How good was Gresley?

[Paul_sterling]

But even then they had a much worse availability than the LMS Pacifics. This meant that the LNER needed 10 engines to do the same work the LMS used eight for.

Hi all,

I've only just read through this thread, and there is one post which stood out to me. Whilst I only have one piece of information in respect of maintenance of LMS vs LNER Pacifics, and it does not consider cost of maintenance, only the time between overhauls. O.S. Nock reported that most of the principal express locomotives of the UK, prior to the BR Standards, averaged between 80-85,000 miles between intermediate overhauls, I'll find the exact numbers later, but in that respect alone, the A4's, A3's and Duchesses, were all very similar in respect of milaege, the rank outsiders were the Bullieds (which were still being sorted out, so not quite as good), and the A1's (which although all less than 5 years old at the time, were achieving 90,000 plus, and more).

Paul.

[Paul_sterling]

Okay, so following up on what I said earlier about mileages between periodical repairs, this is the info according to Nock

Peppercorn A1 93,363
(unclarified) A2 85,671 (the book does not define if this was a Pepp or a Thomson, but I would assume its a Pepp )
Gresley A3 83,674
Gresley A4 86,614
Stanier Coronation 73,188
Collett King 78,897
Bullied MN 75,687
Collett Castle 87,424

To add some clarity to this, the A3's, were in 1950, all at least 15 years old, A4's at least 12, A1's were all less than 2 (but continued in this excellent form for much of their working lives), Castles were anywhere from 27 years old, to brand new. Nock also commented that by that time, it was more common for an engine to stay in front line work right upto the point of shopping, rather than being relegated to less arduous tasks, suggesting that even though the Gresley machines were ageing, they were performing as good as ever, and compared well to other contemporary classes of engine, despite the advances in technology being made since they were built.

Thanks, Paul.

[Hatfield Shed]

The arithmetic mean is a nice easy measurement, but supplies very little insight.

For example I might guess that the figure for the Stanier pacific may relate to their having the heaviest workload, and getting pulled in on an annual schedule - probably aligned with the the reduced winter traffic - to ensure as few failures as possible when the traffic demand was at peak. (73,000 miles looks spookily close to a year's work at the mean 200-ish miles per day that this class achieved.)

If we had the distibutions for each of those classes, there would be much more to see.

[S.A.C. Martin]

Okay, so following up on what I said earlier about mileages between periodical repairs, this is the info according to Nock

Peppercorn A1 93,363
(unclarified) A2 85,671 (the book does not define if this was a Pepp or a Thomson, but I would assume its a Pepp )

If I may Paul - can happily confirm that the A2 class was the Thompson A2/3.

This is based on study of the engine record cards of the LNER pacifics, available in the NRM, York for study in "Search Engine" and also the "Use of Engine Power" document in Kew Gardens, National Archives.

Best wishes.

[Paul_sterling]

Well I'm unconvinced, as the dating of the document would have meant that an A2 would have been a Pepp by then, with sub classes annotated as such. Fair do's for checking the records you noted, but I am still skeptical of any reasonable performance in terms of serviceability from a design which "looks" wrong nevermind getting into the actual technical details.

Paul.

[S.A.C. Martin]

Well I'm unconvinced, as the dating of the document would have meant that an A2 would have been a Pepp by then, with sub classes annotated as such. Fair do's for checking the records you noted, but I am still skeptical of any reasonable performance in terms of serviceability from a design which "looks" wrong nevermind getting into the actual technical details.

Paul.

Apologies for missing this.

Paul, I have the mileages and availability statistics for all of the LNER Pacifics from 1942 onwards to withdrawal. These come from the LNER and then British Railways Eastern Region records, most of which are available in various forms from the NRM and the National Archives at Kew.

It was the A2/3 Pacific class I am afraid. That's factual. You need to not let your prejudices get the better of a factual and constructive discussion. Best wishes.

[S.A.C. Martin]

I've been asked to share the above by a member of the RCTS - so please consider this as a heads up that I am giving what is likely to be my final lecture on Gresley ahead of publishing my book on Gresley. All welcome!

The R.C.T.S. have been a great friend to me, with support for the Thompson book and research and now also the Gresley book by way of making available for publication many of the drawings they have collated over the years. I am very grateful to them for their support.