[Traindude]

If you're like me you love the idea of using the AI fireman when running steam engines, as it helps me concentrate on driving. (There's a reason steam engines were a two-person task!)

However, after running several locomotives on the Coals to Newcastle test route's level-grade loop, I've discovered that the AI fireman can sometimes be a pain in the butt, and it's not specific to any one locomotive.

It seems as though I cannot operate a steam engine with the AI fireman on the level grade loop without serious fluctuations in boiler pressure, and it seems to follow a specific pattern:

1. When I first turn the AI fireman on (Alt-H), he fires until the maximum boiler pressure is exceeded by about 7 PSI.
2. The safety valves go off, and when it does the boiler water level starts to drop rapidly. The fireman compensates by injecting more water into the boiler.
3. When the steam pressure eventually dies down, the injectors are still running at full tilt and my boiler pressure drops away rapidly until the pressure is less than half of the maximum pressure, and/or the boiler water level is about 0.85.
4. The cycle starts again.

I've tried just about everything--turning off (Ctrl-H) and resetting (Ctrl-Alt-H) the AI fireman before the maximum pressure is reached doesn't help--the pressure continues to rise. Neither does opening the throttle and cutoff wide open--it only causes my boiler water level to drop even faster.

In extreme cases the steam generation rate is so high that the safety valves are ineffective. Apparently OR calculates the safety valve steam usage automatically, and if you try to specify a different SafetyValvesSteamUsage parameter in an .eng file, OR simply ignores it.

I am at a loss as to what to do...

Edit: Admin--Sorry I posted it in the wrong subsection. Please move to "Answers, Tips & Best Practice."
<Admin comment> topic moved from "modeling feedback"

[copperpen]

The AI fireman is on by default. The AltH command is there to return to AI after using manual firing CtrlF. I do not see any major fluctuations in BP, and safety valves do not operate in default AI firing mode.

[Traindude]

 copperpen, on 06 June 2020 - 02:58 AM, said:

The AI fireman is on by default. The AltH command is there to return to AI after using manual firing CtrlF. I do not see any major fluctuations in BP, and safety valves do not operate in default AI firing mode.

OK. I will give that a go.