It is too soon to speculate on the cause of the terrible and tragic events surrounding the unplanned collapse of the Didcot Power Station. Early suggestions were that it was a ‘dust cloud explosion’ but this has since been ruled out.
Dust cloud explosions can occur in a variety of industries where flammable dusts and powders are used. Examples include: sugar, coal, wood, grain and other food dusts and certain metals. A powder that may simply smoulder if ignited as a pile will behave very differently if it is suspended in air as a cloud. Quite simply, the surface area exposed to air increases massively and the cloud becomes explosive if ignited. Clouds of this type would resemble a very dense fog where visibility would be down to single meters.
The investigation into the collapse of Didcot is likely to be very long and will focus on the planning of the demolition. The law covering demolition is the same as that covering construction (Construction [Design and Management] Regulations 2015).
Like construction, the client must appoint a principal designer who will be responsible for providing contractors with pre-demolition advice. A range of surveys will have been carried out into the stability of the site, nearby structures etc. to keep people involved and the public as far as possible from the risks.
The risk of uncontrolled collapse should also have been assessed, giving consideration to: the age of the structure, its previous use, the type of construction and the consequences of any materials already removed.
The condition of the collapsed structure is described as unstable and little evidence may remain as to what caused the collapse. If this is the case, the consequence could be that we may never know the answer.
Ellis Whittam wishes to extend its most sincere condolences and sympathies to the families and friends of those involved.