• A KEY and strongly-defended element of the rail, air, and marine investigations into crashes is that there is total witness indemnity from any prosecution based on evidence provided to the inquiry.

This blame-free reporting extends to pilots etc reporting their mistakes on the basis that the greater value of learning lessons far outweighs the delivery of petty punishments.

Any risk of punishment is certain to drive evidence underground and the delays in the follow-up contrast significantly to the way that accident investigation boards have powers, which they use, to secure all evidence including building and maintenance records to prevent loss or alteration.

One other issue we have to face is that we have buildings with a variety of fire risks, some probably as serious as the flammable cladding, and it was the management of those risks which failed as much as the fire itself.

Why, for example, did the escape stairs fill with smoke, when these should have been a smoke-free place of safety accessible from every floor? Why did the outer walls and windows not work as they should have to block fire breaking though from the outside?

Where were the fire-breaks to stop the fire going up under the cladding – a known chimney effect – but with a very vague specification of what was required, and no proving of the practical efficacy of the options?

Finally, aluminium, in powder form, is “burned” to generate molten iron (at c 2,500 degrees C) and the metal itself reacts with water to produce hydrogen, explosively so, once it has melted at around 700 degrees, and this is enhanced by acidity in the water (as happens in fires as the gases dissolve in the water used).

Just as the fire services need to know that oil, or even metals like magnesium, are present, the presence of a large amount of aluminium in a form which can readily react to generate hydrogen needs to be recorded and immediately made apparent to firefighters before they start using water.

I fear any investigation may reveal that in putting pure water on to a burning aluminium foil-coated cladding firefighters can unwittingly make a fire stronger rather than putting it out.

Theresa May’s poorly-considered “witch-hunt” declaration may well deny us a real insight into what has happened and how to deal with it, let the “guilty” tell the true facts and only those who have massively ignored or deliberately acted in a dangerous way.

In the interim we need to have some serious rebriefing for emergency services, with flats still likely to be clad with aluminium-faced panels with “safe” and “unsafe” core fillings, and most new trains making extensive use of aluminium, how should a major fire be handled – with or without water?

Would flooding a stairwell with a heavy does of helium in an extreme fire, provide a survivable space while not feeding in extra oxygen, with the risk of causing flash-overs and explosions?

DAVE HOLLADAY
Address supplied