Model Steam Donkey Engine

[Mcgyver]

Scale and proportion---Where do I start?

Studay a full size one, gotta be one kicking around somewhere within a few hours drive. Ask around with the crowd that participates in live steam shows, bet there's an owner who would welcome the attention. Take measuring tape, calipers, camera and note book.

+1 W. M. Harris's book from Village Press - its a very attractive engine imo.

[Duffy]

Brian, I checked out Harris's design, which is predicated on a 2X1" DA engine.
The finished product is 23.75"H x 18"L x 11.25"W and runs at 100psi. He does not seem to have any superheat, so I guess it drips a while to heat everything.
The cable drums are about 4"D x 3.5"L. This is a BIG project. Be advised that every well driller does not have 5" tube for a boiler shell-you may have to search a bit.

[brian Rupnow]

Okay guys---This is sorta, kinda, it. Overall proportions are going to be very close to this. Length of winch drum may grow a little, and I definitly have to come up with a main base. I will probably come up with some other kind of crosshead guide, but the jury is out on that for right now. Thats a 90 tooth gear on there, which works out to about 3.83" diameter. Overall, I don't think it looks too bad.---Brian

[sasquatch]

Brian, i could be wrong,, but i think there was a donkey engine at the Algonquin Park museum???
Remember a story about an old retired forester that finally found it grown over at a lumber camp.
May have been Brent Connelly who has a few books out about logging in eastern Ont.

[brian Rupnow]

Sasquatch--I've seen the one at Algonquin park, but its been quite a few years now. I think they have an Alligator on display there too in the logging exhibit.

[oil mac]

Brian,
When i was a youngster, i worked in the coalmines, we had various types of haulage winches eight of the collieries had monster endless rope haulages One steam driven , & other seven electrically driven - If everyone is wondering what that is, ,Imagine a long rope spliced into its own tail, Like a big elastic band On this type of haulage set up, the rope was looped twice round a narrow wheel called a Clifton Wheel, which was on its periphery, comprised of sections of chilled iron sections to resist wear

Now my reason for mentioning this type of machine, which is on the periphery of the technology Brian is talking about is the following-- These big engines had a ratchet around the drum periphery, as a holding medium incase of the driver being belled to stop winding especially with a very heavily loaded rope, a run back, could have resulted in the deaths of men further down the haulage incline
Also in spite of the control being by electric motor drive, a friction clutch could be flung out of engagement,quicker than working an electric controller The old drivers of these big engines, could disengage the clutch drop the ratchet in &apply the band brake in a small part of the wheels travel
In the case of having to reverse for any special reason , the driver, could use the engine &the band brake most skillfully

Now back to something more resembling the nice machines Brian is talking of making a model of, Two drum haulage gear, As youngsters, we were taught how to operate small versions of A)single drum, & B) two drum haulages (WE call 2 drum haulages in the U K main & tail haulages) For a few weeks i was given a special dispensation from on high to operate a twenty five horse power haulage Usually a kid of under 19 years of age was restricted to a 10horse power single drum winch

The operation of the main &tail haulages is good fun & a nice task, They are used for pulling tubs or bogies of coal etc over long undulating roads, where the rake or cluster of tubs, or as we called them hutches, could run away on an incline, & the rear ones would derail the ones nearer the front of the line

In this system, There is a main drive shaft upon which two drums revolve. One of either, which is allowed to run free,in contra direction to its neighbour, One always being clutched in to this drive shaft, depending upon which direction you were going, E.G.-- paying out say with the left drum, & returning with the right hand drum, or vice versa, depending upon your signal how you set your clutch, It was then the use of the application of the brake on the "Freewheeling drum was applied, A light application of the brake on the path ,was all that was applied to keep a slight tension on your tail rope

The clutches were generally expanding ring clutches I would expect for the single drum windlasses that You allude to Brian, lowering will be carefully controlled by the application of the brake &the driving engines.

good luck, with your model, it looks a nice project, and a model of some of these old American haulage engines looks really nice, From the photographs i have seen, they look good solid machines, well made

Just before i was born, for a spell, my dad operated a steam haulage engine in a small mine, & my maternal grandfather and his dad had in their day operated big winding engines, One of my pals has just given up his factory, which built steam &electric windlasses , Guess being intrested in these things is in my genetic makeup

[brian Rupnow]

I don't usually do this much "flippin and floppin'" when I first get involved in a design, but its taken a lot of rearranging and moving things about to end up with a model that is pleasing to my eye, allows access to the valve boxes, and more or less resembles one of the original donkeys. I think that a lot of the eye appeal in this model is in the bearing stands and the base, so I have spent quite a bit of time on them. I have altered the crosshead guides a bit and put on a couple of rather nifty looking stanchions to support the outboard end of them. You will never wander down an old logging road and see one quite like this, but then again, this is not intended to be an exact model. This is a model that captures the essence of the old steam donkeys, and will have a functioning winch, clutch, and brake mechanism.----But will still be within the capability range of mid range skilled model engineers.---Brian

[brian Rupnow]

Here we have it in all its naked glory, without the engines and boiler.

[brian Rupnow]

Now, for all of you guys that are setting around bored, suffering from mid winter blues, and just dying to begin a new project------. These are all drawings for the Donkey engine that I know are correct and won't change. How do I know?---Because they are the exact same drawings I used to build the Popcorn engine, and it runs extremely well. There are going to be some drawings that I have yet to develop, and actually make the parts before I will turn them loose on an unsuspecting public, but these ones I am certain of.---Brian

[brian Rupnow]

And here's another bunch of Donkey parts---