Loco transmission

I'm trying to find a transmission for a narrow gauge loco. Engine is 125 hp at 2200 rpm. Requirements are (at least) 2 speeds forward and reverse, and must be able to be towed if the engine dies. Hydrostatic is cannot be towed with dead engine except at very low speed (according to manufacturer) and so not acceptable. I've found that JCB do one which looks OK but I'm really struggling to get any information out of them. Anyone got any ideas

Have you thought about an electric system. Something cannibalised from a small hybrid car. Never looked at the details, but there are firms that specialise in retrofitting electric drive to older vehicles. They might have the components.

I rang the people who do that vintage voltage programme on TV. Have you considered doing a railway loco? No. Would you be interested - No.

I'm not looking for obsolete, it's got to be fixable for the next 20 years. As far as I can ascertain the motors in electric cars rotate very quickly, so we'd need a reduction gearbox. Not sure how well that would backdrive, but it's certainly worth a look if I can't find a mechanical solution. It's also a long way out of my comfort zone. As a starter for 10 the requirement is at least 456 Nm at the input to the final drive. This torque from the engine through a variable gearbox gives a lot more output torque of course I don't think 125 hp is a 'small hybrid car'. Helpfully Tesla say you can tow a Tesla, ideally all 4 wheels should be off the ground. Not practical for a 5te loco on a single track line

You would need to design a separate F/R gearbox but what about a 'traditional' automotive automatic gearbox?

It depends upon how much space you have - but a 125HP engine suggests it is not small.

A FWD box with twin driveshafts might be suitable for a twin bogie loco but at the expense of more complex F/R

Just blue sky thinking of course - but perhaps sowing a seed?

the JCB box is 4 speeds fwd, 4 speed reverse. I can get similar from Rangermatic, but not sure about towing with dead engine. I think I can get marine fwd reverse box, but trying to do it in one unit

I'd suggest looking at a manual trans and clutch from scrapped small pickup trucks. Nissan frontier, Toyota hilux, tacoma or four-runner come to mind. Just food for thought. These are all simple, sturdy, and last a very long time with minimal maintenance.

RHDR used to have and may still have a diesel twin bogie loco which they use(d) for utility jobs like the regular school run. It may be worth enquiring what power and transmission they use, etc.

I think it has Twin Disk 2 speed fwd rev torque converter, which is obsolete but I'll check. Railway in question has 2 other diesels with this box, very successful, but very obsolete

Clutch is a non starter (sorry about the pun) , getting a train moving is very different to getting a pickup going, and changing gear without snatching is also a problem. Speed of an industrial diesel is a lot lower than automotive, so torque converter probably wouldn't match even if I could find something.

Not necessarily looking for cheap, must be reliable. 

Edited By duncan webster on 22/07/2022 23:22:23

Anyone got any ideas

transmission from a Tugmaster for containers

Starts from zero, very compact, works 24/7 in container terminals, automatic transmission

I only know about the ones from the 80s, very tough and reliable, you would have to do your own research there's not a lot about them, they hump up to 30 tons about and make it feel easy

I'm pretty sure any that broke simply got put in neutral and towed away, time is money

https://www.terbergspecialvehicles.com/en/vehicles/terminal-tractors/

Which kind of leads on to agricultural vehicles that use the same sort of kit

GL

Edited By Ady1 on 23/07/2022 01:00:59

https://machineryline.info/-/sale/terminal-tractors/TERBERG/Allison-MT643-MD3060-MD3000-ZF-6WG211--21110218215293338700

Thanks Ady1, that looks like a really good link. I'll be on the phone to Allison's UK agent Mitchell's first thing Monday.

Have you asked Alan Keef, unless that's who you are working for

Homepage (alankeef.co.uk)

They have supplied many NG Locos

Thinking aloud a hydraulic transmission is a pump supplying pressurised fluid and a turbine turning because of that fluid.
When in a dead engine scenario the turbine ( still coupled to the wheels) becomes a pump and the pump

is a ‘turbine’ - I’m not a hydraulic transmission specialist but I suspect that is the reason for “no tow”.

If so then a couple of 3 way valves and a bypass loop would solve it - loop the input and output of the wheel end hoses together and isolate that loop from the main pump.
Now when the wheels turn they pump fluid around in a loop and the pump and associated bits and bobs are not connected. Should be a fairly straightforward install into the system, and no less reliable than the other hoses.

Not sure that is helpful, but who knows.

Dave

Hydraulic fluid just pumped around will soon generate heat that MUST be removed or the heat will soon destroy the system. The details of this thread are rather scant for a meaningful string of suggestions ! No top speed has been specified ! Hydraulic and electric have been ruled out, a clutch system also ! A torque converter seems the only route and some form of auto box. Western Gear built a unit that would easily take 600Ft/lb and 3000Rpm that gave Forward neutral reverse, this was coupled to a 2 ratio second box. BUT it was made 50 years ago. They are bomb proof, but still can be serviced. Just a thought ! Noel.

Voith make a large range of railway mech/hydro transmissions. They are used in lots of the diesel MU's running about the country. Probably second mortgage prices though.

A conventional mechanical transmission will provide a number of speeds, but only one reverse, not too different from 1st or 2nd gear. For a loco, forward and reverse will be required, probably with the need for the same range of ratios in both directions. .

To provide a soft start, a fluid coupling will be required (Can't see a dry plate friction clutch lasting too long, even one from a large truck, given the number of times that it will need to be slipped for starting )i

The RH&DR used to operate a Simplex which had a two speed tranmission, with a Forward/Reverse box between it and the two cylinder Dorman engine. (That DID have a dry plate clutch, mounted on an enormous flywheel.

The Dorman was replaced by a Perkins 3.152. Unfortunate the then Chief Engineer hung the original flywheel on the the flywheel of what had been a genset engine, and the grossly excess overhung weight broke the crankshaft. So it was converted to a hydraulic pump / motor drive, but don't think that ever wanted to tow the loco, or anyn of the other I C powered ones.

There was a time when No12 had to tow a disabled steamer and train from Hythe back to New Romney!.

Nos 12 and 14 were powered by a Perkins 6.354.4 engine driving into a Twin Disc torque converter transmission, driving into a box which fed the drive to each of the two bogies. Being naturally aspirated, the engine would have delivered about 125 bhp at 2,500 rpm. (Can't remember the exact figures - it was a long time ago when I was involved in commissioning No 12 , Maximum speed, with every carriage coupled behind was 26 mph. Tony Crowhurst, who was Chief Engineer at the time died a few months ago, so details are going to be hard to come by. )

RH&DR are presently using "Shelagh of Eskdale" from the Ravenglass and Eskdale. ("Ratty". ) This started life as a 0-6-0 steamer and was eventually powered by an early Perkins 6.354 engine that had started life in a Commer lorry. This drove a swashplate pump. This meant that the transmission had no neutral (As I found, nearly to my cost, when servicing it! )

Never heard of any need to tow the loco.

Howard

Hydrostatic transmission has a variable output (reversible) swashplate pump and a fixed swashplate motor. If the diesel engine dies and you try to tow the loco, the motor acts as a pump. It's tempting to think that if you just connect a bypass across the motor you can tow it willy nilly, but there is a complication. As well as the main variable swash pump there is an engine driven boost pump which keeps a minimum pressure in the system. There is a built in bypass on the motor, but without this boost pump running the manufacturer advises that towing at more than walking speed will cause irreparable damage to the motor. I’ve dreamed up a scheme with a battery operated boost pump, but I’ve no idea what flow is required, and it’s required to run for an hour or so to enable recovery. The supplier of the hydrostatic transmission is not being co-operative, probably because there is little or no profit in it for him.

Why do we want to be able to tow the loco? Well it’s a bit embarrassing to have an engine failure on a single track railway, and a considerable financial loss in ticket sales if you have to stop trains for half a day to mess about removing prop-shafts in the middle of no-where. Another possibility I’m looking at is a disengage-able gearbox between the motor and the final drive. I haven't yet found on that can accommodate two propshafts, one going to each bogie.. Dog clutches on the motor output is another possibility I’m looking at. At this stage I need to look at all options.

I’ve spoken to Alan Keefe, he uses hydrostatics and puts up with the inconvenience, or the JCB transmission I referred to earlier. I think that has 4 fixed ratios in either direction and a torque converter. It’s proving very difficult to get hold of anyone at JCB who knows what he’s talking about. First question they ask is what JCB digger is it fitted to, when I say I want to fit it to a locomotive they go silent. The factory which actually makes the gearboxes doesn’t even answer the phone, when you get on to head office they promise to ring you back, but don’t.

Shelagh originally had a hydrostatic transmission and a Ford 4D engine (I worked on it in the early 70s) It now has a more modern engine and a 4 speed fwd rev box and torque converter. It’s locked in 3^rd gear I think as it is difficult to arrange a gearstick on a twin cab loco. The reverse is selected electrically. One of the drivers on the R&ER put it as 'it works, but it's always in the wrong gear'. That gearbox itself is probably 30+ years old. Just to be pedantic, Shelagh incorporates some parts of one of the original Heywood locos, but not very much. I spent a happy summer in my youth driving it. It didn't have servo assist on the swash control, you needed muscles on your muscles as the only way of slowing down was to heave back on the swash and engine brake. They now have continuous automatic brakes.

Thanks for the info on the 2 Romney locos. Something like the Twin Disc is what I’m looking for, but as far as I can tell they are well obsolete. It’s what is fitted to 2 other locos on the railway, one of which was the prototype for the RHDR, pretty much the same except only one gearbox on each bogie with chain coupling between the bogie wheels.

I’m waiting for Monday to phone the people Ady1 found, they seem to be agents for all sorts of transmission suppliers. So far I've found JCB, an Italian company (who are at least talking to me) and ZF, from whom I'm awaiting a reply.

Thanks for all the replies so far.

How about a ride on mower Hydrostatic gearbox/back axle. Many of these have a pin that you pull out to disengage the integral pump for the "motor". The speed range is infinite from zero to max.

Probably free to a good home from a garden mower mechanic.

When neutral is selected, it becomes a parking brake, so its a very practical unit. I bought a complete Ride-on the other month for less than £200, that included atwin cylinder motor with integral alternator. When I am moving logs around, I can tow a 1/2 ton trailer around with it ; No problem.

Bob

a 125hp ride on mower. This I want to see!

Is it possible to make the gearbox output coupling easy to disconnect? Possibly one of those couplings with two chainwheels and a short length of duplex chain, 4 cap heads and a couple of splitpins and you can tow as fast as you like.