West Somerset Railway General Discussion

That was an interesting choice for the job! It does illustrate the need to use appropriate motive power for the job though. A big loco with large wheels makes it look easy, while same job for a small loco and wheels requires something nearer that locos performance limits.

 

Meanwhile, back to Somerset ... ...
How has the current lockdown affected the infrastructure work? If I remember aright, the grant money was offered for specific work over a specific timeframe?
Pat

 

A picture from today (posted on the West Somerset Railway friends group).

 

Thrashing of engines.
There are comment from time to time about thrashing engines, not limited to this thread, which I swore I’d never post on so here goes.

I’m interested what criteria people use when they say an engine’s been thrashed.
Is it regulator opening, cut off, noise from the chimney or some combination?
If you are not on the footplate, noise and what you see coming out of the chimney are surely the only pointers you have as to how the engine is being handled.

I don’t know if an observer would consider I’ve ever thrashed an engine, however I know that regulators can and do get opened fully. I can say that on everything from a P tank to an S15.
Some engines are just asking to be driven assertively especially ones chucked out of Wiltshire or Hampshire because of a feel of ruggedness, you’re not going to break it easily.
Both groups tend to have small pilot valves so you need to put the reg well across.
The Inspector on my tests wanted to me use ‘the full potential of the locomotive’. So full reg and full gear from a standing start on a 1 in 75. He wants to see the candidate is not scared of it.

Another point is on a smaller engine than class 2 you are often using all the boiler power so there’s no thrashing to be had because you can stand there and wave your water goodbye.
This means it can be hard to get back on the timetable because you’ve haven’t got much up your sleeve, a reserve of power is very handy to have. Not everybody will agree...

One last point, in the modern era we don’t work engines anything like as hard as they used to, they are (working) museum pieces after all.
I’m especially interested to hear from people with footplate experience.

 

In the context of the last time it was used on this thread, I got the impression that "thrashing" was used as shorthand for a loco being (potentially over) intensively used, rather than anything to do with regulator usage or hanging too much on the draw hook. Perhaps not the most conventional use of the word.

 

Surely thepost about WSR infrastructure works should be on the WSR thread????
Apologies...it is. I thought this was the inane waffle thread.

 

I believe they are one and the same.

 

If “thrashing” is a bad thing, then for a steam loco thrashing would involve such poor enginemanship as for the loco to prime and the priming not be dealt with.
“Being Thrashed” results in at best water treatment stains streaming down from the safety valves and chimney. At worst, being thrashed results in bent and broken metal.

 

Not much point opening the regulator of an S15 wide, plenty of go without, and the Urie version doesn't react well to such treatment.

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Interesting to note that David Wardale's work on the SAR class 26 he had the ratchet that is used to hold the regulator handle in position cut away between fully closed and fully open so that once underway the driver was to use the reverser to control with regulator full open. This is from my memory of a footplate trip back in the early 80s.

 

Your S15 must be different to the one I'm used to, then (825/841). That regulator has three positions: off, start and go. The first valve is Ok for getting the train moving but the main valve is necessary for anything else. And if you leave the handle in anything but the fully open position, it gets too hot to touch from being immediately over the firehole door. Just get it going on first valve, wind it back to about 20% and shove the handle right over then control it on the reverser. It just loves it; 8 on, 1 in 49, 25 mph. No Black 5 or B1 will do that.

 

Errr, Shouldn't the "Thrashing of steam Loco's be on a separate thread?
Looking at the photo (Post 36063) looks like the Doniford relay job is underway then.
Nice to see something positive on here for a change.

 

I believe this shows one of the key difference between the Urie & Maunsell S15's, full second valve on a Urie is likely to cause priming which will quickly cause the water to drop and the engine to start fighting itself due to too much steam being admitted to the cylinders; not to mention the poor fireman struggling to keep up with the steam & water usage!

 

I would like to have a go on a Urie one ...

My experience firing a Maunsell one is closer to @Steve. They do seem to like working hard. Put a decent load behind them and the coal flies off the shovel to where it is needed, the fire gets really hot and they steam really well. At night, or through the tunnel, you can see the firehole door glowing cherry red. By contrast, try them on a light load in first valve, and they can be a real handful to fire.

Tom

 

Being relatively ignorant of Southern locos , what are the key differences between a Urie & Maunsell S15? I thought the boiler was pretty similar; after all 30825's boiler was taken for use on a Urie S15 (30499?)

 

There are cosmetic differences such as the step in the running plate and cab, but the significant ones were:
- Urie ones had 180psi boiler pressure, Maunsell 200psi (but later increased on the Urie ones)
- Cylinder diameter reduced from 21 to 20.5" diameter
- Most significantly for their later form, the valve travel was increased in the Maunsell ones. I can't find the figures, but I think it was probably the same as in the N15 / King Arthur, which went from 5 1/8" travel / 1" lap on a Urie N15 to 6 9/16" travel / 1 1/4" lap on a Maunsell S15. There were also some "draughting changes" on a Maunsell one and a larger ashpan. Those valve gear changes were never updated in the Urie ones to bring them up to "Maunsell" spec.

I suspect the valve gear travel is at the root of the differences. Historically, the reputation was that, once they all had the same boilers, that the Urie ones were slightly better slogging on heavy freights, but the Maunsell ones were preferred for the faster passenger and fitted freight work.

Tom

 

Steve, you have the benefits of the Ashford improvements while 21B is still using the Eastleigh version. Harold Holcroft said that Jock Finlayson (chief draughtsman at Eastleigh) always denied that the Ashford version was an improvement. It will be interesting when 828 is running at the Mid Hants so there is a direct comparison.

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No crew who know their job will thrash an locomotive, because of the strong likelihood of picking the wheels up, and priming, yes an engine can sound like its being worked hard, when it is in fact being driven with in its limitations, And no two engines are the same, even classmates will be different, i have fired engines that are being worked hard, but certainly not being thrashed because i have plenty of steam and water in reserve and the drivers got the engine under control and balancing the demand of steam, with whats available as regards s15's, they are very good machines, better i would say than black 5's i can remember the sound of 506, hauling Britiania and its railtour stock and a 47 through Ropley non stop and up the hill, i never heard 70000, 506 sounded like she was doing all the work

 

Dunno about the other S15's, 847 will do barely 15 mph on the gradients with a normal load for us ie 5 or 6.
So every point in opening the regulator wide.
I fired the M7 years ago when it visited us. It was the same. Must be an Eastleigh thing.