P2 Locomotive Company and related matters

As indeed they will be, the first coach Mk1 TSO 4290 has been so fitted. If I remember rightly there are another 12 to go.

 

Another welcome update on the P2!
https://www.p2steam.com/2021/01/?cat=3

Richard.

 

Thanks for posting this Richard! Much appreciated

(BTW I really dig your signature: (Yorkshire. Where Men are Men and sheep are worried...)

Knut

 

Pretty amazing to read that they plan on using CFD to model the steam flow "from the regulator to the blast pipe", to optimize it.

I was also amused to see "If a smoke lifting problem is identified ... some relatively unobtrusive aerodynamic fences or strakes could be applied to solve the problem" - it sounds like a modern F1 car!

Noel

 

Aeronautical Engineer at the Helm so not a surprise really...

 

When you think about it, gasflow is everything in terms of power generation. It's also usually poorly-understood until very recently, so is a fruitful place to find some cheeky extra performance. All thermal engines move energy around in gasses.

IMO, it's no coincidence that Ross Brawn managed that season with Jenson Button and no factory support on the back of a better diffuser than everyone else.

 

Please don’t bring Formula One into this!

 

As a sport I find it dull as, as competitive engineering/full-contact governance-wrangling, it's quite interesting...

 

Fair point, but until 2007’s on the grid at Monaco can we just leave it in the other thread that’s supposed to cheer us up? Thanks

 

Would be interesting seeing it go round Loews hairpin ...

Tom

 

That might have been why they were looking for a turntable

 

With that wheelbase it would struggle with the chicane at pit lane exit!

But dragging us back into reality - that is an impressive piece of engineering design for fabricating the cylinder block assembly. It will be interesting to see the assembly sequence and number of stress relieving treatments required to ensure design tolerances are met.

Regards,

Dan

 

Fantastic to see the use of CFD! This will help no end with power generation and also optimising valve timing and profiles.

Have we covered this already, but, surely the final machining of bores etc is going to happen post-post weld heat treat?

this isn’t going to be a fabrication of finish machine components being heat treated?

Are we still talking about one final PWHT or are there going to be interim fabrications and heat treatments?

Given it’s all bordering on thin wall (engineering definition) fabrication, I presume it’s going to be a case of leave the bores 50thou(?) oversize and then machine those (as well as all holes) once the whole fabrication has been heat treated?

There is a lot of heat going in to this with the volume of weld, so distortion is always a threat.

Or have I misread the part about the assembly sequence? Is the intent to reduce or eliminate distortion entirely through the sequence of assembly? Is the use of a cradle as a jigging fixture in the mix? Tack within cradle-weld all joints-remove from cradle-bake?

That to me anyway is ambitious. Not impossible, but if we are talking about reducing the risk of distortion creating non conformance to DWG to an absolute minimum, leaving material on until a final machine as a competed and fully baked assembly would be the way I would go given my current level of understanding.

Sure, the final machine operations will be a task and a half as one lump, but that would be the most dimensionally conformant cylinder block.


Perhaps I’m missing something, happy to be corrected.

 

As I understand it Honda spent a small fortune developing the car the preceding season and then pulled out, and Ross Brawn took it over.

 

IMHO it's very brave of the A1 team to contemplate a fabricated cylinder of this size. The only one I know of in recent times was one produced by the NYMR as a replacement for the cracked one on 76079 and that was a single cylinder, not a monobloc replacement. This turned out to be an expensive failure as it warped so much that even the machining tolerance was insufficient. In the end a new casting was provided. I sincerely hope that the P2 one is more successful.

It will indeed be interesting to see what CFD throws up.

 

Go on, the whole project is brave, but that’s why we love it!

Was said fabrication for 76079 post weld heat treated?

As we know castings also have residual stresses which is often, in combination with other factors, why they end up cracking.

Say the P2 group were casting 3 part cylinder or a monoblock, I would still query if a heat treatment was included to remove residual stresses that arise from uneven cooling of the casting.

I have every confidence that this fabrication can be successful, and as successful as a casting. The fine details of the fabrication are what are ultimately going to make it so.

Am I right in thinking the cylinder block will also get a proof-hydro test pre assembly in to the frames?

 

Interested to know whether this new approach to cylinder construction will need/ use' liners' ...

 

I guessing but I think it will be a necessity. Steel isn't exactly the best material for a cylinder that will use steam as the operating fluid.

 

....resulting in the exhaust appearing to “leak” from the chimney encouraging it to stick to the boiler top,......
A NACA cowling at the smokebox front instead of elephant ears will prevent that.
Kind regards

 

Whats the current liner material of choice... SG Iron ?