Originally posted by: teqwiz
Wow. I didn't even think a Heli could have lifted more than maybe 5 tons.
Most can't these are exceptions, not the rule.
Your standard Bell 206BIII JetRanger for example can lift just under half a ton (about 900lbs). About the same as many cars and light trucks.
The actual walls are 30 ' square and 7 " thick. some have large windows and are about 30 tons, and the solid ones are are close to 41 tons.
You wouldn't want to try and lift a 30 ton wall with a helicopter that maxes out at 30 tons. You have no margin for safety there.
Some how I imagine that rotor wash, which I imagine to go down, away from the actual lift of the blades would push this around underneath it.
No, it really wouldn't. The mass alone would prevent it. Yes the rotors DO produce an impressive downwash, but it isn't a hurricane.
Since it would hang vertically in order to set it into place for the building. I don't see how this would be safe a still be possible in the reall world. The reason that you use a 150 ton crane in the first place is the safety factor of the equipment being able to support at least three times the weight actually used, so as to handle the panel as safely as possibble.
You don't need three times the lifting power, but you do need some margin for safety. I'd personally have no problem lifting a 25 ton wall with a MI-26.
The whole reason that I am asking about this is that some of the upper management seem to have these new ideas on how to implement building this particular project because of some of these wild stories as I call them.
New ideas are a good thing, and there is value in helicopters for these kinds of projects.
Thanx for your input. There is no way we would have paid that bill. It'll cost $5,000.00 to do it the way we always do. I just wanted to make a well informed decision.
How many walls to be put up? You can probably get a dozen walls put up in 3 hours, might only cost you $50,000 or so when all is said and done.
That might be more than the crane costs, usually is, but that isn't the point.
I recently installed three air conditioners on the roof of a mall using a Sikorsky S-58T. Each A/C unit weighed 2 tons and the S-58T can lift about 3 tons. It cost them $11,000 to have them installed. $9,000 for the actual work plus $2,000 for the trip charge (flight there and back) and the crew.
It would have cost perhaps 1/4 that much to have a crane do it, but because of the size of a mall and how far from the sides the A/C units were going, it would have had to be a lattice construction crane. It would have taken a day or two to build and a day or two to take apart and it would have to have been done in the mall parking lot.
We started at 7am on a Wednesday morning and were done by 10am. There is a value to be attached to that. It was certainly worth $11,000 to the company that runs the mall anyway.
The lattice construction crane probably would have done that much wear and tear to the parking lot anyway.
Grasshopper
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