Health and safety: Wake up call

In April, 15 floors of scaffolding collapsed on a site in Milton keynes, killing a worker and seriously injuring two others.

The tragedy comes at a time when the regulatory environment is pushing scaffolders away from the traditional tube and fitting method toward proprietary modular systems.

Scaffolding safety specialist Simon Hughes of Simian Risk Management predicts that the accident will bring greater pressure on scaffolders to meet tougher safety standards that were introduced last April but which have been largely ignored.

The Work at Height Regulations add a new requirement for all scaffolding to be designed by a competent engineer unless it conforms to a "generally recognised standard configuration". Previously, scaffold design was agreed between the scaffolder and the main contractor, says Hughes.

Another important shift in the last year has been the discontinuation of the British Standard BS5973 and the switch to European BS EN12811. The new standard favours modular scaffolding, which is tested and prefabricated in factories. It insists on a more rigorous method of calculation, where every specification needs proof of suitability. The old BS5973 used the "permissible stress" approach, which Hughes says relied more on common sense and precedent.

In Europe, Hughes estimates that 90% of scaffolding is the modular variety. The UK scaffolding industry uses around 70% tube and fitting. "I feel the UK was quite poorly represented when [the standard] was drawn up," says Hughes.

The UK scaffolding industry has reacted defensively to the new standard, suggesting that contractors should stick to the old one. For one thing, it is familiar. For another, it is effective. "No scaffold erected to BS5973 ever fell down," is a refrain Hughes repeats.

The National Access and Scaffolding Confederation (NASC) commissioned two structural engineers and Oxford Brookes University to put BS5973 to the test with live and computer models, providing it with retrospective scientific rigour. The result was a technical guidance note, TG20, which partly bridges the gap between the UK's favoured tube and fitting method and the European standard (although the NASC stands by certain methods, such as the permissible stress approach to calculation).

Don't get tripped up

But the eventual cultural acceptance of BS EN12811 seems certain, and the HSE believes it is safer. Richard Lockwood, head of the construction safety unit, says it stipulates better tying in to buildings, stiffer corners and avoids diagonal braces, which he says is important since more accidents are caused by tripping than falling. However, you are not breaking the law if you use the old British Standard, he says: "Following BS5973 does not mean you're in breach of the Work at Height Regulations, but it does mean you're not up to date with standards."

Hughes says it's too early to speculate on the cause of the Milton Keynes collapse, or whether it was built to a recognised standard. But he said the tragedy would strengthen the argument for standards in a sector that is difficult to regulate.

"It's a very dynamic time for scaffolding," Hughes says. "Lots of companies are unaware of the new standards or are ignoring them, but at some point they're going to be brought kicking and screaming into the 21st Century."