|
Post by suctionhose on Dec 6, 2018 21:58:42 GMT
Two comments on what has been said thus far:
1. In terms of 'driving' there's a preoccupation with 'firing apparently. Perhaps that is main draw card? I agree. If it wasn't for coal firing I'd give it up for good (BTW we have lots of 'foreign rubbish' over here. Used some Welsh Dry Steam Coal last weekend - sure is different!
2. Some people building exceptional miniatures 'have not yet had a go'! Surely that can be rectified easily enough???
|
|
pault
Elder Statesman
Posts: 1,496
|
Post by pault on Dec 6, 2018 22:10:44 GMT
Ok I have put my tin hat on.
Lots of talk of little and often good advise for some situations but needs qualifying.
Driving by numbers one of my biggest hates but it can work. There is talk of a Romney driver many years ago who overshot a station.when asked why he said some bas#!×d cut down the bush where I brake for the station.
If you have a simple line and the same load every time you can drive by numbers and it will work, but you are an operator not a driver.
It doesn't matter if you have a drivers or fireman hat on its all about energy management.
With our engines if you are a light engine running slowly you won't need much coal or water. Increase the load and speed you need more steam, hence more heat to boil the water, so you need to burn more coal.
To fire at the right rate you need to appreciate how quickly the loco is using steam/water/heat/coal.
It's about an appreciation of the work the loco is doing. Just saying a little and often is meaningless. How little and how often depends on how quickly the loco is consuming things.
The other thing to remember is that when you put cold lumps of coal on the fire they ABSORB heat initially so cool the fire and reduce the heat available until they start to burn.
|
|
pault
Elder Statesman
Posts: 1,496
|
Post by pault on Dec 6, 2018 22:40:14 GMT
Oh as for not needing to fire on the run, don't be driving if it's a gala and I slip into the signal box
|
|
|
Post by simplyloco on Dec 6, 2018 22:45:59 GMT
Two comments on what has been said thus far: SNIP 2. Some people building exceptional miniatures 'have not yet had a go'! Surely that can be rectified easily enough??? I 'had a go' some years ago on our raised 5" track. I was, and remain, singularly unmoved! I'm looking forward to building a gas turbine 3HP prop drive for my 48" MTB hull that has been sitting behind my workshop for some time now... John
|
|
|
Post by Deleted on Dec 6, 2018 22:55:28 GMT
From what I've read and heard by ex-railwayman at the club, you judge when to put more coal/air on the fire by the chimney...fresh coal adds a whiff of smoke, when that stops it's time to think about putting more coal onto the fire. If the smoke is dark or black, you have put too much coal on the fire, have insufficient air or placed the coal badly, place it carefully, filling any holes in the bed, not just thrown on. The fire bed is kept thin, the arch increases the travel of the volatiles and the heat generated which must IMHO make firing easier. The other factor is air, both primary and secondary and both may need to be adjusted according to the job in hand and the type of coal used. I have heard comments of, 'why's that Firehole door open'? This goes against what's taught in the handbook, I am talking other than when frist lighting the fire, the door supplies the secondary air which is very important for complete combustion and again the amount of secondary air required depends on the coal used. There is an awful lot of information in the handbook, it covers all aspects of firing a locomotive correctly. The amount of air supplied either through the grate or the firedoor is just as important as the amount of coal put on the grate. The use of dampers and firedoor is integral to good firing according to the book. It may not be suitable for all miniature steaming but it certainly points one in the right direction, I don't see that there's a lot of difference between full-size and miniature firing. I'll make it very clear that I have far, far less experience in firing a miniature steam locomotive than most if not all here, I do read a lot though and do listen to the full-size fireman at the club, I believe the principles of firing to be the same for both.
Pete
|
|
jma1009
Elder Statesman
Posts: 5,901
|
Post by jma1009 on Dec 6, 2018 23:13:33 GMT
'Little and Often'...
I have not fired 'on the run' when running the fire down prior to taking the loco off the track to go home at the end of day, and have done numerous 'laps' or a considerable distance without firing.
I have given 'tyros' a go, and will ensure when they take over at the station the fire is big and hot but with a layer of black coal on top, and the water level 'up', and all they have to do is just use the regulator and reverser, and not worry about the water level or the fire at all and just enjoy the fantastic experience of of pure 'driving' as opposed to worrying about what would be the fireman's job in fullsize.
After a lap or two with me doing the fireman's job for them, and me sitting behind shouting out 'Notch up the reverser a notch' or 'drop it down a notch' and 'Go On, Open her UP! (the regulator), if they are up for more they then take over the firing at the station and working the injectors at the station.
(Then we proceed to using the injectors on the run and firing on the run, with me shouting 'Put a couple of shovel fulls at the back' etc 'And shut that fire door!', 'Whack the water valve open a quarter turn' then 'Whack open the steam valve 1 and a half turns').
You get the idea..
The problem with the above is it has to be done when the station isn't busy and no long queue forming of punters, because to drive and fire etc a loco this way requires an extended station stop.
So generally I aim to get to the station ready to depart as soon as the trainload of punters have got off and a new trainload have got on, which is pretty much just enough time to roll a cigarette (not that I am allowed to smoke a cigarette when driving these days) or check the level of the tanks or tender.
And on a long club track such as the SMLS at BeechHurst Haywards Heath, or Kinver, or a demanding shorter track with some stiff gradients half the time such as Worthing, you have no option but to fire 'on the run' and work the injectors because if you don't fire 'on the run' etc you will most likely grind to a halt part way round.
Also, on non public fare paying days, I like to do as many laps without stopping as the tanks or tender would allow, and in any event on the Cardiff track for paying punters we gave them 2 laps without a stop.
Incidentally, on the Cardiff track at Heath Park, I did the 'dumpy levels' with the late Bob Page around 1986/7, and the western embankment was pretty much dead level, but the embankment subsequently settled and provides quite a stiff challenge for passenger hauling to this day. One lap alone would be a challenge without firing 'on the run' and 'little and often'.
Cheers,
Julian
|
|
|
Post by delaplume on Dec 7, 2018 0:28:21 GMT
From what I've read and heard by ex-railwayman at the club, you judge when to put more coal/air on the fire by the chimney...fresh coal adds a whiff of smoke, when that stops it's time to think about putting more coal onto the fire. If the smoke is dark or black, you have put too much coal on the fire, have insufficient air or placed the coal badly, place it carefully, filling any holes in the bed, not just thrown on. The fire bed is kept thin, the arch increases the travel of the volatiles and the heat generated which must IMHO make firing easier. The other factor is air, both primary and secondary and both may need to be adjusted according to the job in hand and the type of coal used. I have heard comments of, 'why's that Firehole door open'? This goes against what's taught in the handbook, I am talking other than when frist lighting the fire, the door supplies the secondary air which is very important for complete combustion and again the amount of secondary air required depends on the coal used. There is an awful lot of information in the handbook, it covers all aspects of firing a locomotive correctly. The amount of air supplied either through the grate or the firedoor is just as important as the amount of coal put on the grate. The use of dampers and firedoor is integral to good firing according to the book. It may not be suitable for all miniature steaming but it certainly points one in the right direction, I don't see that there's a lot of difference between full-size and miniature firing. I'll make it very clear that I have far, far less experience in firing a miniature steam locomotive than most if not all here, I do read a lot though and do listen to the full-size fireman at the club, I believe the principles of firing to be the same for both. Pete Spot-on Peter, you're engaging with the right sort of guys............I bet you that if asked no two of them fired in exactly the same way, and over time they will have changed their style/technique....if only because of age !! I think that like any other "Skill" in life you have to get a good grip of the fundamental processes first--- then all else will follow in time and experience Consider this scenario}---- Mallard on it's actual record breaking run....... and an 0-4-0T shunter that it's passing in the freight yards of North London There you might say are the two ends of the spectrum BUT both of those crews would have gone through the Cleaner---Fireman---Driver training experiences. You keep up the good work re}--- the "auld chaps" ....Railway folk are good people and those guys are--I suspect--- a little envious of you if the truth be known... Alan
|
|
|
Post by delaplume on Dec 7, 2018 0:32:05 GMT
'Little and Often'... I have not fired 'on the run' when running the fire down prior to taking the loco off the track to go home at the end of day, and have done numerous 'laps' or a considerable distance without firing. I have given 'tyros' a go, and will ensure when they take over at the station the fire is big and hot but with a layer of black coal on top, and the water level 'up', and all they have to do is just use the regulator and reverser, and not worry about the water level or the fire at all and just enjoy the fantastic experience of of pure 'driving' as opposed to worrying about what would be the fireman's job in fullsize. After a lap or two with me doing the fireman's job for them, and me sitting behind shouting out 'Notch up the reverser a notch' or 'drop it down a notch' and 'Go On, Open her UP! (the regulator), if they are up for more they then take over the firing at the station and working the injectors at the station. (Then we proceed to using the injectors on the run and firing on the run, with me shouting 'Put a couple of shovel fulls at the back' etc 'And shut that fire door!', 'Whack the water valve open a quarter turn' then 'Whack open the steam valve 1 and a half turns'). You get the idea.. The problem with the above is it has to be done when the station isn't busy and no long queue forming of punters, because to drive and fire etc a loco this way requires an extended station stop. So generally I aim to get to the station ready to depart as soon as the trainload of punters have got off and a new trainload have got on, which is pretty much just enough time to roll a cigarette (not that I am allowed to smoke a cigarette when driving these days) or check the level of the tanks or tender. And on a long club track such as the SMLS at BeechHurst Haywards Heath, or Kinver, or a demanding shorter track with some stiff gradients half the time such as Worthing, you have no option but to fire 'on the run' and work the injectors because if you don't fire 'on the run' etc you will most likely grind to a halt part way round. Also, on non public fare paying days, I like to do as many laps without stopping as the tanks or tender would allow, and in any event on the Cardiff track for paying punters we gave them 2 laps without a stop. Incidentally, on the Cardiff track at Heath Park, I did the 'dumpy levels' with the late Bob Page around 1986/7, and the western embankment was pretty much dead level, but the embankment subsequently settled and provides quite a stiff challenge for passenger hauling to this day. One lap alone would be a challenge without firing 'on the run' and 'little and often'. Cheers, Julian That's it to a Tee..........Good folk do re-read this as here's a man who knows what he's talking about...........
|
|
|
Post by delaplume on Dec 7, 2018 0:44:05 GMT
Two comments on what has been said thus far: SNIP 2. Some people building exceptional miniatures 'have not yet had a go'! Surely that can be rectified easily enough??? I 'had a go' some years ago on our raised 5" track. I was, and remain, singularly unmoved! I'm looking forward to building a gas turbine 3HP prop drive for my 48" MTB hull that has been sitting behind my workshop for some time now... John Ah !!----- this takes me back to my Basic Training at Rosyth and then on the old County Class Destroyers with 4 x Rolls Royce Olympus ( Marine ) engines.....I'd be interested to know what precautions you have in mind re}---salt-laden inlet air ?? for those not in the know take a look at this}-------------- www.cast-safety.org/pdf/3_engine_fundamentals.pdf
|
|
|
Post by David on Dec 7, 2018 7:30:56 GMT
I'm surprised you can get around a lap without adding coal or water. I've done it at my track, but not by design! If I don't add water it will be below the bottom nut by the time I get back to the station, and there won't be much of a fire left if I forget to add to it (while stuffing about with the injectors all lap... I know it's the water circuit, not the injectors fault - doesn't make it any more fun knowing that).
Perhaps I'm using too much steam? It's a saturated loco that can't notch up so no help there. There are a few good hills and with say 3-4 adults and 4-5 children (plus me) it can take a bit it get up those hills.
I do use the firebox door to control the pressure. If the boiler is about to blow off I'll open the door to keep stop the pressure rising. I also sometimes throw some coal on to cool the fire a bit. Don't have dampers on the loco, but that's mostly what I used on the boat to control the pressure.
|
|
|
Post by suctionhose on Dec 7, 2018 7:39:48 GMT
One of the attractions of Sydney Live Steam locomotive Society is the demands of public running. We open the gate at 1-30pm and people flood in. For the next 3-4 hours it's full on. There's three separate circuits each with two 7 car trains. Smaller engines double head. Some of us go it alone. Capacity is about 3000 rides for the afternoon.
With an 8 minute ride cycle, 2000kg at a time, interlocked signalling, station masters, guards, other traffic, you are busy! Now with the fuel crisis - the set and forget Char is no more - you're managing smoke & ash, cleaning fires and ashpans, firing on the run, trying not to forget the injector's on and hitting that 1 in 50 on the 30ft curve just right time and time again!
It is demanding and that makes it fun. Doing it well without a mistake is a good performance. No one get's it right all the time....but that's drivin'!
|
|
|
Post by delaplume on Dec 7, 2018 9:17:30 GMT
One of the attractions of Sydney Live Steam locomotive Society is the demands of public running. We open the gate at 1-30pm and people flood in. For the next 3-4 hours it's full on. There's three separate circuits each with two 7 car trains. Smaller engines double head. Some of us go it alone. Capacity is about 3000 rides for the afternoon. With an 8 minute ride cycle, 2000kg at a time, interlocked signalling, station masters, guards, other traffic, you are busy! Now with the fuel crisis - the set and forget Char is no more - you're managing smoke & ash, cleaning fires and ashpans, firing on the run, trying not to forget the injector's on and hitting that 1 in 50 on the 30ft curve just right time and time again! It is demanding and that makes it fun. Doing it well without a mistake is a good performance. No one get's it right all the time....but that's drivin'! Well spoken .. that's exactly my "take" on it here as well.............Good fun and a great feeling of a job well done...
|
|
|
Post by Deleted on Dec 7, 2018 9:27:27 GMT
From what I've read and heard by ex-railwayman at the club, you judge when to put more coal/air on the fire by the chimney...fresh coal adds a whiff of smoke, when that stops it's time to think about putting more coal onto the fire. If the smoke is dark or black, you have put too much coal on the fire, have insufficient air or placed the coal badly, place it carefully, filling any holes in the bed, not just thrown on. The fire bed is kept thin, the arch increases the travel of the volatiles and the heat generated which must IMHO make firing easier. The other factor is air, both primary and secondary and both may need to be adjusted according to the job in hand and the type of coal used. I have heard comments of, 'why's that Firehole door open'? This goes against what's taught in the handbook, I am talking other than when frist lighting the fire, the door supplies the secondary air which is very important for complete combustion and again the amount of secondary air required depends on the coal used. There is an awful lot of information in the handbook, it covers all aspects of firing a locomotive correctly. The amount of air supplied either through the grate or the firedoor is just as important as the amount of coal put on the grate. The use of dampers and firedoor is integral to good firing according to the book. It may not be suitable for all miniature steaming but it certainly points one in the right direction, I don't see that there's a lot of difference between full-size and miniature firing. I'll make it very clear that I have far, far less experience in firing a miniature steam locomotive than most if not all here, I do read a lot though and do listen to the full-size fireman at the club, I believe the principles of firing to be the same for both. Pete Spot-on Peter, you're engaging with the right sort of guys............I bet you that if asked no two of them fired in exactly the same way, and over time they will have changed their style/technique....if only because of age !! I think that like any other "Skill" in life you have to get a good grip of the fundamental processes first--- then all else will follow in time and experience Consider this scenario}---- Mallard on it's actual record breaking run....... and an 0-4-0T shunter that it's passing in the freight yards of North London There you might say are the two ends of the spectrum BUT both of those crews would have gone through the Cleaner---Fireman---Driver training experiences. You keep up the good work re}--- the "auld chaps" ....Railway folk are good people and those guys are--I suspect--- a little envious of you if the truth be known... Alan Thank Alan.. I love talking to those who worked on these wonderful machines. Our club is lucky in having a number of ex-railwaymen who still steam on preservation lines along with younger folk who drive/fire on a number of narrow gauge railways...We are also privileged to have a couple of regular visitors (alas, can't remember their club), both ex-KX men, I'd happily spend hours talking with these gents, always present on 'LNER' days and at the 'Bob Todd' memorial. One of which has built a very nice A4 following 'Doncaster' drawings, it's a beautiful model and steams extremely well, even though the owner 'Brian' tells me that the loco needs an overhaul, IIRC it's at least 20, perhaps 30 years old? regards Pete
|
|
|
Post by Doug on Dec 7, 2018 14:11:54 GMT
I can’t say I have loads of experience, just driven my Greatgrandads Butch. So all my driving experience has been on this one Loco. What I found is that like what has been discussed above that notching back is the best way to drive it. I use about 1/4 regulater only using full on inclines and notch back to centre on the reverser this makes the Loco speed increase too. So I guess that it is set up well if I am driving it so?
|
|
Gary L
Elder Statesman
Posts: 1,208
|
Post by Gary L on Dec 7, 2018 17:05:31 GMT
From what I've read and heard by ex-railwayman at the club, you judge when to put more coal/air on the fire by the chimney...fresh coal adds a whiff of smoke, when that stops it's time to think about putting more coal onto the fire. If the smoke is dark or black, you have put too much coal on the fire, have insufficient air or placed the coal badly, place it carefully, filling any holes in the bed, not just thrown on. The fire bed is kept thin, the arch increases the travel of the volatiles and the heat generated which must IMHO make firing easier. The other factor is air, both primary and secondary and both may need to be adjusted according to the job in hand and the type of coal used. I have heard comments of, 'why's that Firehole door open'? This goes against what's taught in the handbook, I am talking other than when frist lighting the fire, the door supplies the secondary air which is very important for complete combustion and again the amount of secondary air required depends on the coal used. There is an awful lot of information in the handbook, it covers all aspects of firing a locomotive correctly. The amount of air supplied either through the grate or the firedoor is just as important as the amount of coal put on the grate. The use of dampers and firedoor is integral to good firing according to the book. It may not be suitable for all miniature steaming but it certainly points one in the right direction, I don't see that there's a lot of difference between full-size and miniature firing. I'll make it very clear that I have far, far less experience in firing a miniature steam locomotive than most if not all here, I do read a lot though and do listen to the full-size fireman at the club, I believe the principles of firing to be the same for both. Pete That's a pretty fair summary of full-size practice as I understand it, and there is an LMS film on YouTube about firing a locomotive which makes the same point about watching the smoke, at some length. However it doesn't translate easily to miniature locos, because I have never witnessed smoke emerging from the chimney when running, even after putting several shovelfuls on the fire ( I know, I know...). The only smoke I ever see is when first lighting up. Dampers are rare, and (in my limited experience) secondary air gives no detectable benefit (when I experimented it made matters worse). Clearly firing is a critical skill, probably as Julian says, the most important skill of all; but I don't think the last word has been said here about miniature locos. Some of us are eager to learn, so please keep the discussion going... Gary
|
|
|
Post by delaplume on Dec 7, 2018 18:31:12 GMT
Just to set the parameters ( Don't want to stray off-piste, do we ??) can someone actually define what we mean by "Miniature Locomotives" within this thread ??
My suggestion would be}--- 2.5" gauge up to 7.25" gauge Railway ..........Anything larger than 7.25"g and we are straying towards the commercial world.....IMHO
also, are we taking on-board Traction engines etc ??--------- and if so, again what sizes ??
Alan
|
|
mbrown
Elder Statesman
Posts: 1,719
|
Post by mbrown on Dec 7, 2018 21:27:29 GMT
To be honest, I don't think size matters much at all - the principles are identical, but the variables in whatever size are considerable. With firing, much depends on the characteristics of the coal - for instance, how long it takes to get really hot, how quickly it burns away and with how much residue, and so on. Whatever the coal, it is always best to fire onto a bright (incandescent) fire - i.e, when the pressure is going up, not when it is dropping. But how much and how often will depend on the coal, the amount of work the loco is doing and so on. I agree with previous posters that a pump and by-pass can be less "fuss" than injectors - but a better alternative to setting the by-pass and leaving it is to use the pump as you would an injector and operate it to help keep the boiler pressure constant - e.g. if you are shutting off steam for a station and the fire is hot and the pressure just below blowing off, stick on the injector, or close the by pass, so that the cold water stops the safety valves from blowing off and conserves steam. One of the joys of firing is that no two trips are alike - the variables are always.... well, variable.
With driving as opposed to firing, things are more at the mercy of the quality of the loco itself. Is the valve gear well designed and capable of being notched up? And - something I have noticed is lacking on many models - does the regulator really regulate, or is it all-or-nothing? So many miniature locos start with a mighty slip, suggesting either a ham-handed driver or a regulator that doesn't allow a breath of steam to get things started (my own locos are far from perfect in the regulator department).
Apart from the fact that most standard gauge - and narrow gauge - locos that are still running are reasonably well designed maintained - probably more consistently so than our models - all the same principles apply to all sizes, in my opinion. Nevertheless, on the Talyllyn, there is a real difference between driving the old Fletcher Jennings locos and a relatively modern piston valve loco like Tom Rolt. The valve gear on Dolgoch is impossible to set properly so once it is in the single running notch, you drive solely on the regulator. Tom Rolt has a very insensitive regulator but a decent valve gear, so once the regulator is set, you drive mainly on the reverser. I know a lot of miniature locos in both categories....
As someone above put it, it is all about energy control - whether the energy from the coal or the power at the wheels. Beyond that, size is irrelevant.
Malcolm
|
|
|
Post by David on Dec 7, 2018 21:53:12 GMT
notch back to centre on the reverser this makes the Loco speed increase too. I assumed notching up would be done once the train was rolling well and up to speed, with inertia making up for whatever power was lost from using steam expansion rather than steam chest pressure. Then you'd come back towards later cut-off for hills to get more power so you didn't slow down too much. But that's all a thought experiment - it's all regulator all the time with slip eccentrics! FWIW my loco does respond to the regulator to some degree at least. I can ease out of the station and I do have to open it up for hills but can close it again somewhat on the level or downhill. The regulator is shown in this thread and described as being used on the Super Simplex. The B class I'm building uses the same design.
|
|
|
Post by Doug on Dec 8, 2018 10:07:10 GMT
I can’t say I totally understand the physics at work during notching up, but I guessed the speed increase I have seen is due to less back pressure, I am thinking due to restrictions in the exhaust. To clarify what I said in my other post though, David is completely correct in that notch back only happens once underway, although it still pulls away in any forward or reverse position when lightly loaded. I am looking forward to see what speedy is like in comparison even with the obvious poor valve events. My first few outings driving were a rather panicked ridden events, I was very (pointlessly it turned out) concerned that I wasn’t putting enough water into the boiler. Keeping the fire going, water topped up and controls in the right place was quite a stressful experience. Now I try to relax more and I am more confident that if I get into trouble I can put the fire down quickly.
|
|
Midland
Elder Statesman
Posts: 1,870
|
Post by Midland on Dec 8, 2018 10:39:50 GMT
Just to set the parameters ( Don't want to stray off-piste, do we ??) can someone actually define what we mean by "Miniature Locomotives" within this thread ?? Alan Alan Read HS216, D
|
|