Imaginary Locomotives

[rodent279]

49 minutes ago, MikeOxon said:

The earlier discussion regarding re-boilered 'Kings' set me thinking about the unloved 'Bear'. 

 

Churchward is reported to have been a good friend of A.W.Gibbs of the Pennsylvania Railroad (PRR), which influenced the design (and appearance) of the No.100 prototype.  Some think Churchward was led a little astray by French influence, which led him into the complexities of 4 cylinder engines, whereas the American designers managed to do all that was necessary with 2 cylinders.

 

So, what if Churchward had been succeeded by a similarly American-influenced CME? 

 

The PRR had moved on to Pacifics by the First World War and their K4 class could have provided a model for Churchward's successor.  He could have taken the unloved 'Bear' and updated it along American lines, with two cylinders (less weight and complexity) and a longer firebox with combustion chamber, together with a correspondingly shorter boiler barrel.  Someone has claimed that the over-long boiler of the original 'Bear' was acting as a condenser by the time the gases reached the smokebox end!  A higher degree of superheat would be another improvement.  Other alterations would be easily-accessible outside Walschaerts gear, outside bearings on the trailing axle, and a decent-sized cab.

 

I'm afraid this is just another rough-and-ready Photoshop job but I've tried to show what might have  emerged in the 1920s below:

 

 

'Evening Star' had 20" diameter inclined cylinders so, perhaps 21" might have been possible on the more generous GWR loading gauge.  With 6' 3" drivers (lighter wheels) and a boiler pressed to 250 psi, tractive effort should not be very far short of the 40,000lb of the King and with some of the weight carried by the trailing axle.

 

The PRR K4s received 'streamlining' in the 1930s so perhaps this engine could have competed with Duchesses and A4's in this 'modernist' trend.

 

Mike

Looks a little bit more like a cross between a Horwich Crab or Hughes 4-6-0, but possible. The Americans though had the advantage of a huge loading gauge, and cheap, plentifully available fuel, which France didn't, & I suspect that influenced the decision to build 4 cylinder compounds.

[MikeOxon]

I hadn't thought of the Crab, which I believe had 21" cylinders so perhaps my 'Bear' could be made even closer to a 'King' in terms of TE.- 22" cylinders?

[33C]

On 22/08/2021 at 20:23, scots region said:

 

 

Social media has taken to calling it 'Mocktannia' 

 

 

Does look like what would happen if a Frenchman designed a BR Standard. 

Is that a corridor tender? 

[JimC]

59 minutes ago, MikeOxon said:

I hadn't thought of the Crab, which I believe had 21" cylinders so perhaps my 'Bear' could be made even closer to a 'King' in terms of TE.- 22" cylinders?

The GWR gauge wasn't as big as some folk imagine. It was 9ft wide from 1'10 to 4'3 above rail height, and only went wider above that on a limited number of lines, tending to be mainly ex broad gauge ones.

 

[Later]
 

Just to add some more numbers in the mix, a Churchward standard front end was 6'10 between cylinder centres, and 18in cylinders were a tad over a foot in radius, so they were 8'11" overall width. 

 

I've just sketched this out a bit using a Saint drawing. Obviously this is best case with the large driving wheels. The red rectangle shows the area restricted to 9ft wide. The standard cylinder position is in orange, and in green I've attempted to rotate the cylinders round the driving wheel so they clear the red area. An interesting complication is that the cylinders - or at least the valves - are impinging on the smokebox. The valves would need to be level with the outside of the cylinders. Outside valve gear would probably be easier, but I imagine inside gear could be in the normal position, with the rockers arranged quite differently.

Edited August 24, 2021 by JimC

[scots region]

41 minutes ago, 33C said:

Is that a corridor tender? 

 

No, it looks like an access hatch. Ya'know, I'm a little befuddled by it, the Mission impossible films are set in the present day, so why mock up a fake old steam engine.  

[PhilJ W]

2 minutes ago, scots region said:

 

No, it looks like an access hatch. Ya'know, I'm a little befuddled by it, the Mission impossible films are set in the present day, so why mock up a fake old steam engine.  

Strategic reserve?

[33C]

1 hour ago, scots region said:

 

No, it looks like an access hatch. Ya'know, I'm a little befuddled by it, the Mission impossible films are set in the present day, so why mock up a fake old steam engine.  

What's with that porthole window? (ah la A3/4 tender)

[rodent279]

10 hours ago, JimC said:

The GWR gauge wasn't as big as some folk imagine. It was 9ft wide from 1'10 to 4'3 above rail height, and only went wider above that on a limited number of lines, tending to be mainly ex broad gauge ones.

 

[Later]
 

Just to add some more numbers in the mix, a Churchward standard front end was 6'10 between cylinder centres, and 18in cylinders were a tad over a foot in radius, so they were 8'11" overall width. 

 

I've just sketched this out a bit using a Saint drawing. Obviously this is best case with the large driving wheels. The red rectangle shows the area restricted to 9ft wide. The standard cylinder position is in orange, and in green I've attempted to rotate the cylinders round the driving wheel so they clear the red area. An interesting complication is that the cylinders - or at least the valves - are impinging on the smokebox. The valves would need to be level with the outside of the cylinders. Outside valve gear would probably be easier, but I imagine inside gear could be in the normal position, with the rockers arranged quite differently.

I assume the 1'10"-4'3"/9' wide restriction was largely down to platforms?

What/when was the UK standard platform height/distance from track laid down? Must have been way back in the early days, around 1850-ish?

[Compound2632]

1 minute ago, rodent279 said:

What/when was the UK standard platform height/distance from track laid down? Must have been way back in the early days, around 1850-ish?

 

Good grief no. Platforms rose very gradually throughout the 19th century from a few inches above rail level to around 2'6" to 3'0" above rail level - heights increasing for new works of course, with very patchy raising of old work. 

[MikeOxon]

14 hours ago, JimC said:

An interesting complication is that the cylinders - or at least the valves - are impinging on the smokebox. The valves would need to be level with the outside of the cylinders. Outside valve gear would probably be easier, but I imagine inside gear could be in the normal position, with the rockers arranged quite differently.

 

Could the valves be placed below the cylinders, Stroudley fashion?  No idea how the plumbing might work or if it's at all feasible - just a thought.

[JimC]

2 hours ago, MikeOxon said:

Could the valves be placed below the cylinders, 

Well I'm not a locomotive designer, but it looks possible. 

[The Johnster]

8 hours ago, Compound2632 said:

 

Good grief no. Platforms rose very gradually throughout the 19th century from a few inches above rail level to around 2'6" to 3'0" above rail level - heights increasing for new works of course, with very patchy raising of old work. 

Loading gauge and clearance issues are part of what became the remit of the Railway Clearing House, which was responsible for establishing standards in order for stock to be able to run on other companies' railway to facilitate through freight and passenger working as the network developed.  Platform height is a pretty moveable feast in practice, often being affected when track is re-ballasted or renewed, or given cant on a curve to increase the speed of passing trains.  But the basic principles and dimensions were effectually established by Stephenson on the Livepool and Manchester; height above railhead, proximity, width, and ramps. 

 

The L & M, like many of the earlier railway, let's say pre-1850, was concerned with dissuading passengers from getting off trains in motion and built their vehicles too high off the ground to allow this.  Railways were fenced in, not to prevent cattle wandering and trespass on the railway, but to prevent the great unwashed from getting off trains and invading land owned by the gentry, who were terrified of them (and for good reason in the 1830s, the times of the Chartists and clamour for electoral reform).  The obvious way to restrict the boarding and alighting of people from passenger trains was to have platforms that they had to access through gates, doors, and booking offices to get to the trains, which is so obvious now that we don't even think of it, but we have Stephenson's practicality and foresightedness to thank for it. 

 

It was related to the height of goods vehicles, in turn influenced by horse drawn agricultural carts, drays, pantechnicons and so on.  The horse shafts determine an effectivly standard height for the axle, which determines the height of the load bed floor, and early railway vehicles followed this pattern.  If horses were bigger, perhaps platforms would be higher, and if goods were pulled around everyhwere by Shetland ponies, they would be lower, as would modern panel vans and articulated lorries, but the basic dimensions have been around for many thousands of years and are global. 

 

Following standard gauge railways followed suit, and even the GW broad gauge and it's subsidiaries were very much influenced by it through Daniel Gooch, who more or less designed the actual nuts and bolts of the broad gauge network and was himself originally a Stephenson's employee sent down with North Star to supervise it's assembly into what was at that time the only GW loco that worked reliably!  It had been build for an export order that fell through and the GW was lucky to get it, but it was very much a Stephenson product, a follow on from Patentee, and built to Stephensonian clearances, which were generally adopted on the GW despite the difference in track gauge. 

 

Thus the Stephensonian principles established by 1830 on the L & M were passed to the entire UK standard gauge and broad gauge network, which meant that when the broad gauge was lifted there was no issue from loading gauge or clearances and the GW simply carried on with the standard gauge, though it never accepted that Brunel's gauge was not the superior.  Apart from suitability to the overall size of the stock, there is no superior gauge of course, the only important feature is that the track gauge, loading gauge, axle load limit, buffing and coupling equipment, type of brakes, type of heating, wheel profile, rail profile, and general rules and signalling methods, be to a standard across a network which may well stretch beyond that owned by your company.  If this doesn't happen, you get the mess Austrailia was in for many years.

 

Stephenson's methods suit us in the UK and in Europe, but are not the only way of doing things; the Americans accessed their trains from ground level or very low platforms via steps at end vestibules.  This meant that their passenger stock rapidly evolved into long (by our standards) bogie carriages with open vestibules at the ends and open saloons with a central aisle inside, even on commuter services.  This pattern is the universal norm nowadays albeit with enclosed vestibules accessed at platform level.  The steps meant that each end of each coach had to have an attendant to assist passengers into and out of them, a major factor in the high costs of passenger operation in the States in the post war era and thier failure to compete with internal air services at one end of the market and long distance bus networks at the other, both still thriving over there. 

 

These attendant/conductors were usually black, and became drivers of huge social change during the inter-war years in spreading word of better pay and conditions in the industrial north and northeast to their contacts in 'The South', which engendered a huge migration and lead to the very large African-American populations in the cities of the North, and serious social problems when unemployent hit in the 70s and 80s as foriegn car imports and ending of Vietnam War contracts led to jobs becoming scarce; the innate racism of the situation ensuring that we could, and did, accurately predict which section of the community would be affected most...  It also had an immesurable influence on modern American music, which is to say, by extension, all modern music.

 

One might comment that Stephenson's ideas in 1830 and their adoption in some parts of the world or rejection in others has had a massive, I mean really massive, effect on the societies of those respective parts of the world; we just don't think about it in that way!  Of course, very many other factors are in play, but I don't think I'm overstating the importance of railway platforms...

 

Note that urban commuter networks everywhere worldwide all use platforms and sliding door open saloon stock.  Slam door compartments with thier genetic roots in stage coaches and the 3-compartment firsts of the L & M lasted a long time on these services in the UK, still being built up to about 1960, due to their ability to absorb and eject large numbers of people very quickly, but this only works when the platform is open to the passengers before the train arrives in it, not the practice for departing services at most big city termini.

Edited August 25, 2021 by The Johnster

[JimC]

I did this reboilered Bear a while back, I've now added Mike's inclined cylinders with valves below. The rocker to the motion looks like a complication.
As for the steam passages, who knows... 

[JimC]

One thing to add to platform heights etc is that the horizontal rail to platform clearance seems to have been much more standardised early. Even on the broad gauge platform to rail was much the same - as it had to be for mixed gauge with a common inside rail to work.

[MikeOxon]

46 minutes ago, JimC said:

One thing to add to platform heights etc is that the horizontal rail to platform clearance seems to have been much more standardised early. Even on the broad gauge platform to rail was much the same - as it had to be for mixed gauge with a common inside rail to work.

I was about to add a diagram comparing Broad Gauge and Standard Gage dimensions, when I realised it came from @JimC's own website https://www.devboats.co.uk/gwdrawings/loadinggauges.php 

 

 

I hope he doesn't mind me showing it here, since it makes the point about platform clearances very well.  It must also be pointed out, however, that because the track gauge was much wider, the overall width of a Broad Gauge vehicle could also be much greater. 

 

Indeed, a large American locomotive like the Pennsylvania K-4 that I mentioned earlier in this thread fits within the height and width limits! 

 

Imagine travelling down to Cornwall behind something like this running on the Broad Gauge  :

 

[John Besley]

20 hours ago, scots region said:

 

No, it looks like an access hatch. Ya'know, I'm a little befuddled by it, the Mission impossible films are set in the present day, so why mock up a fake old steam engine.  

Exactly, I still dont get it...I expect all will become clear one day.

 

Anyway better still was the I think class 20 used on a 007 film that was made to look like it came from Russia and was filmed on the Nene Valley.... 

[PhilJ W]

Certainly better than the Avalanche Express where a (German?) 0-6-0 shunter was used with the villain and his henchmen occupying the engine compartment, (No sign of any power plant.)

[PhilJ W]

Here it is https://en.wikipedia.org/wiki/Avalanche_Express

[rodent279]

2 hours ago, MikeOxon said:

I was about to add a diagram comparing Broad Gauge and Standard Gage dimensions, when I realised it came from @JimC's own website https://www.devboats.co.uk/gwdrawings/loadinggauges.php 

 

 

I hope he doesn't mind me showing it here, since it makes the point about platform clearances very well.  It must also be pointed out, however, that because the track gauge was much wider, the overall width of a Broad Gauge vehicle could also be much greater. 

 

Indeed, a large American locomotive like the Pennsylvania K-4 that I mentioned earlier in this thread fits within the height and width limits! 

 

Imagine travelling down to Cornwall behind something like this running on the Broad Gauge  :

 

I reckon a broad gauge Pacific boiler, making full use of the loading gauge, would be fat enough, and have a wide enough box, to require mechanical stoking.

Edited August 25, 2021 by rodent279

[Compound2632]

5 minutes ago, rodent279 said:

I reckon a broad gauge Pacific boiler, making full use of the loading gauge, would be fat enough, and have a wide enough box, to require mechanical stoking.

 

That would surely imply that it was an engine too powerful for the work required of it, since pretty much all the work on the Great Western could be done by engines whose fuel consumption was within one's man's skilled shovelling capacity?

[rodent279]

25 minutes ago, Compound2632 said:

 

That would surely imply that it was an engine too powerful for the work required of it, since pretty much all the work on the Great Western could be done by engines whose fuel consumption was within one's man's skilled shovelling capacity?

Probably. I guess had the BG continued, nothing bigger than a 4-6-0 would still have sufficed. 

[JimC]

The bigger loading gauge changes everything. Consider, for example, that the same length train (for loops etc) would carry about 45% more coal. I did try imagining a 20thC broad gauge locomotive, but it rapidly became obvious that everything changes. Why, for instance, would you even consider a wide firebox when there was 6 feet available for a narrow one. Also with the amount of room for large low pressure cylinders between the frames a 4 cylinder compound might be made to work properly... 

[John Besley]

49 minutes ago, PhilJ W said:

Certainly better than the Avalanche Express where a (German?) 0-6-0 shunter was used with the villain and his henchmen occupying the engine compartment, (No sign of any power plant.)

How about the Sherlock Holmes film 7% Solution filmed on the SVR in the 70's used a couple of Ivatt 2-6'p, black 5 and 8F all made up to look like Eastern European including coaches to match, high light was a rooftop chase and sword fight

[PenrithBeacon]

37 minutes ago, rodent279 said:

Probably. I guess had the BG continued, nothing bigger than a 4-6-0 would still have sufficed. 

Yer reckon? 

https://en.wikipedia.org/wiki/Indian_locomotive_class_WP

Not Brunel's BG but ...

Edited August 25, 2021 by PenrithBeacon

[Compound2632]

12 minutes ago, PenrithBeacon said:

Yer reckon? 

https://en.wikipedia.org/wiki/Indian_locomotive_class_WP

Not Brunel's BG but ...

 

Ah, but as the article states, that was built to burn low grade coal - i.e. less energy released per ton burnt than the high-grade Welsh coal the Great Western used. So a big grate helps.