Swanage Railway General Discussion

Or come to the NNR next week. No timetable yet but I would have thought it will run alone even if its on something light like the Quad Arts

 

419 I'm afraid failed at Corfe and is in the sidings there (valve gear?) The freight has been canned. About 30 minutes down now roughly

 

419 made it back to Swanage

 

419 has been turned again. It is now piloting 30120 on the 16:00 Swanage to Norden service, as per the roster, running approx. 20 mins late.

Both locos are facing Norden. <BJ>.

 

Smaller firebox on a 439 tank compared an M7. Tractive effort 18,680 lbf and 19,750 lbf respectively!

 

TE isn’t the clue but maybe small firebox is. Suspect there are other problems though. Just hope it works Saturday

 

Might you allude? Assume you don't mean problems with the loco (passed Swanage's acceptance exam) so assume design?

 

Yes, I understand that. Interested to see what other problems Gricerdon thinks there are for the loco not managing the same load as the M7. My point re acceptance exam was based on the test run last week with 6 coaches - there was nothing wrong with the loco then, it just had nothing left to give! Hence in what he believed the other problems to be.

 

It didn’t start as planned today so perhaps issues developed after acceptance. Just saying that TE isn’t always the best guide to power. Hopefully nothing serious has arisen and it can work Saturday

 

I believe it had 6 on when it failed to reach Harmans Cross, stopped at the bottom of our road. Built up steam for 10 minutes then started possibly with a bit of help from diesel banker. Not sure as I only have partial view of the track.

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There's a factor in all this discussion of the relative capabilities of the M7 vs Caley Tank which is being ignored, which is that one is a home loco and one a visitor. I in no way wish to malign the quality of the Swanage crews, but if you put even a good crew on an unfamiliar loco with a big load, they will take time before they get the best out of the loco. What sort of fire does it want? How fast are the injectors? Are they reliable? How far does the water drop when you shut the regulator over a summit? How responsive to damper or firehole door positions is it? How easy is it to get into big valve - and even more, how easy to get back out again? There are various factors that might make you cautious about the capabilities of an unfamiliar loco. If you gave the crew a week on it, they'd have the loco metaphorically eating out of their hands by the end, but it is unrealistic to think that a crew getting on an engine for the first time will have the same confidence in its capabilities as they have with a member of the home fleet that they have driven and fired scores of times.

Tom

 

Yes that’s all very true BUT I remember M7s taking 12 coach empty stock out of Waterloo in 1962 with no problems.

 

Then the GWR Panniers arrived but the NE men preferred the M7s rather proving the point made by Tom

 

I know nothing about firing a locomotive but living about half a mile from Harmans Cross station I can tell when a locomotive is struggling. The Std Tank powers up the hill easily. Cannot comment on the M7 still learning the sounds of the different locos.

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For a while in the early 60's an M7 would bring an empty train (I think it was the Royal Wessex stock) all the way to Woking at a steady 20mph around noon and stay a couple of hours in the down sidings for cleaning before returning to Waterloo.

 

In wondering why the Caley tank is on light duties another factor to take in to consideration is the temporary speed restriction on the climb from Swanage to Harmans. Whilst working up the 1/78 at 25MPH you have to shut of and drop the speed to 15 then open up again and slog through 400 odd meters of climb before accelerating up to line speed again, as well as you can against the gradient, to try to keep section time. This is very hard on boiler water consumption necessitating more use of the injectors.

I'll expand on what others have said about Tractive Effort. Although on paper the numbers are similar with the boiler pressure near the mark, the problem is in being able to sustain the rate of steam generation in order to maintain that rated TE. This is in large part to do with the size of the firebox. Grate area & evaporative area. I don't have the figgures to hand but these both look to be considerably smaller on the Caley tank. More injector use further increases the boiler load.

The factors @Jamessquared notes above also have a big bearing and the TSR is probably the nail in the coffin. If the crews went on their toes, the M7 could struggle with a TSR and its not unknown for the inexperienced or unfamiliar to stop short of Harmans for a blow up.

 

It’s done ok so far today working with 80104 and will work a 2 coach 1226 ex Swanage next.