Tornado

Im, not an boilersmith, but, something just occoured to me, foundation ring corners were cut out and replacement sections welded in, during the overhaul, If this area was in any way miss aligned during the last ticket, for example lets say there was stresses that had been formed during heat/ cooling cycles, when the section of foundation ring corner was cut out, might that have allowed expansion of the remaining steel, so that when the replacement corners were welded in, they would clearly have been seen to be wrong, But what if the replacement corner forgings were for the redesigned boiler, with a larger water space, these forgings are one piece U chanel, you could have potentially tacked it to the inner box, and it fitted, and because the outer plate has sprung, when you offer up the replacement corner it would possibly not look out, but look right, the box at that corner would be out of true, had someone welded in the wrong foundation corner piece?

 

(Speculation alert)

I wonder if we are all going down the wrong line here in trying to think about the boiler changing size.

What if the boiler was just the same as before, but it was pitched differently? AIUI, if you were to raise the pitch of the boiler, the effect would be to move the front corners of the firebox away from the rear drivers. Conversely, if you lowered the pitch, you'd move the corners towards the drivers.

So I wonder if in the overhaul, the boiler supports have been machined down. That would have the effect of lowering the boiler, and moving the front of the firebox towards the wheels. Whether that was done deliberately (it might be seen as desirable to marginally improve gauging) or simply as a machine exercise without thinking of the consequence I have no idea. But it would seem geometrically a change that would have the impact seen (reduced clearance between drivers and firebox) without needing to posit any physical change to the boiler itself.

Tom

 

I don’t have any solid info on this, other than there are photos of a single new boiler that looks externally complete, but I’ve not seen any photos of two new boilers in the same shot.

 

Not like you to speculate Tom
Reported fact - the firebox, at foundation ring level, is no longer symmetrical when measured across the diagonals.
Speculation (wild) - the boiler was dropped at some point? (Though having seen photos of collision accidents, boilers are very robust!).

 

In that case Tom, both of the front firebox corners would have fouled the drivers, wasn't the problem on one side? You might well be right, don't the boiler mounting have plates that are shimmed to allow the boiler to be sat either slightly higher, or lower? new tyres means the engine would sit higher, so its possible,

 

Dropped? That is unlikely.

Its more likely that the box being out of square is due to the welding / repair situation. We know a fully welded box is going to have residual stress, and given a chance, that stress will distort any unconstrained geometry.

Cutting out and welding in new foundation rings is exactly the kind of change that would lead to the wrappers deciding they would rather live in position y than position x.

No conspiracy, just plain old welded parts move due to heat and residual stress.

If its out of square on diagonal, one driver will be a lot closer than the other one as you rightly point out. Shims will go so far, but there is gauging at the top as well as the side to consider.

Next time, and this applies ot the P2 and others, it would be wise to consider some alternative options.

1. Life of boiler/fbox foundation rings.

2 Constraining up the box when welding and repairing.

3. Threaded stays.

4. Heat treating the whole box to remove residual stresses entirely from any welded stays and foundation rings.

Its hard to overstate how much of an effect all this has. The volumes of heat and therefore stress being added to the firebox is millions of joules/watts of energy that is added to an assembly of this size. Due to the microstructure of steel, this has an effect. It has to go somewhere.

 

It came from a volunteer doing meet and greet at the start of the year, was quite candid, and mentioned the 2nd being complete, and had been checked and regularly tested against spec provided.

 

I have. One of the boilers is coming back as a kit of parts. Your point?

 

No boilers are coming back as a kit of parts.

 

Not what was said at the start of January, but that may have changed???

 

I will defer to Guy on this, but one of the boilers is still a kit of parts, having been ordered in 2019. One has been completed (ie the second of three including the one on Tornado)

My understanding was that repatriation was to be as a kit of parts following difficulties over certification. Given the radio silence from the trust in public, it's hard to know. As I say, if you have other information to inform your position, it would be helpful to share.

 

Meiningen Steam Locomotive Works
Has been building and repairing steam locomotive boilers since 1914.
One would hope they would have got the hang of it by now!

 

Steam Railway just arrived and boiler for the Prince of Wales is due to arrive at Darlington in April.

 

Did they not ask for water jacket thickness changes? If so, why? Have you a reason, other than dropping or residuals, for the box being out of square?

 

All they need now is a team to re-start assembly!!!

Seriously, this unit is the one, that had been followed through construction by a independent engineer, and they were happy with (source Jan 2025 open day).

Whilst it is great that it will be on site, and presumably they are now happy with the boiler on 60163, to have reached an agreement for payment and delivery.

Without a new cannon box, machined to allow the front bogey in, doubts over the inside cylinder operation, what's the point of a boiler delivery???

 

Does it state a year?

 

Indeed. This had to be around the fifth or sixth delivery date given over the last 3 years,

I really must update my overhaul timeline file - I lost the will early last year iirc.

 

Is this the one that is now going to be used for Tornado , because, As I understand it, the one earmarked for POW, will go onto Tornado, and the one that's just a kit of parts is due to be built up over here, and will become the one to be used in Prince of Wales, or are we now on plan z If its due Next month, then, whats the plan now?

 

The point is another media splash for a cash strapped trust - that's all I can see