Flying Scotsman

Definitely sounds likely. I'm not as close to the figurative nuts and bolts of preservation as most of you, but from an 'outsider's' perspective it seems that Scotsman has been modified in preservation more than practically any other loco (with the exception of Hamilton, which hasn't run in modified form…).

I'd argue that preservation probably isn't a great place for 'experimentation', particularly with unique entities.

Simon

 

IMO it was a case of "mine's bigger than yours" but if Tony Marchington wanted a loco with a TE of 40,000+ he should have bought a King, Duchess or A2. In their final BR double chimney form the A3s were capable of anything the ER threw at them so I honestly can't see the need for upping the TE other than bragging rights.

 

But were they bored out any more than was norm for A3s? ISTR seeing numbers that suggested the TE of a GW 2cyl with wheels on the last turning and cylinders on the last rebore was ITRO 10% above the nominal figure. I find it hard to believe that the A3 cylinder castings had more thickness than required to support the design max rebore.

 

It wasn't just boring the cylinders out; the working pressure of the boiler was also increased by over 10% which also increased the weight borne by the frames. Taken together, a locomotive design in which the frame design was known to be one of the weak points was expected to absorb tractive forces up to a third higher than the original design had called for (*) and, moreover, was regularly used on duties that required working up to the new higher capability; in the circumstances, it is hardly surprising there were problems with the mechanical condition of the loco. That's an entirely different order of things than a loco that is just up against its maximum limit of bored out cylinders and minimum tyre diameter. Swindon didn't take locos in that condition and then stick another 25psi on the boiler pressure, did they!

A bit like putting a Griffon engine in a Mark 1 Spitfire and then wondering after a season of display flying why rivets keep popping out and the main spar and engine mounts are showing worrying cracks...

(*)Tractive effort:
A1 as designed and built - 29,835lbf;
A3 as modified - 32,910lbf;
Flying Scotsman as rebuilt - 40,400lbf I think.

Presumably, the frames were designed to absorb the forces inherent in a 30,000lbf loco and ended up being attached to a 40,000lbf loco ...

Tom

 

Where parts/materials (or historic knowledge) are no longer available, some modifications might be necessary/inevitable. Also, the "modern" railway has required additional kit or modifications to allow them to run on the main line.

But as Goldfish says, "experimentation" without the technical/historic knowledge is taking it much further. Too far, perhaps.

Richard

 

I'd debate that.. some J94s have been turned into "interesting" things...
isn't the Rocket replica, Iron Duke, Planet Replica, "douglas" @Midhants, Thomas @Midhants even 47298 got quite a lot of J94 DNA than your average rebuild.

 

Not at all sure about Rocket and Planet having J94 roots.

 

Two austerities are thomas characters, both from the MHR, one is thomas and the other was converted into a tender loco as 'douglas'. As well as that I believe the class' ancestor has two other thomas side tank conversions, one from llangollen.

 

Its not exactly a poison chalice, I imagine they are doing very well commercially out of the works both in terms of income and the positive PR.

 

Precisely - they are a commercial organisation and presumably the price they tendered and the terms they negotiated took due allowance of the commercial risk as they perceived it.

Tom

 

way off the subject !

 

way off the pace...

 

An FoI request to NRM reveals how many tenders there were bidding for the job.

 

I know there were definitely two shortlisted

 

The problem was that the engine had not been set up properly the stress and strains had not been properly assessed,it was expected to work far heavier trains than it should have, and it was not properly maintained afterwards, i dont think that the owner, or the people tasked with the overhaul and future operation looked at the long term good of the engine, it was just run into the ground, too much was expected of it, and the person in charge of the overhaul and operation, had by and large obtained a reputation based on the cludos of the engine, not on the real condition until it changed hands and then all became very clear.

 

20" bore cylinders with 220 psi w.p. was done (4480) but the engines breath a bit better with 19". Could the frames have been developed to absorb the higher T.E. without concern? Yes, but the crank axle is another matter. It would be interesting to know what was happening to this axle when the engine was putting out very high power outputs.

It is also strange that the outside cylinders had different bore sizes. The inside cylinder always wore faster than those on the outside and this was allowed for so far as I know. The outside cylinders were supposed to be the same size and the inside could be a fraction larger - how large a fraction I have not found out. I wonder if the engine still displays the same wearing characteristics that had to be addressed in the 20s and 30s.

As to the biggest mistake. Not taking enough time over the work, carrying it out it inadequate facilities, contacting the work to companies that do not have the necessary expertise; you can add to the list if you want to, I am sure that you all can. But the biggest? Who knows. But it should not have been made.

As to the loadings. The original A1 was designed with 600 ton loads in mind and the A3 was significantly improved over the original design. Loads in themselves were not too much of a problem but the failure to overhaul, to repair and to carry out the modifications made, all to the highest possible standards undoubtably were. People wanting to take more out of the engine than it was reasonable to expect of it totally ignoring the true condition of the machine. Very much another part of the problems saga.

 

There was a very good documentary on DVD released after 4472 had returned to steam in 1999 and it's worth buying if you don't already own it:


It has become even more interesting after all the problems encountered with 4472 during it's latest overhaul have become known.
In the programme Roland Kennington goes into detail about the "improvements" made to 4472 to make her more powerful. I remember watching it for the first time and thinking that's not going to do her much good in the long run. About half-way through her ML ticket we went to see her working through Chilworth with the VSOE and we were standing, watching with an ex-BR Steam driver that my Father knows. His comment was "She is well past it. She sounds like a bag of spanners!" I have never forgot that day as she did indeed sound very rough. It does make you wonder how she carried on working for so long and how she passed all the FTR exams.

 

A very good question, you have to ask who was the approoved examiner, bearing in mind most railways are trusted to carry out their own FTR, i saw some main line engines that you would wonder how did that pass as it wheezed by sounding like it wouldnt last much longer i remember chatting to wayne when he was with NSE, with mike Burke, and the standard of inspection veried from engine to engine, its telling that .

 

I'm left wondering if the Beeb, will update their Timeshift programme about her?....... a lot went unsaid, though still a thoroughly good watch when there's jack all on the box!

Still the end is in sight/ There's an ever growing glimmer of light of this very long tunnel................ "Hopefully" without anymore twists & turns.............................