Sir Nigel Gresley - The L.N.E.R.’s First C.M.E.

Double heading by what though? How were the routes operated before? If you have services that are currently operated by pairs of pre group 4-4-0s then building an 8 coupled express locomotive to run the service seems as if it ought to save money and enable you to withdraw obsolescent stock, if only by cascading the 4-4-0s to replace even older engines elsewhere. I don't know about the LNER, but in the 30s the GWR was using the renewals fund to replace 4-4-0s and older 0-6-0s with smaller numbers of 4-6-0s. If you haven't already done it then it might be instructive to look at shed allocations and see how the mix was changing. Its going to be muddied by increasing train weights and post depression traffic changes, but one can hope something will be visible.

 

In the case of Edinburgh-Aberdeen, I think on the passenger side it was Atlantics piloted by 4-4-0s. According to McKillop, who was driving the 4-4-0s at the time, there was a lot of double heading especially in the summer months.

 

The first standard three-cylinder pacific in Germany (01.1001) was not delivered until the end of August 1939 and went straight to the Gruenewald test centre for initial trials while the first 03.10 light pacific was not completed until the end of December 1939 and taken in to stock in January 1940, so neither actually did any work at all before the war. Both classes were initially permitted to run at 150 Km/h, later reduced to 140 (at the same time as the electric classes permitted 150) the exact reason is not known to me but wartime conditions must have played a large part in the decision.
To complete the story on numbers; 205 Class 01.10 were ordered but early in 1940 the order was cancelled except for those where the raw materials had already been purchased and eventually 55 were completed during 1940. 92 Class 03.10 were ordered; I'm not sure when the order was cancelled but construction continued throughout 1940 and 1941 and eventually 60 were completed.

 

If that wasn't the reason for building a few new big locos, what was the reason? Heavier trains than had previously been run on the Aberdeen road?

 

Thank You for clairifying the timelines.
Proff Nordmann described in 1935 that two cylinder 03 could run 130 kmh but it was not a good solution.
I did not realise that they were ordered so late just before war.

 

I think there was a desire for a locomotive that could meet the point to point timings without a need to push them on the Aberdeen road. That understandably leads to the design of a locomotive with eight coupled wheels as opposed six.

However Gresley's Pacifics, in particular the A4s, showed up the P2s on a mechanical and reliability basis whilst doing the same work.

I think you can make an arguement for building them, and testing them, as stated by Tom earlier, but I think arguing for their retention is much, much harder, particularly now we have statistics like that in the Use of Engine Power document.

 

If you are an innovator rather than an incrementalist, then one of the acid tests is the ratio of hits to misses. Churchward, Stanier, they all made mistakes. But they learned from them.

Was there a story about the Aberdeen road being strengthened in wartime? I'm wondering if the civil engineers were part of the story. When were A1/A3s first allowed up there?

 

Simon - I think you have overlooked the fact that the P2s were offered as a solution in 1933. That they were not, or alternatively according to ones viewpoint, to have problems is trying to do so is not disputed. However, in practical terms, the A4s were not available in any numbers until 1937 or so to be spared for the Edinburgh - Aberdeen line, so this left only the introduced V2s from 1936 as the only possible alternative. I'd disregard the W1 as it was only there for a short time on trial. The A2s could be said to be later alternative.

 

I don’t think that I have, tbh. There were only two authorised for building in 1933 and it was not until 1936 that we had the P2s in more numbers.

But the issue I am trying to highlight is that the argument against rebuilding or replacement is often given as only the P2s could do the work required on the Aberdeen route.That was never true and highlighted, not by me, but by the use of engine power together with obvious photographs of other classes on the same or similar trains.

 

From memory I believe that the V2s were popular performers on the Aberdeen services; does the locomotive records confirm this and provide a valid comparison with the earlier P2s ? As an interesting aside could the use of V2 instead of P2 been a better and more practical move ?

 

Does route availability come into it at different dates? I don't have the LNER RA classification for different types, but the P2s had a lower axle loading than the majority of LNER Pacifics. I have the impression that all the big 4 upgraded routes when they could, and that during the war a number of critical lines were specifically upgraded.

 

The P2s were designed as appropriate new motive power for the Aberdeen road. In service they did the job (with some ifs and buts). Subsequently Pacifics (and even V2s?) did the same job, as well or better. Why did Gresley consider that an 8-coupled design was needed? Why did 6-coupled locos turn out to be adequate after all?

 

On the Aberdeen route by the late 1930s you could and did have the Pacifics, the P2s and V2s working alongside each other. (There was also the W1, but that was in the 1940s).

In the early days - 1920s - it was forbidden to double head with the Pacifics due to axle loads/total weight on the track.

That was where the idea of a Mikado likely originated by the early 1930s when Bulleid and Gresley starting working on the P2 design.

By the time of the second world war, the Aberdeen route is host to A3s, A4s, V2s, P2s and the W1 on trial. Of those classes, the P2s have the worst mileages and the worst reliability with some safety related concerns (crank axle failures) too.

It doesn't seem to me to be a jump to suggest at the point just before a decision was made on rebuilding that the P2s could have been

• scrapped with no replacement necessary
• scrapped and replacements of V2 or better provided
• rebuilt after being stopped for analysis (bear in mind, WW2, every available loco required)
• rebuilt to Pacific format

If the P2s' issues had been in isolation, and other classes weren't doing their work adequately, then I think you could possibly argue for retention of the P2s. But the issues weren't in isolation and other classes were proving adequate for the same tasks. I think it becomes a no brainer, tbh.

 

Could I pick you up on that first sentence Simon.

Were A1/A3s permitted at all on the route in the early 30s? My conjecture is that they were not, so the business case for the P2s in say 1932 was based on increased power to meet the traffic needs within the axle weight constraints set by the civil engineer. If the option of building another six A3s had been available at the time, the business case would have been that much more difficult to demonstrate to the Board.

I did have a quick look at Shed Bash UK which shows two A3s at Ferryhill in 1937, but unfortunately no observations before that.

 

RCTS 2A, page 81:

There's more there but I am writing from my notes. In short, yes the Pacifics were working the Aberdeen route in the early 1930s.

The P2s arrival by 1937 enabled the Pacifics that were working there to be released elsewhere, by the way.

 

The main "issues" surrounding the P2 problems would IMO have been resolved, but for one major world issue. That being down to the "Austrian Corporal's" [aka Hitler] attempted world domination, i.e. WW2. Had Hitler held off his invasion of Poland until around 1945 +/-, then the issues surrounding the P2s could well have been [at a very minimum]well on the way of being cured/rectified......Even allowing for Gresley's retirement in 1941,when he 65.

 

I beg to differ here, the main problem being to carry out the necessary modifications within our restricted British load gauge. The big problem, in my opinion, would be the provision of some side play for the coupled axle wheel sets in the existing rigid wheelbase. To overcome this the frames would need modifying to be closer together and a replacement cylinder block with wider spaced outside cylinder piston rod centres. This could permit a side play of (say) 1" either side for the 1st and 4th coupled wheel sets and give scope for fitting of either a Krauss-Helmholz or Zara pony truck. The cylinders would have to be reduced in diameter to keep within the permitted load gauge width over the cylinders, and to compensate, boiler pressure raised to (say) 250 psi, a pressure not accepted by Gresley until the A4 of 1935, some two years later. I have yet to see anything stated by the P2 2007 Group about this aspect in their version of the P2, so can only assume that the coupled axle wheelbase is still as rigid as the original locos. It is for this and other reasons that I have reservations over this project.

 

Not required: the biggest issue with the wheelbase was the pony truck, for which a new version of the revised (Thompson/Stanier) side control spring pony truck is being used. This has been put through the Vampire software to examine the characteristics of the locomotive's chassis.



https://nearyou.imeche.org/docs/def...esentations/151217-p2-locomotive.pdf?sfvrsn=4

The design study can be found here: https://www.a1steam.com/educational-resources/prince-of-wales/design-study

And the bit you need is this:



https://www.a1steam.com/educational-resources/prince-of-wales/design-study

The issue was never the rigid wheelbase, it was always the pony truck.

Hence, I am a founder member of the P2 Trust (no.103). I have faith in the David Elliott developments.

 

It seems to me from the discussion that the big issue with the P2 was trying to fit it into the relatively restricted UK loading gauge, and that forced some solutions that were not ideal