Thread: winch operation

Originally Posted by Aaron

Ive done playing with it now. I have a Big Haul 4.8t winch for those interested.

Im waiting for Photobucket to finish maintenance to upload the somewhat boring photos.

I didnt use any blocks as it was hardly a steep slope at all.

The effort was very minimal, and I cant imagine more sever conditions been that hard.

In all honesty, the only hard work was setting up the cable. 16mm wire rope isnt exactly string.

Most commonly bought snatch blocks will have too narrow a groove in the pulley wheel for 16mm (5/8") wire cable, you may have to go to a Rigging supplier to get the correct size snatch block for your wire rope, if so buy the largest diameter pulley as 16mm 7 strand (solid wire core) tirfor rope will not take kindly to being wound around the standard diameter snatch block pulley wheel

Originally Posted by Tank

Most commonly bought snatch blocks will have too narrow a groove in the pulley wheel for 16mm (5/8") wire cable, you may have to go to a Rigging supplier to get the correct size snatch block for your wire rope, if so buy the largest diameter pulley as 16mm 7 strand (solid wire core) tirfor rope will not take kindly to being wound around the standard diameter snatch block pulley wheel

Im glad your brought that up. Infact, I thought the same thing and looked at it this morning. Ive got a TJM Ox snatch block, Im not sure what size it is, but the 16mm doesnt look out of place to me (amateur). I was going to do a photo, but its all coiled up now, Ill do it tomorrow.

edit - So its the diameter, not the groove thats the problem?

Originally Posted by Aaron

Im glad your brought that up. Infact, I thought the same thing and looked at it this morning. Ive got a TJM Ox snatch block, Im not sure what size it is, but the 16mm doesnt look out of place to me (amateur). I was going to do a photo, but its all coiled up now, Ill do it tomorrow.

edit - So its the diameter, not the groove thats the problem?

You can use the standard diameter snatch blocks, but the sharper the radius the more damage done to the cable, when a cable changes direction over a pulley under load the inside (the part of the wire rope closest to the groove in the pulley wheel) part of the rope is trying to compress and the outside is trying to stretch, if you for instance tried to run a 16mm wire rope over a 2" dia. pulley under load you would probably damage it and make it unsafe to use, Don't forget that winch/crane and tirfor wire rope has a solid core, a 7th strand same as the six strands around the outside, it is designed not to crush on winch drums and tirfor jaws.
If the 16mm cable sits in the groove of your snatch block, with no gap under the centre and the cable not riding on the edges of the groove, then it should be alright, too wide a groove is not as bad with 7 strand rope as it will not pinch and possibly break wires in the outer strands, it's usually cheaper to buy quality rigging gear (shackles etc.) at a rigging supply place and they should be able to help with advice, Regards Frank.

Taking Tanks point a bit further. The important thing about ropes and bollards is the ratio of the two diameters, i,e D : d where D is the ratio of the bollard/snatch block and d is the diameter of the rope. The larger this diameter the better.

Used to test polymers for a living. One job was testing a solid monofilament that I had made which was about 2 mm in diameter. Tested around 50 mm bollards got one result. Tested around 150 mm bollards the apparent strength went up 10+%. The apparent increase in strength was solely due to diameter of test bollards.

Conversely if had used bollards smaller then 50 mm the apparent strength would have decreased.

Regards


Brendan

PS Are hand winches peferred in Australia over electric winches? Or is it a cost judgement that makes hand winches more common in Aus?

snip

Originally Posted by leeds

PS Are hand winches peferred in Australia over electric winches? Or is it a cost judgement that makes hand winches more common in Aus?

Tirfors are hard work up a slope or recovering in mud. PITA to set up & a PITA to use. And a PITA to store in the car if space is at a premium.

Basically you'll try everything else first before breaking out the Tirfor.

You see leccies used more often.. Hard to know how many have both.

Regards
Max P

This is a mate on the end of my Bighaul Handwinch near Jenolan, i can you they are hard work



I had slid sideways into a tree on a downhill and needed to be pulled sideways to get straight.

The strap on the front was to stop the front sliding downhill



They do work well though.

Baz.