Imaginary Locomotives

[rodent279]

164 locomotives seems rather few to eliminate steam completely from the system west of Taunton, even taking into account the greater availability. Either someone was being over-optimistic in their estimates, or this was to eliminate steam haulage from the trunk routes.

[Zomboid]

Wouldn't many of the steam locos have been replaced by EMUs? The GWR wasn't shy when it came to MUs, and EMUs themselves had been around for decades by then.

 

How many locos do you need if you have every passenger train that had it's entire route west of Taunton run by EMUs?

[rodent279]

1 hour ago, Zomboid said:

Wouldn't many of the steam locos have been replaced by EMUs? The GWR wasn't shy when it came to MUs, and EMUs themselves had been around for decades by then.

 

How many locos do you need if you have every passenger train that had it's entire route west of Taunton run by EMUs?

Fair point, I suppose.

[298]

The comparatively low dc voltage may be because of nationwide clearance issues, and there's no reason why the GWR couldn't have gone for something higher, either 3000v DC or more likely 11 or 15kv AC at 16 ²/³ Hz.

 

I've not seen the figures quoted before but am fairly certain the larger types would have been based on the twin motored Swiss Crocodiles, the 1-Co-Co-1 (or 1C-C1) types having similar and successively higher horsepower ratings as they were developed through time. 

 

Following contemporary practice, the Bo-Bo type would have probably been more boxy and with individual motors per axle, and the trucks articulated to each other as per the later BR class 76.

[RLBH]

On 23/04/2021 at 13:13, Northmoor said:

To be fair, the GWR at that time may not have appreciated the economics of electrification being based on traffic frequency, not tonnage.  I agree electrifying one-coach branch lines would be a nonsense, but they probably looked at electrification as eliminating the one set of infrastructure (for steam), not duplicating it with another.

One of the findings of the studies done for the 1931 Weir Report was that if you totally electrified a railway system, about half of the mileage was in goods yards and sidings. But if you only electrified those parts of the goods yards and sidings where a locomotive might run, you still did virtually all of it. Which points to the importance of diesel shunting locomotives, that way you only need to electrify the exchange sidings.

 

Interestingly enough, both studies (one LMS, one LNER) done for the Weir Report were done by Merz & McLellan, and they found that electrifying the branch lines was a better proposition than doing main lines only, because of inefficiencies brought in by changing engines. The LNER study proposed that a lot of branch line working would be done by three-coach multiple unit trains, which may have been replicated in the GWR study - this would explain a surprisingly small number of locomotives.

 

The 1931 locomotives were:

• A 2,400hp, 110 ton, 2-Do-2 for heavy express passenger work
• A 1,800hp 2-Co-2 for light express passenger and fitted freight work
• A 2,100hp, 108 ton, Co-Co for 40mph goods trains
• A 1,800hp, 108 ton, Co-Co for 35mph goods trains up to 900 tons
  • A regeared version of this with a train heat boiler was proposed for fitted freight and excursion traffic
• A 1,200hp, 72 ton, Bo-Bo for 35mph goods trains up to 600 tons, or 1,200 tons working in multiple
• A 720hp, 60 ton, Bo-Bo shunting locomotive

 

Some of these sound similar to the proposals for the GWR scheme, with some evolution.

[Ohmisterporter]

Six different locomotives with quite small differences in horsepower and operating speeds, especially in the goods train proposals. What particularly strikes me is the lack of ambition in improving operating speeds. 

[Compound2632]

7 minutes ago, Ohmisterporter said:

 What particularly strikes me is the lack of ambition in improving operating speeds. 

 

But in the 1930s the railways still had a monopoly of long-distance travel - travel by air or motor car was still a rather uncomfortable luxury for the very few.

[RLBH]

1 hour ago, Ohmisterporter said:

Six different locomotives with quite small differences in horsepower and operating speeds, especially in the goods train proposals. What particularly strikes me is the lack of ambition in improving operating speeds. 

The only common locomotives between the two studies were the 2-Do-2 and the 1,200hp Bo-Bo - the LMS plan called for just eight of the latter, compared to 91 2,100hp Co-Cos! Oddly enough, the LMS didn't see a need for any shunters either, sticking to purely main line electrification and letting steam handle the yards.

 

The two mixed traffic locomotives, and the two heavy goods locomotives, were mutually exclusive - the LMS study called for the 1,800hp 2-Co-2 and the 2,100hp Co-Co, whilst the LNER reckoned the 2-Do-2 would do all the regular passenger work needed and standardised on the Co-Co for everything else. Even the Bo-Bo was proposed to have high commonality with the 1,800hp Co-Co, although steam thinking does seem to have led them to try to finely matched locomotive power to train size. Speed improvements were expected, but through better acceleration and maintaining speed on gradients rather than higher maximum speeds.

 

The authors of the reports were aware that higher speeds were possible, but considered them inadvisable with unbraked wagons and traditional axleboxes. Their remit was, after all, electrification - not the general improvement of rolling stock and operating practices. For the same reason they recommended electric boilers for train heat.

 

One gets the impression that the LNER had a reasonably good handle on how to electrify and what it was capable of, and wanted to use government money to try and sell it to the board, while the LMS were trying to make the case that it was too expensive to bother with. The LNER proposal to electrify everything on the former Great Northern section, except for the most marginal of branches, showed much better return on investment than the LMS study for heavily trafficked, steep main lines and nothing else.

Edited April 26, 2021 by RLBH

[MikeOxon]

Going further back in time, Dean was asked by the GWR Board to consider electrification for the Severn tunnel but ignored the correspondence.  My imaginary locomotive is back on Page 14 of this thread :

 

 

Edited April 26, 2021 by MikeOxon

[PhilJ W]

Armstrong-Whitworth designed an 0-4-4 Diesel electric locomotive for the GWR. It was very like their 0-6-0 shunter with the rear drivers replaced by a four wheel bogie. It never left the drawing board though.

The A-W shunter.

The driving wheels were a bit larger and the bonnet a bit lower with a small copper capped chimney.

[DK123GWR]

18 minutes ago, PhilJ W said:

Armstrong-Whitworth designed an 0-4-4 Diesel electric locomotive for the GWR. It was very like their 0-6-0 shunter with the rear drivers replaced by a four wheel bogie. It never left the drawing board though.

The A-W shunter.

The driving wheels were a bit larger and the bonnet a bit lower with a small copper capped chimney.

Is that just so it can use tight radius curves? I don't really see the point otherwise.

[PhilJ W]

Intended for trip working rather than shunting hence the bigger drivers. 

[AlfaZagato]

Bigger drivers would ostensibly allow higher speeds.   Fewer drivers does the same.   Trailing bogie improves riding at speed - effectively compensation.

[PhilJ W]

There is a drawing in Brian Webbs book on Armstrong-Whitworth diesels of the loco. With the main lines electrified and the AEC diesel railcars operating branch line passenger services these locomotives would easily be able to handle most branch line freight. It would only require a handful of larger locomotives, diesel or electric to cover most diagrams.

[DK123GWR]

A random idea which experts will probably tell me is completely impractical, but here is my imaginary HST replacement, instead of the class 80x.

As the BR Mk3 was probably the most popular rail vehicle among passengers to be used in this country, why not replace them with a very similar design (in terms of ride and passenger comfort) but updated with modern safety systems, passenger information systems, and control systems suitable for the new motive power.

 

This would of course have to be bi-mode, and given that the most powerful bi-mode design to date appears to be about as powerful as a single HST powercar when on diesel (1,800hp for the proposed class 93) two working in multiple would most likely be needed. As a result of the doubled locomotives, the power produced when operating on electric would probably not need to be as high as the 5,438 of the class 93, although 3,500-4,000hp would be more powerful than the class 91, and allow a single power car to equal the power of an HST in the event of a failure. They would of course be streamlined and geared for 125mph, with potential to regear to 140 mph if required in the future.

 

The main issue that I can see is weight. Adding the electrical equipment to an HST would of course add a lot of weight. Would it be possible within current technology to increase power sufficiently to counteract this difficulty? Presumably reducing the power on electricity (relative to the class 93) would create additional room for diesel power. Any feedback on the concept would be most welcome, but hopefully it would at least be more popular with the general public than the real-life HST replacements.

[ScottishRailFanatic]

Not exactly a locomotive, but how about a cafeteria MK1 from a WW3 Ambulance train?

[Flying Pig]

2 hours ago, ScottishRailFanatic said:

Not exactly a locomotive, but how about a cafeteria MK1 from a WW3 Ambulance train?

 

How could you possibly know about the Strategic Reserve?  It's classified information.  Anyway, here's an in-service view.

 

[Zomboid]

On 27/04/2021 at 18:50, DK123GWR said:

A random idea which experts will probably tell me is completely impractical, but here is my imaginary HST replacement, instead of the class 80x.

 

For me, the way forward is in the past... Having unpowered multiple units (let's streamline them at both ends) and a nice powerful electric locomotive to power it around on electrified lines, driving onto a diesel locomotive to take it forward where necessary. With the process reversing on the way back.

 

Or ditch the electric loco and just have diesel locos drag EMUs if the non-electrified sections are short or infrequently served enough.

 

Bi-modes save on some shunting and coupling, but at the cost of dragging an unused traction system around at all times.

[DK123GWR]

3 minutes ago, Zomboid said:

For me, the way forward is in the past... Having unpowered multiple units (let's streamline them at both ends) and a nice powerful electric locomotive to power it around on electrified lines, driving onto a diesel locomotive to take it forward where necessary. With the process reversing on the way back.

 

Or ditch the electric loco and just have diesel locos drag EMUs if the non-electrified sections are short or infrequently served enough.

 

Bi-modes save on some shunting and coupling, but at the cost of dragging an unused traction system around at all times.

Sensible, but it might require proper planning rather than the half-baked mess of electrification we have on the GW at the moment. The loco change would have to occur at Swindon (for services via Bath) or Bristol Parkway (for trains to South Wales). This would require the installation of suitable facilities to stable both diesel (68s geared for 125mph?) and electric locos (a suitably geared 88 derivative?), and would probably make non-stop services impossible. At least there would have been a need to install loco stabling and changing facilities at Swindon for Gloucester trains, otherwise the decision not to complete electrification would have meant no new trains running until these could be put in place, although this would presumably be an issue at Parkway where electrification to South Wales and Temple Meads was postponed.

 

On the other hand, perhaps this would have forced them to complete the project as planned.

[Zomboid]

Obviously I'm assuming that electrification links logical places, not stopping a few miles short of where the service stops. The GW is perhaps not the best example in a lot of ways - if it was done to Temple Meads and Oxford as it should be (at a minimum, it should really cover Bedwyn, Basingstoke and the Thames Valley branches too), the Exeter line would still be mostly non-electrified, as would the Worcester and Gloucester services.

 

However the ECML, WCML & GEML (if they still serve Yarmouth) would all work as the services that go beyond the wires are a either short, relatively infrequent or both.

[Ramblin Rich]

Resurrect the 442s, fit with 25kV transformer & pantograph -  somewhere. Then tow them when off wires with new push-pull locos. A modernised version of the REP+33/1 format! Not actually changing locos, just couple / uncouple which should be achieved automatically with Dellner style couplers. Keeps the ride and passenger ambience of the Mk3s with more wide ranging ability.

I might have mentioned this before somewhere in the thread but lost track....!

[Zomboid]

The REP & 33/1 format keeps coming up because it was such a great idea.

 

I don't think any of the current designs of auto couplers include ETH, and I'm not certain about the air connections either. Though I doubt it would be beyond the capability of the rolling stock industry to resolve that.

[rodent279]

Push-pull a la SR 33/1 & REP/TC is a good idea, and one that could have been done in times past with the likes of class 309's on the GEML, to serve short off-wire destinations, such as Harwich, if they could have been modified to work in multi with blue star diesels. 

It was never done, afaik, because you still need two types of motive power, and you're still hauling a complete traction package which isn't being used.

I guess, theoretically, a WCML DVT on either end of a rake of mk3's would be able to control a class 86/7/90/91(?), and class 47/57/67, and would be similar to the proposal above.

 

Edit:-assuming a WCML rake as above could work in multi with class 47/57/67, why was it not used for destinations such as Shrewsbury, Blackpool, Llandudno & Holyhead? I guess it's all down to the economics of the operation. You're not saving on traction knowledge, types of motive power, or the need to couple/uncouple. It clearly was worthwhile in the case of Bournemouth-Weymouth, but maybe there was something about that route that made it worthwhile.

Edited April 29, 2021 by rodent279

[Zomboid]

The 33/1 and TC combination was useful for other purposes, such as the Salisbury service. I think TC sets were also used with 73s, though I don't know where they ran.

 

The WCML mk3s weren't able to run with standard 47s or 67s, and 57s didn't come along until pendolinos arrived. Two DVTs on a train plus a loco would probably have been seen as a bit profligate, but I'm sure they left the 86 at Norwich for the Yarmouth runs, and just ran round at Yarmouth. Quite how the shunt at Norwich would have worked on the way back I don't know - was the loco at the London end?

[Clive Mortimore]

1 hour ago, Zomboid said:

The 33/1 and TC combination was useful for other purposes, such as the Salisbury service. I think TC sets were also used with 73s, though I don't know where they ran.

 

The WCML mk3s weren't able to run with standard 47s or 67s, and 57s didn't come along until pendolinos arrived. Two DVTs on a train plus a loco would probably have been seen as a bit profligate, but I'm sure they left the 86 at Norwich for the Yarmouth runs, and just ran round at Yarmouth. Quite how the shunt at Norwich would have worked on the way back I don't know - was the loco at the London end?

Yes.