Edward Thompson: Wartime C.M.E. Discussion

well, best of luck with the hot towels. Just a question, were the mileages for 4469 removed from the data set?

 

That's an interesting question. I do not know the answer right now, but I will look at the spread sheet when I get a minute today and confirm with you. Off the top of my head, I think it does take into account the loss of that A4 - but potentially by simply eliminating it from that year's stats.

 

So just how does Aerolite stack up in the grand scheme of things?

Sorry Simon ..... couldn't resist!

 

If she was still in service, I will have the stats, mind!

 

Withdrawn 1934 - no dice. Sorry. If you do have a loco class you really want the stats for, I have everything from A1 to Z1, 1942-1946 (and in some cases, 1947).

 

B16/1/2/3?

 

Oh, dear. A1/1 60113 in disgrace having failed near Hatfield (34C) and dumped outside the back of the shed on September 4th, 1958. It seems to have suffered damage to the inside cylinder judging by the cover laying on the front buffer beam. According to Yeadon's Register it was in Doncaster Works from September 15th to October 8th for a Casual Heavy repair, presumably as a result of this incident.

 

Great photo - where did you find it? (Or is it one of yours?)

 

I will get those figures to you over the course of the next week or so.

 

My taking, I lived until 1999 at Brookmans Park some 3 miles south of Hatfield.

Somewhere I've got a photo of B2 61671 'Royal Sovereign' in an even worse condition. Must try and find it!

 

Thanks for the enunciation of the area codes although I had assumed the Pacific figures would relate to Kings Cross, Gateshead and Haymarket within the respective area codes. Noting the figures relate to 1942 I could surmise that Haymarket locos would be covering traffic from Rosyth to Colchester hence the use of A3s on the Aberdeen - Edinburgh - Newcastle workings whilst the A4s would be retained for Edinburgh - Newcastle workings, possibly operated further south. What is surprising is the poorer figures for Gateshead locos which suggests a limited route operation (Newcastle - Carlisle / Edinburgh / York perchance) with a greater variety of start/stop running. As I noted in the earlier post I would be interested in the external factors although acknowledging this to be outside the remit of your thesis re Thompson. Related to that I would also presume that the favourable figures of A2/2 Thane of Fife would be related to the fact it was a new locomotive whereas the others would have spent some time in service thus be in greater need of on-going maintenance.

Perhaps once you have completed the Thompson thesis a study of LNER Pacific running might be the next project ?

 

I will see what further details I have I can share with you, happily.

The problem with that theory is that most of the A2/2 was pure P2 retained. Down to the boiler, 3/4 of the frames, all driving wheels, even the connecting rods and walschaerts valve gear.

We’re talking about a difference of 20,000 miles, rostered to the same work, with the same crews, on the same trains.

I have now read some of the wartime board minutes and my immediate thought is that the crew response to the A2/2 and its immediate use are completely at odds with that reported since.

Why, is another matter.

I think a holiday from writing first and then conside what I have.

But I’d be lying if I said I hadn’t thought about it.

 

It’s a great photo. Thank you for sharing it.

 

Looks like it was squeezed through the shed with Vaseline! Smashing photo, though a one off incident tells us nothing.

 

Someone mentioned the V2s earlier - in interests of providing a comparison with the similar A2/1s I will endeavour to add them in due course.

Glancing at my notes, annual mileage across the whole line for V2s seems roughly around 36-40,000 miles across the war. Respectable figures - almost always higher than the majority of the Gresley Pacific classes (bar the Scottish A4s).

The W1 and Great Northern also present some surprising stats. But that’s for another time. Good night all.

 

Thank YOU and Goodnight !

 

It is still not clear to me why Thomson rebuilt the P2s as pacifics with divided drive.
In Yeadons book it is stated that all the Raven A2 frontdrive pacifics bar one, 2404, had new crankaxles within two years from new.
Bulleid pacifics did the same and Gressley P2 were not imune either.
Has it been written up somewhere?

 

Thompson rebuilt them as Pacifics as they were proving problematic during wartime, their annual mileages falling drastically as the war went on. There were issues with the axleboxes, broken crank axles, and several other issues together with overall availability. They were all suffering the seemingly universal issues with conjugated valve gear.

The divided drive came about due to the stress on all three cylinders driving onto one axle on the P2s. Hindsight and the P2 Trust's work shows that the crank axle was under-engineered in this area (Gresley had used the A1/A10/A3 crank axle type on the P2s). This crank axle type has been beefed up for the new P2.

By splitting the drive, the stresses of the three cylinders were spread across two axles and not one. The A2/2s did not ever suffer a crank axle failure again.

It also allowed Thompson to experiment in a very limited way for new build designs going forward. The extensive testing of no.2005, the prototype, compared for a year to the original P2s, informed the design process going forward.

The Raven A2s are not the Thompson A2s. They are a different type, all gone by the 1930s. Thompson reused the A2 identifier to show that the locomotive type was an express loco fitted with 6ft 2in driving wheels.

In several locations, quite a few books, and also written at length on here as well. Happy to talk you through it by PM if you would prefer.

 

Not really as the worst crankshaft stresses come from bending and here Thompsons solution is not better than the one schemed out here.

https://i.imgur.com/QnlK5Tp.jpg

 

I mean, we could argue the toss on this, but I've given you the historical reasons and the context - and it quite clearly did work, and the locomotives with divided drive continued in service until the early 60s and end of steam (in case of A2/3).

So I would humbly suggest Thompson's solution wasn't elegant, but it clearly worked and solved the problem that presented itself. Demonstrably so.