Keep an open mind on risk to avoid catastrophe

I've chaired a number of safety committees in my time: for my own company, for Construction Industry Council, for London Underground, and the Standing Committee on Structural Safety for HSE/ICE/IStructE. I do it because it's a) important to me, and b) might make a difference. I also do it because raising the bar in safety helps the company I work for. 

When a catastrophic event occurs, the consequences spread beyond the site or the project where it happens very quickly and can adversely impact the wider industry. Think of box girder collapses and the costly impact of redesigning all bridges of that type under construction or on the drawing board. Think of the Heathrow tunnel collapse and the consequential cessation of sprayed concrete lining on the Jubilee Line Extension. 

That was a different project, but close enough in concept and application to justify a pause for lessons to emerge from the event. It took 18 months to start up again. Many of the costs to the project's supply chain of the resultant delays would not have been fully recovered. Safe design and construction is too often taken for granted without fully appreciating the massive business and reputational impact of unsafe design and construction. And we can all get caught up in the collateral damage.

I care enough about not hurting people to want my industry to be safe. There's a strong moral case for that to be a sufficient motivation in itself. But we should also recognise that there's a benefit to our companies. We all have a stake in each other's safe performance. Anything we do to improve it across the board is an act of enlightened self interest. And there's nothing wrong with that as a motivation. 

In a recent meeting of one of the committees I chair, the flaw in slotting all hazards and probabilities of occurrence into a 5 by 5 matrix became apparent. Very low probability, very high impact catastrophic events would score a 1 and a 5 respectively. The resulting risk score of 5 would not take it to the top of the risk register. But the impact of an event like the Heathrow tunnel collapse is far greater than a typical 5 which might appear in other risk assessments for the project as "very high". It's off that particular scale. It might be 10 on a scale of 1 to 5, or even higher. 

There's another near miss reported in the latest CROSS Newsletter (http://www.structural-safety.org/publications/view-report/?report=4452). A precast concrete temporary retaining wall failed, almost spilling its backfill onto a railway.  

The lesson? Don't let your thinking be constrained by the artificial boundaries of a risk assessment matrix. Keep an open mind. Pay appropriate attention to those catastrophic events that, thankfully, occur very rarely, but when they do they make us all wish we'd taken them more seriously. And when you're comparing the consequences of failure, make sure you think big. Don't underestimate their impact just because you're working in a 5 by 5 matrix. 

If you do that, we'll all benefit from each other's  serious and mature thinking on avoiding catastrophes.

Gordon Masterton is Chairman of the Standing Committee on Structural Safety.