P2 Locomotive Company and related matters

Only over 4 months since the last ‘monthly’ newsletter. Only news is a belated admission of yet more delays to the new boiler (originally due in 2020) and trackwork at DLW.

Given that there was only a two paragraph update on engineering progress on No. 2007 in the last (very thin) TCC in December this project has now clearly ground to a halt.

 

To be fair they have had their hand full trying to get a square peg into a now trapezoidal hole on Tornado by all accounts... and of course getting DLW ready fcomplete with donations boxes for the hoards about to descend on it later this year ( one hopes)
Concerned that is there now anyone on the books capable of progressing, or at least managing the development of ,the valve gear ?

 

I would hope that David Elliott's "brain dump" to whomsoever is charged with that will have worked out and that he will have left copious notes to his successor(s). It's not as though the gear is untried, it's a modification thereof.

 

Does that mean that the A1 Trust's in-house engineering team will work full time on the P2 or that the A1 Trust's in-house engineering team has disappeared?

 

The latter, is my view, all of those who gave up their time look to have become fed up, and it is being left to full timers to look after her.

That in no way is derogatory to anyone who has helped in construction or general maintenance.

It seems to be a recurring theme, with many others under the same sort of agreement.

 

Theres some rather disconcerting parallels here with another LNER pacific, sorting out an engine after the previous people did not have the skills to get it right,
It might make sense to have him take on the P2, boiler when the kit of parts finally makes it over to these shores. and possibly have the final assembly done at Riley's when the engine reaches the stage where everything is fitted, then it could use the ELR for test running and shakedown, Of course, it would in effect, be the death blow for any independence of the A1trust, but I would argue, that its already at that point,

 

All nice in theory, overnight you double the price to finish her, and are we sure the engineering expertise exists to complete the inside motion???
Given the right set of people brought together assembly is relatively straightforward, lots of pieces are ready, the piece that was damaged, the pony truck cannon box, is awaited to start that.
The sequence, given to me was, Pony Truck in, Cylinder Block in next, after inside motion operation tested and confirmed, boiler (ready in germany), complete pipework, i know that is simplistic.
Same goes for the Tender, it is all at DLW, what it requires in the trust to swallow some pride, and get a set of competent volunteers back on side, and work could commence, its an easy win.

 

Nice to read some sensible information instead of fantasy claptrap from armchair "engineers"....

 

That’s not a bad proposition, but take a look at the Lents/Franklin/Elliot valve gear design in more detail. There is no inside valve gear as such. There are two camshafts one driven from rotary motion on either side of the loco. One camshaft actuates the valves on the left hand cylinder and one valve on the inside cylinder. The other camshaft actuates the valves on the right hand cylinder and the other valve on the inside cylinder. So there is no inside motion / gear as such.

 

Sounds like there is plenty of scope for development work (modifications, and with little or no 'in-service' experience) before 2007 is let loose on Network Rail's tracks.....

 

Maybe i should have said Inside Cylinder Valve operation????
That was what they talked about, getting a cam based operation to sync the cylinder operation, using a lever based operation.
Its only 10 weeks since i was at DLW, memory loss inbound!!!

 

Are there known principles behind this type of set up,?
I ask because its not a system that is widely used in the UK, and more to the point, is there anyone living, who understands it, how does it vary from Capriotti valve gear as this uses cams to operate the mechanical parts of the valve layout.

 

Blimey.
And some people think Bulleid valve gear is complicated!

 

Are drawings available? I'd be very interested to peruse if so...

 

Could we place the above in the P2 thread please folks?

 

Cylinders and valve gear



The idea to model No. 2007 on Cock o’ the North meant that rotary valve gear was inevitable. Some changes have been made to the proportions of the cylinders to compensate for the increased boiler pressure available from the 250lb/sq in diagram 118A fitted to Tornado. However, the Lentz gear used on the original offered only limited cut-off settings and may have contributed, in part, to No. 2001’s high coal consumption. The Trust looked at British Caprotti valve gear using a derived drive for the centre cylinder; this valve gear was perfected in its application to No. 71000 Duke of Gloucester and offers infinitely variable cut-offs, although the 71000 SLT is still developing and refining the gear. In the end the availability of drawings and technical specification for the Franklin derivative of the Lentz meant it was decided to follow this route, incorporating the improvements made in the U.S.A. into the valve gear.

Cylinder

 

Thanks but was aware of that. I presume patents have now elapsed, but the Eliot design, which I assume is novel ? ...does that require patent protection ?

 

I’m just this minute back off holiday. I thought the valve gear was well documented on the website? I’ll see what I can find and link it. The nub of the Elliott mods, iirc, were mainly to the steam and exhaust passages to even up the pressure drops and, importantly, to keep the steam and exhaust channels apart to avoid heat transfer from one to the other.

 

I suggest this page from the P2 website is a good place to start for those not familiar with the new P2’s cylinders and valve gear. Embedded within is an excellent (and now poignant) video by David Elliott where he takes the viewer through the key design changes from the original.

https://www.a1steam.com/p2monobloc#/

There’s much more detail here, in the document issued to launch the Valve Gear Club, which I can’t find in the website now, apart from in a very simplified form. Yes I know it’s on Facebook, but hopefully the privacy level is set to Public.

https://www.a1steam.com/Portals/0/adam/Content/8OEufULbq0uiqvHvsSmkXA/Link/VGC MAR 2024 REV 8pp_WEB.pdf?fbclid=IwZXh0bgNhZW0CMTEAAR3KNnCbxeL7QI1b5eitPhgXRdFDx6imsX1DNEicX2Ar0rAeUFjkPHVYY3g_aem_JEoqhwQEFxX2Ues5MtCTMQ

 

There are several live steam model engineered versions of the P2 with fully working gear, the technology is understoofd by sevral