Greetings all,

Question for the engineer types here: After you start out and you are building speed, how do you know where to set the reverser/johnson bar to? Are you using sound, feel, or "I was told to put it there by my mentor"? Please enlighten me!

Thanks, -Jason

Diesels have reversers, steam engines have reverse levers.
You hook up by sound, feel and even a back pressure gauge if the engine is equipped. After you use the gauge a few times, your ears and your butt will tell you where the "G" spot is quicker than the gauge if you've paid attention.
Steam engines will tell you a lot if you listen and pay attention.

JasonB,

Yep, steam engines have reverse levers if equipped with a power reverse, or the big version, called a "Johnson Bar" if not so equipped.

If you've ever driven a standard transmission automobile, then the action is the same. In the auto, you eventually (quite quickly) learn when to change gears. You listen/feel the engine rpm, the cars speed, and if you're accelerating fast or slow, uphill or downhill, etc.

The loco is the same. There is a feel for speed/power/acceleration that you instinctively move the throttle and Johnson Bar combination. There is no "set" position for one relative to the other, the combination is a complete variable, and the engineer chooses what he feels is the best combination.

Listening to a pacing audio of N&W 1218, recently, it seemed the timing of the exhaust changed, even though I had the impression the speed hadn't, I assume because the two engines run at slightly different speeds due to slight differences in tire wear, etc. So my question is if the process is the same for an articulated loco, or do you just get the hang of it after a few tries?

Bob B

I don't recall if 1218 (A class) had compound or not, obviously had simple...

SImple... the engine will sound like 2 steamers as the exhaust is directed out the stack from the pistons.

In compound, the engine has a high pressure set of cylinders, and a low pressure set, the high pressure is smaller and is closer to the cab, the low pressure is the front set of drivers. Steam is sent to the high pressure cylinders first then sent to the low pressure cylinders, then to the exhaust, this makes it sound like a single engine with no syncopating exhaust barks.

Changing the Johnson Bar will change the exhaust clipping and the bark sound will adjust as well.

Often times the Johnson bar will be set nearly full out to start a train, and once you get rolling you will cut it back, you will probably be just wasting steam out the stack. Uphills, downhills, curves, gets to be an artform working the throttle and reverser for optimum running, and each engine may have its own little quirks making you adjust differently from a different engine.

Thanks all for the answers and the corrections...I'm still learning.

Sounds like it's something you can't really learn from words, but rather need to put into practice with an experienced hand on board.

Cheers, -Jason

Once you have run for awhile,you get the feel of the locomotive...and sometimes she doesn't feel the same way two times in a row! You learn to listen to what she says. An old engineer once told me that you should be able to run the locomotive blind because her sound is the only thing you need to make the magic with throttle and reverse.

could be the quality of the coal, or water used, what the fireman does, steam pressure...weight of train...

All those things and more will effect the timing of what you do,but it does not change what you have to listen for. I might have 5,000 tons hanging on the drawbar one day ( yeah..I wish....), and 900 tons of Pullmans the next day. the parameters would change,but your approach to running the locomotive should not.

"Listen to your engine. She's talking to you."