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

To get the ball rolling I will nominate the Midland Railway practice of fitting those little windows in the cab spectacle plate right above the firebox. Certainly with the 'Royal Scots' as originally built, one would need a step-ladder in the cab to see through them.

 

Irish Railways Turf burner?

 

So many potential answers given the current political crisis but I'll be sensible and go for Brunel's atmospheric railway; a great idea in principle but it was pretty useless.

 

George Stephenson's comment was that it was just stationary engines using air instead of rope. He had a point!

 

The problem was that the theory was about 100 years ahead of the available technology/materials to deliver it, Bulleid often seemed to similarly be somewhat ahead of what technology could deliver.

 

The idea of uncoupled driving wheels, such as Webb compounds and Drummonds double singles

 

When it worked it worked well ! Faster, smoother, cleaner and quieter than steam.
The main problem was that the valve sleeves in the top of the air pipes were made of leather and had to be kept greased to retain flexibility. That would be quite a task in its own right (Dawlish/Teignmouth sea wall stretch in a winter storm would have been fun !) but apparently the grease, presumably animal fat in those days, attracted rats who ate the leather thus reducing the vacuum. The same problem occurred on the London and Croydon Railway. With modern synthetic rubber it would be no problem and there are currently two or three short line operations and some on-going experimental work.
Perhaps we should set up a few miles somewhere as a demonstration line ? Using Brunel style carriages, of course. WTBN ?

 

Dare I say 10000 Hush Hush...

 

Churchward also had the same idea, they would perhaps let in a little more light but Collett immediately abandoned that feature.

 

There was some sense to it. Coupling the wheels adds quite a bit to the rolling resistance, so keeping them as double singles allowed more power to be delivered to the rails. I know the old one about wheels slipping in opposite directions, but this was a result of the slip eccentric to drive the valve for the low pressure cylinder, and was solved by inserting a by pass valve between the high pressure cylinders and receiver to divert the HP exhaust to the blast pipe.

The reason is because the wheels, while nominally the same diameter, are all slightly different so want to rotate at different speeds. The coupling rods prevent them doing this, but uses power to do so. This is why you do not move an engine with its rods off: the wheels will immediately move out of phase, requiring the axle to be jacked up to allow the rods to be replaced.

Jim Markland (Bolton fireman) tells the story of a 4F going to Horwich Works due to a broken crank pin, something the class was prone to. The coupling rods were off but it ran under its own steam as a 2-2-2. The crew was amazed at how far it would roll with steam off compared with a normal 4F.

 

Edward suffered a similar fate and perfumed similarly laudable in the Railway Series

 

Feed water heating? It was popular in other countries but never really caught on here. Drummond (always one for gadgets and innovation) persisted with his design of heater in the tender for many years, Stroudley and Dean (for a short while) also dallied with heating the water in the tender/side tanks. Gresley used both ACFI and Worthington heaters which were much used in the USA and France but none lasted very long on the various LNER locos they were fitted to.

 

Diesel-electrics and electric locomotives work very well with uncoupled driving wheels.

 

Didn't the Pennsylvania T1 class duplex 4-4-4-4 have a similar problem with one coupled group of wheels slipping?

 

Yes but that's with separate traction motors on each axle. If you consider an 0-6-0 diesel like an 08, take the rods off and it becomes an A1A, because there is no traction motor on the middle set. Which is rather closer to what happens on a steam loco.

 

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Thermic syphons? but there are a number of more obvious ones like Webb's water grates and various firebox designs with cross-tubes.

Interesting re feedwater heating. It was very popular outside the UK but the loading gauge no doubt made it difficult to fit in here. Wardale seems to have been a fan of the Elesco closed-type system (which involved a circular drum on or near the smokebox), but intuitively the exhaust steam injector seems a better bet, as it is essentially modular and has less moving parts. A feedwater heater needs at least one and in some cases two pumps, one to pump water from the tender to the heater and one to pump the heated water into the boiler, which almost certainly means additional maintenance, particularly of the latter. Towards the end of steam in China, the feedwater heaters (Worthington-type) seem often to have been blanked off, locos relying on their two live steam injectors (but I guess the exhaust steam feed to exhaust injectors were blanked off in this country towards the end e.g. see the late images of Britannias).

 

Grotesquely underpowered 'railmotors'. Discounting Churchward's successful design(s), the majority were real turkeys. The Cochrane-boiler (transverse!) fitted to the GNoSR pair were notably poor. The carriage portions survived, converted to 'conventional' stock, one of which O.S.Nock recorded seeing on a WWII KingsX-Scotland service! :

[Image originally Railway Magazine Issue 100 October 1905]

 

It seemed a good idea in the 1940s for the Southern Railway to build a modern loco to work its branch lines as the M7s were approaching 50 years old by then. Unfortunately, the sleeve-valved double-bogied fireman-roasting No. 36001 wasn't really a very suitable loco for operating lines like the Lymington and Swanage branches!

 

The LYR ones weren't bad, one just made it to BR, the two late survivors, 10617 and, I think, 10600, ended up on the Horwich branch and the Radcliffe to Bolton section