Boiler pressure/firing practices

[Justin.Smith]

When I was visiting a couple weeks ago, I sat right behind the engine and could see the pressure gauge. I saw that between stations the pressure would drop about 50 psi, down around 100 psi, and then climb when stopped at the station. I saw this on two different engines.

Is this practice, letting the pressure drop so much, normal? That isn't easy on the boilers. Do they adjust the fire as they run, or pretty much leave it at one setting? From watching the pressure, it looks like the fire isn't adjusted much

[Steve DeGaetano]

50 pounds? That is terrible for the boilers, if true, and represents a complete lack of knowledge of how to fire a boiler.

[Cannonball7]

I am pretty sure that the WDWRR operates its engines at 140psi. Just about every time every time I've ever been behind the engines, the pressure has varied between 135-142psi. The crew is also constantly monitoring the fire. You can tell from the sound from the stack when they've increased/decreased the fire's intensity.

I find it hard to believe that they let a 50psi drop occur. At least, I've never seen that... Maybe one of our engineers from WDWRR on the boards can clarify for us.

[Justin.Smith]

Per these links the boilers are 150 psi.

http://www.steamlocomotive.info/vlocomo ... isplay=338

http://www.steamlocomotive.info/vlocomo ... isplay=337

http://www.steamlocomotive.info/vlocomo ... isplay=336

http://www.steamlocomotive.info/vlocomo ... isplay=339

[Steve DeGaetano]

I don't think you'll hear the stack sound change much with increased fire. Increased blower, however...

[Cannonball7]

I don't think you'll hear the stack sound change much with increased fire. Increased blower, however...

I am pretty sure I didn't articulate the sound well in my earlier post... There is a "roar" when they are putting a lot of fuel on the fire vs. when they've backed that off. It reminds me of grandparents home that had an oil furnace. The more oil that is shot on the fire wall...the louder the roar of the fire.

Hope that makes sense...

I became attuned to the sound after taking the "Magic Behind the Steam Trains" tour (several times) where they show how they light the fire and adjust the fuel flow to the fire.

[Steve DeGaetano]

Per these links the boilers are 150 psi.

http://www.steamlocomotive.info/vlocomo ... isplay=338

http://www.steamlocomotive.info/vlocomo ... isplay=337

http://www.steamlocomotive.info/vlocomo ... isplay=336

http://www.steamlocomotive.info/vlocomo ... isplay=339

Those links also state that the engines are standard gauge.

Anywho, I agree that the MAWP is 150 pounds. It would be weird to run at 140.

And Cannonball, I really think you are hearing the blower. The sound of the fire wouldn't be transmitted up the stack.

[steveb48]

And Cannonball, I really think you are hearing the blower. The sound of the fire wouldn't be transmitted up the stack.

Well maybe but there is a difference in sound between a small fire which is loosing or maintaining pressure and one which is building pressure. It's subtle but a fire that is building will have a fuller chuff sound. Sort of like turning up the bass. If you back off on the oil, the sound with get thinner like turning the bass down.

Steve

[Main Steet Jim]

When I was an engineer on WDWRR, we operated between 120-130 psi on the gauge. The popoff valve "popped" at 140-145 psi (depending on locomotive). I *always* maintained my pressure, never letting it drop below about 110-115 pounds. If it's dropping *50* psi, they're running hard, and someone's not keeping up with the fire.

When we would sit at ToonTown station (now Fantasyland), we would *slowly* build up to just under that "popoff threshold" (again, depends on what locomotive it was) to build up pressure for the uphill run to Main Street. At Main Street, pressure would have been maintained at about 115-120 psi, then again from there to Frontierland. Keep pressure at about 120 psi and bring the fire down a little for the *downhill* trek to Fantasyland, and just before going under the Cast Drive overpass, start to pull fire up again to build up to 135-140 psi while sitting at ToonTown. Never more than about a 20 psi difference on one trip. We were *constantly* adjusting the fire depending on how hard we were running (how fast, to keep on schedule), and our location.

If it's varying *that* much (50 psi), someone didn't get trained right in the cab.

[Cannonball7]

And Cannonball, I really think you are hearing the blower. The sound of the fire wouldn't be transmitted up the stack.

Well maybe but there is a difference in sound between a small fire which is loosing or maintaining pressure and one which is building pressure. It's subtle but a fire that is building will have a fuller chuff sound. Sort of like turning up the bass. If you back off on the oil, the sound with get thinner like turning the bass down.

Steve

Thanks, Steve! You said better what I was trying to convey to the Board.