They were used on sites for erection of steelwork until better mobile cranes came along but don’t know when they came about as not out on sites until many years later.
In 2000 I worked across the road from a crane hire company and saw the gradual increase in the capacity of cranes.
These days you see some mobile crane that are huge 6,8,10 and 12 wheeled or bigger.
A 15 or 20 tonner was the norm. You need a higher capacity crane as the load they can lift is determined by the reach required. It’s something like 20 tonnes at 5 mtr radius but at 20 mtrs radius that drops to say 5 tonnes.
I often see our local crane hire companies cranes trundling back to the depot at around 4 pm, some little and one or two 50 tonners. There was a commonly used crane called an Iron Fairy for small jobs but not seen one of those for some years.
The term used by our Erection supervisor was the he want a 20 tonne Stick for the job. That was his term for these telescopic cranes.
On the motorway in recent years seen some massive ones, if I remember I passed a 500 tonner..
There is one according to the internet that has a capacity of 20,000 tonnes goodness knows what they use that for obviously a large load at a big radius or height. You then have 16 wheels.
The wheels are only generally for moving from site to site. When on site there are outriggers spread out so the crane goes from say 10 foot wide to 30 foot wide.
Some of these big cranes have separate jobs transported on another lorry and assembled on site “ rigged” the usual term.
The crane industry is a science in itself. Some big stuff can take days to rig and de- rig. Tower cranes another field altogether.
On TV the one installed to refurbish the Claridges Hotel was inserted into a lift shaft in the middle of the hotel it was good to watch.
Don’t think that I would like to be a tower crane operator 200 feet up in the air ( or higher)
I have seen Tower cranes being transported on 4 or 5 lorries the Tower and jibs in large sections but then you get the counter weights. I think that the police only allow a certain number of these crane sections on the road at one time, probably a max, of 3.
Cranes sort of developed from a set of block and tackle hung from a beam or a tripod. All started from the need to hoist the sails etc. on sailing ships and hold the masts in place.
Allan C.
Message Thread
« Back to index | View thread »