Imaginary Locomotives

[PhilJ W]

Still waiting for the technology. 25,000 volts and sea water is not a good combination. Hybrid locomotives seem to be the answer with either battery or diesel built in.  

[Zomboid]

There would be no issues which would make it impossible to electrify Dawlish. You might need to use bigger or specially designed insulators, but sea walls with wires are nothing new. In the UK there's the section at Saltcoats on the Ardrossan branch in Ayrshire, and several sections of the Helensburgh line too. The weather in Scotland might be a bit different to Devon though.

[rodent279]

10 minutes ago, Zomboid said:

There would be no issues which would make it impossible to electrify Dawlish. You might need to use bigger or specially designed insulators, but sea walls with wires are nothing new. In the UK there's the section at Saltcoats on the Ardrossan branch in Ayrshire, and several sections of the Helensburgh line too. The weather in Scotland might be a bit different to Devon though.

Are there any 25kV stretches that regularly get the sort of inundation that Dawlish gets? I wonder if a solid conductor, as used in tunnels, might be more appropriate, maybe with some sort of shrouding to shelter it from the worst of the waves?

Could some sort of sluice/barrier be built, that can be raised in bad weather to keep waves from directly washing onto the railway?

Maybe, heaven forbid it, we should just nail the issue once and for all, and wall or otherwise enclose the railway in properly?

[Zomboid]

A solid conductor might be appropriate for the mechanical forces of the waves. But that kind of thing can be included in the specification. Electrically it's just a matter of providing insulators to whatever level is appropriate. You could use 100kV insulation if necessary.

 

Don't know how the weather at Dawlish compares to other places, but there's sea walls with electric railways in other countries too.

Edited April 23, 2021 by Zomboid

[Miss Prism]

At the time the GWR electrification was first proposed, 1500V d.c. overhead was envisaged. High-voltage a.c. technology wasn't developed by then.

 

[Compound2632]

59 minutes ago, Zomboid said:

The weather in Scotland might be a bit different to Devon though.

 

Not as wet and miserable as the South Devon coast, you mean?

[Suzie]

Working AC has been around since a long time ago (LBSC 25Hz in 1909 for example), I am sure that I read that 25Hz AC was in the frame for the Great Western electrification - long before the 1500V DC stipulation was made.

 

When using AC the branches are not expensive to do if they can be fed from a substation on the main line (like the Braintree branch) where all you need to supply is some poles and wire.

[Zomboid]

12 minutes ago, Compound2632 said:

 

Not as wet and miserable as the South Devon coast, you mean?

Ayrshire has plenty of holiday camps, so I imagine the climate is just like the English riviera.

 

In fact, the only thing between the beach and the Sandylands holiday park at Saltcoats is the electrified line to Ardrossan and Largs...

[rodent279]

27 minutes ago, Compound2632 said:

 

Not as wet and miserable as the South Devon coast, you mean?

What's the Cornish for "dreich"?

[AlfaZagato]

1 hour ago, rodent279 said:

But is stopping every train to change engines at Taunton/Exeter, and again at Plymouth, a desirable outcome?

Really you want a change of engines made at either Exeter or Taunton, and the replacement (electric) loco working through to destination. That would make more sense than a change from steam to electric at Taunton, then back to steam at Plymouth.

The Milwaukee Road in the US did almost exactly that for just short of 60 years, until the equipment wore out.   First the Harlowton-to-Avery section, then the Othello-to-Tacoma section - a total of 645 miles, with a gap between the two amounting to 216 miles.   Steam would change at either end of either section, and electrics took trains through the mountains.

 

Timing was concurrent, as well.   The wires were up in 1916.

[rodent279]

1 minute ago, AlfaZagato said:

The Milwaukee Road in the US did almost exactly that for just short of 60 years, until the equipment wore out.   First the Harlowton-to-Avery section, then the Othello-to-Tacoma section - a total of 645 miles, with a gap between the two amounting to 216 miles.   Steam would change at either end of either section, and electrics took trains through the mountains.

 

Timing was concurrent, as well.   The wires were up in 1916.

Fair point, but 216 miles is virtually the entire London-Plymouth main line. We're talking about Taunton-Plymouth, under 90 miles.

[PhilJ W]

There are many factors to be taken into account on coastal lines, exposure and sea bed conditions for example. The LT&S line at Leigh-on-Sea runs closer to sea level than Dawlish but equally as close to the sea. However it is more sheltered and the seas around it are shallow and go out a long way at low tide and large waves such as those at Dawlish are unknown.

[Compound2632]

23 minutes ago, Zomboid said:

Ayrshire has plenty of holiday camps, so I imagine the climate is just like the English riviera.

 

Well, the other variable is the hardiness of the holidaymakers.

[Clive Mortimore]

3 hours ago, JimC said:

Trouble is you start looking at 3 sets of infrastructure, steam, diesel and electric, 3 sets of staff etc etc and the operational complications as well. 

Yes but no but yes but no but on our imaginary railways we have enough dosh that our staff are well paid and we have enough with all the skills that are needed.

 

Surely part of the fun of imaginary model railways is having more locos than are needed so to give them all a run we change them more than is necessary.

[2251]

11 hours ago, Miss Prism said:

At the time the GWR electrification was first proposed, 1500V d.c. overhead was envisaged. High-voltage a.c. technology wasn't developed by then.

 

1500V DC was the BoT standard at that time for overhead but the report was based on 3000V DC.

 

As for the point made earlier about coal deliveries, the GWR was not intending to generate its own power. The costings were based on electricity "delivered to the substations". By the time this was under consideration, the National Grid had been built and (I think) the sub-grids paralleled, at least occasionally.

 

The report itself was by Merz & McLellan, then a pre-eminent firm of consulting electrical engineers.

 

The board seems genuinely to have been keen on the idea and Lord Horne, the Chairman, referred to it at some length at the February 1938 AGM.

[Compound2632]

7 hours ago, 2251 said:

1500V DC was the BoT standard at that time for overhead but the report was based on 3000V DC.

 

As for the point made earlier about coal deliveries, the GWR was not intending to generate its own power. The costings were based on electricity "delivered to the substations". By the time this was under consideration, the National Grid had been built and (I think) the sub-grids paralleled, at least occasionally.

 

The report itself was by Merz & McLellan, then a pre-eminent firm of consulting electrical engineers.

 

The board seems genuinely to have been keen on the idea and Lord Horne, the Chairman, referred to it at some length at the February 1938 AGM.

 

Aha, I hadn't appreciated that this proposal was so late in the day. The schemes I mentioned dated from c. 1910-14 and were killed off chiefly by the Great War. 

 

I'm surprised, though, that there was such a thing as a "BoT standard"?

[2251]

56 minutes ago, Compound2632 said:

 

Aha, I hadn't appreciated that this proposal was so late in the day. The schemes I mentioned dated from c. 1910-14 and were killed off chiefly by the Great War. 

 

I'm surprised, though, that there was such a thing as a "BoT standard"?

By that date, very much so.

 

The Pringle Committee had reported in 1927 recommending electrification at 750V DC (third rail) and 1500V DC, with up to 3000V in special circumstances where permitted (overhead).

 

The report is here:

 

https://www.railwaysarchive.co.uk/documents/MoT_Pringle1927.pdf

 

The key bits are these (page 6 of the report):

 

 

 

Those recommendations were then embodied in the Railways (Standardisation of Electrification) Order 1932.

 

 

Edited April 24, 2021 by 2251

[2251]

To be clear, the last quote above is not from the1932 Order, but is a mistake on my part (it is the extract from the report a second time) and I cannot manage to delete it.  

[John Besley]

22 hours ago, Compound2632 said:

 

Not as wet and miserable as the South Devon coast, you mean?

Baint' wet and mizzable yer this week, sun bin splitting the paving slabs

[cctransuk]

4 minutes ago, John Besley said:

Baint' wet and mizzable yer this week, sun bin splitting the paving slabs

 

.... an' wind's bin blowin' 'em 'round like confetti !

[john new]

On 23/04/2021 at 20:22, rodent279 said:

But is stopping every train to change engines at Taunton/Exeter, and again at Plymouth, a desirable outcome?

Really you want a change of engines made at either Exeter or Taunton, and the replacement (electric) loco working through to destination. That would make more sense than a change from steam to electric at Taunton, then back to steam at Plymouth.

Whilst that makes sense didn’t many trains stop and dither about with adding pilot locomotives over the Devon banks anyway. Not a great knowledge of the ex-GWR but IIRC also complicated by always adding the pilot locomotive inside between the train engine and the train.

 

if you are stopping anyway to do things with the traction one off/one on and away would be as quick or quicker even if the traction type was dissimilar.

 

Given new express passenger locos were built roughly in a timeline parallel to the electrification proposal (Castles and Counties) did the report cover the cost of not building as many of them as electrics would be doing the job.

[rue_d_etropal]

Quote

if you are stopping anyway to do things with the traction one off/one on and away would be as quick or quicker even if the traction type was dissimilar.

 

The Metropolitan switched steam and electric locos at Rickmansworth, and it took no longer than normal station stop.

[PhilJ W]

9 minutes ago, rue_d_etropal said:

The Metropolitan switched steam and electric locos at Rickmansworth, and it took no longer than normal station stop.

And with screw couplings and vacuum pipes to disconnect/connect and close to live third and fourth rail.

[2251]

Here is some more information about the locomotives proposed, from Chacksfield's biography of Collett. There were to be four varieties (the way the information is set out is rather less than clear: why people cannot use tables for this kind of data I do not know):

 

Class I -- 2550 hp, 1-Co-Co-1 (8 off)

Class II -- 2100 hp , apparently 1-Co-Co-1 (40 off)

Class IIa -- 1400 hp, apparently 1-Co-Co-1 (55 off)

Class III -- Bo-Bo (no hp figure given) (61 off)

 

Classes I, II, and IIa were for "main line work" and the class III for "local trains, banking and shunting."

[John Besley]

8 hours ago, 2251 said:

Here is some more information about the locomotives proposed, from Chacksfield's biography of Collett. There were to be four varieties (the way the information is set out is rather less than clear: why people cannot use tables for this kind of data I do not know):

 

Class I -- 2550 hp, 1-Co-Co-1 (8 off)

Class II -- 2100 hp , apparently 1-Co-Co-1 (40 off)

Class IIa -- 1400 hp, apparently 1-Co-Co-1 (55 off)

Class III -- Bo-Bo (no hp figure given) (61 off)

 

Classes I, II, and IIa were for "main line work" and the class III for "local trains, banking and shunting."

Did any preliminary sketches appear?