If The Pilot Scheme Hadn't Been Botched..........

[cheesysmith]

With modern computer control there is no way a hydraulic drive can match the pulling power of a diesel electronic with creep  control. As for high speed trains, electric drive allows the use of hybrid drive, diesel or wires. Just don't use the IEP as your example. Nothing wrong with the idea, it is just a example of how not to purchase a train.

 

The only place hydraulic drive has the advantage is lower powered light weight trains. By this I mean below 1000hp. The 180s are a better high speed DMU than the voyager, if you ignore the bad build quality and poor after sale support from alshom. They are probably the ultimate sprinter. 

 

We are a bit ahead of ourselves here. But the faults with the hydraulic drive would have been more obvious with a proper trail period. Poor ride, fragile engines and more maintenance needed. I think the WR hydraulic are fascinating from a engineering view, but not what the railways needed.

[Nearholmer]

It’s about dates, and steps of progress in design. Engine weights were falling, so even small date difference made a difference, masking the theoretical inherent advantage in the transmission - which pretty much evaporated once a.c. traction packages emerged anyway.

 

Its worth getting a book called something like “Hydraulic vs Electric”, my copy is elsewhere so I can’t remember the author, but he does give extensive quotes from my old school and work colleague Clive Burrows, who was an absolute fan of the hydraulics, and went on to become Head of Fleet on the western after privatisation, and a leading light on traction policy with ATOC. The book is very balanced, and contains a lot of engineering facts and figures presented very lucidly.

 

 

[cheesysmith]

Something else overlooked is BR reluctant to rebuild and upgrade old locos as technology advances. It was obvious even when the pilot scheme locos were being built that more power in less weight would b coming along. 10203 was three tons lighter with more power than its two lower powered sisters.

 

Why were the class 40 not rebuilt with updated engines in a class 47 body? Why did they not rebuild the peaks into class 47 bodies? The first 20 class 47 used modified electrical equipment from the class 46. It would have been a LOT cheaper and allowed a bigger fleet of higher powered locos with lighter weight. 

[cheesysmith]

I have said book. And one thing that comes out clear is a lot of the problems BR had was with the accessories fitted. Poor cooling systems lead to overheated engines. The problem would have been on the cooling system, not the engine, but seen as a engine failure. BR did not have the maintenance in place to make use of what it ordered, and expected what it bought to work without modification out of the box. The heavier medium speed engines used in the DE locos were more tolerant of abuse and lack of maintenance, so were a better choice whilst BR was learning how to use what it had bought.

[cheesysmith]

Also, how much of the problems came from BR being able to do it in house , and being very conservative in its designs? Just look at the ride problems of the MK1 coaches. Leaf springs are a poor choice for suspension as the friction varies too much and alters with wear. But they had always been used, so they continue to be used. Who else sees the peaks and the 40s bogies as just a steam loco frame, as that is what they already knew? They added weight but caused more problems with poor suspension and uneven weight and lacking secondary suspension with the long term damage to the network. 

[Mike_Walker]

58 minutes ago, Zomboid said:

The Maybachs in the British hydraulic locos sound magnificent, but they don't really offer anything else that's especially useful which a DE doesn't. And presumably it would have been possible to connect a generator to the output of those prime movers too...

They did and the result was D0280/1200 Falcon...

[Titan]

1 hour ago, Zomboid said:

By the time you've coupled up enough of a train to justify 2700hp that's going to be a negligible difference.

 

The issue of weight was nothing to do with performance, and all about hammer blow to the track.  The lighter you can make a loco, the less the cost of track maintenance, particularly if that loco is run on express passenger. Diesel Hydraulics had a further advantage in this respect in that the unsprung weight was much less without a heavy motor suspended from the axle, and unsprung weight makes a significant contribution to track damage in itself.

Edited October 27, 2021 by Titan

[Nearholmer]

55 minutes ago, Titan said:

The issue of weight was nothing to do with performance,

Que?!

 

I think you’d better go and look at tractive/braking effort calculations.

 

Featherweight locos are certainly easy on the track, but they can’t pull heavy trains, and they can’t stop otherwise-not-braked heavy trains.

 

During the 50s, 60s and into the 70s, the power/weight ratio problem wasn’t about making the weight smaller, it was about making the power greater. The engine powers available, without resorting to mega-complexity and high maintenance costs (= Deltics) were too low to sustain the sort of long distance express passenger services needed to compete well with air and motorways. Then we got HST, with two engines!

 

 

Edited October 27, 2021 by Nearholmer

[KingEdwardII]

I'm still of the opinion, long held, that the real crime was not to push on with major electrificiation of lines across the UK. While I'm not an opponent of HS2, I still find it galling to be putting so much money into that while major main lines across the UK are still not electrified. The UK is way, way behind compared with most other European countries. The latest hybrid diesel/electric trains are ingenious but really a sticking plaster covering the real problem of unelectrified main lines. 

 

I find it fascinating watching the government dodging this issue while blowing on windily about "net zero" - it seems that it is fine for other people to foot the bill for that, but they are most unwilling to stick their hands into their own pockets for such a lofty goal.

 

Yours, Mike.

 

PS. I still love steam locos - in the right place, on preserved lines. Magnificent beasts, but not modern transport.

[Nearholmer]

I happened to be reading about the history of compound steam locos yesterday evening, and it struck me to realise that the brilliant work being done by Chapelon was cut short in 1951, when the SNCF stopped all significant development on steam traction, to concentrate fully on developing electric traction. Good decision, even if the projects that were canned would have been brilliant.

[rodent279]

Duplicate post

Edited October 27, 2021 by rodent279

[Zomboid]

1 hour ago, KingEdwardII said:

While I'm not an opponent of HS2, I still find it galling to be putting so much money into that while major main lines across the UK are still not electrified.

Without wanting to go too far off topic, it's not an either/or. HS2 is needed for the reasons that it's needed (WCML capacity primarily), and proper electrification of major routes is needed for completely different reasons.

 

Both things are investment in the rail network, but they're not otherwise related.

[BernardTPM]

3 hours ago, Nearholmer said:

I’m not at all convinced that hydraulic transmission would have been a long/medium term good idea for large locomotives, even though it would undoubtedly have permitted (did permit) a higher power to weight ratio

 

3 hours ago, Zomboid said:

Does that really stack up?

The most direct comparison would be with the Class 21 and Class 22. Built by the same company, at the same time and having the same engine but different transmissions.

DE version weighed 73 tons, the DH weighed 68 tons.

 

You could also compare the 79 tons of the B-B Warships to the 136 tons of the Class 40 too. Not really like for like though, despite being contemporaries and rated at 2000hp*. It was possible to build lighter, powerful DE locos as Deltic showed.

In summary, there was a bit of weight saved in the transmission, but faster running engines and integral bodies were probably more signiicant.

* D800-3 as built.

Edited October 27, 2021 by BernardTPM

[Allegheny1600]

3 hours ago, Nearholmer said:

I happened to be reading about the history of compound steam locos yesterday evening, and it struck me to realise that the brilliant work being done by Chapelon was cut short in 1951, when the SNCF stopped all significant development on steam traction, to concentrate fully on developing electric traction. Good decision, even if the projects that were canned would have been brilliant.

Just adding to your story here!

Chapelon had quietly developed his latest designs to be able to produce around 5000hp and when the upper echelons at SNCF realised their latest electric locomotives were going to be producing a “mere” 4000hp.

A hasty redesign was in order to save the embarrassment of the latest electric locomotives being outclassed by steam locomotives! I understand it was this that put the nail in the coffin for French steam, ultimately.

 I do agree that ultimately, electrification was what was needed but those designs that were canned would have been world beaters for sure.

[Allegheny1600]

Earlier in this topic, mention was made of the Germans (Voith) building a “big” diesel hydraulic not too long ago.

Yes, they did and it was a monster!

5000hp and there were around half a dozen big ones and a few more in a smaller, 4000hp version.

Unfortunately for Voith, only smaller concerns bought into this concept, there’s no real D-E equivalent* in Europe but the big railway in the shape of DB simply wasn’t buying big diesels anymore.

But - the diesel hydraulic system isn’t dead.

 

*what’s developed subsequently is the hybrid concept that takes you up towards the 9000hp mark.

[KingEdwardII]

2 hours ago, Zomboid said:

but they're not otherwise related

They are related by the huge sums of money involved.

 

I'd be quite happy to have both electrification and HS2, but I find it very odd to have HS2 and half of the other lines limping along in the mid 20th century. 

 

Yours, Mike.

[Traintresta]

6 hours ago, Ramblin Rich said:

All the first generation DMUs were mechanical transmission with gearboxes and fluid flywheels (apart from the Southern DEMUs with electric transmission). It's the second generation 14x and 15x series that have hydraulic transmission.

Your thoughts around mechanical engineering still hold in that DMUs need mechanics, but not the same skills as for hydraulics.

Given the ideas behind transition to electrification, getting experience with electric transmission made sense and hydraulic transmission is really (sadly) a bit of a dead end.

Quite right, I went off on a bit of a tangent there and my next train of thought was 'if they were ultimately aiming at electrification, why did they not pursue ETH more aggressively?'  This would have had a knock-on effect to diesels and the need for a train heating boiler would vanish, saving some weight in the process.  I believe the ETH equipment was small and of negligible weight in comparison?  Clearly electrical transmission was the way forward so hydraulics were indeed a dead-end technology.

[Traintresta]

5 hours ago, cheesysmith said:

Something else overlooked is BR reluctant to rebuild and upgrade old locos as technology advances. It was obvious even when the pilot scheme locos were being built that more power in less weight would b coming along. 10203 was three tons lighter with more power than its two lower powered sisters.

 

Why were the class 40 not rebuilt with updated engines in a class 47 body? Why did they not rebuild the peaks into class 47 bodies? The first 20 class 47 used modified electrical equipment from the class 46. It would have been a LOT cheaper and allowed a bigger fleet of higher powered locos with lighter weight. 

Traditionally re-building of diesel locomotives tends to re-use the platform and upgrade the equipment.  You could upgrade a class 40 by uprating the prime mover and adding new electronics but only if you were looking at a new locomotive programme on a budget would you be likely to swap the internal equipment into a new body.  It is also unlikely that they would modify the mechanical elements to accept EE 3-axle bogies, purely on a cost/convenience mindset although I suspect it could have been done.  The 1Co bogies were 28tons each in weight, if you could reduce that by a third you would have a loco of similar weight to a class 47 or 50, but it is highly unlikely to happen.

 

The equipment for the first 20 class 47's was not modified equipment from Class 46's, it was originally ordered for the 46's but the last 20 were cancelled and the equipment moved over and installed in the first 20 new class 47's.  The 47 was a development of the 44/45/46, re-packaged in a different body and riding on different bogies.

 

6 hours ago, Zomboid said:

The Maybachs in the British hydraulic locos sound magnificent, but they don't really offer anything else that's especially useful which a DE doesn't. And presumably it would have been possible to connect a generator to the output of those prime movers too...

There was originally a plan to order 200 Hymeks with electrical transmission. Given that they were build along traditional Diesel locomotive lines with a heavyweight frame on cast bogies, they would probably have been just as effective as the hydraulic versions and would have been mechanically equivalent to half of the D0280 Falcon but with a little more power due to four more cylinders.

[Nearholmer]

3 minutes ago, Traintresta said:

There was originally a plan to order 200 Hymeks with electrical transmission.

Why? As in what work was there for them that another proven design couldn’t handle? Maybe the clue to why it never happened rests in the answer to those questions.

 

Was cruel to give WR Class 31 though, very cruel.

[APOLLO]

Well I for one am glad they botched it up, makes modelling the 50's / 60's far more interesting - And thanks Heljan (etc) for modelling the botch jobs !!!!!!!!!!!!!

 

Brit15

[Allegheny1600]

7 minutes ago, APOLLO said:

Well I for one am glad they botched it up, makes modelling the 50's / 60's far more interesting - And thanks Heljan (etc) for modelling the botch jobs !!!!!!!!!!!!!

 

Brit15

Pity Heljan copied the prototype though and botched the models!!!

Well, too many of them anyway!

[JohnR]

On 25/10/2021 at 21:34, Pandora said:

A magazine published an article with drawings of the LNER diesels, I think it may have been The Railway Magazine in the 2016 or 2017 volume. i do not have a copy.

Please may I ask the forum to look through their magazine libraries  and post  the title and date of the magazine and article.

Trackside October 2021 had some drawings.

[Nearholmer]

Are they based on solid information?

[peach james]

16 hours ago, Tumut said:

HelloAll,

 

The Victorian Railways / VR of Australia purchased 26 x B class double ended GM-EMD / Clyde Engineering CoCo 1500 hp diesel electric locomotives, and was derived from the EMD F7 model. The VR found that one B class could cover the equivalent runs of three steam locomotives. ( Which, as it later turned out, was found to be generally true on all Australian railways. )

 

B62 was the first diesel locomotive in Australia to achieve 1 million miles in service from September 1952 to December 1957. To give some context to this, the VR had a geographic spread equal to Britain, with approximately 5,600 route miles. A former Signalman at Melbourne Spencer St No.1 Signal Box told me that the B class were always intensively used, in that they would arrive with one train, be uncoupled, and quickly attached to another for the next departure.

 

Then again, fuel cost wise, in 1953 they cost AusPounds 80- / hp, compared to AusPounds 60- / hp for steam, but as one diesel could cover three steam runs, and not require refuelling or re watering whilst doing so, the benefits are obvious.

 

Also at the time Australia relied on the bulk of locomotive coal coming from NSW underground coal mines, and supply could  be variable. ( Northern NSW and Queensland open cut coal mines were a mid 1960s development. ) Later on, the VR ran an oil pipeline from refineries at Altona, near Newport, to South Dynon Loco ( North Melbourne, near Spencer St ), so fuel supply was no longer a problem. Also, in comparative terms the cost of steaming coal rose whilst the cost of diesel fell, so dieselization was a no brainer even then.

 

In the case of BR, the cost and quality of British coal was declining, cost per ton was rising, and the cost of importing oil was falling, so the elimination of steam by 1968 had a significant effect on lowering fuel costs. One aspect of the case for electrification was that it was , and is, more fuel efficient to burn coal in a power station than burn it in a steam locomotive, though not as visually interesting !

 

Regards, Tumut

Your numbers are suspect...there are more recent (late 70's) numbers from South Africa in The Red Devil, and the figure I have seen over here was that at 6%n, steam burning coal was cheaper than diesel burning oil.  That's in relation to 614T, and the ACE experiments- there are some write ups of it in The Red Devil, as well as various ones found in Trains magazine.  It is more n efficient to burn fuel in a power station, regardless of if it is oil, coal, or natural gas, because you can have whatever weight of equipment you want, and you don't have to move it with you.  From a capital prospective, I am far from convinced that the 25kv electric system the UK has chosen to implement is the most capital efficient- I suspect that 3000VDC overhead might be cheaper, depending on the standards of track and speeds expected.  (a la MIL western lines, as posted above by me...).  I suspect there is a large gap between what can be made to work reasonably safely (even in current safety climates) and what is elected to be done in the UK, alongside what is going to end up being done in Ontario with GO...I think that they are trying to make a Daimler when an Austin Mini would do  (or Cadilac and Ford, for those over here...).  

[Nearholmer]

15 minutes ago, peach james said:

From a capital prospective, I am far from convinced that the 25kv electric system the UK has chosen to implement is the most capital efficient- I suspect that 3000VDC overhead might be cheaper,

 

I'd be really interested to see the maths that leads you to that conclusion, because for a given load demand the OHLE for 3kV DC will need to be larger CSA, and hence heavier (which leads to knock-on complexity in getting the tension/resilience right), and because you will need rectifiers, which aren't complicated these days, but are an added expense, likewise more substation switchgear is likely to be needed on the dc system, and probably either more grid intakes or a "railway side" HV ac distribution system.
 

25kV and 2x25kV autotransformer systems are very widespread, and spreading wider still, for good economic reasons, even if the UK has invented special ways of making them cost more than they need to in the recent past.

 

 

 

 

 

Edited October 27, 2021 by Nearholmer