An interesting idea for center-mounting a winch

This site has an article about the Foer's (of Ibex fame) system of winch mounting. I've seen center-mounted winches described before, and know the basic benefits (centralized weight, pull forward or backward w/ one winch, etc.) but his is notably different.

For one, it uses a snatch-block in the rear to re-direct the cable to the front. To winch forward you pull out the cable (as normal), but to winch backwards you don't have to re-route the cable, you just pull the pin on the snatch-block and pull the snatch-block out. Plus:

An interesting side effect of the Foers' winch mount is that ... the 4WD can drive along the cable... This effect can be used to prevent sliding down a side-slope or to spin the 4WD on the spot by pulling the front to one side and the rear to the other side.

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That is very clever. It allows a permanently mounted winch to serve either forward or rearward recoveries and further stabilizes the vehicle, plus other benefits. Well worth the read. Thanks for posting.


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It's a nice idea, indeed, though there are a few things that are less than ideal.

The cable is being spooled onto the drum under the vehicle, where it's hard to keep an eye on it. Likewise winch maintenance, cleaning etc. is not going to be easy. I don't suppose it would stay particularly muck-free under there either!

Every pull from the rear is done with a snatch block which doubles the amount of cable required.

There is a small but not insignificant loss of pulling power when pulling from the front - going 180 deg around a snatch block absorbs around 15% of the winch's pulling capacity. (I stand to be corrected about this figure).

Depending on the capacity of the winch, the centre of the rear cross-member could be pulled inwards with a force of around 20,000 to 30,000 lbs! (Double the winch's pull, which in the case of an electric winch might be significantly more than the rated pull, at the moment of stall).

I was thinking about this a little last night while I was trying to get to sleep.

It seems to me that to have the 'ability to drive along the cable' as described in the article this vehicle would have to be set up such that you could re-route the front cable back to the winch drum and connect it so that it spools on at the same time that the other end spools off, without getting hopelessly tangled. That may be too much to ask.

It also occurs to me that you could approach the same problem (ability to drive along the cable in an off-camber situation) by attaching two snatch blocks along the side of the vehicle, like on the end of the front and rear bumpers. Then you could run the winch cable out to an anchored snatch block in front of the vehicle, back through the two vehicle-mounted snatch blocks, and anchor it in the rear of the vehicle.

Then you could pull the vehicle along the cable just like a cable car.

Lynn said:

I was thinking about this a little last night while I was trying to get to sleep.

It seems to me that to have the 'ability to drive along the cable' as described in the article this vehicle would have to be set up such that you could re-route the front cable back to the winch drum and connect it so that it spools on at the same time that the other end spools off, without getting hopelessly tangled. That may be too much to ask.

It also occurs to me that you could approach the same problem (ability to drive along the cable in an off-camber situation) by attaching two snatch blocks along the side of the vehicle, like on the end of the front and rear bumpers. Then you could run the winch cable out to an anchored snatch block in front of the vehicle, back through the two vehicle-mounted snatch blocks, and anchor it in the rear of the vehicle.

Then you could pull the vehicle along the cable just like a cable car.

Click to expand...

The setup as described works pretty much just like that! It doesn't spool on and off the winch at all - in fact, the winch doesn't get used at all, just the cable. The cable is effectively attached to the rear of the truck, runs around a snatchblock attached to an achor far away to the rear, back through the truck, all the way to a snatchblock on an anchor far away to the front, and then back to front bumper. Now you just drive, forward or backwards. The rope is fixed at both ends to the truck, and the truck can run, as you say, like a cablecar.

You could just do it with a piece of rope and two snatchblocks, apart from the problem of keeping it off the bodywork. But as you say, a couple of extra snatchblocks (or fairleads, or just a piece of tubing) could be rigged to achieve this.

I have to say that I can't think of many situations where the whole thing would really be feasible though, despite it being such a neat idea! Crossing a fast-flowing river, perhaps... But you'd need a lot of rope, and some really hefty anchor points onm the banks!

Thanks for sending the link Gary!

One of the potential sticking points with mounting position is "where?", particularly if you have a rig with the fuel tank on one side of the centrally-located driveshaft, and exhaust on the other.

One of the greatest advantages I see to this is weight distribution...from as much as a foot or two in front of the front wheels, to centrally or rear mounted, and another advantage is being able to mount the fairleads directly in line with the frame, regardless of mounting position.

The trick, on a rig like mine (and many other trucks), really is "where"...and "how" to transfer the line to the front of the vehicle with a minimum of bends or pulleys, avoiding hot exhaust and so forth.

I'd almost rather mount a pair of small, lightweight winches and assume a doubled pull every time, like the M8000 build posted a while back.

...Not that I haven't spent a couple long evenings staring at the truck trying to sort out how to make this work...

-Sean

Quite a while ago I saw a write-up on a Mog that had a centrally mounted winch. It was a pretty sweet setup, but he had the advantage that it was just a flatbed mog, and he had good access to the winch via a trap door in the flatbed. Even if you put a trap door in the floor of a camper box, it wouldn’t be ideal for accessing a winch.

With a large vehicle (necessitating a large winch) it seems to me it may be worth trying to design a central system. However, on a smaller rig, I think I would prefer a carrier-mounted winch that could be attached at the front of the vehicle, attached at the rear of the vehicle, locked inside the vehicle, or left at home.

On military trucks center mounted winches seem to be more common. Mine has a center mounted hydraulic winch and I can either move the cable to the front or the rear.

The Austrian version of the MAN KAT, called ÖAF has a similar setup as explained above. The cable from the center mounted winch goes back around a block with a pulley in a special holder for easy remove, and then to the front. At the front it can pull with normal force of the winch. At the back twice the force is available. This is a neat setup and I first thought to convert mine too.

But seriously, how often a winch is used and how often such a setup is really needed?

This remembers me to check out whether the winch still works.

michaelgroves said:

I have to say that I can't think of many situations where the whole thing would really be feasible though, despite it being such a neat idea! Crossing a fast-flowing river, perhaps... But you'd need a lot of rope, and some really hefty anchor points onm the banks!

Click to expand...

Really steep hill; no stinger bar needed...

On your and other OEM center mounted winches, how is the winch line routed end to end? Pulleys, fairleads, etc.?

How do you ensure an even wrap side to side?

If you did this as a modification...each pulley or fairlead point would be loaded when the line was loaded, whether it was a front or rear pull. There's an awful lot more structural design that needs to take place for this setup on a vehicle that wasn't already designed for it.

Thoughts?

I don't want to be hustling a big, heavy winch out of anywhere, much less end to end, at a time when I need it...which is unlikely to be on flat, dry ground!

devinsixtyseven said:

On your and other OEM center mounted winches, how is the winch line routed end to end? Pulleys, fairleads, etc.?

How do you ensure an even wrap side to side?

If you did this as a modification...each pulley or fairlead point would be loaded when the line was loaded, whether it was a front or rear pull. There's an awful lot more structural design that needs to take place for this setup on a vehicle that wasn't already designed for it.

Thoughts?

I don't want to be hustling a big, heavy winch out of anywhere, much less end to end, at a time when I need it...which is unlikely to be on flat, dry ground!

Click to expand...

Yes, those are the things I was concerned about too, in my first post of this thread. Neither solution - centre mount winch, or demountable winch - is ideal in every respect. Even the idea of two winches has the drawbacks of weight, cost and space.

(The line is usually routed through sections of conduit where necessary (or inside a chassis member), on the implementations I've seen. Needless to say, the conduit is just there as a gentle guide, not to put any angles on the rope!)

That referral (above) to a Unimog with a center mounted winch, fed front and rear, was probably mine, a 1957 Unimog 404. I built this bed about 10 years ago and it has served well, as you can tell from the more recent 'well worn' pictures. The winch has to be mounted at just the right angle so the rear turn-around sheave spools the cable edge to edge on the winch without assist. The route to the front has to be picked also, in this case the winch cable comes out the front through the path of the PTO shaft, and is a straight shot to the rear. Once all the locations are known, then the bed is built to support the winch.

The winch is mounted with 3-point flex, as are all major components on the truck (cab, bed, winch) so the frame can flex as designed. The rear turnaround point is equipped with three sheaves allowing winching off to the side in the rear, double line only. The front is used either single line or double line.

I had this same setup on a 1952 Willys, used a lot in the 60's when I started offroading, so the idea is not new. Driving along the cable was used several times to cross side slopes safely in the TN hills. Another use is to run the rear double line out to the anchor point, then attach the stuck vehicle (Jeep, whatever) to the front, either single or double line. The rear attachment cable automatically tightens and the winching mog hardly has to have ground traction at all.

More info at http://www.rockymountainmoggers.com/bobmoglite.html

I am attaching a few pictures. I've also got a rear-to-front winch setup on my U-1300 Unimog with hydraulic winch, too. If anyone has questions, just ask. I have recently discovered this forum and it's great!

Bob

Lynn said:

I was thinking about this a little last night while I was trying to get to sleep.

It seems to me that to have the 'ability to drive along the cable' as described in the article this vehicle would have to be set up such that you could re-route the front cable back to the winch drum and connect it so that it spools on at the same time that the other end spools off, without getting hopelessly tangled. That may be too much to ask...chop...
Then you could pull the vehicle along the cable just like a cable car.

Click to expand...

Think of the truck as being a pair of longhandle undies hanging on one of those clothes lines that has pulleys on each end (the sheaves). It'd be like the longhandles walking back and forth. Ok, dumb analogy, but once the cable is tightened, the winch does not do the moving, the truck wheels do.

Bob

Thanks, Bob, for the clarification.

And yes, that was your truck I was referring too. Sorry I couldn't give due credit.

I saw John Foers winch design a few years ago and found it very interesting. HERE is a link to his patent with a lot of drawings and info on the design.