Bulleid 'Leader'

The generator would presumably be the same size as the one needed on a diesel electric locomotive with the same motors. The question is how would you use the steam to turn the generator.

 

I would imagine a vane fitted to a take off on the main steam pipe, governed by the regulator to restrict the steam flow, it could take the form of a ducted fan, with top and bottom blowers, that spin the generator, any other possible ideas?

 

You're wanting to squeeze an awful lot of kit into this locomotive, Martin. A high-pressure steam boiler (which has never been made to work in a railway application, despite numerous attempts); a steam turbine; a generator; traction motors, plus all the fuel and water; plus probably a condenser to enable the turbine to generate good efficiency ...

Now, if you stripped out the fuel, water, boiler, turbine and condenser you could scale them up hugely for better efficiency. Then your locomotive (subject to the vibrations and shock of rail travel) is much smaller and simpler, with far less useless dead weight to carry around. All you need then is a wire to carry the electricity to the railway, which, ooh, I don't know, you could probably string up harmlessly out of the way above the tracks ...

Tom

 

I'm uncertain a truly successful "general purpose" turbine has ever been developed for railway use. Lomdon-Liverpool was pretty much it for Sir William's machine, No.6202 and the Swedish application, with a whole class of turbines, was primarily a freight slogger, reflected in it's design. The principal factor rendering turbines less suited to rail than either shipping or electricity generation is, of course, that they're designed with an optimum fixed rate of rotation away from which, efficiency drops off drastically.

The above, of course, applies to fixed pitch turbines. Whether any sufficiently robust variable pitch design exists, afraid I don't know. Neither am I aware of any trial of the remarkable Tesla turbine, so couldn't pontificate on the suitability of that for rail applications.

Anyhoo .... efficiency be damned. From our collective viewpoint however, the principal objection to turbines has to be the downright unattractive constant, near monotone "whoosing", utterly unlike the delightfully syncopated music of reciprocating engines. Honestly, it sounds like steam escaping!

In earnest, niche gricing interest aside, how many would turn up in anticipation of hearing this at the head of their train [just 1'27"]?
https://www.google.com/url?sa=t&source=web&rct=j&url=https://m.youtube.com/watch?v=ZsrzUjcHeAs&ved=2ahUKEwjRo97e0rjxAhV1olwKHSRLAGIQo7QBegQIChAB&usg=AOvVaw24q_o5V53FDN09Cymc9Cij

 

Its interesting to look at the results of trials between a Southern Mogul & Leader.

The Mogul managed 4% Thermal Efficiency compared with Leaders 1%

The SAR Class 26 (The Red Devil) which is a pretty conventional loco on 3ft 6 gauge & a fairly restricted loading gauge managed 15% across its output range.

It seems to me that there is a potential for some pretty massive (100% +) efficiency improvements on conventional locos before you end up with te unconventional.

 

Didn't an American railway, Chesapeake & Ohio? try some sort of steam turbine electric loco which wasn't a great success?

 

Indeed they did. Thank Bob for Mr.Douglas Self's magnificent resource covering much of the weird and the wonderful:
http://www.douglas-self.com/MUSEUM/LOCOLOCO/chesturb/chesturb.htm
Also there's detail of another such machine, on the Norfolk & Western
http://www.douglas-self.com/MUSEUM/LOCOLOCO/nwturbine/nflkturb.htm
In the UK, Armstrong-Whitworth had a go too:
http://www.douglas-self.com/MUSEUM/LOCOLOCO/armstrongturbine/armstrng.htm

Unlike the US machines, I was (no more than) aware of the A-W. Methinks the fact that, even amongst NP membership, precious few of us are familiar with these machines speaks volumes concerning the success of the concept!

 

The only one of these attempts to try something different which was reasonably successful was the LMS Turbomotive

 

Successful it was, but not uniquely so, as the Swedes managed it too. See clip attached at end of my ramblings in post #204 above.

 

I think most of the attempts at a steam turbine loco that had any form of success managed it by virtue of getting rid of the condenser and forced draft; but the effect of that was to wipe out most of the thermal efficiency gains of using a turbine in the first place. The root of the thermal inefficiency of steam locomotives is throwing away the latent heat of evaporation in the steam via the exhaust.

Tom

 

There was a superb (and comprehensive) fairly recent series on the design and development of the steam turbine within the pages of Model Engineer, complete with enough of the theory for the enthusiastic student to explore design themselves. It's a while since I read them, but the main things I remember are that Parsons, de Laval and some of the other early turbine engineers were clearly exceptionally able; Parsons in particular just seemed to understand what the steam wanted to do and what the design needed to be to extract maximum efficiency, without necessarily being able to give a sound theoretical justification. A lot of his instinctive design decisions were later proven to be either theoretically correct or pretty close to it. I think it's fair to say the Tesla turbine received fairly short shrift, if the name attached to it were not so famous I suspect it would have sunk without trace long ago.

There's recently been the first installment of a new series by the same author, intended to cover the turbine design of 6202, in particular regarding the features intended to improve its efficiency over a wider speed range. Should be worth a read.

 

Personally I’d disagree. I’m a pensioner but have virtually no recollection of BR steam. I also have no objection at all to foreign steam, and have had some great experiences in South Africa and Germany - big locos doing what they were designed to do.

As an engineer I find the Wardale’s work fascinating and would love to see just what an unfettered clean sheet of paper design might have achieved on the UK main line. Sadly the majority only want to live in the rose-tinted past. For me there’s plenty of room for both.


Sent from my iPad using Tapatalk in

 

After an admittedly iffy start, involving many totalled fan blades, SAR/SAS got the condensing system on their Class 25 locos working passably well. There's something to be said for having a near waterless expanse, the size of The Karoo, to focus the engineering mind, plus, the unique tenders, where the banks of cooling fans lived, were not merely big, they were very bl○○dy big!

With the advent of dieselisation, 87 of the 90 condensing locos were rapidly (and one suspects, gleefully) rebuilt in comformity with the Class 25NC locos. David Wardle's solitary Class 26, 'The Red Devil' (happily preserved) is a development of Class 25, rebuilt according to the principles of L.D.Porta

Here's the type CZ condensing tender associated with Class 25.

[Image courtest bahnbilder.de]

AFAIK, only one of Class 25's condensing flavour (as opposed to Class 25NC) remains in anything close to working order.

 

Drifting the thread a little bit more, but given that the Southern had a (admitedly not very succesful) Sentinel semi Doble Railcar running on the Devils Dyke branch it seems strange that Bulleid didn't look slightly more in that direction, Leader COULD have ended up as something more along the lines of the Egyption State Railways Sentinel Railcar at Quaintain Road.

 

I'd argue it was successful, as far as it went, although (in common with so many steam railmotors) the "Dyke Sentinel" was underpowered, meaning there was no possibility of adding any trailer. In fact, the total lack of any coupling/buffing provision is a pretty strong clue that no trailing load was ever intended. Insofar as the design spec went, it did precisely what it was supposed to. One of those random thoughts, but I've occasionally wondered whether a transfer to the IoW (pretty sure it would've been 'in gauge') mightn't have been better all round.

It's ultimate wartime demise, one county east, was caused by failure of the monocoque design, which cracked under conditions of repeated overloading. History shows that the downfall of many 1st gen steam railmotors was a direct result of their success in attracting more passengers than they could cope with, causing their replacement by either PP or conventional loc hauled trains.

 

The Bulleid Society web site has a piece about Malcolm Root’s latest painting (“The Last Spark”, featuring Bulleid’s Leader) which will be produced as a low print run if sufficient orders are received. Malcolm has offered a contribution from the prints sold towards the overhaul of No. 96 Normandy and No. 21C123 Blackmoor Vale. Full details here.

Tom

 

What a great painting of the Leader.

 

Wouldn't need a small boiler. A WC/BB boiler would be perfectly adequate, and could be oil or gas fired, remotely controlled and monitored by CCTV. Replace the chain drive on the bogies with gears or rods. Many other improvements possible - it could be made into the most efficient steam engine ever built.

But, sadly, it would not compete with electric, and at best would still require more labour - in use (needs someone to manage the fire as well as a driver) in preparation and disposal than a diesel. Even if the thermal efficiency could be brought up to diesel levels.

Bullied's vision was brilliant - its execution left a great deal to be desired.

 

i'd agree with the oil-fired West Country boiler, but I feel that any engine unit based on a reciprocating engine, whether sleeve valve or more conventional, is not the way to go. Four small, reversible (whether inherently or by gearing) turbine "traction motors" would be a far more elegant solution building on the strengths of the Stanier Turbomotive whose weaknesses seem to be that it required a separate reversing turbine and a lack of spares that kept it out of traffic for long periods.

 

One would, of course, want to remember the other foray into turbine steam locomotives in the USA.

The Pennsylvania Railroad S2.

https://en.wikipedia.org/wiki/Pennsylvania_Railroad_class_S2

It was reasonably successful, although it would try to collapse its firebox due to steam demand if started too quickly.