The risk of a disaster remains,” warns Standing Committee on Structural Safety chair Bill Hewlett.
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He is reflecting on temporary works in the modern construction industry.
“The hazard is inherent in construction. There have been some major collapses this century.”
When failures occur during a construction project, the consequences can be horrendous, as seen in Kolkata last year when a section of the Vivekananda Flyover collapsed killing at least 20 people.
After the disaster WSP head of bridges and ground engineering Steve Denton told New Civil Engineer that a relatively high number of built-environment failures occur during construction.
Understanding structural failures
“Over the years we have examined structure failures around the world to understand the reasons for them,” he said last year. “One of the clear things you see is the disproportionate number of failures that occur during construction, despite the construction phase accounting for only a relatively short period in any structure’s life.”
There has been a wealth of work in the UK to attempt to stamp out the risk of catastrophic failure during construction projects. Following disasters including the collapse of the Loddon Bridge Interchange, which killed three people in Berkshire in 1972, professor Stephen Bragg was appointed to chair a committee investigating the issue.
The Bragg Report, as it has come to be known, has been credited with helping the industry take great strides on in-project safety, and in particular that of temporary works. Published in 1975, it made 27 recommendations, including the appointment on each site of a temporary works coordinator to take responsibility for overseeing the safety of this critical part of many schemes.
Then, in 1982, the British Standards Institute (BSI) built on many of Bragg’s themes when it published BS5975 a code of practice for falsework.
The smaller end of the industry is still a focus for the Health & Safety Executive
David Thomas, Temporary Works Forum
While these two planks of safety policy are credited with overseeing a major change in the way temporary works are managed, with positive results, there is a drive to avoid complacency.
Changing circumstances in an ever-evolving industry have led to new advice aimed at simplifying best practice guidance for in-project works.
Titled Principles for the management of temporary loads, temporary conditions and temporary works during the construction process, the 10-page document was published by the Temporary Works Forum (TWF) in September.
“The document stems back to early 2017,” says TWF director and secretary David Thomas.
Summing up guidance
“We postulated that while there was a lot of guidance available on temporary works, we ought to be able to sum it all up in 10 principles to give people a simple set of steps to follow to have a fighting chance of avoiding things going wrong.”
This intent proved somewhat ambitious and the final document lists 21 main principles, alongside the need for a single responsible person in each company, and a separate introductory section. But the idea remains to offer a simple overarching document for use by construction companies of all sizes and specialisms across the world.
“We’ve tried to steer away from UK-specific terminology, as we would like to think this will be useful to a global audience,” says Thomas.
“Legislative regimes are very different by country and some have more guidance on temporary works than others. But the underlying principles are the same.”
He says that complying with the TWF document is likely to require firms to meet local legislative demands, although he stresses they would remain responsible for doing anything extra required by law.
More research needed
It is not just those outside the UK that can benefit from the guidance, though. Thomas says that while the domestic industry has learned from previous disasters, there remain areas where more work is needed.
“Much has been done by big contractors in the UK on temporary works safety, but the smaller end of the industry is still a focus for the Health & Safety Executive,” he says.
Thomas cites a report published in 2011 by Loughborough University and the Construction Industry Research & Information Association for the HSE. This study into catastrophic events found that “insufficient consideration was being given to the management of temporary works in its widest sense”.
Thomas says: “I’m not convinced the industry as a whole has fully grasped the recommendations of that report.”
He says too few designers think about construction methods.
“They don’t think enough about how structures are built.”
It is not just those at the very start of a project’s conception who could focus more on temporary works safety, Thomas adds.
“Planning and management of temporary works could merit closer attention. The four Cs are critical – co-ordination, co-operation, communication and competency. Each stage of a project needs to be thought about and that stems from a permanent works designer, through to a site engineer.”
Passing the right information down
He says the right information must be passed down the supply chain so subcontractors can plan their part of a project correctly and safely.
“There is always more to do to ensure things can be built safely – it remains an area of focus. Temporary works remains a raw academic discipline, it is a relatively new area for research.”
Hewlett says Bragg’s insistence on a temporary works coordinator on every site made a real impression 40 years ago.
“The idea of having, on every project, one allocated person who has sole responsibility of temporary works has really worked. Engineers tend to be nervy people and they take a role like that very seriously. When I did the role I always had in my mind: ‘If this falls down, how will I stand up and say I did all that was practicably possible?’”
But he adds that the industry was ripe for new guidance this year.
“Times have moved on. Main contractors are more like management contractors now as they don’t do much work directly and they use subcontractors more. The labour force is different, more multinational. And the HSE is now very interested in the small and medium sized enterprises market.
“Another driving force is the international work. The idea of a principles document is that it becomes a lingua franca for engineers across the world. As a management regime, using these 21 principles will put you in a pretty good place.”