Loco musings ex the 71000 thread

Which 8f ... the WD ?

 

Yes, downrated after the rebuild. Unofficialy, I might add.

 

As piece of BR history theres a place in the Line up for a Crosti or even an 'ex crosti' - that might have a strong case for accessing some 'heritage' funding
Never heard anyone interested in rebuilding one of the surviving 9f's as one though...

 

So far as recreating a piece of history; yes. So far as making a better 9F. . . . .hum! Who would want to support an engine that has been deliberately handicapped? ICBW but I doubt too many would rush forward to support such an idea.

 

Hmmm, I wonder why?

While we're about it, how about a new build "Great Bear", Webb double-single compound etc...

Tom

 

class8mikado said: "As a piece of BR history theres a place in the line-up for a Crosti...."

Are you sure about that, class8mikado? There are plenty of successful and potentially useful locomotives missing from preservation, such as a Fowler LMS 2-6-4T for a start.

Why would you want a 9F converted to a Crosti? They were not successful, thats why they were converted back to non-Crosti operation. They were not successful because: a) they failed to demonstrate any significant improvement in efficiency. b) the preheater and final smokebox suffered severe corrosion. c) they were said to be prone to priming. d) the proximity of the final chimney to the cab made for unpleasant conditions on the footplate.

No, with respect dont lets bother about resurrecting failed experimants, and concentrate on the missing good ones of which there are plenty.

46118

 

I can't remember the title of the book which I read half a lifetime ago, but am fairly certain that the Crosti boiler was smaller in diameter than standard to accommodate the pre-heater. The application of pre-heaters to older and less efficient locomotives in Italy resulted in greater efficiency savings than the 9F experiment largely because the 9Fs were better engines in the first place and the Italians had a less constricting loading gauge in which to put the extra fittings.

David

 

The Crosti boiler was smaller and,IIRC, the locos were only classed as 8F after they had the pre-heaters removed. Ray.

 

I am not saying that 71000 should be rebuilt with piston valves but for those who have put so much time and money into restoring the machine it must be disheartening that the locomotive's most interesting feature should be so recalcitrant. Part of the problem facing the engine is that it is a one off prototype. With more engines of the type being run you would get your feedback so much quicker and be able to test a wide range of solutions to arising problems far more quickly. 71000 is in the same position as 10000 and 2001 here but in many ways worse since the owning group do not have the vast resources of a full blown railway company behind them. On the evidence presented so far, if the design were to go into series production would you choose the BC gear? I wouldn't, but you already know that. Wind the clock back. B.R. requires a batch of class 8 express passenger locomotives. You cannot build a pre nationalisation design - think of the politics. What do you do?
D of G may have been built in 1954 and Chapelon reverted to piston valves before that date but others made the decision to reject poppet after it. A question. Could 71000 match the continuous performance of say one of the Chapelon Pacifics used by the Est? If it couldn't then what is the problem with looking back to the 1930's. The irony is that these pacifics were felt to be unsatisfactory on the grounds of leakage. (Could be better performers)
I wish the D. of G. people the best of success in raising funds and keeping their engine where it belongs. out on the rails.

 

Maybe a tad harsh. The LMR was not precisely overendowed with Class 8s, they probably did need to replace Princess Anne. So what alternatives did they have?

The best existing design was surely the Peppercorn, but it would scarcely have been sensible to have one running all alone in the LMS area. They probably could have built another Duchess, but I suspect the ammunition it would have given certain other regions who wanted to build more of their native designs would probably have been unacceptable, and an unrebuilt Bulleid might not have survived Midland shed maintenance very well even if you accepted the one member of class in region thing.

 

From an engineering point of view certainly, without a shadow of doubt.

But when you look at some possible political issues... it was a time when the WR was kicking and screaming about being forced to use BR standard classes: they wanted another batch of Manors and some more 28s, and possibly more Castles, not BR standards which from their POV were a disaster for standardisation, shed spares etc. So if the Kremlin had said, "We're going to build another LMS engine because its standard, even though you're not allowed to build GWR engines to maintain your standards" then the accusations of hypocrisy would have been heard in Australia...

And, coupled to that, yes, every design team did want to build an all out express loco, of course that came into it too, and was probably a lot of it. And hopefully it did have a good number of components that were standard with the rest of the range, and I suspect the less glamorous ones like wash out plugs can be as important in shed maintenance terms as the headline stuff.

Goodness knows I'm not after excesssively defending the design team that gave us as pathetic an attempt at standardisation and innovation as could have been achieved at the time, but I think there may well have been more to the DOG than *just* ego.

 

The sad thing is that if one were asked to produce the "perfect" steam locomotive in 1950 one would look to the design schools of France, Germany and the U.S.A. in combination. Even Argentina would get at look in. Alas it is unlikely the U.K. would.

 

I am beginning to get an inkling that the answer to the Dukes problem is more akin to automotive engineering than steam engineering.

Everything except the valve gear is pure steam, I wonder if the diesel guys would get a handle on the problems quicker if asked.

Just another way at looking at an annoying problem.

Cheers Dave

 

Im sure that as many minds are put to the task as possible will help Big dave, but apart from having two valves that go in and out instead of just one that goes side to side the similarities with a combustion engine are some what abstract...

Two sides to the coin argument - im sure that with ' spares' a new princess/ duchess locomotive could have been put together. The duke, as well as being a prototype 8p ( new design firebox, valve gear and cylinders) was also the prototype rolling Chassis for the next batch of 7MT and 6MT Locos ( New frame arrangement, trailing truck design)...

 

The railways were going to need locomotives with a far greater power output than that offered by an 8P. The view held by those who designed the Standard classes was that 2000hp was sufficient. It most certainly was not. This view was a source of frustration for those who recognised that people wanted to travel ever more quickly and if passenger trains were going to increase in speed then freight would have to follow suit - just to keep out of the way. You could say that before WW2 Gresley and his team were providing engines whose capacity exceeded the needs of traffic however, post war it was on the Eastern Region that the lack of development in locomotive capability was the most frustrating. They got what they wanted in the Deltic class as the class 4 diesel electrics did not meet their requirements.
I know that I keep looking back to pre-war continental practice but this is where the research was done. Based on that research could a steam locomotive capable of maintaining over 3000h.p.have been built in the UK? No good reason why it couldn't. The task would not have been readily achieved within BR given the nature of the petty inter-regional politics so it might have been best to involve North British or Beyer Peacock (builders of better locomotives for export than we built for ourselves in some respects)
Thanks to paulhitch for input and Jimc too. Big Dave could well have a valid point that the expertise required by 71000 coud lie within the automotive industry.

 

I agree that the sort of performance you postulate who have been possible, but such a loco would have to have been mechanically stoked to produce such an output for any length of time I'm sure. Unless it also featured a gas producer firebox I fear the carry-over pollution in UK urban areas may have proved to be unacceptable.