Photos needed. Shed full of S**t Auction

[Tony Wheeler]

Originally Posted by Richard Farrant

a cranking handle with a flat bar slides in the end of it.

Thanks Richard, I finally get the idea now! I hadn't considered that slot in the outer boss, which is the correct size for the Dawn crank handle, and provides variable cranking radius by sliding through to the desired position according to cable load. That would be essential with this modification kit because the winch is fixed permanently in low ratio, so you'd need to shorten the handle to wind it rapidly, particularly when reeling in loose cable after winching.

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Presumably the folding shaft extension is designed to protect it from damage through tree strikes etc., and while the locking mechanism isn't quite clear to me there's obviously a retaining cage of some kind, possibly sprung, to keep it in both the locked and retracted positions. All in all a rather clever design and no doubt a very welcome piece of kit when bogged in a jeep with no CMP nearby to tow you out! Yes it would be a bit slower than a power winch but sure beats trying to push it out with spinning wheels covering you in mud!

BTW it turns out my own winch is a No.5 so I'm not sure what's on this jeep because it looks identical to me. Is there any major difference between the No.2 and No.5 ? As you can see it came with a home made short handle as well as the Dawn handle, and while the short one is much faster to use and a lot more ergonomic, it starts to become hard work for anything heavier than a ton so I switched to the Dawn handle. It's a pain in the neck to swing through such a wide arc but I need the extra leverage for lift towing.

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[Mike Cecil]

I assume a Dawn No.2 simply means a two ton capacity winch, which is what the 'Kit's Recovery' specified, along with 120 feet of 3/8 inch wire rope. (So is a Dawn No.5 a 5 ton capacity winch with, presumably, a heavier/thicker rope?)

The winch assembly and fitting was described in MGO Equipment Memorandum 13 of Sept 1944 - which I assume is what Ian is using as his main reference. The kits were manufactured by Ford Motor Company (there is more to the kit than the basic Dawn winch), with 230 kits ordered under CD-E8745.

Problems were encountered in the supply of the correct diameter wire rope, which slowed delivery until a variation to design was authorized.

Have never been able to find anything definitive on the number built, but judging from photo images, I'd guess not very many made it onto the front of jeeps.


Mike C

[Tony Wheeler]

Originally Posted by Mike Cecil

So is a Dawn No.5 a 5 ton capacity winch with, presumably, a heavier/thicker rope?

The same thought occurred to me the other day Mike when I learned it was a No.5 but I couldn't find any info on the net. However I believe it's just a Dawn ID number rather than a capacity rating, and there's certainly no such claim on the winch itself. It looks pretty much the same as the one on the jeep so I don't see how it could be 2 1/2 times stronger. Also if the front of that Cab 12 weighs in the vicinity of 2 tons as I imagine it would, then based on the force required on the long Dawn crank handle I would consider that to be a reasonable rating, bearing in mind they're usually on the conservative side. I'm sure it could lift more, especially with less cable on the drum, but even if it could lift 5 tons, which I'm inclined to doubt, I would definitely rule it out as a rating for all practical purposes. I'm pretty sure you're not supposed to hang off the end of the handle with your feet kicking wildly in the air trying to turn it!

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[Lynn Eades]

So the pioneering spirit is dead then

[Brett Nicholls]

Hi Guy's,
Another AWM picture and ......again Dawn winch mounted on a Ford Jeep! Obviously Fords were not quite as good as the Willys and needed the extra help

Oh what can of worms I think I just opened

On a serious note - I some how think the installation was easier on the Ford's due to the front cross member shape but I have no proof - it's just a hunch. Note also the front grille intact vertical bars.

Regards,
Brett.

[Richard Farrant]

Originally Posted by Brett Nicholls

Hi Guy's,
Another AWM picture and ......again Dawn winch mounted on a Ford Jeep! .

I can see now how the folding handle was stowed.

[Lynn Eades]

Brett, Re the "Can of Worms"
Maybe the Ford chassis was robust enough to handle the load?

.......and it is a Ford because????

[Tony Smith]

More pics in THIS THREAD.

I'm trying to find to old "For sale" thread when I sold my Dawn Winch, and I think it was either Ian or Brett who ended up buying it. Was lots of pics in that listing.

[Tony Wheeler]

Originally Posted by Tony Wheeler

I'm pretty sure you're not supposed to hang off the end of the handle with your feet kicking wildly in the air trying to turn it!

Upon reflection my own winch cannot be considered indicative, because the cable drags on the crossbar due to poor installation. This would greatly increase the handle force required, particularly with heavier loads.

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For a proper installation we can calculate the handle force required from the gearing (24.5:1 reduction in low ratio) and the mechanical advantage provided by the crank handle radius (485mm for the Dawn handle) relative to the cable winding radius (approx 50 - 150mm depending on how much cable is wound on the drum). For a 2 ton lift this works out to between 19 and 57 lbs. A standard two gallon plastic bucket of water weighs 20 lbs, which means that for the first layer of cable on the drum you could lift 2 tons easily with only one hand, using only the force required to lift a bucket of water. Even with the drum fully wound you could comfortably exert 3 times that force using two hands. If you really put your back into it you could probably manage 100 lbs, which would lift 3.5 tons with the cable drum full, or 10 tons with the cable drum empty. For someone of my weight (approx 85 kg) you would only need to hang off the handle if you were lifting 7 tons with the cable drum full, or 20 tons if it were empty. Based on these calculations you could reasonably rate this winch at 3 tons, requiring 57 lbs handle force, ie. 3 buckets of water, with the cable drum half-full.

We can perform a similar calculation for the Dawn No. 2 winch on the jeep. While it appears to be identical to my Dawn No.5 winch, closer inspection reveals it to be considerably smaller, the only common part being the pinion gear. As a double reduction winch the relative size of the larger gears indicates a ratio of around 16:1 on this unit, which being approx 2/3rds of the No.5 ratio would lead to a rating of 2 tons instead of 3 tons.

Irrespective of any nominal rating it's the wrong choice for the jeep application in my view, being far too low geared.

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[Tony Wheeler]

Originally Posted by Tony Wheeler

Irrespective of any nominal rating it's the wrong choice for the jeep application in my view, being far too low geared.

Having just seen this pic of the Dawn No.2 winch drum bare of cable I may need to reconsider, as the inner diameter appears to be considerably larger than the No.5 drum on which my calculations are based. This would improve the situation although I suspect it was still geared overly low for the required purpose.

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[David Dunlop]

Not to detract from this thread, Tony, but what is the purpose of the metal boxes covering the front bumper mounting points? Never seen that setup before. Part of the winch kit perhaps?


David

[Lynn Eades]

David, I would suggest a bumper extention as the winch mount sticks out forward of the bumper.
Interestingly this is a slat grill (first 10,000 and all of course were on Willys Chassis)
That the guard is already damaged and that there is a sheet of mesh in front of the radiator.
There is a hook on the front bumper, that I would guess is for a 2:1 pull.
(rope eye back onto the Jeep?)
I see also that the park light has been moved and that the bonnet is unbolted and sitting forward.

[Richard Farrant]

Originally Posted by Tony Wheeler

and while the locking mechanism isn't quite clear to me there's obviously a retaining cage of some kind, possibly sprung, to keep it in both the locked and retracted positions.

Hi Tony,

It may have an arrangement at the folding joint, not unlike that on the crank handle support legs of semi-trailers. One part of the shaft could have a male extension that enters in to a hole in the other part and hinge joint could be slotted to allow the shafts to lock together.

Richard

[Tony Smith]

Originally Posted by Tony Wheeler

........ because the winch is fixed permanently in low ratio, so you'd need to shorten the handle to wind it rapidly, particularly when reeling in loose cable after winching.

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I'd like to see a better pic of the mounting of the vertical post that supports the crank handle/shaft. Is it fixed in a vertical position? If it pivots about the chassis rail, then the drive gear could be withdrawn from the Low Ratio position and re-inserted in the High ratio position. The attachment of the cranking shaft to the drive gear seems too over-complex for a fixed alignment.

[Brett Nicholls]

You read my mind Mr Smith

Regards,
Brett.

[Tony Wheeler]

Originally Posted by Tony Smith

If it pivots about the chassis rail, then the drive gear could be withdrawn from the Low Ratio position and re-inserted in the High ratio position.

That would be one solution Tony, another one would be to make the post itself removable, and have two separate locating positions on the chassis rail, eg. short piece of box section for it to slide into, with a simple locking pin.

Either way though it would explain the redesign from the early version where the post appears to be fixed vertically on the bumper bar, or at best, hinged at the base with a locking pin hole in the brace plate for high ratio position. Perhaps they found this arrangement was not robust enough in high ratio, which being only 4:1 would require considerable force on the crank handle. And of course if it was indeed fixed vertically, then they would quickly discover in trials that 16:1 was impractical in most situations, and certainly impractical for winding in loose cable.

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Either way I think you're onto something Tony because if you look at the 9th Div jeep winch you'll notice the drive gear is at least half way out, which indicates they haven't pushed it back in far enough for the Dawn locking pin to engage:

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This is something I do myself routinely on my Dawn No. 5 winch, purely through laziness when changing ratios. It's not necessary to engage the locking pin, but of course when I go for a spin around the backyard the handle sometimes falls out, and next time I need to use the winch I have to search for it in the long grass! In the case of the jeep that can't happen, and since you'd be changing ratios repeatedly you wouldn't bother with the Dawn locking pin each time, it would just be an unnecessary nuisance.

Whatever the case in practice though, the fact that the drive gear is so far out in this photo tells us the entire shaft is removable, which can only be for the purpose of changing ratios. That would make this winch infinitely more practical.

I suspect the shaft attachment only looks complex because they've retained the Dawn handle mounting parts, it's possibly just a piece of box section or channel enclosing them and welded to the long shaft. However I'm not sure why they'd retain those parts, rather than simply join the two shafts with a welded sleeve. Perhaps they wanted to maintain the integrity of the Dawn handle mount for interchangeability purposes, esp. for the first batch which must be considered a trial mod only. Given that these winches were used elsewhere in standard form it would make sense not to ruin them for those applications, at least not until the jeep mod was fully proven in the field. Even then it would still make sense not to ruin them if possible.

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[Tony Wheeler]

Just to clarify, these are the Dawn locking pins I'm on about. You can see the drive gear is fully home when the locking pin is engaged, as opposed the 9th Div jeep where it is partially out:

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These pins are spring loaded and will engage automatically when you push the drive gear in, but only if they're well lubricated. If they're dry of lubricant like my high ratio locking pin they will jam and hold the drive gear partially out, just like a sticky door lock plunger jams on the striker plate. However it's actually much better that way because you don't have to disengage them when changing ratios, which would be even more of a nuisance on the jeep because you'd have to reach over to do it. The only reason I lubricated my low ratio locking pin is because the handle kept falling out when I did laps around the back yard. That can't happen on the jeep, so once the locking pins got a bit sticky through mud and dirt and water etc. you'd leave them that way deliberately.

Thinking further on the shaft attachment I don't believe you could weld it solid with such a long shaft, you'd need some movement in the joint to allow for the inevitable misalignment due to the moveable post, and also as the chassis flexes. That being the case they've probably gone about it in the simplest way possible, using the existing Dawn parts rather than designing and fabricating new parts.

Anyway nice work Tony, you've convinced me it was designed for high and low ratio use. As such I'm even more impressed with this jeep mod, maybe I'll stick the Dawn No.5 on the front of my F15A!

[Tony Wheeler]

Originally Posted by Tony Smith

The attachment of the cranking shaft to the drive gear seems too over-complex for a fixed alignment.

What about a piece of box section or channel, which fits over Dawn part A, or similar but thicker fabricated part A, and slotted for upward removal of the post and shaft assembly, which can be repositioned further back on the chassis, after moving the drive gear to the high ratio position. In other words a two-piece assembly, with the shaft detachable from the drive gear. Why else would you have a pin and slot arrangement, which is clearly the case here?

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On this jeep version they've clearly dispensed with Dawn part B so it's likely they dispensed with part Dawn part A too, and used a much thicker square block, say 1" thick, drilled for the shaft and held in place by the Dawn nut, and pinned on the sides for the slotted box section piece.

That would work nicely I reckon, although it does involve two separate operations to change ratios. On the other hand it may be a lot easier than with a floppy joint. Either way you have to handle the gear end to poke the shaft in the hole so there's probably not much difference.

Of course the ideal set up would be a uni-joint of some kind, with a post that swings back on a pivot so you don't have to remove it to change ratios. However I don't believe that's what were seeing in these jeep photos.