The return of Diesel hydraulics?
 

This type of loco was not around for very long on the network.
It was around for a bit in the industrial sector but now it is less common.
I beleive that becuase it did not have time to develop.
Could this form of technology be revisited?
I like to beleive it, I mean we could find out that after all the known problems have been solved, it could be more efficient than diesel electrics.
There was a bit more character in the Hymeks and westerns than the diesel electrics, with perhaps the exception of the class 55's.

I dont think there were many problems with them they gave years of very good service.
The only thing was that they were non standard to the rest of the country.
I agree with you lovely locos and it would be a treat to see them running again but i dont think that will ever happen.
ccmmick

Could some kind person give me an "idiots" guide to how the diesel hydraulic engines worked. I understand that diesel electrics generated electricity to drive the traction motors. What did the diesel hydraulic generate to power their traction motors ?

And am i right in thinking that most DMU's were direct drive diesels ?

Thanks

Some of the present day DMU's such as Class 170, 175, 180 and 185 are diesel-hydraulics.
Germany has continued to develop Diesel-hydraulics and this type of loco is quite common in mainland Europe.

Hi Foxwall
This might help you
I worked on these locos at St Blazey a beautiful engine but very complex

http://en.wikipedia.org/wiki/Diesel_...esel-hydraulic
ccmmick

The Diesel -hydraulic was a western design, as usual the Western were doing there own thing not conforming to what the other regions were doing in loco development. An as now has been proved the Diesel-Hydraulic was a poor design otherwise they would still be operating on the mainlines today "Not on preserved lines" or running as excursions with fitter cover just in case they go BANG on the main line but thats just my view.

Inwr20. The Warships were based on the German V200's I believe. The diesel-hydraulics were just non standard to the rest of the B.R. fleet, all the other regions opted for electric transmission while the erstwhile G.W.R. went on it's own merry way and no-one at the top tried to stop it. The least reliable of the hydraulics seemed to be those built by North British; the class 41's, 43's, and 22's.
Cheers,62440

I agree with you the early North British were crap also the 600s
But the 800s and 1000s were good locos they gave very good service.
We had the type 22s at St Blazey fased out in early 70s and replaced by Rats.
ccmmick

Thanks rather complex, so basically oil under pressure powered the traction motors.

And to think not so long back i thought all diesel locos were powered like diesel buses or lorries but with bigger engines.

What about the hymeks?
How has the service they gave?
This type was more of a mixed traffic design.
I agree that the western region had no real interest of the outside world.
It just goes to show that GWR was not prepared to die.
It was not until the closure of swindon that practices faded away.

I thought that transmission by oil was called "hydrostatic" transmission. Where the engine drives a pump and the pressurised oil drives a hydraulic motor. Like on some combined harvesters and earthmoving vehicles.

Surely diesel hydraulic was like an engine driven automatic gearbox with torque converters (more than one) and cardan shafts (propshafts !) driving the wheelsets through a reduction gearbox.

Have we an "expert" to confirm this ??????

The western all over, they always thought themselves superior it appears.
An attitude that was still all too common until comparitively recently.
The Hymeks were pretty little engines though, they don,t look dated even now.
I believe the diesel hydraulics revved a lot higher than diesel electrics, this may well have been one of the reasons for their demise, since it would follow that would wear very quickly?
Just a thought.

There were such things as torque converter locomotives; Canadian Pacific had some. But I assumed, because they bothered to call them that, they were distinct from other diesel-hydraulics such as Krauss-Maffei ML4000s.

Taken from an article about Warship class 42's

Class 42 Details:

Introduced: 1958 Engines: Two Bristol Siddeley-Maybach MD 650 V-type of 1152bhp at 1530rpm. Weight: 78 tons Maximum Tractive Effort: 52400lb Transmission: Two Mekydro type K104 hydraulic transmissions containing permanently filled single torque convertor and four speed automatic gearbox. Driving Wheel Diameter: 3' 3½"

Aha ! I found this description of the transmission on the class 52 (Westerns) and it illustrates quite clearly the way the transmission is laid out. Now I do understand !!:D :D

http://www.westernloco.com/media/cut-away.swf

Hold the cursor over each number to get a description.



Philip

Well there you have it very good pre65
ccmmick.

Now what about Gas Turbines
I bought a book a couple of years ago on Gas Turbines very interesting they were a bit before my time but they fascinate me.
ccmmick.

I agree, the Western Region, as was the GWR, were not frightenend to be different, with diesel-hydraulic transmissions being successful in Europe, why did the WR have so many problems with their own machines? Was this merely a lack of understanding by our engineers, or was it with the designers?
Any how, the truth of the matter was that, in my opinion, they were a sight to behold, and the Westerns especially were more streamlined than most designs of their day in that they had basically the same profile as their coaching stock. Incidentally, when I was a young lad I had a small model railway and had two Hymeks, two Warships and a Western, but had to part with them. Funny thing hindsight, now I have a son who is into trains, I wish I had kept them as we are currently building a new layout, they would ahvbe looked great on it!