There are several new high-rises going in around town. They all have one or two of those cranes that go up a couple hundred feet and look like a TV tower, then have a 100′ or so horizontal boom with a shorter counter-weight opposite it.
They are quite puzzling to me
1. How do they assemble & disassemble the thing? That is, what is the bootstrap process after the first 30 feet?
2. How do they keep from tipping over when loaded with steel beams or pre-case concrete? (One of them came crashing down in a recent windstorm)
3. Does the operator really sit in that refrigerator-sized box at the top ot the tower or it it all remote control.
Replies
IIRC they have 20' sections of tower. The crane crawls up and locks on, and new section is set...repeat.
There is also a counter weight to offset the boom or jib load.
Yup, the operator climbs up the tower..some times and hour to get to the controls.
Spheramid Enterprises Architectural Woodworks
"Success is not spontaneous combustion, you have to set yourself on Fire"
When I first saw them in the 1960's they were installed in the elevator shafts and as the building went up so did the crane in pieces and was removed through the elevator shaft.
Next time watch and see the counter weight move back and forth, compensating for the load.
Evidently it was the inventions of these cranes led to the massive and affordable tall buildings we now take for granted.
I don't know whether anyone has seen these small cranes that look very similar but come on and I believe stay on a big trailer. They don't go the height but maybe 50 feet or so. A very unusual design and I've seen where they park between some houses and are able to service several houses at once.
roger
it was the inventions of these cranes
They sure helped, buyt the gin pole was pretty effective for a long time."Put your creed in your deed." Emerson
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
I didn't think anyone else was left that even knew what a gin pole was. :)I was in a crew, ironworkers, erecting one of these in the 60's at Turkey Point Nuke Plant, in Homestead, Fla. As you get higher, over 150', when the crane boom swings, there is a definite twisting of the tower. The gears drag, the tower will twist and then "jump" back into place. The operator does not feel this but sitting in the tower, just below the gears, you could feel and see the effect. We had an apprentice (punk) with us one day who was nervous and one of the guys said "I hope this ***** does not fall" We all about fell off the tower laughing as the punk grabbed on to the frame with both hands.
When we went to Germany two years ago, we had the chance to see them used for one and two level houses. They are very compact and I have wondered why we don't see them here except for the high rises.
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That's the new one I've seen recently.
roger
See them in action. Pretty cool toy.http://www.youtube.com/watch?v=4ToniXxHsSg&feature=related
http://uk.answers.yahoo.com/question/index?qid=20061116065114AA0CnDD
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try this
http://www.youtube.com/watch?v=vx5Qt7_ECEE
Thanks!
Went to look at the utube link and eyeballed some others....this one crashed! Man, I'm glad that's not me cursing....would make for a really bad day!
http://www.youtube.com/watch?v=05_ahAulMSE&NR=1PJ
Everything will be okay in the end. If it's not okay, it's not the end.
OK you saw the video of how they raise & lower themselves.
Initail set up & take down is usually done with a very large telescoping boom crane like this one--- 550 ton from Ness Cranes of Seattle Wa.
Edited 1/20/2008 11:23 pm ET by plumbbill
Our company was the architect for the new operating engineers training facility southwest of Chicago. Part of our job (mostly our strucutral engineer) was the foundation for the tower crane they use for training. This site's crane ended up with a foundation of four 42" diameter caissons going 20' deep with a 13'x13'x3'(can't remember for sure) concrete cap. There is a steel base section that gets set prior to pouring the cap so that it is locked into the ground. The base was leveled plumbed to within .01" in all directions. This is a small crane at only 100' or so high so it was assembled using truck cranes. Bigger units in the city are self-erecting once the boom, house, and counterweights are set on the second section of tower. They climb the base 20' at a time hydraulically and then another set of tower is inserted.
If you go to http://www.asiplocal150.org and click on photos, then cranes, photos 14-17 show this crane in it's old location.
I'm never worried about the concrete, but the welding that happens at the base is what concerns me.
View Image
what all the fire trucks doing?.two ways to screw up concrete 1) concrete driver 2) concrete finisher
If you look at that picture closely, you can see that a tower crane has collapsed and the tower and main boom are laying across the foundation, a street, and hit the beige office building on the way down.
Edited 1/21/2008 10:58 am by boiler7904
That was a weld failure.
I took that pic from the roof of a job I was on in 06'.
The counter weights hit the building on the right, the other end hit that apartment & killed a microsoft lawyer.
Just goes to show you that something good can come out of even the worst tragedy.
If your view never changes you're following the wrong leader
That comment is rather poor taste and unprofessional.
That's been said about me many times.
If your view never changes you're following the wrong leader
typical
And admit it -- I just said what you were thinking.
If your view never changes you're following the wrong leader
Not even in jest or with a smiley.
"unprofessional."
?
dark humor ... unprofessional for a carpenter / contractor ?
I thot that was a resume requirement.
Jeff
Buck Construction
Artistry In Carpentry
Pittsburgh Pa
Dark humour is good but the internet does not transmit it so well without the help of punctuation.
"without the help of punctuation."
whadda ya need ...
a rim-shot?
Jeff Buck Construction
Artistry In Carpentry
Pittsburgh Pa
4. What do they feed on? Carpenter ants?
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