On crane removals always use the same crane company, usually the same type of crane, the MK80, and the same operator. This has proven to be a good combination, meaning you do not have to redefine procedures every time before you can get started. This was also the crane we used for the removal of the beech beginning of February I wrote about a couple of days ago.
I was concerned last week to read in the newspaper that there had been an accident on Friday with that very crane. The Liebherr MKs are great once set up, but the whole way they folds up is intricate, to say the very least. I am always struck how the operator is able to pivot the whole length of the boom round by hand during set-up – that is how precisely the whole construction is balanced – yet it turns out that the down side of that is that during set-up the construction does not handle wind at all well…
Friday there were intermittent gusts of wind of quite variable strength, one of these caught the MK at precisely the wrong moment, almost shearing the boom off. In view of the fact that the crane was set up right next to the motorway and the boom was now hanging over traffic, this led to the busy motorway having to be closed for the whole of Friday afternoon. Far from ideal.
I am not quite sure what the take-away lesson from this is. Well, obviously, that cranes and wind do not mix well. But to be fair these were tricky conditions, it was not as though there was continuous gusts, they were few and fairly spaced out – but when they came they were strong. I also suspect that what happened here was a perfect storm in the sense that a strong gust caught the crane at exactly the wrong moment.
The main thing I take away from seeing a tool I am familiar with looking so very broken is that thinking positive is all very well, yet sometimes it can be a good idea to consider situations from a glass half empty point of view, not assuming everything will go as well as possible or as planned.
Interestingly I had cancelled a job the day before due to the weather forecast: a very large London plane right in the centre of town that is due for a canopy reduction, removal of dead wood etc. The canopy is very wide, spanning a road, two tramlines with overhead power lines, a busy pedestrian area and the entrance and exit to a public underground parking space. For organisational reasons we were really committed to do this last Thursday, as that was the day after the carnival ended here and the bicycle parking spaces below the tree would be clear, which would be convenient. The forecast for Thursday remained obstinately bad during the whole week, strong winds and rain from mid-morning onwards. The client for this job is the council, they had their crew lined up, also a security person for the public transport company to supervise the work around the power lines and the trams, so quite a bit of organisation had gone into the job already.
The closer the date came the uneasier I became, working scenarios back and forth in my head. Then I realised I was applying glass half full-type planning optimism. Ok, it will be a bit wet, but we will bosh it out, everything will go perfectly and we’ll be fine.
This kind of thinking has to be a red flag. The tree in question is a good thirty meters tall, fine to climb when dry, less easy in the wet, add wind into the mix and things start to look more than just a bit sketchy. I realised that my assessment of the situation was being biased due to trying to accommodate a date dictated by (justified) organisational concerns of the council. Taking a step back though brought back to the front of my mind the facts that this is challenging climbing in a challenging environment – and that therefore from a risk-assessment point of view I could not justify performing this kind work in adverse conditions. When weighing up operational versus organisational considerations, the safety aspect of the operational angle trumps the organisational one of having to shuffle dates.
I am not saying any of the considerations above are relevant to the crane accident, yet it brought home to me how easy it is to get fixated on a target, especially if you are already invested in it and you “only” need to do this or that to achieve it. This is the moment to take a deep breath, maybe get a second opinion on it, consider alternatives or options – and most certainly not to cut corners. In this case, the responsible people in the council were very understanding when I explained what the issue was, so we have rescheduled the work on the tree for in two weeks, hopefully in better conditions – this makes it more fun, and safer.