Best & Worst Locos to Drive

Could go either way with that statement, but I'll stick with my guns and say missing the presence of locomotives which didn't have to be flogged or assisted up the grade.

 

I have always understood that the Horwich Crabs and later the Black 5s performed very capably on the Highland?
I would have thought that if a more powerful loco had been needed, they would have been provided. Later LMS practice wouldn't have put up with inadequate motive power (having learned from early problems).

 

Always got the impression from the reading that the LMS went too much for cost efficiency at the expense of getting people there on time, which was a cardinal sin on the Southern. Charles Fairburn's mantra of 'if it's nice to begin with...' also rings true from the passenger perspective.

 

Didn't Tuplin speculate that something similar, but with lever reverse, might have happened on the footplate of Lady of Lyons, as he thought it unlikely they would have been so reckless as to go that fast deliberately.

 

Would that be possible with a pole reverser which is locked in the quadrant? I'll have to re read Tuplin's book.

 

Tuplin's speculation was that they attempted to move the reverser at high speed and it flew into full gear. One must be very wary of Tuplin though. Whilst he was a professional mechanical engineer in a different field, as well as a great steam enthusiast, we are all amateurs when we are away from our speciality, and his theories were not well regarded by the professional steam engineers.

I find this whole topic very puzzling. There seem to be any number of references from back in the day to difficulties in adjusting cutoff with the lever reverse, and there appears to have been a definite GWR policy to replace lever reverse with screw reverse on passenger locomotives, piston valve as well as slide valve. If ease of adjusting cut off was not an issue with the piston valve locomotives, what might have been the motivation for replacing the simpler and cheaper lever reverse with the more complex screw reverse?

 

So true! Something we all ought to remember.

This was the era of other improbable claims, notably in the U.S.A. Without a Flaman recorder or dynamometer car around I am inclined to be cautious/suspicious about claims of this kind.

PH

 

Two possibilities, for which I offer no evidence to back them up, just supposition: One is that a lever reverse in the cab takes up a lot of space (and my experience of GWR cabs is that they aren't exactly commodious at the best of times), so changing to a screw reverse may have been felt to improve crew comfort somewhat. In addition, the bigger the loco, the heavier the motion, for which you would need taller and taller pole reversers to move easily; at some point there must come a size and weight of motion where a lever revers is no longer practical within the confines of the cab.

The other possibility is that a lever reverse may only have about ten or so gradations (i.e. notches) between mid and full gear, whereas a screw reverse - while not infinitely variable - offers greater fine control. So conceivably the GWR felt the efficiency from greater control more than offset the extra expense of fitting.

Tom

 

I would just like to point out that the screw reverser was a John Ramsbottom invention for the LNWR, showing the GWR the way forward!

 

Far more lock positions are available with a screw reverser compared to a lever - so with the screw cut off settings only a couple of % different are possible - important on high speed long distance trips. However the screw reverser would certainly have been more expensive to produce & recondition than the lever alternative. Those big reversing levers need some strength to operate with the risk of one moving into full gear at speed with attendant risk of injury.

 

You could be right, I seem to remember that the lever I saw the driver having trouble with on the 4700 was nearly as tall as him

 

We've been talking about GWR reverserrs but, don't forget, all the railways went over to screw reversers for all but shunting locos. The GWR generally went for Stephenson's link which requires the link and eccentric rods to be lifted. With larger locos, the valve gear gets rather heavy. Even though it can be balanced with a spring or counterweight the balancing is far from perfect and the valve gear will have a tendency to drop into a full gear if unchecked. Which way will depend on the layout of the gear but it is generally into forward gear.
Even with Walschaerts, which is a much lighter gear requiring only the radius rod to be lifted, it is generally harder to wind a loco into back gear than fore gear, even if balanced by a spring. Gravity is pretty strong stuff. I've had to drive a Walschaerts loco after the balance spring had broken and, believe me, winding it into back gear was a test of physical strength. It would have been impossible with a pole reverse.

 

Dean used screw reversers, later using steam reversing on some larger locos.

 

Gents - Couple of questions I'm curious about:

(1)What's the maximum shifted by certain classes? On railtour duties apparently an A4 has shifted load 10, on the ELR at bury the 3F 47324 has handled load 6 between rawtenstall & bury, up to heywood which IIRC is a 1 in 36 gradient it's allowed load 4.

(2)Which loco is easiest for a novice/trainee to learn on? Eg simplest cab layout etc & simple to fire.

(3)What was 71000 like generally? Obviously it was an experimental loco that had quite a bit of new kit fitted. It's performed reasonably enough in pres & mainline, however I do know that the caprotti valve gear has given issues before now.

Apart from that the duke has performed well & seemed very popular while at bury. Dunno if it's just me but from ground level or platform level it seems quite big for a 4-6-2. At least now 71000 is on the recovery road after changing owners & is at tyseley having overhaul & supposedly some bits are being re-engineered.

 

Right where to begin?!
Luke I believe the maximum shifted by a GW 38xx in preservation was back in 1993 at the East Lancs when 3822 took 22 bogies unassisted out of Bury. There are stories of V2's taking similar loads out of KX in WWII and the loco being halfway up Gasworks Tunnel.
Going the other way I believe the SVR now has a load 6 limit on it's smaller loco's such as 1501, 7714, 5764 and 4566 Yes they are capable of more but how much more do you wish to add to the next overhaul?

As regards the Duke the owning group have put right many of the wrongs that were bestowed upon it in its previous life I'm not sure of the technical stuff but I think there were various components that weren't as they should be shall we say! But what the 71000 people have done is fantastic, I wonder would have happened if 71000 had worked straight from the box? Would we have been looking at a few more Dukes built?

 

The SVR's limits are 200 tons for 4566 and 210 tons for the other three locos mentioned.

 

What a loco will work is far more than you'd really want to put behind it in preservation. The load for the V2 during WWII mentioned above was just short of 900 tons with 28 bogies. An A4 was seen with 29 bogies but the actual weight was a bit lower. These were far from isolated cases on the LNER. There is a mention in Adrian Vaughan's 'Obstruction Danger' of a collision at Curry Rivel Jct in 1923 between an 0-4-2T No. 215 and Star class 4-6-0 (an express passenger engine!) 4048 Princess Victoria, this latter hauling 32 loaded cattle wagon and 20 of general merchandise, 712 tons including the 20 ton brake van. A regular job from Dallam Branch Sidings to Arpley yard in Warrington was generally 90 empty wagons - about 650 tons - behind a Jinty. It wasn't far and slightly down grade all the way, but even so...

Generally, most engines will get on the move whatever you put behind them, but there's inevitably a price to pay.

 

If those 90 wagons behind the Juinty were unfitted the main problem would surely be stopping it!

 

You can't really give a maximum for a class unless you also give the gradients and durations etc. As an example, on the Bluebell (maximum gradient 1 in 55; and a fairly sustained climb mostly at 1 in 75 or steeper for about 7 miles in one direction), our P class locos are limited to the equivalent of two Mark 1s. When 323 went to the Battlefield Line, there were plenty of photos of her taking three Mark 1s plus a van, but presumably over much more benign gradients. When she is used as a pilot engine, she will routinely take 6 vintage bogie coaches out of the carriage shed (load about 185 tons) which is quite steeply uphill round a reverse curve, but the shunt only takes a minute or two of sustained work.

The biggest load I have personally had was about 420 tons tare / 450 gross behind the S15 (8 coaches, plus a West Country being towed in light steam doing no work) going to Kingscote. My impression was that, to meet the requirements of the timetable, the loco had plenty more power in reserve (whether you define that in terms of cylinder power or capacity to make steam) than a P class does with two coaches going up to Imberhorne Summit.

There's lots to think about when considering sensible load limits for each type of loco on a given line. As @LMS2968 says, most locos would probably haul more than we give them, but long term, if you consistently work an engine close to its limit, you just run the risk that each overhaul becomes more expensive, or comes at a lower mileage (which amounts to much the same thing).

Once you get beyond the inherent issue of being able to place coal in the right part of the grate, my personal view is that if you really want to learn, going somewhere with a lot of variety of engines will ultimately pay dividends, since it will force you to really think about the relationship between the state of the fire, water level, pressure and your position on the line, and how that relates to what you need to do at any particular point in time. So a better question than "which is easiest ..." would be "where can I get the most experience..." But if I really had to choose one loco above others as a fireman, it would be the SECR H class.

Tom

 

Black Prince has moved a 1000 ton stone train at Foster Yeoman's Merehead Quarry (they have also shifted 1700 tons there with a pair of 9Fs 92212 and 92203). I have a vague recollection that they claimed Black Prince broke a record held by The Great Bear.