[P Escue]

I’ve a few questions about manual firing. I’ve done it, but not often. When shoveling, I’m use to R to increase the shovel rate, and Shift+R to decrease the shovel rate. However, CTL+R in the shortcut key listing simply says Shovel Full. So, my question is what is Shovel Full? I assume Shovel Full is to give the fire a full shovel of coal, but I don’t know how this will affect the shovel rate, if anything. Does it for example, after doing CTL+R, continue at the last rate setting or does it stop the rate or what? I would like to know what it does before using it (and I cannot find anything in the manual).

I’m used to looking at the ideal fire mass in the .eng file for a given locomotive. I noticed that in the extended HUD (ALT+F5) in Locomotive Information under the Fireman, gives Ideal, and Actual Fire. Again, I’m assuming that, that is the Ideal Fire Mass and the Actual Fire Mass. However I noticed that the ideal fire mass in the extended HUD is much larger as a rule compared to the one in the .eng file, nor can I detect a ratio between the two. So, I’m assuming (that word again) that I should go by the one in the extended HUD. Also, I believe that the Fire Mass percent given in the F5 HUD is a the actual fire over the ideal fire.

In Rail Simulator I believe you could see the color of the fire and determine how hot the fire was. Is that implemented in OR? If not, is that something we want to think about added to OR?

Thank you for the help,

Phil

[P Escue]

Just went to Coal to Newcastle page and it looks like the ideal fire in the extended HUD is based on a calculation of the size of the grate area.

Phil

[scottb613]

Hi Phil,

Yeah - while ORTS does many things well - I don’t think manual firing is quite ready for prime time. We’ve had a number of private conversations with the developers - and from how I understand it - one of the missing links is that the “fire” itself is not really modeled properly. We’re also missing any kind of nicely formatted display to make it easy to get key parameters needed when firing. I’m no pro - this is just what I’ve gleaned from discussions.

Regards,
Scott

[darwins]

Yes. We are still a long way from manual firing well. There has been a lot of discussion but the fire in OR is pretty much a continuous flow mechanical stoker model. The problems are mostly around the sheer complexity of modelling a coal fire. The coal itself burns it two different ways, with rapidly burning volatiles like oil combined with slow burning solid carbon like coke - that is even without considering the amount of non-combustible material that will make clinker or ash. Then to deal with that we need to consider two different air flows primary and secondary that are needed for efficient combustion - which reflects in smoke colour and heat output. Draught of course influences these, and there has been some work done on natural draught and blower draught as well as blast draught. Finally at the extremes you could either have a "hole" in a thin fire allowing colder air to rush in through the grate or so much cold coal piled on without sufficient draught that the fire temperature would drop dramatically!

[Jonatan]

This has been a pet peeve of mine for a while.

I think MSTS had a pretty decent way of "simulating" firing for the AI but in both sims manual firing is a bit meh. I mean, it works but is a bit meh. The whole fire mass thing is weird as I've never heard of a fire being measured as a "mass", which in the simulator can be up to a few tons in some cases!? (Coal is heavy but not that heavy, how much do they expect us to cram in there?)

In MSTS the AI fireman simply bungs coal in until the fire mass was at 100% and then took a break until fire mass dropped to about 50%, the rate at which this happens depended on how much fuel was consumed. It may not be very accurate or realistic but it gave an illusion of a human tossing in a few scoops every so often instead of the mechanical stoker darwins mentioned. It also resulted in the smoke changing color so you'd have intermediate puffs of black smoke which is what happens irl whenever a shovelfull lands on the firebed.

This very basic approach would be good for the short term realistic "feel" while a better solution could be worked out for the future. But as it stands then no, manual firing isn't even a challenge as with the trials I've done trying to wrap my head around the new physics parameters I still can't get a boiler to respond accurately.

[scottb613]

Hi Jonatan,

While it's been a very long time since I manually fired with MSTS - it seemed to work pretty well. I recall it being a real challenge to run well (Bill Hobbs ENG Files) - you had to carefully manage the fire with the blower, drafting, fuel feed, and even the firebox door. There was a big difference between using a cold-water injector and a feedwater heater injector - you could seriously kill steam production by using too much cold water. Sometimes you needed to kick in the cold water though because the hot water system couldn't keep up with demand. You had to plan ahead a bit for tackling grades. I do miss these things in ORTS as well.

Regards,
Scott

[Jonatan]

Hi Scott,

On a properly set up locomotive it might've been, but as we know most models even in the MSTS era weren't given much operational accuracy, most people just like seeing the train go by and were fine with however the AI did things. The Hobbsian treatment were few and far between. I know I did my best with the eng files I made for my own models to get the firing to "feel right" and it could involve juking the physics with some interesting values.

Another point from MSTS was the water level moving with the grades, this alone made things more challenging for managing the water. I realy realy miss that and wish Peter would add it back in.

We can hope for improvements.

[Laci1959]

darwins, on 18 February 2023 - 04:30 AM, said:

Yes. We are still a long way from manual firing well. There has been a lot of discussion but the fire in OR is pretty much a continuous flow mechanical stoker model. The problems are mostly around the sheer complexity of modelling a coal fire. The coal itself burns it two different ways, with rapidly burning volatiles like oil combined with slow burning solid carbon like coke - that is even without considering the amount of non-combustible material that will make clinker or ash. Then to deal with that we need to consider two different air flows primary and secondary that are needed for efficient combustion - which reflects in smoke colour and heat output. Draught of course influences these, and there has been some work done on natural draught and blower draught as well as blast draught. Finally at the extremes you could either have a "hole" in a thin fire allowing colder air to rush in through the grate or so much cold coal piled on without sufficient draught that the fire temperature would drop dramatically!

Hello.

Why do you need two different airflows? Where do they get into the combustion chamber? Certainly not the door where you throw the coal in. At least with us, the heater closes immediately.
Order:
1. Dip the paddle into the coal.
2. He holds the shovel with his right hand, turns and opens the door with his left hand.
3. He turns back, holds the shovel with both hands, turns again and throws the coal into the fire, spreading it in the right place.
4. Closes the boiler door and turns back to the coal.
In MÁVAG locomotives, the air enters the combustion chamber from below from the ash box. Just like a coal stove used in an apartment.
If the slag is already thick, the heater will catch fire. He moves the live embers aside and places the ashes in the ashtray. It is usually done during water sampling at the designated stations.

Sincerely, Laci 1959

[darwins]

Quote

Why do you need two different airflows?

Good question.

Primary air to burn fixed carbon gets in from below (through the grate).
Secondary air gets in from above to burn volatile matter (mostly hydrocarbons).

In most UK locos it gets by leaving fire box door partly open;

In many locos in USA and some European countries there are vents built in to the firebox doors so the doors can be closed;

Some locos with mechanical stoker have special vents into the firebox from back or sides.

Possibly in Hungary the doors are built with air vents either in the doors or near them.
This picture is from Hungary - https://m.blog.hu/aq...ek_orient_2.jpg
There seem to be holes in the door! (for secondary air)

Quote

Where do they get into the combustion chamber? Certainly not the door where you throw the coal in. At least with us, the heater closes immediately.
Order:
1. Dip the paddle into the coal.
2. He holds the shovel with his right hand, turns and opens the door with his left hand.
3. He turns back, holds the shovel with both hands, turns again and throws the coal into the fire, spreading it in the right place.
4. Closes the boiler door and turns back to the coal.

UK
1. Open fire door
2. Shovel 6 to 8 shovels of coal into right places
3. Partly close fire door - to get light grey smoke
4. Wait about 2 minutes until smoke is clear
5. Repeat

Sorry video is in English only, but you can watch here https://www.youtube....h?v=F4J2wcDP3YA

[Jonatan]

darwins, on 18 February 2023 - 11:08 AM, said:

...In many locos in USA and some European countries there are vents built in to the firebox doors so the doors can be closed

We do indeed have vents on our doors, they can rotate to either be open or closed like on a stove. You can see the fire glow through them!
https://absolutman.files.wordpress.com/2013/09/dscn8532.jpg