[sanjiv]

Recently I was asked to replace a observatory installed at about 110 feet height. I have to build a Dome of size 17 feet dia with standard installations. But the problem is how to reach such height ? please advise

[HuFlungDung]

You're gonna hate me, but here goes: a 150 foot crane

[BillTodd]

Is the dome light enough to be fitted from with-in the obervatory (i.e. could a few people lift the dome over their heads?). If so, scaffold the inside the observatory upto a suitable level (safely!) then hoist the dome up on guide ropes, have enough strong guys on hand to lift it over their heads into place.

[sanjiv]

It is to be made of steel

[BillTodd]

It is to be made of steel

Oh well, It'll be too heavy to man-handle


Looks like a job for a crane :shrug:

[litsc]

You might want to consider using a gin pole alternative, this is very dangerous and should only be done by trained personnel, but alot of times when a crane can't get close enough it will allow you to hoist small loads safely to that elevation. You should also research internal zenith ladder systems, they are made just for the assembly of a radome from the inside of the dome floor. Good luck, work safe.http://www.tower-technologies.com/GinPole.htm

[Finemess]

I built and installed a radar dome recently. It was built of plastic (except fasteners). Even so assembled it was quite heavy. We got it to the roof via crane as no one wanted to accept responsibility if a worker was hurt or otherwise injured. Yours sounds like an interesting project. I would study carefully how the existing one was made. You may find it was assembled panel by panel on site.

[handlewanker]

Hi Sanjiv, why don't you use the old method of a sky hook....LOL.

When I was an apprentice we used to get told by the wise olde birds to "go for some striped paint, a left hand screw driver, a long wait or a sky hook" among other nonsense tasks.

So to put it into a more realistic mode, why don't you use a heavy load lifting helicopter that is used to move those loads that you can't get a crane to.

Of course if the cost is too prohibitive, and the Heath Robinson approach is considered try tying a load of ballons to the dome and progressively filling with helium (or hydrogen if you're real dumb) and adding more until the load becomes light enough to manhandle.

Working at that height would mean surrounding the tower with a scaffolding platform, unless you have suicidal tendencies, in which case you'd attach enough balloons to your belt and go up with the dome....LOL.

Joking aside, it's time to use lateral thinking, so if you consider the proposals I've mentioned, then maybe it will trigger an idea to solve your problem.

I hear the Graf Zeppeling company are back in business................nein?
Ian.