Things that seemed a good idea at the time, but in practice are pretty useless.

I meant to write *most* steam locos. Something like, say, a 9F would be a bit hopeless without its rods.


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Upon checking this it seems that 22" pipes (another source refers to 20" pipes) were installed (but never put into use) on the South Devon banks but the level Exeter to Newton section which did run for a while had 15" pipes.

 

I can't find my notes at the moment, but wasn't the idea to not only create a vacuum in front of the piston/engine but to also pump pressure in behind it ? Presumably there would be some loss of pressure in the process but it would still have a noticeable effect on the tractive power.

 

The longitudinal flap would only be able to seal in a vacuum, any pressure would lift it. Presumably the modern experimental system with a magnetic connection between the in tube piston and the carriage could work as you describe.

 

Nobody has mentioned the Crosti-boilered 9Fs yet, or the booster cylinders on the S1 class.


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Actually, the principle has a modern descendant, although one where the problematic mechanical seal is totally absent, 'coupling' between the piston inside the tube and the carriage being accomplished by magnets and onboard electrical systems stated to be supplied by a low voltage supply, fed through the track, although in a video of the Brazilian installation, it looks more like a conduit to my eye.

The company behind fully operational installations in Indonesia and Brazil (at least) is Aeromovel (whose website's images are 'unsupported' by my android .... dammit!). It's worth noting both these applications fall more into the 'people mover' category, rather than full-blooded 'railways'.

 

Thanks. I have to say I would summarise Wardale's comments (p 156-160 in The Red Devil etc) somewhat differently (in respect of a choice between Elesco feedwater heater v exhaust steam injector). He lumps the "open type" Worthington feedwater heater and exhaust steam injectors together, his reason for preferring the Elesco "closed" type to either of the former being the higher temperatures that could be imparted to the feedwater.

 

Advertisement from the 1947 edition of the US-produced 'Locomotive Cyclopaedia'. Whether the wheels end up round, oval, or different diameters is another matter. I think it is called 'The American Way'..............

 

Ultimately I think we are saying the same thing. Providing independent drive to multiple axles in a steam locomotive, or for that matter a Diesel-hydraulic is a pretty useless idea. Apart from that, uncoupled drive wheels are not a bad thing.

 

I'm sure I've read of something similar being used to round off sharp flanges on the N7 class. With the leading coupled axle they got a lot of flange wear and once the flange got too sharp they had a bad habit of splitting points. So a cutting tool in the form of a brake shoe would be fitted for the leading coupled wheels until the flange was smoothed off. I think it was a depot exercise rather than fitted out on the road, though.

 

.... and approaching the desirability of roundness issue from a rather different direction:

http://www.douglas-self.com/MUSEUM/LOCOLOCO/polygon/polygon.htm

(Douglas Self's website is a wonderful repository of weirdness!)

 

The Clayton Class 17?

 

If we are going to include Diesels then the North British built D6100 Diesel electric and D6300 Diesel hydraulics can be included.

 

I’d suggest a difference between principle and execution. Nowt wrong with the principle of those diesels, but a pity that NBL didn’t adjust to the Diesel world.

My nomination for this thread would be the Fell locomotive, trying to apply mechanical drive when it was clear that something more sophisticated would be required.


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The point of the Fell engine was sound: mechanical transmission has a very high efficiency, much higher than hydraulic or electrical. It was worth the experiment, if only to find the problems.

 

The really is one of the problems in engineering. On paper something might show great promise, but in reality it doesn't quite work out. The gas-turbine locos 18000 and 18100 could be an example of this with high fuel consumption at medium power outputs.

 

In my defence, I did say "the majority".

IIRC, those last pair found gainful employment on a very specific service, for which they were eminently suited .... actually outlasting several of the next generation of Sentinels (of which the LMS only ever had a couple).

A few 'engine units' found their way into industrial use (one ex-Jersey Eastern Rly Sentinel comes to mind, as it survived in for many years), so whilst most can't have been a great return on the original investment, others weren't a complete waste of money.

Problems seem to have revolved around a few of major drawbacks. On routes where their use actually increased patronage, many were unable to haul a trailer to cope with the extra demand. As economical as they undoubtedly were, in terms of fuel and water, the first gen units each still required a full crew and IIRC, automated systems on the later striking Southern example caused a few issues with the unions. Neither engine nor carriage sheds are really ideal place to store railmotors. Even lines as impecunious as the Isle of Wight Central were faced with providing separate accommodation, which can't have been cost effective when considering neither of their two examples (one purpose built, one a rather Heath-Robinson conversion) lasted a decade in service.

Part of me would love to see IWC Railmotor No.1 recreated ..... just not the sensible part. The carriage portion, heavily rebuilt in Southern days, lasted until just after WWII, was a sad loss. With it's unequal bogies (one 7ft and one 8ft wheelbase), it would've made for a unique experience!

 

The only other gas turbines I can think of apart from the WR ones and GT3 were some on the Union Pacific in the USA. Did they work any better?

 

Certainly not british and not steam traction, may I suggest this one? https://de.wikipedia.org/wiki/Schienenzeppelin

Knut

 

APT-E as well.


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