2006-10-10 11:42:29 · 13 answers · asked by John H 1 in Education & Reference ➔ Other - Education
Ok, I guess I will take the opportunity to give a serious answer to this question. First the question is what kind of crane do you mean. The simples crane, used for most typical construction, is a hydraulic crane. This is little more than a big truck with outriggers and a hydraulic boom. It then uses a winch to do the lifting. It taves very little time to put one fo these together, which is why you do not see it.
The second kind of typical crane is a traction crane on tracks. These can lift a lot more than a hydraulic crane. The benefit is they are still mobile like a hydraulic, but they can lift more. There are ones that can lift 100+ tons at once. They look like bulldozers on the bottom, but have a long book of a truss like structure and a compound pully winch that angles off the back to lift more. These take a few hours to put together, and they can assemble themself. Again, the short time needed to put it together is why you do not see it.
Next you have tower cranes and climbing cranes. These are used for very tall buildings, or where there is very little space on the job site. The tower crane is erected similar to a building with a full foundation. As was said before, another crane usually starts the process, and they erect it to the desired height. Climbing cranes are being used more an more these days. On a very tall building where not even a tower crane could reach, they actually build a crane to the side of a building. It moves on a track up and down the side. As the building goes up, the crane actually builds more tracks above it to move, thus it can continue up the building. This is one of the most practical ways for tall structures. The reason you do not see this being constructed... because while it is building itself you think it is just building the structure so you do not even realize it. Hope this helps...
2006-10-12 03:57:41 · answer #1 · answered by Craig B 4 · 0⤊ 0⤋
I saw one erected once - it was fascinating. They started out with a big
mobile crane - then they added piece by piece until they finished it.
2006-10-10 11:56:49 · answer #2 · answered by wallyinsa 3 · 0⤊ 0⤋
Natural Penis Enlargement Guide - http://LongPenis.uzaev.com/?knOQ
2016-06-26 20:45:39 · answer #3 · answered by Vesta 3 · 0⤊ 0⤋
hahahahhahahahahahha..sorry that was a pretty funny question..i no what u mean..but haha..craned get erected
2006-10-10 11:51:45 · answer #4 · answered by Ohkay 5 · 0⤊ 0⤋
Everybody knows erections happen early in the morning! That's why nobody sees it because we're all asleep :)
2006-10-10 11:45:19 · answer #5 · answered by Anonymous · 0⤊ 2⤋
Now that, is a GOOD question.
There are two near my house right now, and I never saw them go up.
Hmmm. Perhaps goblins put them up in the middle of the night.
2006-10-10 11:45:52 · answer #6 · answered by Anonymous · 0⤊ 1⤋
If you get up early enough an a Sunday morning... that's when most of them go up
2006-10-10 11:54:50 · answer #7 · answered by Anonymous · 0⤊ 0⤋
Because the crane fairies do it when we are asleep
2006-10-10 11:46:25 · answer #8 · answered by Red 3 · 0⤊ 1⤋
Because you don't live on a building site?
2006-10-10 11:51:01 · answer #9 · answered by cheekbones3 3 · 0⤊ 0⤋
poor you. you obviously aint paying attention, or your simply not around. it's the same with houses bein built down the road they seem to just appear
2006-10-10 11:48:56 · answer #10 · answered by SIMON T 3 · 0⤊ 1⤋