Running a steam loco on a 1/30 grade - does it have to be chimney first?

[TEAMYAKIMA]

I have a 1/30 grade on my exhibition layout - inspired by a real 1/30 grade on an industrial railway. The grade takes the line off-scene, but is implied to run for several miles.

 

I ave always run uphill trains chimney first, on the basis/assumption that the water in the boiler would fall back onto the firebox. Whereas if I ran tender/bunker first the water would do the opposite and the firebox would be 'exposed'.

 

I now have a 0-6-0t which I would ideally like to run up the grade bunker first i.e. left to right in the photo below so that the 'interesting' side of the loco (air pump etc) would be shown to the viewers - would this be totally wrong?

 

               

Edited January 21, 2023 by TEAMYAKIMA

[Wickham Green too]

Yes, you need to keep the firebox crown covered to avoid melting the fusible plug - or worse damaging the firebox platework. Running smokebox-downhill with a very full boiler might avoid that problem but could risk carrying water over into the cylinders when returning to level track .... though with a tall-ish dome rear-placed, as you have, you might get away with it.

[The Stationmaster]

Ideally yes, particularly for regular working where an engine is only working that stretch of line.  In reality in the everyday scheme of things with engines working over various short stretches of gradient it might not necessarily happen that way.  But the preference was always to be chimney leading at the uphill end of very steep gradients and to be that way round on long stretches of gradient even if they were undulating.

[Titan]

Come to think of it any passenger train braking hard will have the water slosh to the front of the boiler with the same effect as going down a 1:20  or so gradient, until the brakes are released or it stops.

[RFS]

Or you could build your engine like this, as on the Brienzer Rothorn railway in Switzerland.

 

 

 

[PhilH]

Tbh it’s all about boiler management. Not quite 1 in 30 but  for instance, several heritage railways run over relatively steep gradients, 1 in 49 on the NYMR, and 3 1/2 miles of 1 in 60 on the MHR spring to mind….undoubtedly there are others. They don’t have the luxury of turning engines to suit. Back in the day on the ‘real’ railway crews had to work the engines how they were presented,  couldn’t always run them the ‘right’ way round..

 

Keep the water in sight in the glass, know that when working chimney first with the regulator open you get an artificially high water level, the opposite when bunker/ tender first, the crew will be used to working the line and will manage the water level accordingly

[Jeremy Cumberland]

With a short boiler and a tall dome, you should be fine running the engine backwards uphill. The water level at the regulator valve will be higher than running the engine chimney first, but if the valve is high up in a dome, and the dome isn't too distant from the firebox, this ought not be a problem.

[The Stationmaster]

54 minutes ago, RFS said:

Or you could build your engine like this, as on the Brienzer Rothorn railway in Switzerland.

 

 

 

But the steepest gradient it has is 1 in 4.  

 

Not even the GWR had anything that steep - its steepest adhesion worked gradient which I can find was 1 in 23 (one of the Pontnewynydd branches).  It also had a branch including a section at 1 in 13 but it was cable worked (Pwllyrhebog - inherited from the TVR)  but it also had engines with an enlarged water area around the firebox because they worked up & down the incline attached to the cable and worked on the section beyond it by normal adhesion.

[Nearholmer]

Leighton Buzzard NGR has a long stretch of one in twenty-something (1:24 or 1:25 according to various sources) but several of their locos face “downhill”, in fact ‘Elf’ used to face uphill, but since overhaul has faced down, so they clearly know how to manage the issue. They’ve got another short stretch out of Pages Park that is also very steep, but the other way, and the recently reopened section is also steep by railway standards, so maybe it’s six of one to half dozen of the other!

 

 

Edited January 17, 2023 by Nearholmer

[kevinlms]

56 minutes ago, PhilH said:

Tbh it’s all about boiler management. Not quite 1 in 30 but  for instance, several heritage railways run over relatively steep gradients, 1 in 49 on the NYMR, and 3 1/2 miles of 1 in 60 on the MHR spring to mind….undoubtedly there are others. They don’t have the luxury of turning engines to suit. Back in the day on the ‘real’ railway crews had to work the engines how they were presented,  couldn’t always run them the ‘right’ way round..

 

Keep the water in sight in the glass, know that when working chimney first with the regulator open you get an artificially high water level, the opposite when bunker/ tender first, the crew will be used to working the line and will manage the water level accordingly

Is this not why loco crews and others, signed for route knowledge rather than for knowledge on a particular locomotive class. So they would know about a particular steep spot and from that 'know' about possible difficulties in maintaining boiler levels.

[PhilH]

25 minutes ago, kevinlms said:

Is this not why loco crews and others, signed for route knowledge rather than for knowledge on a particular locomotive class. So they would know about a particular steep spot and from that 'know' about possible difficulties in maintaining boiler levels.

Knowing the road was/is paramount on a steam engine for exactly that in addition to the signal, speed restriction etc.knowledge which every driver has.When I was out on the mainline with LSL a gradient profile for the fireman’s assistance was often provided in addition to the driver or traction inspectors route knowledge. 
For interest I attach the gradient profile for the MHR. Apologies for it being upside down but my iPad seems to upload photos that way. If anyone can alter it I’d appreciate it, or indeed let me know how I can fix this problem

 

Edited January 17, 2023 by PhilH

[Michael Hodgson]

Here's a Welsh two-faced engine that has only ever run chimney first.

I don't think the Festiniog Railway could afford turntables.

 

And presumably not a problem with a vertical boiler loco.

[LMS2968]

Your wish, etc . . .

[Titan]

27 minutes ago, Michael Hodgson said:

Here's a Welsh two-faced engine that has only ever run chimney first.

I don't think the Festiniog Railway could afford turntables.

 

And presumably not a problem with a vertical boiler loco.

With the firebox being in the middle gradient would only have a slight effect on the level above the crown sheet if even noticeable.

[Jeremy Cumberland]

On 17/01/2023 at 14:26, Michael Hodgson said:

Here's a Welsh two-faced engine that has only ever run chimney first.

I don't think the Festiniog Railway could afford turntables.

 

And presumably not a problem with a vertical boiler loco.

 

They actually had turntables at Boston Lodge and Glanypwll (Blaenau Ffestiniog). The Boston Lodge one might still be there (it survived into the preservation era, although long disconnected from the running railway). I don't know how much they were used, though. Most photos show the engines always the same way round (single engines facing uphill, double engines with the fireman on the valley side, giving more opportunities for wielding a shovel).

Edited January 19, 2023 by Jeremy C

[Hal Nail]

Funnily enough I was reading about 10 mins ago that locos always ran smoke box first up to Liskeard from Coombe, and that was only 1/40.

[Butler Henderson]

2 hours ago, Jeremy C said:

They actually had turntables at Boston Lodge and Glanywll (Blaenau Ffestiniog). The Boston Lodge might still be there (it survived into the preservation era, although long disconnected from the running railway). I don't know how much they were used, though. Most photos show the engines always the same way round (single engines facing uphill, double engines with the fireman on the valley side, giving more opportunities for wielding a shovel).

According to Festpedia https://www.festipedia.org.uk/wiki/Turntables the Boston Lodge one was in use intil at least 1934 and is stated as now being underneath a garage. It would be useful to allow the single locos to face uphill when they work on the WHR to Beddgelert

[rogerzilla]

On 17/01/2023 at 11:57, Titan said:

Come to think of it any passenger train braking hard will have the water slosh to the front of the boiler with the same effect as going down a 1:20  or so gradient, until the brakes are released or it stops.

Indeed, and if the water was already near the bottom of the glass, the fusible plug could give up.  Putting the injectors on and closing the dampers might not be the first thought if a signal is suddenly thrown to "danger" in front of the train or there is an obstruction spotted up ahead.

[Michael Hodgson]

17 minutes ago, rogerzilla said:

Indeed, and if the water was already near the bottom of the glass, the fusible plug could give up.  Putting the injectors on and closing the dampers might not be the first thought if a signal is suddenly thrown to "danger" in front of the train or there is an obstruction spotted up ahead.

But does the fusible plug fail instantaneously when it becomes uncovered?  Surely it takes a little time to reach melting point, but which time some of the water probably comes surging back again?

[Wickham Green too]

Would do if the loco 'stopped on a sixpence' ........... but .................

[LMS2968]

A dropped plug isn't an instantaneous reaction to a water surge, but they can be cumulative. A driver might allow to be uncovered for only a few seconds to have it fail, as it has already been uncovered many time in the past. This is why plugs are consumables and regularly replaced, not just when one gives up the ghost.

[rogerzilla]

Braking from 90mph to a red could take about a minute.

[PhilH]

2 hours ago, rogerzilla said:

Indeed, and if the water was already near the bottom of the glass, the fusible plug could give up.  Putting the injectors on and closing the dampers might not be the first thought if a signal is suddenly thrown to "danger" in front of the train or there is an obstruction spotted up ahead.

But if you are managing the boiler properly you don’t let the water get near the bottom of the glass….

[melmerby]

Build a loco for a gradient?

Pwllyrhebog incline had locos with a sharply tapered boiler and the dome over the firebox and always ran chimney first up the incline..

https://www.google.com/url?sa=i&url=http%3A%2F%2Fwww.gwr813.org%2FGWR794b.htm&psig=AOvVaw32Yxy5FXkPDF9e0leMsPb7&ust=1674154263199000&source=images&cd=vfe&ved=0CA4QjRxqFwoTCLiNhuPk0fwCFQAAAAAdAAAAABAJ

 

They were cable assisted.

[LMS2968]

12 minutes ago, PhilH said:

But if you are managing the boiler properly you don’t let the water get near the bottom of the glass….

Not necessarily. If you are in charge of a poor steaming engine struggling with a heavy train against a gradient, and you're watching the pressure gauge dropping back, and the level in the gauge glass is falling, what do you do? If you put the feed on, you are putting (comparatively) cold water into the boiler, and its immediate effect is the cause the pressure to drop further. So you use the feed sparingly, allowing the water level to fall in order to maintain enough steam pressure to get you to the summit. This process is known as 'mortgaging the boiler', and once over the top the driver can ease up and the pressure can rise. And there's the danger.

 

As the summit is passed and the engine starts downhill, the water, already not too high in the glass, disappears down to the smokebox end. What's more, when the driver had the regulator open, the flow through the valve lifted the water level; if he now closes it this means a further fall in the level. The Horwich Crabs had a bad reputation for that. So the fireman, who had managed to keep half a glass during the climb watches the water disappear below the bottom nut as they go over the top.

 

It isn't as easy as just saying, 'Keep enough water in the glass.'