On 29/12/2011 19:04, andrew wrote:
Bill wrote:

I've been dithering about buying a high lift farm jack type device for a
couple of jobs, one of which is pulling a boat upright on a trailer

I've carried Hi lifts for more than 20 years and they're not very useful for
pulling as you tend to use a lot of the active length in taking up slack. I
also have a 5 tonne chain and ratchet winch which is much more controlable.

Hi Lift jacks do require a lot of care in use because of their inherent
instability.

AJH

Agreed. Also, the one I have (Machine Mart, istr) isn't very easy to use
because you have to maintain something like 50 pounds plus of load on it
while you are starting, or the mechanism doesn't work at all. Presumably
there is a "knack" in using them, or perhaps it is easier with two people.

But I think I would go along with Andrew and say the chain hoist is
intrinsically stable. The other gadget of mine which gets more use is a
wire rope ratchet puller (cheap as chips). You can't use it as a hoist
because it only goes one way, but it's fine for "dragging" jobs.