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The skill of the Engineman

Discussion in 'Steam Traction' started by Big Al, Aug 22, 2021.

  1. peckett

    peckett Member

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    The Thames Clyde was booked for a Royal Scot ,don't forget the loco on this went thro' to Glasgow. The Waverley , Leeds to Carlisle mostly 5Xs. Also Holbeck had A3s which were used on the Thames Clyde just before diesels took over.
     
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  2. peckett

    peckett Member

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    Freight trains would be queuing up to get thro Bedford ,drivers were allowed to procced at 5mph to the train in front ,it was called " On Block".Unfortunately the driver of a Corby to London tube/pipe train was running short of water and decided to get a move on ,to pick up water on Oakley troughs, just north of Bedford .Couldn't stop and crashed into the train in front ,loco went down the embankment .Both Driver and Fireman lost their lives. This was about 1950.
     
  3. Steve

    Steve Resident of Nat Pres Friend

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    Constant steam demand is quite a hard thing to accomplish on the road. I've known several drivers who say that they set the regulator and cut off and then let the loco do what it does in the belief that it is creating a constant steam demand and making life easier for the fireman. However, for a given cut off, the steam demand is dependent on number of piston strokes/unit time; in other words, speed. Thus if the gradient eases slightly and the loco speeds up, the steam demand increases, conversely, if it slows down, the demand reduces. The only way you can actually have a constant steam demand is by constantly altering the cut off as the speed varies, notching up as speed increases and conversely as it decreases.
    Personally, I like to run at a constant speed necessary to keep to the timetable. On the NYMR, that means plodding up Goathland bank at about 17 mph once you are clear of the 10 mph restriction at Grosmont. With a 7 coach train and a Cl.4 or 5 loco, for me that's full regulator to get the maximum steam chest pressure and about 50% cut off depending on the loco and the boiler pressure. Once it starts to drop below 200 psi (225 psi boiler) performance starts to fall off and you have to compensate. To keep that constant speed means winding the reverser out a bit on the curves and back in on the straights. It's quite moticeable how much effect some of the curves have.
    Between Pickering and Levisham the line is relatively flat, compared with the remaining 12 miles. However, those six miles are usually timed at 18 minutes, the first mile of which is effectively restricted to 10mph so the remaining 5 miles are timed at 12 minutes. The mathematicians will soon realise that, on a 25 mph railway, keeping to that time is therefore virtually impossible and, to do your best, you need to get up to line speed as quickly as possible. That, again usually means a wide open regulator and longish cut off to get up to speed, after which a partly open regulator (70-100 psi in the steam chest) and 25% cut off will keep things merrily rolling along.
     
    Last edited: Aug 27, 2021
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  4. Fred Kerr

    Fred Kerr Part of the furniture

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    Sorry to say but it DID happen. The "control" workings tended to be a normal freight service that would be nominally cancelled then replaced by a train with a similar headcode where the Destination Letter was replaced by a "Z" to indicate a "Control" working. Agreed that the traction was usually a Class 44 with the 8 axles giving better braking power but since they were crewed by Toton men there was no difficulty. Having been in Corby North signalbox when I was instructed to release a "control" working hauled by a Class 44 from Corby Sidings returning to Toton I recall it was operated as a Class 8 and managed to pass Manton box in 15 minutes from starting. Don't forget that whilst coal trains were fewer Class 44s appeared on coal trains to Corby to serve Corby Steelworks and IIRC to Wellingborough for onward service to a power station in the Bedford area (Willington ?); both locations allowed Toton crews to operate on out-and-home workings. The fitted head you mention followed from the ECML experience whereby a fitted head allowed trains to operate as 7* - allowed to run at higher speed without a Diesel Brake Tender given the braking capability of the fitted head plus the heavyweight Class 44 traction. IIRC it was only trains with Class 44 traction that operated such "control" workings
     
  5. Fred Kerr

    Fred Kerr Part of the furniture

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    Having travelled on the Waverley when returning to visit relatives in Edinburgh I can confirm that the Waverley was a "Jubilee" turn given that it was replaced by an LNER Pacific - usually an A3 - at Carlisle. As noted the Thames-Clyde was a 7P turn which was a Royal Scot then A3 Pacific before replaced by Holbeck Class 45s during 1962. In 1961 the northbound Waverley was 44852 but in 1962 it was D14 and this returned on the overnight sleeper - 22:10 Edinburgh - St Pancras as far as Leeds. In 1961 the Waverley was worked between Edinburg and Leeds by a displaced Haymarket A4 but that trial only lasted a couple of weeks hence my disappointment at finding 44852 at the front from Leeds.
     
  6. Allegheny

    Allegheny Member

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    What an interesting thread!
    I've learned a couple of things. Thermal cycling of the boiler isn't good (presumably this mainly relates to the firebox temperature?), and secondly, it's not considered good practice to mortgage the water level for more power.
    A question occurs to me, if you're driving an undulating route, would you let the water level fall on the uphill sections and rise on the downhills to help maintain constant temperatures?
    Obviously, this is probably easier said than done. The effect of the gradient on the gauge glass levels will complicate things but may actually help, and the draught will vary depending on how hard the engine is working.
     
  7. peckett

    peckett Member

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    So your now saying you were a signal man a t Corby North box!! What next ?I'm not going to mention the number of mates who worked in that box as relief signal men. I worked beside the Corby to Kettering line 7 days a week ,I didn't see anything you describe.
     
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  8. Jamessquared

    Jamessquared Nat Pres stalwart

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    I think it's a bit more subtle than that. For example, mortgaging the water level for more power - I think you would often mortgage it to maintain steam pressure, in part because higher pressure uses less water, so ultimately will help you. Obviously that is within the limits of maintaining an adequate water level. Peter Smith's book on the S&D has several descriptions of very fine judgement of water level to maintain progress over steep grades on locos short of steam. There are lots of times on the footplate when you are judging whether you would rather have more pressure and less water or vice versa.

    On undulating routes: my experience is heritage line, not mainline. But for example, on the Bluebell, the up direction is predominantly uphill, with about 8 out of 11 miles at 1 in 75 or steeper. It goes in basically four separate banks, with short downhills or level stretches between. So the normal practice is to allow water level and pressure to drop somewhat over each mini-summit and recover on the descents. Any other method results in the loco blowing off hard if you reach a summit close to working pressure and the driver then shuts off: you have a big fire, hot brick arch and the injector won't suppress the pressure for a few minutes until they cool off a bit.

    The fireman's skill (one of) is judging that fall-off; particularly on the last summit at Imberhorne, which is the steepest (and therefore has the most demand for power); has a complete knife edge descent following (so results in the biggest shift of water level from up hill to downhill) and where you have a long wait in a station in the middle of a town where making a noise is frowned upon. On a smaller loco and Welsh coal, the ideal is for the flames to have largely gone and the fire to be jumping on the grate (not too thick) with the pressure holding steady near the red line without the injector; then when you put the injector on near the summit, the pressure falls back - the judgement is to do it early enough you actually have some water left on the descent, but not so early you kill the pressure to the point the loco won't make it. On a Chatham loco that typically means go up at about 150psi and knock it back to 130 over the summit (but no lower than 125). On a Maunsell engine (200psi) typically go up at about 190 and knock it back to 160 or so at the summit (but no lower than 140). On a BR standard go up at 215 and knock it back to 180 (but you could scrape over at 150). The bigger the engine, the wider the margin and therefore the easier it is.

    Tom
     
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  9. Allegheny

    Allegheny Member

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    I'd need to check, but I think that a given volume of water at boiling point contains more heat than the same volume of steam, so a boiler with a higher water level would contain more stored energy. Good point about steam at higher pressure containing more energy. I was going to say that this depends on the opening of the regulator and the steam chest pressure, but of course, the steam will expand as it passes through a partially opened regulator.
     
  10. Big Al

    Big Al Nat Pres stalwart Staff Member Moderator

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    On maintaining pace on the main line I've heard from drivers of two methods.
    Keeping the same regulator and varying cut off slightly or keeping the same cut off and tweaking the regulator. Both are good loco men so I won't comment on which is better, if indeed it matters.
     
  11. 35B

    35B Nat Pres stalwart

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    Yet @Fred Kerr did. That suggests the workings were unusual, and that he happened to encounter them when you didn't.
     
  12. Jamessquared

    Jamessquared Nat Pres stalwart

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    Hot water does contain more energy than the same volume of steam, but I’m not sure I’ve ever thought it a reason to keep the water up! The bigger concern is if the water level is too high the loco might prime. Everything you do is a complex juggling act between the state of the fire, water level and pressure; and balancing them according to the demands of the road.

    Tom
     
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  13. talyllyn1

    talyllyn1 Member

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    I posted this a while ago in another thread:-

    It would probably seem safe to assume that crews on "top link" work would be masters of the work and on top of the job. A now deceased family member was a fireman at Monument Lane in the 1950's and a regular on the Jubilee-hauled two-hour expresses from Birmingham to London.
    To relieve the boredom of the job he and his shed-mates had a competition going. They would fill the box right up at New Street and see how far they could get before they touched the fire again. One of them claimed to have reached Rugby before picking up the shovel!
    Quite what this did for timekeeping, efficiency or the firebars is anyone's guess.
     
  14. Cosmo Bonsor

    Cosmo Bonsor Member

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    I agree with Steve. I try to run at an even pace, adjusting if I'm ahead or behind the map in my head. By which I mean I have virtual timing points with which to gauge progress. For example, 7mins to the top of Freshfield, 3 mins from Three Arch to arriving at Horsted and so on.
    There is a reverse curve on a gradient which slows you down a lot. I reckon it's uphill both ways! I usually give it a bit to maintain speed.
    A few weeks ago, I had the Q and a very good ,consistent Fireman. I drove the same way each trip and the engine ran better and faster each time as it warmed up and got nice and oily. Interesting to see.
    Track condition is another variable. The reverse curves got relaid when I was away. I gave the S15 a bit to get through and went much faster than I intended.
    Coaches are yet another. On the gentle down hill to Tremains a set of MK1s on rollers will push you, but with Mets and sheds you might need to keep steam on.

    Which brings me to braking, probably the hardest part of driving.
    A service application at the speeds we go is about 6'' of vacuum. The skill is smooth braking and accurate stopping.
    Going north the run in to stations is uphill, level and level. Coming back, it's downhill, downhill and level.
    Uphill, the drill is get down to 10 mph for station limits, keep power on to about 1/4 to 1/2 way down the platform and stop.
    Downhill is easier, it's 10 all the way until you stop.
    Level is more interesting, I have a landmark at which I put in a service application. This will get me to 10 mph. Fully release the brake, run in at 10, then stop where you want. Two applications is my aim.
    Coach set vary in their braking characteristics and you have to work out how they behave.
    I found braking down our hills the hardest part to learn. Keeping a steady rub on the brakes to maintain an even speed. Without looking at the gauge which is usually behind you. You first have to get a bite in the tunnel. The best way is to hear the air go in the valve, them a moment later feeling a small 'tug' through your feet telling you the brakes are biting.
    Air is another thing to learn, I like the Stoudley valve, but it only works on the engine on our railway. I have been lucky enough to drive /Fenchurch in Holland and trains on IOW and Poland etc.
    Question for the mainline boys, what is the service application on vacuum? I imagine feeding the lot in and blowing the brakes off sub 30.
    Lastly more annecdata, I did a film job running from Kingscote to the tunnel at 25. Where I stopped was up to me, so I ran into the remains of the platform at West Hoathly at 25 and stopped smoothly at the end. It was no harder than what we usually do. Good fun, sometimes play is a good way to learn.
     
  15. torgormaig

    torgormaig Part of the furniture Friend

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    I understand that this was not an uncommon practice in some areas. All very well until something goes wrong and you have to drop the fire in a hurry:eek:.

    Peter
     
  16. Allegheny

    Allegheny Member

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    I've just done a quick calculation, at 15 bar (about 225 psi) a gallon of water contains 32.8 x at much heat as a gallon of steam. I didn't realise it was as much as that!
     
  17. torgormaig

    torgormaig Part of the furniture Friend

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    A gallon of steam? What's that? Water, as a liquid, I understand being measured in gallons but steam, which is a vapour, surely cannot be measured in such terms.......or am I missing something?

    Peter
     
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  18. Allegheny

    Allegheny Member

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    A gallon is just a measure of volume. It can be used to measure any fluid, or even solids if you wanted to.
     
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  19. LMS2968

    LMS2968 Part of the furniture

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    But water is a liquid: indefinite shape but constant volume. Steam is a gas so indefinite shape and indefinite volume. So the amount of steam in a gallon could vary quite a lot, in accordance with the Universal Gas Law: P1.V1/T1=P2.V2/T2. Really, we should be talking about mass of water v mass of steam.
     
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  20. Eightpot

    Eightpot Well-Known Member Friend

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    It should be remembered that the volume of a gallon (or litre) can vary according to the temperature.
     

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