Steam & Excursion > PM 1225 Cab Ride

Yes, it's a link to Facebook, but that's where SRI has posted 8 minutes of cab ride from yesterday's North Pole Express trip. They put a camera up in the back corner of the cab roof, it's pretty good video! It would be fun if a few of the experts here can provide the commentary on what the crew is doing.

https://www.facebook.com/video.php?v=904091919608822&ref=notif&notif_t=notify_me

Steve Krause
Chillicothe, IL

Well, Here Goes....

Interesting steam valves commonly used in the video:

At the fireman's right knee are two red handle valves: The large one is not used often (runs stoker too fast for coal to burn properly).
The smaller handle regulate the stoker engine with a much 'finer' degree of precision. Its the one most often operated.
with a substantial train behind her, the 1225 fires REAL easy --and once the stoker feed-rate is 'set' you don't have to fiddle too much.
In lite duty fan trip service (under 50 cars) you spend a lot of time fiddling with the fire & the coal feed-rate.

The Standard MB stoker has its "elevator tube" (the vertical section) in side the firebox. The coal comes out the top of the tube like cold lava. Over top of the feed tube outlet is a casting with with horizontal steam jets that blow the (cold & wet) coal off the 'lava mound', across the semi-circular 'firing table casting' and out across the fire bed.

In the video, sometimes the fireman bends over and examines the stoker screw rotation rate through these slots (there's also a light bulb fixture under the deck for illuminating the stoker 'pit'.

The steam jets' delivery pressure is regulated by the 5 small valves in front of the fireman's right knee. There is a larger manifold control valve that turns the jets on & off without upsetting their original specific adjustments. The five areas of the grate controlled by the jets are: the right & left rear corners, the right and left front corners and a jst labeled 'Fine Coal' -- feeds all ares of the grate.

With jets set too strong, the fine coal accumulates, unburned, at the front of the grates --- building up under the brick arch --NOT a good thing..
With jets too weak, coal accumulates, unburned, at the back of the grates; also, not a good thing.....

Notice the folks looking into the stoker while the stoker id feed coal.
CAN YOU SEE ANYTHING THROUGH ALL THAT HEAT & LIGHT?

The Truth? Neither can they SEE anything significant! Plus the fire don't need that blast of cold air whipping around in there.
As you can see, with the stoker running the coal burns too bright right at the stoker 'pot' --can't see any further than than about 4 0r 5 inches into the inferno.

The best time to look in there is when steam demand is calming down. With the consent of the engineman, reduce the stoker feed rate, calm the jets down, and, with a light throttle ---continue to burn of the 'volatiles' from the coal bed. When the bed has calmed down, and with a light 'blower' (artificial stream draft --up the stack...) you can now INTELLIGENTLY assess the condition of the firebed. Ideally, the firebed wants to be an all-over uniform depth, less than 6 inches, with no 'holes' --dead spots---, and no mounds of unburned coal. (while seeing if adjustments to the jets and the feed-rate and also check the back corners for bare spots --that's where the draft ( the air-flow through the grates is the strongest)!

So, the easiest Bad Habit of a new fireman is to be looking into the firebox while feeding coal and chugging strong.
When you see that, smile to yourself -- cause he ain't fooling ANYBODY!

On the engineman's side, the the video shows him reaching out with his left hand to a valve handle on a long rod, reaching back towards the fireman's side.
On C&O's "AMC-pattern" engines, that rod is connected to a right-angle gearbox that rotates the steam valve-stem to the feedwater pump system (Worthington SA-type, in this case).

It was intended to allow the engineman to adjust the feed-rate ahead of making changes to the throttle and steam-demands of the firebed. There is also a fireman's FWP steam handle at the same gearbox. In the old days, some engineers you'd get told the fireman: "I pump my own engine!" -generally meaning that he carries the water WAY TOO high, and its going to be a hard trip on the fireman!

Typically, with a globe valve, about 2 full turns opens it about as wide as it gets --- the handle may turn 6 to 8 times --- all the way open; but, 90% is opened in the first two turns.
The FWH systems typically are run with less than a full-turn OPEN... Crew co-operation is important in the successful art of pumping an engine.

There's not much else going on in the video.

Hope that helps...

Wes C.

The one area that is not shown, due to that screw reverse gear is, where the valve gear is set for such a low throttle setting. I was also a bit curious as to why someone was using a coal scoop to throw coal into the firebox.

Thanks for posting the link and thanks also for the informative and interesting analysis.