Can I readily clamp a pipe with 450 weight without it slipping?

[wells]

TL;DR Summary

Holding 80ft pipe and pump at 450lbs without slipping with two clamped 1' 2x6 wood

I'm planning on lifting a submersed well pump that is hanging on a 80' 2" galvanized pipe. Total weight is estimated to be 447lbs based on:
pump ~ 50lbs
pipe 3.6lbs per foot
water 1.36lbs per foot

The plan is to use two pieces of wood (1 foot of 2x6) with two clamps to hold the pipe in place while getting a new grip with the crane.
To get more grip I'm thinking of applying a locking plyer around the pipe on top of the 2x6.
The question is that realistic? Can I readily get enough of a hold on the pipe to not have it slip?

Based on this professional clamp which can hold 3,000 lbs it should not be too hard.
http://waterbuckpump.com/kwik-klamp-1-drop-pipe-holder/
The lift is to be supplied by a small electric winch able to lift 3500 lbs. The plan is to build a tripod with 4x4's, braced at the top and towards the bottom. Add a 2x6 brace between two legs and mount the winch on it. Then use a winch pulley at the top for the winch cable to go through, thereby keeping the lift weight on the bottom of the tripod, vs having the winch mounted on, for example, a truck, which would add a sideways potential that could cause a failure should the friction build up on the pulley.

 

[jrmichler]

Your idea should work. I suggest using a pair of 4X4's with 1/2" threaded rods for clamps. It would be much easier to use.

It's a good idea to check the clamping by lifting the pipe a short distance, tightening the clamps half tight, then slacking the cable to see if it holds. If yes, tighten the clamps full tight. Then you know that it will hold with a reasonable safety factor.

 

[berkeman]

Thread closed temporarily for Moderation...

 

[berkeman]

After a Mentor discussion about safety issues, this thread is now re-opened.

@wells -- Welcome to the PF. So it sounds like there will not be any people under the lifted weight, right? Thanks.

 

[Baluncore]

I alternate two loops with prusik = sliding friction knots, to hold pipes when lifting or lowering submerged bore pumps on metal or poly-pipe. It costs less and there is less chance of dropping tools or parts down the hole.

Consider replacing an old metal pipe with a pressure rated poly-pipe to reduce the weight and corrosion problems. A single length of poly-pipe can be coiled as it is deployed or recovered without need for many threaded joints.

With friction knots, “grip” is an exponential function of the number of rope turns around the pipe. You can get a better grip on steel pipe by increasing the number of turns around the pipe by one. Take care not to crush polypipe by using too many turns.

 

[sophiecentaur]

Slipping could be reduced if the two sides of the clamp had a radiussed groove which would fit round the pipe for, say 30% of its circumference. Drill a shortish 4X4 (or bigger) piece of timber with a hole cutter (many sizes available) and then cut it lengthways, removing a longitudinal slice to produce two D section grooves. That would make a brilliant 'chuck' with two pairs of bolts to keep it together.
If you can actually get to the old pipe and if it is not needed again, you could drill a hole through it and put a rod through the hole. No slippage there.
The Kwik Klamp looks cool but expensive for a one-off application