Tornado

No - because it was well publicized at the time that the first choice was another apple green pacific - 4472 Flying Scotsman.

We'll agree to disagree, Ben, and leave it at that. Definitely have a pint chap, sounds like you earned it today!

 

So it seems the rumours of the machined foundation ring are true, how did they get away with using it?

 

I hope the moderators lock this thread, yes I know I know I know I could not bother reading it, BUT the speculation is killing me.

 

Is that the speculation about locking the site or about Tornado?
Personally I would prefer for open discussion on the thread, but it really is pure rumour, conjecture and plain simple gossip at this stage. (With some knowledge mixed in)
Let's give that discussion a rest and wait for the engineering inquest result, please!!!

 

I think I did. Lizzies large tubes are really heavy! Lol

Have one yourself!

 

I have heard that they did use a machined foundation ring. I do not know 100%. if so, I believe that is quite a major deviation from the original design.

However, I am sure this was considered, tested, etc.

More speculation on my part.....going back to that Engineering party I went to in Cardiff all those years ago.

 

Just what are you meaning by a machined foundation ring and a deviation from design? Which design? The fact that the original A1 had a forged and riveted foundation ring means that Tornado's has got to be different from its predecessors. As for machined, well the new foundation ring for 4472 has been 'machined' but there's nothing unusual in that.

 

I reckon that's a fascinating piece of rubbish! How the outer firebox and water can be too hot, I don't know. I'll agree that the narrower the water spaces, the greater the bending moment in the stays but if the water space is increased it will affect the tube layout and almost certainly affect the number of superheater flues and the knock on effects of this. Loco boiler design is always a compromise.
Like everyone else, I'm speculating and would dearly love to peruse a set of boiler drawings but I doubt that opportunity will arise.

 

As I understand it Steve the foundation ring corners could have possibly been made by machining from the solid using conventional cutting tools rather than being forged/pressed to shape. I believe that when you machine a material it introduces stress points that can lead to premature failure, you can reduce the stress by heat treatment but the grain structure is still weaker. Is there any president for a machined foundation ring today?

 

Can't even watch Dave ja vu tonight!

It's that dammed episode with M Schumaker and...yes Tornado! Arggggg

Lol

 

I think what he means, Steve, is that a narrower space between inner and outer fireboxes could hinder circulation and locally cause the water to be hotter in that area than desirable.

I would, however, agree with you about the increased bending moment imposed upon the stays.

 

Maybe the boiler was damaged when it ran out of water on top gear?

 

Or when the bacon went up the chimney

 

The water can never be hotter. It would turn to steam and, if this created hot spots on the firebox plate due to them not being in contact with water, it would cause localised burning of the firebox plates. I don't think that this is a problem.
Thinking about the boiler design in general, the use of a welded firebox eliminates the flange and, if the same corner radius is maintained, it ought to allow a wider water space than the original A1 without compromising the tubeplate layout in any way.

 

So then Ben, what do you mean by a machined foundation ring?? I would hope most people would m/c a foundation ring to some degree?
What are your credentials for boiler design, have you ever been involved with boiler manufacture?

 

No relevant credentials at all.

If you forge the ring and then cut the U in it, the metal is going to behave in a very different way to a folded U. If you wish I can get the old Mechanical Engineering books out from uni and go into a very long and dull explanation, but then I would be kicked off for being extremely dull and wasting storage space on the server!

 

But to be fair to Ben, it does make sense when you think about the way sheets of metal work. One which has been shaped will react differently to heat, to one which has been cut and filed/machined/etc. I can't remember of the top of my head a specific example, but something my uncle always pointed to me as an explanation was to be found in the afterburners on jet aircraft. Same component, made two different ways, and tested - one failed and the other didn't, despite being outwardly identical in shape, material and weight. The difference was in their manufacturing, which gave one different properties to the other.

 

My German steam tech books suggest machined U rings were used in Germany fairly often and without trouble.