To quote the NSW Minister for Better Regulation and Innovation, Kevin Anderson: It is the Government’s intention to create a robust registration scheme that delivers on the Shergold/Weir recommendations and applies to all types of practitioners who perform the function of preparing plans and making compliance declarations, including engineers. While the current focus and much of the discussion within EA is around registration, that is just a starting point and will not by itself ensure that the required standards of design and construction are being met. Being registered demonstrates that a certain level of competence and experience has been achieved. Mistakes will still be made and thus we must have rigorous processes of design and construction whereby each stage is independently checked and reviewed by competent engineers. The reports in this Newsletter cover a range of issues and you may have had similar experience with some of these such as cold-formed steel trusses (AUS-4), glazing systems (AUS-5) and carrying out modifications in old buildings (AUS-10). Problems related to maintenance of structures (or lack thereof) have been with us for a long time and AUS-12 poses the question – should a Maintenance Manual be included with the as-built documents for all structures? Issues around temporary works continue to give rise for concern; this time related to the erection of prefabricated concrete (AUS-11). A recent ENZ news item about a scaffold collapse in NZ should be read by all engineers involved with construction. It is very much about sharing lessons learned and concludes with the words: No one wants an accident on their watch, and it’s too late to do anything when it has happened. This has led to the formation of a Temporary Works Forum in NZ; there has been a very active Temporary Works Forum (TWf) in the UK for several years; there is one in HK; and one is being established in Australia. An even more serious collapse was that of the Pedestrian Bridge in Miami, Florida in 2018. The US National Transportation Safety Board has just released its final report which makes for sobering reading. CROSS will be making further comment on this in due course.

View Newsletter   Download PDF Version Download PDF Version  


Temporary event structures: 'Saddle Span' type tents - October 2010

Download PDF Version Download PDF Version  


Temporary stage structures - January 2012

Download PDF Version Download PDF Version   Download Word Version Download Word Version  


Structural stability/integrity of steel frame buildings in their temporary and permanent condition - February 2017

Download PDF Version Download PDF Version  


Newsletter No 4 - November 2006

CROSS, on behalf of SCOSS (Standing Committee on Structural Safety), have continued to receive reports on the concerns of engineers and the lessons to be learned. In this issue are several very practical reports; the protection of scaffolds from impact, liquid metal assisted cracking (LMAC), and issues about cold formed steelwork framing and fixings to steelwork. In addition there are two follow up reports on adapted masonry support props. Further material on previous reports is welcome and enables trends to be detected. Indeed a guiding principle of SCOSS is that evidence gathered from reports will be used to issue alerts or to influence change. The reports on scaffolding and on temporary props have been brought to the attention of HSE who are considering them in wider contexts, and the subject of LMAC has previously been the subject of a SCOSS report. Recommendations on these and other topics will be made early in 2007 in the next biennial SCOSS publication. If readers have a concern, either related to published reports, or on new topics, or wish to pass on a lesson that they have learned then make a report to CROSS.

View Newsletter   Download PDF Version Download PDF Version   Download Word Version Download Word Version  


Newsletter No 10 - April 2008

The reports in this issue highlight a lack of competence or a lack of supervision of aspects of construction which may not be primary structures, but are serious in terms of safety. A brickwork gable wall collapsed without warning and narrowly missed a pedestrian; a substantial blockwork wall collapsed due to wind loads in the temporary condition after the workforce had left for the night; four heavy ceilings collapsed, again, by good fortune, when there were no people underneath. These all serve as reminders that the application of sound engineering and good practice, or simply the use of good building craft by competent people, are essential when dealing with fixings and apparently minor components. If any of these cases had resulted in deaths or serious injuries the effects on the individuals involved and their employers would have been devastating. It is simple after the event to see what has gone wrong and why the failures occurred. It is difficult to make sufficiently strong recommendations so as too ensure that the people likely to be involved with these topics in the future are made aware of the risks and the importance of their role. CROSS has shown the relevance of confidential reporting in highlighting trends before there are tragedies, and this is enabling SCOSS to take action to give more publicity to safety critical concerns. As ever CROSS seeks, and needs, more reports from individuals and from organisations. Reports from those who have the support of their employers will be very welcome when sending a description of a concern to be shared with others. There is a report form at the end of this Newsletter.

View Newsletter   Download PDF Version Download PDF Version   Download Word Version Download Word Version  


Newsletter No 14 - April 2009

There is encouraging support from the infrastructure and public sectors for the work of CROSS. Following meetings with SCOSS and CROSS, the Highways Agency have agreed to back the scheme and recommend it to their suppliers. The Highways Agency is an Executive Agency of the Department for Transport (DfT), and is responsible for operating, maintaining and improving the strategic road network in England on behalf of the Secretary of State for Transport. This includes managing traffic, tackling congestion, informing road users, improving safety, minimising adverse impact on the environment and more. Their suppliers include consulting engineers, construction companies, and materials providers. LABC is the member organisation representing local authority building control departments in England and Wales. It promotes the design and construction of safe, accessible, environmentally efficient buildings that comply with the Building Regulations and now also supports CROSS. The Scottish Building Standards Division has supported the programme since the SCOTCROSS scheme in 2007. It is anticipated that liaison with, and the support of, these major bodies will lead to more reports about roads and bridges, and more reports about building control issues, thus widening the network of those who can benefit from the lessons learned by others. In this issue is an important report about public art works on or near highways and the need, in some cases, for appropriate engineering input to the design and construction of large sculptures. There is also the summary of a report about the slippage of a bridge being erected over railway published with the permission of Transport for London together with reports about similar incidents from the past. Of course to make the programme as effective as possible reports are needed on a continuous basis so if you have a concern, or know of an incident that involves structural safety, that could be passed on then please contribute. Details of how to do so are on the CROSS website as are all of the Newsletters.

View Newsletter   Download PDF Version Download PDF Version   Download Word Version Download Word Version  


Newsletter No 15 - July 2009

Several of the reports in this issue indicate a lack of competency amongst those designing or installing the works, and/or a lack of adequate supervision. None of these examples affected large structures; the failures were of relatively minor works, but there were fatalities and serious injuries, and all had the potential for fatalities. It may be that there have been an increase in the numbers of site related problems that have occurred since the demise of the resident Clerk of Works/ Resident Engineer, together with just the poor standard of site control and management which seems to occur on many sites. It is important for all concerned in the industry, and the general public, that CROSS receives details of failures so that a comprehensive picture may be established in order to support any proposed action. Earlier in the summer there was a presentation on CROSS to a meeting of international regulators and building control bodies: CEBC/IRCC (Confederation of European Building Control/Inter-Jurisdictional Regulatory Collaboration Committee). There was agreement that defect reporting is an important mechanism for improving safety and saving money and several countries are interested in similar schemes. Meanwhile development is proceeding on the new CROSS web site which will be launched in the autumn. All subscribers will automatically be added to the system which will feature easier access to information, a data base of reports, and simple registration for new subscribers.

View Newsletter   Download PDF Version Download PDF Version   Download Word Version Download Word Version  


Newsletter No 21 - January 2011

CROSS is very pleased to announce that the Highways Agency has implemented Confidential Safety Reporting in its procedures in Interim Advice Note 136/10 (see page 2). This relates to structures of any kind on the Highways Agency Motorways and Trunk Road Network and is an important step in the development of the scheme. SCOSS has recently issued two alerts: the first is Timber framed buildings in fire situations: the role of the designer following a number of severe fires in timber framed buildings during construction. The second is: Temporary structures: Saddlespan type tents which highlights the need for adequate engineering input for specialised temporary structures. In this issue are more reports on serious concerns that have been sent to CROSS and from which lessons can be learned by the engineering community. The first is the fall of part of a bridge due to the use of the wrong type of bolts and is another example of the importance of choosing the right fixings. The second is about the deflections caused by pouring concrete onto permanent metal decking which can affect the safety factors of primary and secondary beams and connections. There are then three reports on defects during construction which were caused by ignorance or negligence and were spotted by engineers on site. How many defects are not seen or are ignored and result in lowered levels of safety or serviceability? Internet search engines offer a huge resource for finding out about any subject and when directed towards building collapses they find a daily catalogue of disasters often with a death toll attached. These are mainly from areas of the world where there are limited controls on building, many of the structures have not been properly designed or constructed, and defective materials may have been incorporated. Vigilance is required everywhere and ways of publicising concerns are a way of maintaining and bolstering standards. CROSS needs reports all the time so that lessons can be learned and if you can contribute please do so.

View Newsletter   Download PDF Version Download PDF Version   Download Word Version Download Word Version  


Newsletter No 23 - July 2011

This Newsletter starts with a report about the use of water filled containers when used as ballast for temporary structures such as those erected for music festivals. In Scotland in the winters of 2009/2010 and 2010/2011 there were many collapses of, mainly agricultural, buildings during periods of high snow loads and reports on these have been consolidated to provide an overall picture of the events which took place. The CROSS panel have provided comments and the information, in co-operation with the Scottish Government, has been forwarded to the British Standards Institution for consideration. A further report is about dangerous and almost simultaneous snow slides from 100 domestic roofs, and there is a salutary lesson in a news report about a column constructed with no foundation. Finally the British Parking Association is requesting information about the condition of multi-storey car parks. CROSS needs reports all the time so that lessons can be learned and if you can contribute please do so.

View Newsletter   Download PDF Version Download PDF Version   Download Word Version Download Word Version  


Newsletter No 24 - October 2011

This Newsletter is the first to be published on the new Structural-Safety web site (www.structural-safety.org) which combines the activities of SCOSS and CROSS. For those who were receiving publications from either group there is no need to re-register, and those who wish to register for the first time will find a link on the home page of the new web site. The need for continued vigilance has been illustrated in recent weeks with the dramatic and deadly collapses of two major temporary stage roofs: one in Indiana USA, and one in Belgium, with a total of eleven fatalities and many injuries, and several other recent collapses of similar structures. The subject is being considered by SCOSS and their views will be published in due course. There has also been the collapse, with two deaths, of a cantilever stadium roof being erected in Holland, the death of a man in London from falling masonry, and the collapse of a large canopy under construction at a UK school with several injuries. Reports in this issue of the Newsletter start with the comprehensive description of design error provided by a major firm of consulting engineers. This is much appreciated as it has been provided with the full backing of the company concerned. CROSS is a platform for sharing information without revealing names or identifiable details and the more widely CROSS is trusted the more effective it will become. Other reports deal with construction issues including tower crane bases, the care needed when using certain epoxy grouts where there are high ambient temperatures, another retaining wall failure, and more concerns about lack of control and supervision on sites. DRD Roads Services in Northern Ireland have become the latest Government Department to join CROSS as a backer and this follows the arrangements already in place with the Highways Agency in England. Their Safety Management Procedures now include a section on the confidential reporting scheme and any issues that would help with lessons to be learned will be passed on through senior management. The Department is responsible for: • regional strategic planning and development policy; • transport strategy and sustainable transport policy; • provision and maintenance of all public roads; • public transport policy and performance; • certain policy and support work for air and sea ports; and • policy on water and sewerage services and management of the Department’s shareholder interest in Northern Ireland Water. The CROSS programme depends on receiving reports and individuals and firms are encouraged to participate by sending concerns in confidence to structural-safety.

View Newsletter   Download PDF Version Download PDF Version   Download Word Version Download Word Version  


Newsletter No 25 - January 2012

There have been recent collapses of temporary stage structures in the USA and in Europe which have resulted in fatalities and numerous injuries. The reasons why these failures have taken place have not yet been published, although initially wind has been reported as a possible contributory cause. The types of temporary structures which have been involved appear to be similar to those which may be used in the UK. SCOSS has just published an Alert; “Temporary stage structures”, about the possible risks and it is aimed at those who may commission or procure or licence temporary stages and other temporary structures, for example large outdoor TV screens, which offer potential risks to the public, These may include owners of sites and venues, promoters, contractors and their designers, local authority licensing officers and building control officers, and insurers. The first report in this issue deals with licensing of temporary structures such as stages and demonstrates that there are concerns amongst local authorities about the current situation. There is then a report about potentially dangerous issues during the construction of a school, and two about the sudden failure of timber roofs. Finally there are four reports about issues connected with the installation of photo voltaic panels on existing roofs. Engineers may be concerned if they identify something which they judge to be amiss but are uncertain as to the proper course of action. The Royal Academy of Engineering has recently published “Engineering ethics in practice: a guide for engineers”, which gives case studies from several disciplines and will help engineers decide how to act. Further details are given in this Newsletter. The CROSS programme depends on receiving reports and individuals and firms are encouraged to participate by sending concerns in confidence to structural-safety.

View Newsletter   Download PDF Version Download PDF Version   Download Word Version Download Word Version  


Newsletter No 36 - October 2014

Thanks to all of those who have submitted reports, a selection of which are given below. There are others in the pipeline and the data base continues to grow. However the success of the programme depends on receiving a constant supply of material. Ten thousand subscribers receive these Newsletters and if you benefit from them then please contribute by sending concerns, in complete confidence, to Structural-Safety. More reports are ALWAYS needed. In this edition the first report is about the failure of a tower crane leg, probably due to fatigue, and raises the issue of whether the history of an often used part should be known. There is another report on the quality of imported structural steelwork and rebar and a repeat of the frequently quoted advice "buyer beware". Two concerns on wind follow. The first relates to a two storey site cabin being blown over. The second is on the use of the Eurocode. Then come two reminders of winter with more on the splitting of RHS stanchions and a warning about snow slides from curved roofs. During site excavation a dangerous temporary spoil heap was spotted by a passing engineer who persuaded the contractor to use safer practices; an admirably responsible attitude. Another reporter describes how the load testing of a very deep beam came to a premature end. Finally it has been observed that the design of rebar in slabs with twisting moments may not always be in accordance with recommended practice. Two of the nine cases are about design, two are about events during the normal use of a building, and the others relate to site operations. This is consistent with the usual proportions of reports. Lessons can be learned from all of them. At recent events in London; the ICE Health and Safety in Construction Conference, and the Capita Safety Lecture, it was stressed that learning from others is a key aspect of successful safety cultures.

View Newsletter   Download PDF Version Download PDF Version   Download Word Version Download Word Version  


Newsletter No 47 - July 2017

In humanitarian, social and engineering terms the catalyst for profound change is often a catastrophe whose name is remembered for years to come. Grenfell Tower will become one such tragedy and the ramifications of the fire will resonate into the future. The heartfelt sympathy of everyone goes to the families and friends of the victims who died, those who were so grievously wounded, and those whose futures will have been so damaged. Other tragic fires such as Bradford Football Stadium (1985), Kings Cross Underground (1987), and Piper Alpha (1988), resulted in changes to Stadium design and construction, underground railways, and offshore platforms respectively. Their names remind us of the event but not of the human cost. Fifty-one years ago, a small gas explosion at high level on the Ronan Point block of apartments triggered a disproportionate and progressive collapse. Eventually this resulted in changes to Building Regulations in the UK and elsewhere, changes to the approaches to structural robustness, and new generations of safer towers. A form of failure not previously encountered led to a transformation by learning from a disaster. The same must happen with Grenfell Tower where performance across a range of issues has clearly not been as intended, with consequences that have so horrified the public and experts alike. The full implications will not be known for some time. It is of course essential that as much as possible of the forensic evidence will be collected and preserved. Importantly the announcement of a Public Inquiry means that evidence and recommendations will be in the public domain and not, as is often the case with collapse investigations, hidden behind non-disclosure agreements. The terms of reference must be wide, the Inquiry must proceed quickly, and its findings must be published as soon as possible and widely disseminated. Particularly those with implications for other tower blocks and perhaps other large buildings. The voices of those with knowledge and experience, as well as the public, must be listened to and recommendations implemented. Communities rightly expect their homes, hospitals, schools, and places of work to be dependably safe and secure. Not vulnerable to unconfined fire or other disastrous events. SCOSS was set up in 1976 to monitor issues of structural safety in the built environment and it has exercised that role ever since. From 2005 CROSS has collected confidential reports on concerns about structural safety. Consequently Structural-Safety (SCOSS and CROSS combined) has a unique insight into the causes of many failure events and into how lessons can be learned and disseminated to benefit the public and the industry. This information will be available to the Inquiry. Those engaged in the development of large buildings be they clients, architects, quantity surveyors and cost consultants, structural engineers, mechanical and electrical engineers, fire engineers, regulators and local authorities, researchers, main contractors, suppliers, sub-contractors, surveyors, resident engineers and clerks of works, must always have a care for the safety and well-being of occupiers and those who may be sent in as rescuers. Government departments too. There are high ethical standards to be maintained as well as legal duties and the exercise of diligent and competent work and oversight. Structural engineers can, and should, demonstrate leadership where issues critical to life-safety are involved. There must be action from government and industry.

View Newsletter   Download PDF Version Download PDF Version   Download Word Version Download Word Version  


Newsletter 57 - January 2020

There is growing concern about the number of problems requiring remedial works in buildings. They result in additional costs, delays, reputational damage, and a loss of confidence in the credibility of parts of the industry. Revealing the causes of failures should benefit everyone and it is perfectly possible to have a no-blame culture whereby anonymised versions of failure occurrences can be published. In cases where there is a legal dispute, parties will not disclose information which could either incriminate themselves or breach confidentiality obligations (such as for arbitration). Unfortunately, this means that some of the best lessons to be learned are often not available. A further potential source of undisclosed information is the insurance industry which does not generally publish the lessons that might be learned from claims. Recent letters to The Structural Engineer discuss the rising cost of PI cover and its effects. One author has experienced a four-fold increase in premiums over the past two years which, in addition to affecting their business, is a reflection of the risks, actual or perceived, seen by insurers. The same author asks whether the causes might be due to, amongst other factors: over-reliance on computer calculations, poor checking, and poor supervision on site. Rhetorical questions, although all have featured prominently in CROSS reports over the years and will continue to do so until the culture changes. Another cause frequently mentioned is the very low level of professional fees which must affect the quality of service that designers are able to give. To this can be added the sometimes iniquitous pressures from value engineering processes which may give neither value nor do they result in any engineering improvements. These factors are exacerbated by the refusal of some clients to have independent, or indeed any, inspections on site. The industry is being forced to review its attitudes and conduct as a result of the Grenfell Tower fire, and we must strive to ensure that there is not a structural failure of similar magnitude due to some combination of the known, and frequently expressed factors reducing the safety of buildings. Clients, designers, contractors, lawyers and insurers must work together more effectively to share critical information and Structural-Safety will strive to achieve this aim. There are many pre-cursors which we ignore at our peril and the opportunities that CROSS provides for the industry to learn and improve are more important than ever.

View Newsletter   Download PDF Version Download PDF Version  


Newsletter 59 - July 2020

There are common themes to the reports in this edition and they are: • Problems with design co-ordination • Problems over quality of site control • Problems over inspections on site • Problems over changes on site Around half of CROSS reports are about problems on site and a root cause is that designers are not represented to see that what is constructed complies with the design. In recent years some owners have become reluctant to engage structural engineers, or independent inspectors, to review works on site having been persuaded by contractors that they can scrutinise themselves the works they are building, or simply in a bid to save money. When something goes wrong due to poor workmanship or inadequate supervision, the subsequent costs are likely to be far higher than the costs of proper inspection. Indeed, the unwillingness of clients to pay for this can be a contributory cause to the resulting problems. Do clients, or their advisors, recognise the requirements of CDM and their responsibilities thereunder? Reports in this issue include cases of reinforcement not being properly placed, of communication problems on major repairs, of insufficient fire protection not being identified in a timely manner, and of main structural steel members being butchered to allow for the passage of drainage pipes. Other issues highlighted are related to the design phase, which account for about a quarter of CROSS reports, and again the unwillingness of clients to spend money is a factor; this time in relation to professional fees. On design and build jobs, the client for the detailed stages is the contractor and the continual push for the lowest price affects the quality of design and the ability for adequate communication to take place amongst the team. Contractors want early involvement in projects to ensure buildability and efficiency, but the quality of design must not be compromised. Ideally this this should result in problems being identified before the works start. One of the potentially most serious issues on site is when changes are made without authorisation either deliberately or in a thoughtless manner. If the change is one that affects structural safety or fire safety aspects and potentially compromises lives, then the cost of proper communication, responsible co-ordination, and independent scrutiny becomes trivial.

View Newsletter   Download PDF Version Download PDF Version  


Email Updates

How to Report

Online submission:
Submit by post: