P2 Locomotive Company and related matters

As I understand it from reading on here the boiler on Tornado is its original, refurbished. The asymmetric boiler currently being discussed is new.

 

It's only different by five stays though, not a huge difference. As for the reason.......

 

Are you quite sure it's "only 5 stays"?

 

I was talking about the asymmetry!

 

Only on NatPres could people get obsessed about an asymmetrically-placed firehole. It's as bad as Ian "Hubnut" Seabrook's obsession with windscreen wipers on motor cars.

If it makes no difference to its performance in service, then what's the problem?

 

Firstly, I don’t believe the firehole door is asymmetrically placed (that really would be a turn up for the books!). Rather, it is the staying pattern that is asymmetric.

Given that (1) the stays are an integral part of the safe and reliable functioning of the boiler (2) different types have different physical properties and (3) this is a new boiler, not an old one that has had some stay holes drilled out, then that difference is notable. It may in the end not make a difference to the reliability of the boiler, but it is clearly a curious situation and the logic behind it (if there is logic, rather than a cock up) would be interesting to know.

Tom

 

The firehole ring is a very solid stay and flexible stays within two or three pitches serves no purpose.
My guess is that there was not enough simple stay material at hand and to get the job done five flexibles were put in to the left of firehole.

 

Is the pattern of Stay installation a hangover from original design or from new design with more emphasis on siting of stays dictated by new stress analysis?

Rather than a Rule of Thumb method as may have been used back then?

 

The fire hole door is central. Look at the flap catch and then upwards. Remember that the actual fire hole ring is rectangular on Meinigen boilers and the LNER style door is bolted over this.

 

Being close by, thought yesterday would be an ideal opportunity for a few pics and see what the plans are next.
Drove down to a deserted DLW, then realised that it was the 2nd week of the month, not the 1st or 3rd......
Try again next week.

 

More likely they miscalculated the number of flexibles required (manufactured outside?) and used normal stays instead, away from the corners where flexibles are less needed.

 

Probably the most plausible explanation so far ….

 

Yes, they thought that we wouldn't notice:

MEININGEN 0 NAT PRES RIVET COUNTERS 1

 

Or, just maybe, it could be based on experience with the other boiler. Has anyone compared a photo of the boiler on Tornado as its currently configured? I note that the mix of stays on this boiler is significantly different from Tornado's boiler when it was first constructed.

 

Look up thread to my earlier post….. #4153

 

The U shaped found rings have the U section on the inside... Struggling to understand why anyone would think they are on the outside...

I would be very surprised if the addition of a large number of flexible stays has not been authorised and underwritten by a new stress analysis, either FEA or a classical mathematical analysis. The insuring body will want to know why there is a difference, and what that difference entails in terms of loadings.

The longer you look at the pictures the more you realise someone somewhere has seen fit to make significant changes, not just to the back head but the side as well. Old design, lots of rigid stays, new design, a lot more flexible stays.

The new design also has a lot fewer welded on lugs hanging around on the plates. Clearly, someone has made a decision to remove a lot of the welding in the firebox. That takes me neatly back around to a point iv made many times over the years, welding stress and plate support.

Are the flexible rivet style stays welded in position? Hard to tell from the photos. If not, ask yourself, why has an engineering team seen fit to remove a massive amount of heat input in firebox fabrication...

 

Just to pose another question for which only a poke around will probably answer - the new boiler(s) are supposed to have increased water spaces ( and therefore a slightly smaller inner firebox, and also grate area) - is this evidenced on the photos ?

 

Other than seeing an inverted shot showing the bottom of the foundation ring I doubt you can tell?

 

AFAIK the fkexibles are welded inside but the outside is a radiused head able to swing slightly with lateral movement of the plate. This is sealed by the welded domed cover you see.

 

I'm not quite sure what you are referring to here but on Bulleid boilers the U shape is visible externally even though the effect is internal. It looks very different to the more normal flat sectioned foundation ring bar. Here is the U shaped foundation ring for 34101 Hartland's boiler being made at Grosmont in 2011.

I should perhaps add that the new cylinder has nothing to do with Hartland. It proved to be a failed attenpt to fabricate a cylinder for 76079.

Peter