Winch hook capacity

[cranetruck]

Received a "5-ton" winch snatch block today, purchased from a fellow SS member, thanks Ted, it's a beaut! NSN 3940-00-105-9933.

Its rating is 4 ton lift and 10 ton winching and it makes me question the rating of the chain and hook, standard for the winch. It is obvious that it is not designed for a straight pull, certainly not at full winch capacity.

A discussion is welcomed.

 

[gimpyrobb]

But if using a snatch block to go from vehicle and back, doesn't that half the load on the winch? So effectivly, the snatch block would see more "load"?

 

[Stonepicker1]

The hook and chain assy nsn: 4010-01-027-0356 used on the Duce and M809 series trucks front winch has a safe operating load rating of 11,250 lbs. The winch itself is rated at 20,000 lbs.

 

[cranetruck]

Thanks.
Found confirming data in TM 5-725 "Rigging".

So, the 10-ton snatch block is pretty much a necessity for the 20,000lb winches.

 

[mudguppy]

not to hijack, but is there a good [and economical] source for stocking up on rigging, snatchblocks, and the likes? do some of these sponsor/vendors have offerings and selections?

i just want to make sure i get some good'ol' USA products that are safe to use.

 

[rockman]

Coleman's had some snatch blocks, however, the weight add to the shipping. TSC sometimes has some also.

 

[11Echo]

Sam Winer has binfuls of snatchblocks. One like this goes for $75.00.

 

[rizzo]

Sam Winer has binfuls of snatchblocks. One like this goes for $75.00.

IIRC 35 at colemans

 

[rizzo]

Thanks.
Found confirming data in TM 5-725 "Rigging".

So, the 10-ton snatch block is pretty much a necessity for the 20,000lb winches.

we have been over this before and never agreed on an answer.

I think the ratings are messed up somehow.

the block that comes with the deuce is rated at 10k. if the winch is rated at 10k why use the block? you can still only pull 10 k with it because of the rating.

It seems like they rate them to match the winches rating so you know which block is the correct one.

http://i20.photobucket.com/albums/b213/frankrizzo1972/my trucks/snatchblocks1.jpg

IIRC the deuce chain should be 1/2 and the 5 ton 5/8.

 

[rizzo]

anyone know what grade the chains are?

 

[m16ty]

Yea rizzo, you and I have talked about this before. The deuce snatch block is rated at 5 tons (10,000lbs) but if the shatch block is used at winch capacity it would have double that on it.

 

[cranetruck]

So, the chain and hook on the 20,000 lb winch limits its use to 10,000 lb at all times. However, the chain and hook part can be removed and a clevis installed in its place for universal use.

That's my plan after learning about the ratings. I checked my junk, looking for a 10 ton clevis, couldn't find one, but did find one rated 14-ton, which is too big (the pin is 1-3/8 dia).
Would anybody want to swap my 14 ton for a 10 ton? These buggers are expensive, a new 14 ton clevis costs over $100!!! Will consider good US brands only, McKennon, Crosby etc.

BTW, the 10-ton snatch block for the deuce is good for changing direction of the pull, doesn't have to be used to double the capacity....also, the 10,000 lb capacity of the deuce winch is only for the first layer, its much less with more layers.

Edit: added image.

 

[m16ty]

BTW, the 10-ton snatch block for the deuce is good for changing direction of the pull, doesn't have to be used to double the capacity....also, the 10,000 lb capacity of the deuce winch is only for the first layer, its much less with more layers.

Edit: added image.

Even if you are just using it to change direction there is still double the load on the snatch block hook. You have the load of the winch pulling one way and the load of the object on the other. It still doubles the weight on the hook.

 

[Maxgussam]

Received a "5-ton" winch snatch block today, purchased from a fellow SS member, thanks Ted, it's a beaut! NSN 3940-00-105-9933.

Its rating is 4 ton lift and 10 ton winching and it makes me question the rating of the chain and hook, standard for the winch. It is obvious that it is not designed for a straight pull, certainly not at full winch capacity.

A discussion is welcomed.

I'm glad you are happy with it. Hope you can put to good use!

Ted

 

[BEASTMASTER]

use them until u break em. if the hook staightens out get another one. i've pulled out d-8s sunk to the top of the tracks and never broke a hook. thats with only 5/8 chain too..if it breaks just replace it.

 

[Militoy]

I use my PTO winches quite a bit - and I believe you'll likely find that well before you bend a hook, snap a shackle or stretch a chain, you will shear the shear pin. I switched over to a mild steel pin from the OEM aluminum/brass alloy type long ago - and I still have to carry spares. Just keep your cable clean, well-lubed and change it out if it gets kinked or frayed. And - in the name of all that's holy - keep away from the cable when it's under tension!

 

[cranetruck]

This is what I believe should be the real hardware for the 20,000 lb winch, 5/8 inch chain and sling hook plus the correct cable socket.......

 

[pevrs114]

Cranetruck alluded to it, someone asked about good places to get rigging, shackles, clevises, hooks, blocks, etc.

I'm a fan of Crosby, Inc. They are an industrial provider for rigging equipment.

AWDirect also carries rigging supplies, but not at the same ratings as Crosby has.

 

[Squirt-Truck]

Bjorn,
That is interesting, considering that I have never seen 5/8 chain used on the 20Kwinch. It is always 1/2" chain. That being said, G70 chain (as specified) has a minimum breaking strength of over 45k. That gives the proper working load safety factor for WINCHING, not lifting, of 2 to 1. THe proper end termination should be as shown, the bolted spelter for field repair ability. The hooks, for 1/2" chain should spread before the chain fails, this is by design to prevent chain failure in pure pull and the resulting flying parts. (I have a cool video of one of the 5/8" snatchblocks departing the scene due to a connector failure.) The winches on the 5-tons, 20k rated, will make 20k of pull on the first lay. (Four turns minimum.) Blocks are ofton rated for lifting, here the safety factor is 4 to 1 over the 125% proof load IF lifting is overhead of personnel.

I have seen snatch blocks that have capacity ratings and those that have max line pull ratings. There seems to be no consistancy. If you are concerned, we can get together at my place in Marietta one day and proof the blocks in one of the TO machines, I can go to 120,000# on these and record the load and deflection.

FWIW, we break 1" IWRC rope in these to certify the rope for service, snapping 5/8 FC in no challenge.

 

[m16ty]

Bjorn,
That is interesting, considering that I have never seen 5/8 chain used on the 20Kwinch. It is always 1/2" chain. That being said, G70 chain (as specified) has a minimum breaking strength of over 45k. That gives the proper working load safety factor for WINCHING, not lifting, of 2 to 1. THe proper end termination should be as shown, the bolted spelter for field repair ability. The hooks, for 1/2" chain should spread before the chain fails, this is by design to prevent chain failure in pure pull and the resulting flying parts. (I have a cool video of one of the 5/8" snatchblocks departing the scene due to a connector failure.) The winches on the 5-tons, 20k rated, will make 20k of pull on the first lay. (Four turns minimum.) Blocks are ofton rated for lifting, here the safety factor is 4 to 1 over the 125% proof load IF lifting is overhead of personnel.

I have seen snatch blocks that have capacity ratings and those that have max line pull ratings. There seems to be no consistancy. If you are concerned, we can get together at my place in Marietta one day and proof the blocks in one of the TO machines, I can go to 120,000# on these and record the load and deflection.

FWIW, we break 1" IWRC rope in these to certify the rope for service, snapping 5/8 FC in no challenge.

I think you hit the nail on the head. The ratings for overhead lifting are alot lower than they are for winching. That would explain the low ratings.