Thread: The Right Winch

thanks, what is the GBS of 11mm and 12mm? What do you consider a good pulley block? Is it more dia of the pulley?

Originally Posted by uninformed

thanks, what is the GBS of 11mm and 12mm? What do you consider a good pulley block? Is it more dia of the pulley?

11mm about 1400kgs. SWL, about 7000kgs GBS, 12mm about 1700kgsSWL, about 8500kgs GBS. This is for 7 strand Independent Wire Rope Core (IWRC) of good quality, so I would knock up to 200Kgs of chinese ropes esp those supplied without an eye thimble on the hook end.
Diameter of the pulley is critical to not kinking and breaking individual wires, when a wire cable passes over a sheave pulley the outside of the rope is stretched, while the underside is compressed. If the groove in the pulley is too wide the rope will crush, if it is too narrow it will cut the outside wires and if the dia. is too small the rope will kink and twist, esp. if the rope is fed through the pulley against the "Lay" of the rope. The pulleys on sale through 4wd suppliers in my opinion are about half the dia. they should be. Google Riggers Guide or the Guttenberg book of rigging and knots to learn about lay of the rope and how they sholud be installed on Winch drums or which way they should feed through a pulley, Regards Frank.

That's pretty interesting Tank. I know my dyneema rope is crushed in all sorts of flat shapes. Quite often changing from flat horizontal to flat vertical but the rope is still kind of straight, or perhaps in its lay of the rope.

I was told don't wind it on all neat and tidy, for when winching the rope tightens under pull into it's spooled self and makes it very hard to pul out. So I loosely spooling it on with a bit of crossing over, but this chews up space on the drum and the rope crushes on the winch housings for the last 4 or so meters.

oohhh if life was simple, i wouldn't have to worry so much.

I agree with a 9000 / 9500 winch you should look towards an 11mm rope.

Also, what's not been mentioned to date is how much rope you can get on a drum. Normally speaking you get about 100' of 9mm wire on a 9000lb winch and Normally you can get about 110' of 11mm rope on the same drum.

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Frank, If those pulley blocks are 50% too small, what about the drum dia? Most drums on recreational 4x4 winches are approx 75mm dia. My PWB ANCHOR winching blocks are 125mm dia....so it seems there may be some problems from the get go, or is there a difference between it being pulled tightly around the drum compared to around a rotating pulley?

FWIW, my winch blocks are max load pulling of 8 tonne, designed for upto 11mm dia rope and they are greasable.

A 250mm dia winch block is a big bloody thing to carry in ones recovery kit.

regarding wire rope, should winch cable have a core like rope? Is there a specific grade that is best? You mention 7 strand, how many strands in each strand?

newhue, I have heard the same re laying synthetic rope on the winch drum, through can not confirm or deny it as fact/best practice. Something about 3x dia of rope, space between each wind around drum.

Yorkshire_Jon I think you got that back to front mate. You are going to fit more length of smaller dia rope on a drum of given width and height.

Went through the same process as Tank when trying to choose a winch. I was horrified when I found that none of the usual rope people were selling had a suitable SWL.. Also the cost of rope with a reasonable SWL was more than most winches!

I ended up with 12mm Dynamica. It has a GBS of 16tonne (at the splice) and is UV resistant. BUT the RRP is also $1250 for 50mts!

Also I find it ammusing when people say that hydraulic winches are better than electronic because with the engine off an electronic winch will flatten the battery in a minute.. That is a minute more winching that is possible without an engine with a hydraulic winch.. and it is quite likely that that minute will get you out of the river where at least you can get your gear out and make a cup of tea

Originally Posted by uninformed

Yorkshire_Jon I think you got that back to front mate. You are going to fit more length of smaller dia rope on a drum of given width and height.

No, it's right. The drums are not normally full. A full spool will take a little more length than standard whilst accommodating a slightly larger diameter.

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Originally Posted by Yorkshire_Jon

No, it's right. The drums are not normally full. A full spool will take a little more length than standard whilst accommodating a slightly larger diameter.

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Ok if you are referring to what is supplied stock Im not really sure. But usually the limiting factor is the tie bars across the drum. This makes a fixed drum height and I would have thought you will get more wraps of a smaller dia??