A crane to build a crane to build a crane


Staff Member
Ever wondered how they build big cranes?

Well you start with a small crane and use that to build a bigger crane.

Then you use that bigger crane to build an even bigger crane.

I took these photos a few years ago when they were building the apartment block next to us.
At one point I thought the crane was going to come through the window - it was just 1 metre away!

This sequence is actually the tall crane being dismantled, but the same principle applies.

They probably build that one up with each few new levels.

Believe it or not, for some tall buildings the cranes which are fixed to the outside actually build themselves.
They jack up the cab, winch a new section into place and then lower the cab again.

Cranes are quite fascinating when you see how they're built and used.
I have watched the new crane being built in Rosyth dockyard over the last few months. It will be used to assemble the new aircraft carriers. The crane is a real feature on the landscape now. Its just Mahoosive.

Some photos of it squeezing under the Forth bridge at low tide. And fully built. Look at the size of the cab on the leg to get some idea of how big it is. :o

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Back in the early 90’s I worked as a radio operator in the maritime office of the company that built the Second Severn Crossing. Our role was to cover the maritime operations on the river and co-ordinate site traffic with normal river users, act as an auxiliary coastguard and safety office.

I’ll always remember the day that we attempted to lay the first caisson on the river bed. The principle of construction was that a caisson (a hollow box of concrete weighing in at several thousand tonnes) was constructed on land and then transferred to two crawlers on loan from NASA. These would then roll down a slip way and on to a specially constructed barge called the “SAR III”. From here the box was taken out into the river and held under a platform, similar to a large oil rig, called the “LISA A”. The LISA A had an enormous twin crane that would lift the box off of the back of the barge and then when the SAR III had moved clear, lower it on to the sea bed at low tide so that it could be dropped in the exact spot. Once there it would be anchored to the river bed and filled with concrete to form a base for one of the bridge supports. In order that the SARIII remained in the correct position under the LISA A it was held in place using a dynamic positioning system that relied on a team of surveyors setting up laser reflectors on the LISA A and in the case of the first caisson, on shore.

Come the day of the main event, the press were on hand as well as some local dignitaries to witness the final part of this massive operation. Those on the sea wall were asked not to wear anything reflective to affect the operation of the laser system. It so happened that on the sea wall that day there was a member of the senior management who wasn’t exactly the most popular man in the world shall we say. He was wearing a life jacket with reflective patches on each side of his chest. (I know, you can see where this is going!!). The SAR III positioned itself under the LISA A and then switched to the dynamic laser system to hold it under the crane. The lasers searched for the reflectors and yep, one of them locked up onto the jacket of the senior manager. As he strutted off down the sea wall, several thousand tonnes of concrete and barge followed him down the river. The frame that captured and lifted the box was already over the box itself and so one of its legs left a good 10 foot scratch along the side of the box. For many years this was (and maybe still is) visible on the right hand side of the first caisson under the bridge on the English side.

Finally, on getting home after a long days work, I switched on the local evening news, only to see another member of the management explaining to camera that the “trial run” had gone perfectly and that the main attempt would happen the following day.

Suffice to say, it wasn’t a trial run, the senior manager returned to head office and wasn’t seen on site again and we had a good chuckle for many a day after.
I'm gonna pass that on Sunday, might try take some pics as I go by on that rusty old bridge!

Last time i was up that way they were doing works on the road bridge and i was quite happy for it to take 10 minutes to cross, so i could stare at the marvel that is......
Ahh' you were on the train, on the rail bridge... I was in a 4x4, stuck on the road bridge... much better place to marvel at the rail bridge from:)

On topic - company near me builds cranes. They test build every crane and all the larger ones build themselves.
The first bit of the aircraft carrier arrived a week or so ago. I went along to watch it arriving. It's gonna be a big un.
All they need now is some duck tape to hold it all together.

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