The Health and Safety Executive’s Mike Cross is heading the Major Hazards in Construction project. He tells Declan Lynch why the industry should pay attention to its top events.
A ‘top event’ is the very worst thing that could happen on a construction site if events were to go badly wrong. Concentrating on such potentially disastrous outcomes and ensuring they are factored out of the construction process will improve risk management overall and − hopefully − the industry’s poor health and safety record.
These are the ambitions of the Health & Safety Executive’s top event project manager Mike Cross and the HSE’s Major Hazards in Construction project. This aims to improve understanding of the causes of ‘top events’, assess the effectiveness of current controls and determine whether further action is needed to improve risk management.
Cross says the project − being run by CIRIA − has been prompted by the recent number of incidents in construction, which have, or could have, resulted in multiple fatalities including, on occasion, among the general public.
“Just as piper alpha drove change in petro-chemical safety, so tower cranes are now having the same effect in construction.”
“It looks in particular at top events, and raises consciousness of them,” says Cross. ” What do I mean by a top event? Go on to a construction site and imagine the worst calamity occurring, and if it did, what would be the impact? That’s a top event.”
The term evolved as the petrochemical industry looked hard at, and subsequently changed, risk management following the Piper Alpha disaster in 1988. A more mathematical approach to risk was adopted to work out potential outcomes, which could then be analysed to reduce risk, as part of a project’s ‘safety case’.
A top event is any catastrophic event raised in the safety case. It is a term now used by risk management professionals in addressing high hazard potential.
Recent UK construction examples of top events are the timber frame collapse in Peckham and tower crane collapses in Liverpool and Milton Keynes.
“These are events where many people could have been killed − the fact that many were not has been described as ‘miraculous’. Just as Piper Alpha drove change in petrochemical safety, so tower cranes are now having the same effect in construction,” Cross says.
“The number of people killed in tower crane accidents has not greatly altered over the past 10 years but because the recent accidents have been high profile there is a clamour for ‘something to be done’. Hence, the Major Hazards in Construction project and the focus on top events.
“And what we’re looking at is people applying themselves to existing duties, regulations and requirements in an appropriate manner to prevent top events occurring,” Cross says.
“Gold standard legislation in the Health & Safety at Work Act and high quality regulations in place in the Construction (Design & Management) Regulations 2007 means we start from a good position.
“Investigations of top events often discover that people concerned have no appreciation of the levels of risk.”
“I don’t think a natural starting point is that there are major holes in our current legislation. That said, does the construction industry want to wait for the next major catastrophe in order to act, or does it want to get ahead?
“The project is asking the industry to scratch its collective head and ask: ‘Where are we?’ “We are all aware of what can go wrong in construction but we need to get underneath the skin of that and analyse the potential and extent, and underline the common causes.”
Cross says the two main audiences for the Major Hazards in Construction project are the HSE and senior players within the construction industry. “It gives my colleagues at the HSE an opportunity to look at whether the executive is pointing in the right direction − I think we are, but we’re willing to learn.
“The project also enables the industry, its professional institutions and also CONIAC (the Construction Industry Advisory Committee) to address the top event question with sufficient seriousness and purpose.”
The challenge for those in the industry’s boardrooms is whether they have a sufficient hold − as legally they must − on risk management and analysis of major hazards in construction.
“If a company says they are on top of it − well, how do they know?” he asks. “If they think it is because they have a good track record with no accidents, that may or may not be an indication of whether they have a grip on their major accident potential.”
Past achievement in safety, he believes, is no real indicator of future performance: a truism especially appropriate to top events.
Two areas deserve particular attention as being inherently more risky than others − the refurbishment sector, where a disproportionate number of accidents occur, and temporary works, where often an insufficient level of skill is employed.
“Companies having a good track record may not be an indication of whether they have a grip on their major accident potential.”
Cross says that top events generally occur because of a lack of understanding of risk potential and believes there isn’t an intrinsic recognition of risk, and that competency can be an issue in both design and construction.
“What is often discovered during investigation of a top event is that people concerned have no appreciation of the levels of risk they were running and a failure to have the right people involved in the project at the start. Sometimes the project has been insufficiently researched, with poor site investigation or structural design.”
Cross points out the obvious: that in construction, what is required is a good general knowledge base, good design and good execution of design.
“A lot of failures of temporary works are where these have been incorrectly designed or they weren’t constructed properly,” he explains. “Training and competency are underlying issues as are companies’ systems and processes.
“Having properly trained people in the right place during the construction process at the right time is crucial.”
Cross says that top events are usually provoked by a combination of factors, rather that just one critical factor.
“Major accidents are handled in other high hazard industries by ‘defence in depth.’ This is defence in design, ensuring redundancy in a structure. A single failure does not cause the holes in a Swiss cheese to line up,” he says.
“Should construction have that approach to design, particularly in temporary works?” he asks, citing cases where anchors for formwork have failed due to a single fixing failure, sending everything down.
Putting more redundancy into a structure, however, could challenge the principles of value engineering and lean structures. “This is something for the industry to consider,” he says.
The project and the man in charge
The Major Hazards project is being carried out over a series of stages.
- Phase 1 and 2 of the project, which have included data collection and surveys, have now been completed. Phase 3 is now underway. This analyses the case studies to see if there is an underlying trend.
- All the information will be pulled together and the final phase will be communicated the results through seminars, and the media. A report will be published by CIRIA and HSE by late summer.
- The findings will be reported to CONIAC and the next steps will be determined. With at least one top event occurring per year, everyone hopes the project will be a success.
Mike Cross - career history
- Degree - Entomology and Parasitelogy, Newcastle University
- 1980-1994 - Health and Safety Inspector, North East
- 1994-1999 - Head of Operations, Wales & South West n 1999 - Head of Operational Policy
- Now - Head of Operations (Construction - NW England) Head of HSE’s Construction Engineering Specialist