PTO basic's?

[Desoto61]

I've heard unsubstantiated rumours that the Military rated all their equipment to 50% of its civilian counterpart. In other words, a 3/4 tonne mill spec truck, would actually be rated as a 1.5 tonne truck in the civilian world. I've heard this is true for the winches as well, having been told that the M37 winch was rated at 7500lbs for mill spec service, but its actually closer to a 15000lb winch in real life. I would assume that this was done so that under battle field conditions, the GI's could get away with thinking they've overloaded a vehicle, but in reality its still be capable of performing its duty just fine.

For the most part I think you are right, or at least close. The design specs of most of the military equipment I deal with is conservative compared to the actual limits. I don't know that they downrate it 50%, I'd think more like 75% but that's academic. Naturally with these machines more likely to be in severe conditions than their civilian counterparts that extra margin of safety leaves extra room for operation under less-than-ideal conditions.

As for the winch I don't think it's downrated quite that much. I thought the Braden service manual specified that 12k lb and under winches used a dry brake while over 12k lb used a wet brake. I thought the primary difference of the miliary winch was better sealing against water infiltration since they could be used for fording deeper water.

[maineSS]

I've heard, but never actually verified, that the earlier Bradens had a smaller shear pin dia. than the later 10,000 lb ones. It would be interesting to compare things like the drum shaft dia, gears, etc from a 7500 lb rated winch to a 10,000 lb one and see if any differences exist. Maybe Paul from the Texas Powerwagon Museum would have some data?

[Rodney]

Wire Rope

What are the wire rope capacities of the different Dodge/Braden winches? If one were to go with a stainless rope, what type would he use? I do not know of a stainless fiber core rope, but it might be out there.

[MasterYota]

I can't speak about the varying winch capacities, but I can speak a little about my experience with stainless wire rope. It was terrible. I had about 100' of 1/2" stainless cable on an 8000lb. winch. It was so stiff that it was a total PIA to wrap on the drum. Whenever the tension on the cable slacked at all, the cable would go all snaky on the drum and make a real mess. I'll never use it again.

I would choose a much more limber steel cable, or even the newer synthetic rope before using the stainless stuff. I will admit however that the design of the stainless cable probably played a role in its handling characteristics. I used it before I had any knowledge of cable makeup (my knowledge is still at a minimum!) such as strand count, wrap direction, ect...

[maineSS]

When I get my winch rebuilt, I'm going to evaluate some of the synthetic alternatives. Yale Cordage, whom I work for, makes synthetic rope for extreme duty application in industry, and we've made some stuff for the 4x4 Offroad market. I'm looking at a product called Uniline, which we bought a company to aquire, which we're going to be making with exotic fibers like Dyneema and Pobon. It has a tightly braided outer cover, but the center is composed of parallel non-braided strands- the strongest type of construction.

[Desoto61]

I'll be interested in your findings. I've seen some stuff on the new synthetic winch cables and wondered if it was worth the expense. Seems be a lot safer than the steel cable but less durable.

[maineSS]

The biggest problems synthetics have are (1) UV exposure, (2) sharp edges, and (3) Dirt pickup. You can coat the fibers or jacket the rope to minimize UV exposure, and jacketing definitely helps prevent dirt from infiltrating and abrading fibers. Pulling over a sharp edge is a big No-No. Yale has been developing ropes to replace steel cable in the Western logging industry, where the weight saving and handling ease are big concern in Highline operations. We also do a lot of Utility pulling rope for 765 KV line construction, Arborist climbing line, and Marine racing (America's Cup, Southern Ocean stuff).