Steam Banking up Shap

Would make a change to what were normally used to seeing. Lickey I must say is a fierce climb although I haven't been up the route I would like to on a steam trip at some point, The climb to Exeter Central from St David's is a nasty climb as on 2 occasions we have had incidents where engines have nearly trashed themselves as 76079 lost it's grip near the station at Central and 80080 Spun out at Central aswell causing damage to herself even with 80079 banking. Surprised that nobody's mentioned Beattock.

 

I was on that one as well

Not one of the finest moments in Post 68 steam history as far as I am aware..................

 

On the other hand, it did wonders for Nat Pres' member count! Everyone who wasn't on it had to join to find out what had happened!

Tom

 

So, what did happen??

 

What event are you referring to re 80079 & 80080?

 

Absolutely horrendous.

 

Er so why exactly did it all go so badly wrong with Tangmere & the Pocket Rocket?

 

After 80 lost her feet the train came to a stand. Both locomotives were then unable to get the train moving until (wait for it) a member of the SVR support crew climbed down from the support coach (which was at the rear of the train) and got into the driving seat 0f 79 and hey presto, the train got moving again. How? He got a further half a turn of the reverser to put it into full forward gear proper.

I had never seen that video before - thanks for posting it.

 

Overloaded. I believe it was stated on here that the load was 13 and it should not have been more than 11.

 

I understand what you mean when pointing out "civil engineering peculiarities". When you write of "cold" engine I am sure that you are referring to the problem of cylinders lacking a sufficient temperature to avoid losses due to condensation. Later designers were well aware of this problem which is why insulation and steam jacketing were considered to be very important. If the engine you are using is limited by the condensation issue then this can only be seen as poor design. Sadly the solution to the condensation issue appears in very few machines. But you know this.

Do you drive a car? How frequently do you have to make use of the maximum power that the engine is capable of? I seldom extract the maximum out of my vehicle, overpowered for most of the time it is in use certainly. But from time to time it does have to deliver the best that the designers intended.

Back to Shap. Would it be impossible to produce a steam locomotive design that could work twelve, fourteen, sixteen coaches over the route without cause for concern and recourse to assistance? Of course not. A Pacific is not the best design for the job, lack of adhesion, but the type can put in some remarkable performances given favourable rail conditions amongst other things. The hangover from the Midland small engine policy lasted for a long time.

300+ tons on the Devon Belle could be dealt with too. And a machine that could do this would not be uneconomical whilst working against a more modest requirement. An interesting new build challenge.

 

Exactly. In the very early days of railways it was common to aim for minimal gradients for most of a line with short rope-worked inclines to deal with unavoidable changes of level. This was both a practical solution and a natural sequel to the lines of many canals with flights of locks and long pounds with few or no locks in between the flights. Camden Bank was rope worked for a little while when the London & Birmingham first opened.

Even as locomotives became more powerful and the ropes were abandoned, some lines still kept to this pattern. Think of "Brunel's billiard table" but the gradient at Box. The Lickey is roughly parallel to Tardebigge Flight on the Worcester & Birmingham Canal.

 

No, by a cold engine I mean one in which the fire bed has not reached incandescence, the brick arch is still cool etc. In those circumstances, adding coal tends to initially cool the fire and cause pressure to drop - not what you want. It takes ten or fifteen minutes of steaming to get things nicely warmed through, after which things start to run more efficiently.

At Ilfracombe, the line started to climb at 1 in 36 within about a hundred yards of the platform end, and carried on at that gradient (and on quite a twisty line, limiting maximum size of locomotives) for a bit over two miles. To take the Devon Belle as an example of a train worked over the line on a daily basis: normal summer load was 9 Pullmans plus a West Country, about 500 tons tare, perhaps 530 gross including the passengers and their luggage, which hits the bottom of the bank at no more than walking pace. Gravity alone exerts a force of about 33,000lbf to which you can add rolling resistance on a twisty line. Hard to think of a loco in the country that could have accelerated that load from a near stand up the hill with a cold fire without recourse to a banking engine. Moreover, even had it been possible, the fireman would have then been faced with a forty mile run to Exeter at the top and his fire likely pulled to pieces. Far more sensible to simply station a banking engine in the area - it would have had plenty to do all day. (The gradient on the other side was 1 in 40 for about 2.5 miles, so trains needed assistance in both directions).

The comparison with a car is invalid: cars are designed to work under a wide variety of speeds and with frequent stops and starts. Nonetheless, the designers will still optimise them for peak efficiency to be somewhere within their normal working speed range. To a much greater extent, because they are burning fuel even when the regulator is closed, a steam locomotive works most efficiently when running at a near constant power output, the actual power being broadly determined by grate area. Efficiency falls off both when needed to work above their optimum (because of fire throwing) and below their optimum (because of the difficulty in avoiding blowing off). In those circumstances, it is more efficient to provide assistance in short sections where it is needed so that the locomotive can be sized according to the demands placed by the majority of the route, than to have a loco that can cope with the gradients but is simply too big for what is needed elsewhere. Banking also enables the train engine to work at its normal efficient working rate up a gradient so that the fire (and fireman!) are in a good state to continue at the same level of effort as soon as easier grades are reached: no point flogging the engine to get up a hill and then having to waste all the time gained while the fireman spends the next thirty minutes trying to get the fire back into shape.

Tom

 

A very recent example of this was Galatea crawling up Shap on the 30th of May - should've had a banker!!

Cheers

Alan

 

70013, after a lengthy stop at Tebay, from the restart attained 33mph at Milepost 33. Successive speeds were 29 at Scout Green, 25 at MP36, 22 at MP37 and 22 at the summit. Suggests the loco was developing c1200 EDHP. Such a performance I suggest whilst admirable is hardly likely in to-days environment to endear steam to the operating authorities.

Michael Rowe

 

Believe HST's require a banker/assistance if running on one power car up the Lickey, they were banned on the South Devon Banks too but believe they are allowed now providing a run through Totnes can be had.