Imaginary Locomotives

[DavidB-AU]

A Dean bodge.

 

 

Cheers

David

[DavidB-AU]

I believe that under Napoleon III a blanket speed limit of 120 km/h (75 mph) was introduced which remained in force for upwards of a century

Which indirectly gives me an idea. Push-pull operation in the UK was mainly limited to branch lines, but why not on main lines? Particularly on suburban services where a fast turnaround is required. I'm thinking particularly of Liverpool Street which had the most intensive steam service in the world.

 

Now consider what Chemins de Fer de l'État did from 1933 with 2-8-2Ts and sets of Voiture État à 2 étages. While double deck would be out of the question, surely something was technically possible to match the capacity of a pair of Quadarts and be suitable for push-pull operation.

 

Cheers

David

[Corbs]

I remember a documentary about suburban services, apparently the turnaround time for steam at Liverpool Street was 3 minutes!

[Zomboid]

Which indirectly gives me an idea. Push-pull operation in the UK was mainly limited to branch lines, but why not on main lines? Particularly on suburban services where a fast turnaround is required. I'm thinking particularly of Liverpool Street which had the most intensive steam service in the world.

 

Now consider what Chemins de Fer de l'État did from 1933 with 2-8-2Ts and sets of Voiture État à 2 étages. While double deck would be out of the question, surely something was technically possible to match the capacity of a pair of Quadarts and be suitable for push-pull operation.

 

Cheers

David

Maybe control response would be a problem on trains longer than a couple of carriages?

[cctransuk]

Which indirectly gives me an idea. Push-pull operation in the UK was mainly limited to branch lines, but why not on main lines? Particularly on suburban services where a fast turnaround is required. I'm thinking particularly of Liverpool Street which had the most intensive steam service in the world.

 

Now consider what Chemins de Fer de l'État did from 1933 with 2-8-2Ts and sets of Voiture État à 2 étages. While double deck would be out of the question, surely something was technically possible to match the capacity of a pair of Quadarts and be suitable for push-pull operation.

 

Cheers

David

 

Probably because UK coaching stock in those days was not stable enough, nor crash-resitant enough, to be safe when propelled at speed.

 

Only modern construction techniques have permitted high speed P-P operation and, even then, there was initially much sceptisism - I can remember the Glasgow - Edinburgh trials.

 

Regards,

John Isherwood.

Edited January 5, 2018 by cctransuk

[Corbs]

Would that count against suburban services where it is not sustained speed, but periods of fast acceleration and braking?

[Compound2632]

I remember a documentary about suburban services, apparently the turnaround time for steam at Liverpool Street was 3 minutes!

 

Better than Paris Bastille which seems to have been 10 minutes, based on a similar principle of the engine that brought the previous departure in taking the next departure out, in rotation round six platforms.

[Regularity]

Which indirectly gives me an idea. Push-pull operation in the UK was mainly limited to branch lines, but why not on main lines? Particularly on suburban services where a fast turnaround is required. I'm thinking particularly of Liverpool Street which had the most intensive steam service in the world.Now consider what Chemins de Fer de l'État did from 1933 with 2-8-2Ts and sets of Voiture État à 2 étages. While double deck would be out of the question, surely something was technically possible to match the capacity of a pair of Quadarts and be suitable for push-pull operation.CheersDavid

Just have a stud of Holden decapods with push-pull gear.

[cctransuk]

Would that count against suburban services where it is not sustained speed, but periods of fast acceleration and braking?

 

I would imagine "periods of fast acceleration and braking" would affect the stability of the stock - but the bottom line was that such stock reduced itself to matchwood in the event of a collision involving compression.

 

If you doubt this, look at a few photos of pre-war railway accidents.

 

Regards,

John Isherwood.

[Compound2632]

The Liverpool Street operation was a finely-balanced act that came a bit unstuck when four-wheelers were replaced by (rebuilt as) bogie carriages - the shorter coaches had more sets of buffer springs in compression for rapid acceleration: hence "Buckjumpers"; more powerful engines became necessary despite the number of seats being unchanged. The decapod was built to demonstrate that steam could match the acceleration proposed with electrification; it wasn't a success and eventually electrification came - after all the best way forward for an intense suburban service.

[Regularity]

The decapod’s problem was its weight: major bridge strengthening work would have been required. Having proved a point, it became a solution looking for a problem, whilst creating other problems.

[The Johnster]

The fastest possible turnaround is with multiple unit or locomotive (any type) powered push pull stock with switchable head and tail lamps.  If a driver is in each cab at each end of the train, the incoming simply switches out and the outgoing one switches in; less than 10 seconds should be possible, but whether this is desirable is another matter, and AFAIK no railway anywhere has considered the additional labour cost of 2 drivers, one of whom is idle half the time and the other the other, if you see what I mean, to be worth the time saved 

A Dean bodge.

GWR2600T.jpg

Cheers
David

 

Reality was weirder.  Can't find a photo, but may I present for your elucidation and delectation (drum roll), the Rhymney Railway K class as rebuilr post-grouping by the GW.  An outside framed and typically Victorian 0-6-2ST, fitted with a Belpaire standard Swindon parallel boiler, and hence needing (another drum roll) pannier tanks!!! 

 

Nice looking loco in both forms, though the latter might raise eyebrows at a show.  All gone pre-WW2 AFAIK, as one in plain black with BRITISH RAILWAYS lettering would have been, to my mind, a thing of great beauty!

 

As an RR loco, it was the mineral version of a very pretty outside framed 2-4-2ST which must have looked gorgeous in RR full passenger livery, based on MS&L/GC.

...

 

Some steam operated services had very fast turnarounds, and the ultimate limitation is how quickly the guard can walk from his van to the tail end, pick up the lamp, put it on the new tail vehicle, and walk back to his van if 'auto' work is involved.  Of course, the punters have to get off and new ones on as well...  I am familiar with the WTT for the long vanished Clarence Road branch in Cardiff's docklands; a very intensive commuter service for what was at one time the business heart of the city.  Autos were allowed 2 minutes turnaround and loco hauled stock, 4/5 coaches of it, 7; this had to include the run around move, lamps, and brake continuity test when the loco was re-coupled.  At some very busy periods, loco hauled stock was taken out by a fresh loco, which of course had to perform the brake test; this was allowed 3 minutes.

Edited January 5, 2018 by The Johnster

[Zomboid]

The fastest possible turnaround is with multiple unit or locomotive (any type) powered push pull stock with switchable head and tail lamps. If a driver is in each cab at each end of the train, the incoming simply switches out and the outgoing one switches in; less than 10 seconds should be possible, but whether this is desirable is another matter, and AFAIK no railway anywhere has considered the additional labour cost of 2 drivers, one of whom is idle half the time and the other the other, if you see what I mean, to be worth the time saved

Rush hour at Bank on the Waterloo and City is pretty much like that.

Dwell times aren't 10 seconds, though.

[rockershovel]

The decapod’s problem was its weight: major bridge strengthening work would have been required. Having proved a point, it became a solution looking for a problem, whilst creating other problems.

Speaking of imaginary locos, I’ve just seen a picture of the Decapod “rebuilt” as an 0-8-0. There are obvious new frames, a new boiler, new steam pipes unlike anything anywhere else: a tender, in fact it’s hard to see any part of the original loco in the “rebuild”

[Compound2632]

I remember a documentary about suburban services, apparently the turnaround time for steam at Liverpool Street was 3 minutes!

 

... and quite apart from the locomotive, brake test, and staff issues, I imagine this was only possible because there was a door to every compartment - one egress per ten (twelve?) passengers, rather than one to a hundred with modern stock. (Perhaps an exaggeration but that's how it feels!)

[BernardTPM]

... and quite apart from the locomotive, brake test, and staff issues, I imagine this was only possible because there was a door to every compartment - one egress per ten (twelve?) passengers, rather than one to a hundred with modern stock. (Perhaps an exaggeration but that's how it feels!)

and almost everyone was off before the train stopped.

[Northmoor]

I imagine this was only possible because there was a door to every compartment - one egress per ten (twelve?) passengers, rather than one to a hundred with modern stock. (Perhaps an exaggeration but that's how it feels!)

I wrote some time previously about the downsides of the 4-DD units, that the advantages of a door to every compartment being nullified by people having to climb over those in the seats to access the stairs.  But yes, a 12-car VEP arriving at Waterloo could empty in about 15 seconds.  I reckon it takes more like a minute from a 12-car 450 most mornings. However, as a 450 is warm and quiet there's a lot of people not very awake (often me included).

[The Johnster]

and almost everyone was off before the train stopped.

 

This was not actually a selling point, especially for the railway staff who had to shut about 120 doors that the entitled ba^%ards left open.,,

[rockershovel]

This was not actually a selling point, especially for the railway staff who had to shut about 120 doors that the entitled ba^%ards left open.,,

I wouldn’t say “entitled”, more a case that given the crowding levels on peak time suburban services, no one ever thinks that THEY are the last ones to board

[Dr Gerbil-Fritters]

Two interesting beasts from an interesting slideshow on the web.

 

The 8AT looks rather less hideous than the more well known 5AT

 

This is even more outlandish than the concept developed for American Coal Enterprises 

 

The ACE3000, taken from here

 

 

[sir douglas]

crikey.JPG

This is even more outlandish than the concept developed for American Coal Enterprises 

 

cab forward garrat?

[Corbs]

I prefer the 8AT to the 5AT. Although, it does just look like a kriegslok

[Dr Gerbil-Fritters]

cab forward garrat?

 

cabs at both ends...

[Zomboid]

Some kind of Garratt-leader hybrid monster which crosses a line man was never meant to cross.

[rockershovel]

I think that Super-Garratt is rather dramatic! Oil-fired? Any details anywhere?