Does anybody know if these cranes pick up a layer of ice when in clouds at below freezing temps? They must be susceptible to it in the same way as aircraft are. is it an issue with cranes too?
There are cranes on much higher buildings in colder climates than ours.
Moscow IBC for instance, that don't seem to suffer any problems.
Funnily enough ice is less of a problem in very cold weather. The temperature at the surface was around -3C, so at 1000ft it would be (around) -5C. It's quite possible for water in a cloud at that temperature to still be liquid, but if a piece of cold metal arrives (eg a helicopter) then the water will freeze on the helicopter.
If the temperature in the cloud is, say, -20C then it's far far less likely that the cloud has liquid water in it as it will have frozen. It will have ice in it, and the ice will bounce off the helicopter so not stick.
It's the build up of ice on the aircraft which is quite frankly frigging dangerous.
The forecast I quoted above which was issued at 04:59 on that morning says
TAF EGLC 160459Z 1606/1615 08004KT 0800 FZFG BKN001
between 6am and 3pm:
FZFG means Freezing Fog i.e they are forecasting such icing conditions
BKN001 means clouds start at 100ft so getting under these conditions is not doable
So the information was available in advance that the weather was unsuitable for such light aircraft flights.
There are words 'get-home-itis' and 'press-on-itis' in the flying world. People decide to fly into innapropriate weather conditions because of pressures to get home, to pick somebody up, to do something which really doesn't warrant the risks involved.
This happens to experienced pilots too. 'Failure to maintain visible separation' is the probable cause of far too many accidents, everybody knows it is dangerous to fly close to the ground or tall buildings when you cannot actually see them, yet these accidents still happen. The goal is to learn from these accidents to prevent more.
Though the insurance company will pay out depending on who was to blame. And the poor guy on the ground who had zero part in the decision making for that flight is dead.