Imaginary Locomotives

[Corbs]

2 hours ago, tythatguy1312 said:

something that's always irked me is why British Rail didn't even consider EMD during the modernisation scheme of 1955, despite their well-earned reputation for reliable diesel locomotives, in stark contrast to a number of British Rail's designs. How would an EMD Built loco have survived in the UK?

They did consider it. E.S.Cox mentions it in Locomotive Panorama. 

The US were seen as leading the way in diesels at the time but for a few reasons (UK economy and accessibility to skills and spares being two of them) they decided to go in-country.

[rockershovel]

43 minutes ago, whart57 said:

1955 was ten years after the end of the war and Britain's financial situation was not so dire. However there would have been a lot of unhappiness around the country if the government had sanctioned the purchase of American locomotives for British railways. The expectation was that British industry was the best in the world and planes, trains and automobiles would come from British factories.

The British economy was still pretty dire, leading to the persistent currency crises of the 1960s and ultimately, the Wilson Devaluation and end of the Sterling Area. 

[whart57]

Still pretty dire, but not so dire that it was impossible, financially at least, to buy American diesels. Politically however it was a different matter. The RAF was kitted out with British designed and built planes - Hawker Hunter, the Canberra and the V-bombers, BOAC and BEA flew Vickers Vanguards, DH Comets, VC10s, foreign built cars were curiosities on British roads and most "white goods" and consumer electronics were British made, all those Bush TVs for example. The expectation was that British trains would be pulled by British engines.

[AlfaZagato]

Licensing production of EMD engines, as was done with German designs, wasn't as viable.   EMD's were reliable partly because they weren't chasing super-high horsepower quite by '55.    According to a chart on Wikipedia, the highest horsepower offered in a single EMD engine by '55 was the 16-cylinder 567C at 1750bhp.   That only manages midrange of Type 3 expectations on it's own.

[rodent279]

1 hour ago, whart57 said:

The expectation was that British industry was the best in the world and planes, trains and automobiles would come from British factories.

I think that pretty much sums it up. Not sure it ever occurred to anyone that others may be able to do as well, if not better. The notion that something could be built better, outside these shores was damned well preposterous.

 

Yet, interestingly, when it came to electrification, looking abroad for inspiration is exactly what we did. We looked at the French experiments with high voltage AC, & developed our own. It wasn't without it's problems, but on the whole, the first 25kV AC electrifications, and the rolling stock & locomotives, were a much greater success story than the pilot scheme diesels.

Edited February 14, 2022 by rodent279

[PhilJ W]

29 minutes ago, AlfaZagato said:

Licensing production of EMD engines, as was done with German designs, wasn't as viable.   EMD's were reliable partly because they weren't chasing super-high horsepower quite by '55.    According to a chart on Wikipedia, the highest horsepower offered in a single EMD engine by '55 was the 16-cylinder 567C at 1750bhp.   That only manages midrange of Type 3 expectations on it's own.

English Electric had been building diesel engines and locomotives and exporting them since the 1930's. They were a serious competitor to EMD.

[AlfaZagato]

1 hour ago, PhilJ W said:

English Electric had been building diesel engines and locomotives and exporting them since the 1930's. They were a serious competitor to EMD.

I wasn't contending that.   I'm curious how availability compared between the makes.   

 

Also, didn't EE mostly export within the empire?   I believe that has been discussed before.

[rodent279]

35 minutes ago, AlfaZagato said:

I wasn't contending that.   I'm curious how availability compared between the makes.   

 

Also, didn't EE mostly export within the empire?   I believe that has been discussed before.

I believe EE did have some exports to S.America.

[Corbs]

When was multiple loco working 'figured out' by locomotive manufacturers? Surely on the global stage this must have been a huge change in motive power policy, switching almost entirely from 'build the right loco for the job' to 'allocate required amount of power units for load'?

Edited February 14, 2022 by Corbs

[The Johnster]

The big breakthrough in multiple working with diesel-electrics seems to have been in the States in the 1930s with EMD's streamliners and others.  The locos were not actually all that powerful, but Americans had the space in passing loops and with block signalling margins to not worry about the length of their trains, so simply hooking up as many 1,500hp or so units as they needed to pull the loads was an easy solution.   Paradoxically, this situation held back development of high-powered diesel-electrics in the States; the railroad companies were happy with their overweight underpowered locos and there was not much demand for anything much bigger.

 

I'm not conversant with the technological problems of muttiple working of locos, but emus had been worked in this way since their introduction in the late Victorian period, so it wasn't a great unknown; presumably the higher power outputs of the prime movers were not amenable to this sort of control.  By 1955, Modernisation Plan time here, the Americans had barely progressed in 20 years and EMD-type locos with a single cab at one end and gangway connections were still being built in volume. 

 

So, when BR looked for locos that would replace steam until the electifications were complete by about 1980 (and how did that work out for you, gentlemen), they realised that EMD type locos would not do in a british environment.  What they thought they wanted was a loco of about 2,000hp to replace 8P steam, based on the figures obtained from the Rugby Testing Station, and we now know that those figures were seriously flawed and steam power underestimated by about 30%.  Ergo, what they really needed was Deltic, but that was a prima donna that was never going to be acceptable in normal service, and uncomfortably close to the loading gauge.  An all round 8P diesel equivalent could not be built in the UK in 1955, because the train length limitations mitigated against twin or triple units (note at this point that Ivatt had got it spot on with the twins, one = to a Black 5, 2 to a Duchess, and not nearly as long as twin class 40s would have been), and axle load limitations prevented the use of heavy generator sets that could handle more than about 1,800hp, make that 1,500 for acceptable reliability. 

 

This is all before political considerations came in to it. I believe GM did tout for business here, but the orders were too small for them to consider bothering with, and of course the WR reacted to the generator issue by going down a hydraulic route that was ultimately doomed by their failure to realise that the German V200 that they based the Warships on was a secondary main line loco and blasting along with 14 coaches on the CRE was not really going to work for long.  This at least showed that we were not averse to foreign ideas, pity we didn't understand them.  When D200 was used on a press run out of Liverpool Street, Brian Roberston, BRB's boss, riding on the footplate, pointed out the fundamental problem, that it couldn't match 7MT Britannia performance never mind an 8P.

 

So, being the brits we are and under pressure to introduce diesels from the chattering classes who'd been impressed with the American airconditioned streamliners, we compromised and ordered the plethora of useless Type 2s, all of which could run in mulitple, but were still not up to 8P performance, or 9F for that matter.  The second generation benefitted from lighter generator sets that could handle higher power outputs from lighter super- or turbo-charged diesel engines, resulting in much more successful 33s, 37s, and 47s, and arguably the WR got it pretty close to right with the spec for the Hymeks, but those could not work in multiple and it was considered that 47s didn't need to either.  A 47 could manage 8P or 9F work, just, but it took another 15 years before the widespread use of type 5 power really got to grips with the loads and by that time the top link express passenger work was electric or HST.

 

By the time the 59s arrived on the scene, the American had progressed, and these and the 66s derived from them are the backbone of the current diesel fleet.  Train speeds have increased, most freight now runs at 75mph and some at 90mph, and faster passenger trains have meant that signalling margins can now accept longer freight trains that need to be put inside loops less; our current railway is, ironically, much more suitable for 1950s American loco practice but there is no need now for it.  We had a flirtation with multiple working on some heavy freight jobs such as the Port Talbot-Llanwern iron ore trains, 3x 37s then 2x 56s, but by and large a British freight train is hauled by one locomotive, though it might sometimes have a dead friend in the consist.

 

20/20 hindsight; we could have done worse than volume producing the Ivatt twins, which would have been suitable for most of BR's loco hauled work in singles or pairs for the next 30 years so long as airbrakes, eth, and aircon could have been accommodated.  20s could have done everything an Ivatt twin couldn't, including yard shunting, which would have avoided the embarrasment of 08 hauled trip freights getting in the way of everything at 15mph for 30 years after steam finished.  2 classes with multiple working capability, job done until the HSTs came along.

[rodent279]

I still say a fleet of 20's and 37's would have handled 95% of BR's traffic needs, all but the heaviest freights and fastest passenger trains. The heaviest freights could be double or triple headed. Add a fleet of 33's to give a bit of supplier diversity, and you just need a fleet of high power, fast diesels for the non-electric fast passenger services.

I'm not sure that Rugby's data was flawed, so much as misinterpreted. If your 8P steam loco can develop 2500dbhp, then putting a 2500bhp engine in a diesel loco will not give you an equivalent loco, as only between 75 & 80% of that 2500bhp appears as useful power at rail, depending on the transmission. So your 2500bhp is now down to a little under 2000 hp, and in simplistic terms you've got a loco that is 4/5ths of the 8P. Add in the ability of a steam loco to be flogged in the short term well beyond it's sustainable limit, which a diesel can't really do without risking damage to it's transmission, and you've got a serious deficiency.

[rodent279]

1 hour ago, The Johnster said:

arguably the WR got it pretty close to right with the spec for the Hymeks, but those could not work in multiple

Hymeks could work in multiple, but only with other Hymeks-they had an orange triangle MU code.

[Corbs]

2 hours ago, The Johnster said:

 

 

20/20 hindsight; we could have done worse than volume producing the Ivatt twins, which would have been suitable for most of BR's loco hauled work in singles or pairs for the next 30 years so long as airbrakes, eth, and aircon could have been accommodated.  

 

Now there's an interesting one for the 'what if' liveries etc.!

[DavidB-AU]

Lack of interoperability between loco types was a bit flaw on the modernisation plan. Although fierce competitors, EMD, GE, Alco, etc did adopt more or less standard MU capability and it was not unusual to see all three working in multiple. There were some issues early on, e.g. early Alcos with 244 engines had manual transition and could generally only work with each other or had to lead locos with 251 engines, but this was later resolved. There were also issues of locos with dynamic brakes not being able to trail locos without them, but again this was also resolved. A modern GE or Progress Rail loco straight out of the factory today can still work in multiple with an EMD loco built 70 years go (there are EMD locos that old still in revenue service).

 

Cheers

David

[The Johnster]

18 hours ago, rodent279 said:

I still say a fleet of 20's and 37's would have handled 95% of BR's traffic needs, all but the heaviest freights and fastest passenger trains. The heaviest freights could be double or triple headed.

 

I'd agree, but 37s were second-generation diesels and could not have been specified in 1955 (matters developed considerably and apace around 1960), and the Ivatts and 20s could.  There were few 1955 plan type 3s; the D600 Warships, and debatably the 33s, which I consider 2nd generation. Double headed Ivatts were capable of type 5 work, not much longer than a Duchess with tender, and if multiple control between the two classes could have been achieved, a very useful variety of power output combinations would have been available.  There was a limit to how many locomotives could be used in multiple, though. as for many years the usual maximum length of trains was 60 short wheelbase wagons including brake van.  The length of loops and layby sidings was determined by this, as were signalling margins, so a triple headed train of full length may have caused signalling problems or been foul of the entrance to loops.

 

When the triple-headed Port Talbot-Llanwern iron ore trains were introduced in the 70s, clear pathing had to be guaranteed for them between Leckwith Jc and Pengam in Cardiff, about 3 miles of very busy main line including Cardiff Central station.  Similar arrangements applied between Ebbw Jc and East Usk in Newport, but were already in place as 90-wagon traditional freights had been running between Severn Tunnel Jc and Pengam Jc for years. 

 

In the Uk, in those days, it was not just a matter of increasing the loads and coupling more locomotives together until you had enough power to pull them.  This was the American solution, but they were able to build locomotives with much higher axle loadings to a loading gauge capable of accommodating higher rated generators, and had room to double, triple, quadriple and more, with mile-long freights that their Janney couplers could cope with.  It has developed into R/C control of multi-loco lashups at the front, helper lashups in the midde, and banker lashups at the rear of massive trains that could not be accommodated anywhere in Europe.  Don't forget there were still a large number of XPO minerals with relatively fragile 3-link couplings in service here.  On the European mainland, a common solution was a relatively short twin unit, permanently coupled with cabs at the outer ends, and both diesel and electric locos of this sort appeared, especially on the other side of the iron curtain; there were triple unit electrics on the Kiruna-Tromso iron ore line, all of which points to train length being a limiting issue there as well.

 

The permacoupled twin unit locomotive setup might have been viable here, but for some reason seem never to have been considered.  It sort of materialised in the form of the Blue Pullmans and the HST, with a train between the units.

 

 

[AlfaZagato]

Semi-permanently coupled locos still fall into the same logical fallacy that led to many inept early UK diesel classes - that Diesel locos should replace steam locos like-for-like.   American roads originally wanted the same idea.   It took EMD selling A-B sets, or the like, to convince the roads to use multiple working.   

 

Twin locos also still holds the same issue of overall length.   

 

I also fail to see why the high weights on individual American Diesels is an argument against MW practice?   Maybe against importation of prime movers or whole locos from the US.   

[The Johnster]

54 minutes ago, AlfaZagato said:

 

I also fail to see why the high weights on individual American Diesels is an argument against MW practice?

It's not.  It's simply that the development of diesel traction in the States was not hampered by the same train length and axle loading restrictions that it was here 20 years later, and little progress had been made in the States in those two decades (fair play, there was a war, and the 1930s diesels were acceptable to the railroads so there was little driving progress),  But here, we needed diesels at least as powerful as the biggest steam locos, and had difficulty in squeezing the equipment into our smaller bodyshells and keeping the axle loads down withing permissable bounds.  MW was adopted in the States despite the (relatively, to British thinking) heavy axle loadings because the power put out by single units was too low to handle replacing superpower US steam, or for that matter the heaviest and fastest UK work.

 

We were much influenced by a loco's power/weight ratio, again a product of our length and axle loading limitations.  To compare two 1955 diesels, both 2,000hp 'type 4s', a Class 40 diesel-electric (based on a pre-1955 Southern Railway design built by British Railways); length, just short of 70 feet, weight just short of 150 tons, carried on 1Co-Co1 underframe, and a Class 42 'Warship' diesel-hydraulic, length 60 feet, weight 78 tons, integral pre-stressed monocoque body on B-B bogies.  If the Warship is about 70 tons lighter than the Class 40, that means it can easily haul 2 more of the usual type of British passenger coaches from the 1955 at the same timings, or haul the same number of coaches as the 40 at faster timings, and burn less fuel in the process, or any combination of those 3 factors. 

 

But it wasn't as simple as that.  The 40 proved a better locomotive for the heavy unbraked freight trains that were still common then, because it had a better 'brake force' rating, down to its extra bulk.  When air brakes came to be fitted in the late 60s, it was found that they could not be squeezed in to the limited room avaialble on the Warships, not a problem on the 40s, and the Warships were all withdrawn by 1971, after just 10 years of service while the 40s soldiered on for nearly another 2 decades.

[Mike 84C]

I  thought post war currency restrictions were a limiting factor for BR in importing prime movers and complete locos. Britain had to export in the post war era. 

 Was'nt our war debt to the US only paid off during Gordon Browns premiership?

[DavidB-AU]

5 hours ago, AlfaZagato said:

Semi-permanently coupled locos still fall into the same logical fallacy that led to many inept early UK diesel classes - that Diesel locos should replace steam locos like-for-like.   American roads originally wanted the same idea.   It took EMD selling A-B sets, or the like, to convince the roads to use multiple working.   

 

American railroads wanted like for like because the union requirement was one crew per locomotive. That's part of the reason why the road switchers were so popular, where a single 1000hp diesel loco could replace one steam loco (the job often being done by the oldest steam locos still in service). The early A-B or A-B-A sets were originally numbered as a single locomotive to get around the union requirement at the time.

 

You also have to remember just how incredibly big and powerful some of the American steam locos were. It often took 3 or 4 1950s diesels in multiple to provide the same capability as one 1930s steam loco. Look at this video of the UP Challenger on a modern double stack container train on Archer Hill (this was done as a one off publicity stunt for APL). This train usually had 3 x GE Dash 8s and would typically reach the summit at around 20-25 mph. The Challenger is doing 35 mph and isn't even working very hard!

 

Cheers

David

Edited February 16, 2022 by DavidB-AU

[whart57]

I don't know how you can do justice to North American railways on a model railway.

[PhilJ W]

2 hours ago, whart57 said:

I don't know how you can do justice to North American railways on a model railway.

Many American homes have large basements and quite a few have extensive model railways in them. Even then as with most model railways there has to be compromises.

[The Johnster]

Homes over there usually have basements that cover the entire footprint of the house, and the houses tend to have much bigger footprints than ours. These basements, used for layouts, are capable of modelling a mile or more of route in 3.5mm scale, or several miles in 2mm, and the layouts intrude into the central area of the spaces on peninsulas.  They are also frequently mulit-level spirals, loops, and corkscrews, increasing the route length further, with mountain scenery floor to ceiling. The compromise is with curve radius; Americans seem quite relaxed about very sharp curves, even on the scenic parts of their layouts.  This is possible because of the advantages of bogie stock with buckeye buffer/couplers.

 

Not all American modellers have such wonderful spaces, and many model situations other than main lines with mile-long trains of course. 

[AlfaZagato]

I certainly don't have a nice basement to build an empire in. 

 

I do know of at least one club layout, though, with a minimum 60" radius.

[62613]

16 hours ago, DavidB-AU said:

 

American railroads wanted like for like because the union requirement was one crew per locomotive. That's part of the reason why the road switchers were so popular, where a single 1000hp diesel loco could replace one steam loco (the job often being done by the oldest steam locos still in service). The early A-B or A-B-A sets were originally numbered as a single locomotive to get around the union requirement at the time.

 

You also have to remember just how incredibly big and powerful some of the American steam locos were. It often took 3 or 4 1950s diesels in multiple to provide the same capability as one 1930s steam loco. Look at this video of the UP Challenger on a modern double stack container train on Archer Hill (this was done as a one off publicity stunt for APL). This train usually had 3 x GE Dash 8s and would typically reach the summit at around 20-25 mph. The Challenger is doing 35 mph and isn't even working very hard!

 

Cheers

David

They certainly love their black smoke over there!

 

[The Johnster]

The 8x4 solid baseboard format, basically the equivalent of our 6x4, is alive and well in the States as well. and is used for Lionel and American Flyer 0 gauge layouts; this is more in the sense of retro train sets than 'proper' modelling (whatever you take that to mean), but nonetheless a valid format.  Curves are seriously insane on these!  It seems to be the goto for media representation of model railways, as with Rev'd Lovejoy on the Simpsons and Sheldon Cooper on Big Bang Theory.