Edward Thompson: Wartime C.M.E. Discussion

Richard, if you like you are more than welcome to join the small band of readers who have now read the current draft in exchange for your views. That goes for everyone who would like to "peer review" for something to do during lockdown. I am more than happy to share the manuscript out.

 

That was not what I was led to believe from those who drove locos with conjugated valve gear hence my original query. I would be interested in the experience of footplate crews - especially those with main line Gresley loco experience.

 

You're obviously not convinced by my experience of 60007/60009 & 60800 or engineering knowledge so I'll have to leave it to others to convince you.

 

I'd love to read through your draft Simon, but I don't think I'd be able to add to any discussion more than others have already done. There are some very knowledgeable people here, far more so than myself! I have learned much that I had no idea about from reading this thread, which is precisely why your book will be so interesting. It's going to fill a huge gap in LNER history, and is going to be a massive and necessary re-appraisal of a much-maligned character, of whom we have been fed many misconceptions and altered truths over the years.

Richard.

 

I'm certainly looking forward to buying a copy, not least so I can gleefully lend it to one or two blinkered individuals who won't hear a word in favour of Thompson - and this is in GWR country!

 

Steve, noting of course your avatar (which I’m always a bit envious of!) - what are your views on the slipping of British Pacifics? All a much of a muchness or are some really that bad compared to others?

 

My experience of pacifics is limited to several West Countries (no BOB's!), 60007, 60009, 60163, 60532 & 71000 so not too much to go on. However, I can't really say I've noticed much difference between them and most other locos, although those with no carrying wheels are definitely better. Besides the obvious weather factor, location can play a part. For example, it's much easier to get a clean start from platform 2 at Grosmont than platform 3 or 4. I find that a warm loco is much easier as the wheels have dried out and there is less 'cold' steam (water vapour) finding its way out of the cylinders and condensing on the wheel and rail. The feel of the regulator varies from loco to loco and some are much easier than others in this respect. I prefer the Standards to Black 5's and the B1 for this. Perhaps it is due to the arrangement of the regulator rods as you are not trying to twist a long shaft.

 

Since I was not aware of that experience I had no way of judging whether your response was that of an "armchair warrior", a gifted amateur or a qualified engineer. Had you given some indication in your original reply (e.g. in my footplate experience of 60007 / 9 & 60800) then it may have given better credence and I might not have had to retain my uncertainty regarding the operation of the conjugated gear.

 

In The Red Devil, David Wardale had a picture of cylinder drain pipes discharging over the rail head and described it, quite rightly, as 'The Kingdom of Railway Stupidity'

 

Fred - if you have been on this forum since 2006 and you haven't yet worked out that in locomotive matters (and many others) @Steve really knows his onions, then I'm afraid you really haven't been paying sufficient attention!

Tom

 

Thank you Steve. Pretty much confirming my belief. A lot of the criticisms of the locomotives involved in the whole "what slips more" perennial debate are likely going to be down to the environment the locomotive runs in more than the locomotive itself, and the driver.

It's really interesting to hear you speak on this. One thing notable - the standard 5MT is a development of LMS and LNER engineering. The chassis is LNER through Doncaster, the boiler, cab and tender are LMS. Best of both worlds?

 

Gents - agree we should all be more mindful of each other's various skills and talents - but also, we all make mistakes. Let's not get bogged down in the small stuff. I am very grateful for Fred's and Steve's excellent contributions to this topic (and long may that be the case).

 

On the Manx 'Peacocks', the drain pipes discharge over the suspension and bearings on leading pony truck, something even the most ardent lovers of these superb little locos concede isn't exactly their best design feature. With inside bearings on it's leading truck, big sister Metropolitan No.23 is probably better in this regard .... pity we're unlikely ever to find out for sure.

 

Two other random thoughts about slipping:

1) We should probably distinguish between slipping on start and slipping at speed; those are two different phenomena. The early Bulleid Pacifics gained a reputation for slipping at speed, which is where I think the faulty initial reverser design comes into play (it didn't readily allow small changes in cut-off and a sudden large change might be sufficient to induce a slip). By and large, those issues gradually got ironed out, and most drivers adapted their driving style so as not to touch the reverser too much once up to speed.

2) For a passenger locomotive with rigidly coupled stock (i.e. buckeyes) is that the entire weight of the train has to be started at once with a direct drive from the piston. I can't think of another situation where that is true: in most other vehicles (whether it is a car with the power mediated through a clutch; a diesel-electric locomotive where there is an intermediate electrical system; a boat where the screw moves through fluid etc), the drive train allows a degree of slip on starting. A steam locomotive doesn't have that ability. That makes starting a heavy train particularly difficult.

Tom

 

Interesting point, given that the GWR & LMS didnt use Buckeyes might that account for some of the differences, in particular given that the sort of trains that Pacifics would mostly be used on would be formed of the newest stock?

 

Something that hasn't been fully raised here is the issue of starting a train on a curve. That it takes more effort to do so caused by the resistance of the rolling stock is generally agreed. However, for the loco the problem is that the outside rail over a given track length is longer than the inside one so the driving wheels have to travel further on the outside rail, or less on the inside one. This means that at times only one side of the locos driving wheels are gripping and the other side not. If all bits of track at starting points were straight this would make starting a train easier.

 

I know that the BR Mk1s had buckeyes, but which previous generations of stock had buckeyes? I'm just wondering how much that would have been a factor when the Bulleids were building their reputations, when I presume they would have been hauling trains made up of Maunsell and Bulleid stock.

 

Don't forget to add flange lubricators to the list of variables which add to the fun on curved track.