New Build P2

I can vouch for that. I was able to ride, just before it was scrapped, on 60113 Great Northern's footplate which Thompson had had his mits on. How the crew managed to fire and drive that thing was a miracle it was like a snake. On another point all news seems to have dried up about the Doncaster P2 Locomotive Trust.........If I ever get to see one of these before I go belly up I'll be a very happy man....

 

I don't wish to sound trite as first hand experience from the steam era is a godsend for those of us who weren't around to experience it, but if this was 1960 (before it was scrapped), then wouldn't 60113 have been particularly run down in its condition?

I have been researching this locomotive for over four years for a model build (that's another story entirely!) and one of the things which strikes me is the sheer amount of extreme views to one way or another about the lone A1/1 without quantifying the relevance of the evidence provided.

The A1/1 when you rode it may certainly have been a rough machine, but if it was just before withdrawal (due to a worn centre cylinder), then it stands to reason the locomotive was on its last legs and that your experience was not indicative of the locomotive's performance when it was new, or well maintained.

Much of that I have read on this locomotive - be it from O.S. Nock, (who was gracious in Thompson's aspirations for the locomotive type and noted its ability to steam exceedingly well, and its ride quality, described in British Locomotive Performance as "smooth" I seem to recall), Cecil J. Allen (who to be quite frank, in his book British Pacific Locomotives casts some rather supurious aspirations on both designer and locomotive that have little evidence and are cast into a different light when you read Peter Grafton's book on Edward Thompson), or any of the other timekeepers and locomotive drivers of the time, make the case that the locomotive was better than the single chimney A1s and A4s of the time (prior to their fitting with kylchap exhausts in the late 50s/60s) and the equal of a kylchap fitted A4 in many respects bar the smoke deflection (although it is intimated the A1/1 may have been intended to have been fitted with the A4 style front end. I wonder if it had, would it have been half as maligned as it is?).

Its biggest problem seems to be that is was a single locomotive with many unique components which were never made in the quantities that other classes had available to them, and a somewhat jaundiced view of the locomotive based purely on its name and debatable aesthetic qualities (though I find it a very handsome machine, perhaps not with the same clean lines as the A3s or A4s, but purposeful in the same way the Peppercorn machines appeal to me).

Sadly I can't verify (I was not there to experience it!) the actual condition or quality of the machine except by academia, so my question remains: isn't any locomotive poor when in a run down condition, and not well maintained? To single the lone A1/1 for such criticism seems unfair in light of its circumstances. There are several well documented accounts of how bad run down Gresley Pacifics were in the twilight days of steam, should they contribute to the reputation of their class as much in this respect?

The A1 Trust's first study is back soon, judging by the railway mags this month. I had heard this time last year that the frames for the DP2LT had been, or were in the process of being, ordered, but perhaps that was wishful thinking on the side of the mags which reported thusly.

I think most red blooded enthusiasts would love to see a P2, if not for the beauty of its form, then for seeing it alongside a supposedly massive locomotive like a 9F and putting the size into perspective!

 

The driver told me it was a rough riding loco all it's life. I came back on Silver Link which was as smooth as anything. They were both pretty much run down. Why they ever scrapped Silver Link I shall never know it was a scandal. If they build a P2 before I go belly up I'll be a very happy man. I thought they were absolutely gorgeous looking locos. I also am told that the B1's were very rough riding.

 

I'm more interested in the A1 Trust's P2 because I prefer the original form that 2001 and 2002 were built as and one of the most beautiful designs in loco history. Not so keen on the A4 front although if the Doncaster group pull theirs off maybe someone should start on a streamlined B17.

Wonder what 2007 would be named though I think each had of the 6 P2's had Scottish themed names.

I think the Doncaster group want to do a replica of 2001 in streamlined form I believe.

I too find it slightly sad that 2509/60014 Silver Link and indeed 6220/46220 Coronation weren't preserved especially with their places in history.

 

AE Durrant, Swindon and a man who very much had his eyes open, commented in his book Swindon Steam, on Thompson Pacifics "The philosophy behind them was appreciated, but the execution clearly, and visibly, faulty". He then goes on to wax somewhat lyrical about the Peppercorn A1s.

 

I'm just reading "LNER 2-8-2s & 2-6-2s" by J.F. Clay & J. Cliffe at the moment, which contains some interesting notes on the performance of Nos 2001 & 2002 as built.
The suggestion is that No. 2001 was very heavy on coal when being worked lightly, due to the amount of steam being admitted to the cylinders by the poppet valves. The book concurs that No. 2002 was more economical, using piston valves, and infinitely variable cut-off (No. 2001 had pre-set cut-off positions, and was less controllable).

Evidently the centreline of the axleboxes was not under the centreline of the frames, which led to rupturing of the oil film on the journals, and the crank axle would have benefitted from a larger diameter crankpin, and larger crank webs.

The book also mentions the inadequate bogie design too, and various suggestions from the likes of Andre Chapelon as to alternative designs.
I'm sure I've read in the past that the pony truck design of one of the 2-6-0 classes would have given a more satisfactory performance. Was it the K4 pony truck?
I've also read that a Krauss-Helmholtz pony truck would have been a better alternative, but whether this could be fitted on a 3-cylinder locomotive I don't know.

Are the A1 Steam Locomotive Trust considering any of the above modifications to the design, or will the new P2 be built as per the originals?
Clay & Cliffe suggested that, had the crank axle and axlebox issues been addressed, the P2s could very easily have been a much more successful design.

Richard.

 

I have always wondered if the cylinders not being located over the bogie was a cause of the snaking I experieced?

 

^^ @ Richard Roper - As has been stated previously, the A1 Trust are using the latest rail vehicle modelling software to simulate the performance of the chassis. This will include a modified front truck design. As for the boxes, I'd be very surprised if roller bearings aren't used as per the A1, as there'll be as much commonality as possible between the two loco's. I don't know about the crank axle, but again I'd expect it to follow the A1 design unless there's good reason not to.

 

Thank You for the info Sheff. Sounds like the new loco will be a very worthwhile project!

Richard.

 

On most engines, the C/Ls of boxes and frames were offset. The only British examples of centralised boxes I can think of are Bulleid and BR Standard pacifics and 9Fs. As far as I know, all the LNER pacifics had offset boxes, but I'm open to correction.

 

Unlike the Peppercorn A1's, the P2's drove to a common axle so a different crank arrangement will be needed.

With regard to no. 60113's ride, it may have more to do with thrust and resonance in the reciprocating masses rather than the position of the cylinders.

Foxy

 

Bulleid introduced the centering of the boxes on his Pacifics precisely because of his experience with 2001, but the hot box problems centered around test runs on the Vitry static plant and weren't generally experienced out on the road.

All the post Gresley LNER Pacifics had ride problems, incuding the Peppercorn A1's - mainly snaking on plain straght track - on the A1's at least they were apparently cured by introducing stronger bogie side control springs. Whether this was ever applied to the by-then-unpopular Thompsons I don't know.

 

What interesting replies......it's always fascinated me..thanks very much

 

Good little book that...

As others have stated the A1SLTs P2 will borrow heavily From the Developed Peppercorn design that is Tornado.
Boiler, Cab, Tender Practically identical to Tornado, Smokebox/ Draughting subject to appropriate modification (Double Kylchap) in line with 250psi, smaller cylinders (19 5/8ths ?) and valve gear based on BR Caprotti(ideally) Cylinders as 3separate casting
Cartazzi Geometry to be re examined, coupled axles on roller bearings, Pony truck to be as modified for the V2 (as opposed to original gresley swing link).

So whilst looking like Cock of the North the Build will be more Peppercorn/Harrison than Gresley...

 

As long as it looks like Cock O' The North as built, they can make what details improvements they like as far as I'm concerned.

 

The vast majority of locos have offset axleboxes simply because to do otherwise would mean moving the frameplates inwards and thus reducing the width of the firebox. Centralised axleboxes are only really possible on wide firebox locos.

The main reason for centralising the axleboxes is to reduce, if not eliminate, the bending stresses induced in the area of the horns, which is where most frames tend to crack. As long as the spring loads are central to the box there should be a fairly even load distribution across the bearing surface. The big problem with any conventional steam loco plain bearing is that the bearing is in the crown to take the vertical loads and not in line with the cylinders to take the thrust of the piston. A roller bearing largely overcomes this.
Reciprocating steam engines are effectively a double acting hammer, intent on destroying their component parts from the day it is first put into service.

 

Me too, as long as it looks like it ok by........the caprotti valve gear would very interesting.....can't wait.....

 

I dream of a P2 being unleashed on Shap, the Long Drag and other inclines of note and putting Kings and Duchesses firmly in their place.

 

This sounds good... Not an Engineer myself, just an interested bystander. But from what I've learned through reading and from 40 years of being interested in steam, the modifictaions should bring about a pretty outstanding locomotive. If only it could be extended to its full potential on today's railway!
I'll be following this project as it develops, and lending some support.

I must also admit to being really impressed by the 2 locos covered by chapter 1 of Clay & Cliffe, namely the P1 2-8-2s. If they had been built with long travel valves and 220Lb boilers, I'm pretty sure they would have lasted longer trhan they did. The photo of No. 2394 on the Scrap Line at Doncaster in 1945 shows a very imposing looking machine, albeit in sad circumstances.

Richard.

 

Potentially a very good boiler, very good steam distribution and better traction than a pacific (yes 242a1 i know it isnt always that simple) but to quote the theme tune from 'Dukes of Hazard' Straightnin the Curves (?), Flatnin the hills...