Winches & Cables or Hydraulic Lifts

[Terrence MacArthur]

Suppose you wanted to use 2 winches to lift and lower (static lift) 250 pounds, which included a performer. Two half ton winches would only give you 2000 pounds, less than a 10 to 1 ratio. Two 1 ton winches would be a bit of overkill. Are there any such things as 3/4 ton winches?

 

[Robert]

Pretty sure the winch would not be rated for that type of lifting. Probably will state so in the instructions, leads to not just negligent but criminally negligent if there was an injury. Danger Will Robinson, proceed with caution.

 

[BillConnerFASTC]

What it lifts and what its designed to hold are separate issues. The machine should ideally not lift much more than the design requires, and the motor stall when overloaded. I just was called in to look at a home built lift in scenery and it failed and there was an injury. Among many problems, the motor was way too strong and when the limit switch failed, the lift pulled itself apart, snapping a 3/16" wire rope. That's over 4000 pounds for a lift to raise 200. Put up a 1000 pound package hoist today and sure you could hang 8,000 pounds on the batten and it wouldn't fail, but it won't lift that or much more than 1000 pounds.

 

[porkchop]

If you're talking about chain hoists similar to CM Loadstars first off: no, no, no, and no again (yes I will continue to beat this dead horse hypothetical situation or not). If you had chain hoists actually designed for performer flying (they do exist) then those lifting devices would have been built with an adequate safety factor and provided you and the manufacturer agree as to what that should be (perhaps your insurance company says you have to have a 20:1 safety ratio or something extra high like that) then you could use those lifting devices for their full rated capacity.

What is more common when talking about using a winch to fly a performer is to use a drum winch similar to the BigTow Series that is specifically rated for performer flying at the speed and capacity that you need. In this case you would also be able to use the winch at full rated capacity (you would have spec'ed the winch for any above-and-beyond safety factor when ordering/renting) and if you used a multi-line winch then all lifting points could run back to the same lifting device which improves safety by preventing a situation where lifting points are moving at different rates of speed or some are moving and some are not.

To answer the question you asked, 3/4 ton chain hoists do exist, but they are very uncommon. In most situations it's much easier to just get 1 ton hoists.

 

[de27192]

Suppose you wanted to use 2 winches to lift and lower (static lift) 250 pounds, which included a performer. Two half ton winches would only give you 2000 pounds, less than a 10 to 1 ratio. Two 1 ton winches would be a bit of overkill. Are there any such things as 3/4 ton winches?

What you are overlooking is that the winches ALREADY have a safety factor incorporated into their SWL.

A half ton winch should have at least a 5:1 FoS already so if you try to work to a 10:1 safety factor from it's SWL, then you are probably creating a 50:1 FoS which is pointless and as Bill points out could even make it worse.

So if your load is 250lbs and you have a 1000lbs winch with a 5:1 FoS then you are looking at a 20:1 FoS on the lift.

But as has been mentioned... when flying people, the weight of the performer is only one consideration.

 

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Merged threads... Again. Please stop making new threads on this subject.