Rich, I have a few questions

I watched that as well, great show!

I did raise an eyebrow when Rich stated that the 261 was much smoother at speed than the 765........ 

Thanks for the questions.

Slamming the throttle shut was in response to the drivers slipping. If the audio is clean enough, you should be able to hear the slips.

When running in signaled territory the operating rules require that the engine crew call the signals aloud when they are seen. Who sees the signal first depends on the lay of the land. If we are on straight track or a right-hand curve, the Engineer will see it first. On a left-hand curve, the Fireman will see it first. When you see it, you call it aloud.

This was the first time we had operated the 261 on a heavy train. In adjusting the cutoff I was "feeling her out" to see where she was happy with this heavy throttle and a big train. We spent a lot of time with the throttle wide open and the best she could do with a 34 car train on .4% was about 45 mph.

At the time this video was made, the 261 was a freshly overhauled 4-8-4 passenger locomotive, while the 765 was a tired, worn out freight hauler. That's why we leased the 261 for these trips in 1994. The 765 was not serviceable because her running gear was worn beyond service limits. The 261 rode like a Cadillac compared the the 765 of 1994. Today, with the 765's running gear back to spec, the difference would be much less noticeable.

Running a steam locomotive is part skill, part experience and part magic. There is a lot of "seat of the pants" running where you just have to KNOW how she is supposed to feel and sound.

Rich,

Thanks for the reply.  The audio while you were speaking was such that I could not hear the drivers slipping, but I thought that was the case. The video did mention that 765 was not serviceable for the run.  The reason for asking about operating a steam locomotive, it appears that you are reacting to "inputs" that are not apparent in the video such as subtle sounds and movements of the locomotive and that can only be explained by experience, like "feeling her out".

Larry

LLKJR posted:

Rich,

 

 The reason for asking about operating a steam locomotive, it appears that you are reacting to "inputs" that are not apparent in the video such as subtle sounds and movements of the locomotive and that can only be explained by experience, like "feeling her out".

 

Larry

There are some VERY "subtle inputs" of large main line steam locomotives, that would never be able to be picked-up on an in-cab video.  I don't recall if NKP 765 does the same thing, but on SP 4449 there is an ever so slight "shudder" prior to her drivers losing traction and then slipping. When that "sensation" is felt, quick action in closing the throttle can prevent a serious/violent wheel slip. 

Yep, the 765 will also shudder just as the drivers start to lose their grip on the rail. It's subtle...you feel it in the seat of your pants.

I have never had the trill of operating a locomotive, but from my experience with race cars (limited) and with farm and construction equipment, you have to use your eyes, ears, hands, feet and butt to take inputs from the machine and it will usually tell you what it needs.  I also remember Jack explaining that as a steam fireman, you can't just react, because by then it's too late, you have to be aware and anticipate.  I'm sure the same goes for the engineer.

When operating a steam locomotive it makes a HUGE difference if we can anticipate things that are about to happen as opposed to reacting to something that has already happened.

Does the throttle need to be slammed completely shut or just partially shut?

Matt A posted:

Does the throttle need to be slammed completely shut

Absolutely YES!

or just partially shut?

Any amount of superheated steam still flowing into the valves and cylinders, will maintaing the slip. Thus, ALL the steam must be shut off, until the drivers stop slipping and regain traction with the rails. 

Usually the throttle has to go all the way closed. The bottom line is that you have to stop the slip. Once the wheels start slipping, the coefficient of friction between them and the rail drops tremendously. If you don't completely stop the flow of steam into the cylinders, the wheels will continue to slip.

Once they grab the rail again, the coefficient of friction climbs, the wheels grip the rail and you can come back out on the throttle.

Go to about 3:45 to see what happens when you don't let the wheels grab before opening the throttle again:

https://youtu.be/NUPIynJq7tg

(YouTube won't allow the video to embed)

I I enjoyed that show as well . Didn't,t understand some of it until now. Interesting questions to me.  I'm glad you asked it Larry.