I was always interested in the UP Big Boy class growing up, just because they were so, well, big. Now I'm fascinated by them, as I continue to learn more, because they had so many weird "gadgets" on them (continuous blowdowns with separator? rail washer? car sprayer?!).

In any case, do any of you gurus know how their exhaust steam injectors worked? They seem to have a live steam line attached to them from the turret (which doesn't make sense if they were supposed to operate off of exhaust steam), AND a centrifugal pump operating with steam from who-knows-where (there seem to be too many pipes/hoses leading to it).

Thanks in advance . . . do any locomotives still in service use these contraptions?

Thanks in advance!

JPS

Here is a little first hand information. To start, it has been my pleasure to fire Union Pacific Challenger 3985 which has the system you describe. Here is a basic run down.

When operating under steam (that is when exhaust steam is present) the system has a change over valve that allows the exhaust steam to be used as the primary steam for the injector. Should the exhaust steam be terminated (the engineer closes the throttle) the change over valve then allows for live steam from the turret to be used to continue the operation of the injector.

The system is a high steam volume low pressure injection system. As such, there is not enough suction to draw water from the tender and place it into the boiler. For this reason, a centrifugal water pump mounted below the cab is used to push water to the injector. The exhaust steam, or live steam is then used to inject the water into the boiler. The water also passes through the smoke box before being injected into the boiler. Elesco claimed that at full exhaust steam the injector would place water into the boiler well over the boiling point. I read once that water temperatures of 350 degrees F were even recorded.

This system has many advantages. It uses exhaust steam which otherwise is lost to the atmosphere. It pre heats the boiler water which is much better for the boiler and also saves on fuel. It works with live steam or exhaust steam.

From the fireman’s seat I can tell you the system works very well. It was my experience a number of times to have the throttle closed while the injector was on. The change over valve works very well. Never once did the injector “break” or stop working. On UP supper power, there was a small light mounted in the cab ahead of the fireman. When the fireman primed the injector (filled the injector with water) the light would turn on and the word “spill” would appear. The fireman then knew that the injector was primed and he could then haul back on the handle and inject water into the boiler. This system was for nigh time use. The spilling water dumps onto the right-or-way just ahead of the second set of cylinders on the fireman’s side. You can not see spilling water at night, thus the introduction of the light. Additionally, the fireman can look out the cab window and see a small stream of steam flowing from the water pump when it is on. This allows the fireman to know that the pump is working.

If you would like more information about the pumps feel free to contact us at www.wasatch-rr-contractors.com. This month we will introduce a new program called “Technical Questions” If you are seeking some specific historic information, it is likely to be found in the extensive WRC library.

Happy steaming!

John E. Rimmasch
Wasatch Railroad Contractors

Thanks! I must say, I had no idea the challengers had those as well. I'll have to make my way out there to see it first-hand one of these years.

As long as I have a UP steam expert here, are you familiar with the steam turret device(s) on the 4000's (and challengers, I think)? I see multiple wisps of steam coming from that unlikely area in old film footage. I know the blowdown separator is up there somewhere, but I don't know how it worked, and can't see it needing more than one "chimney."

I really appreciate the time! I'll definitely check out your "technical questions" feature when it comes online.

JPS

The UP Challengers had the Poor Man's feedwater heater more commonly known as Elesco exhaust steam injector because the Challenger front end design didn't allow for a Worthington SA system. I found the reference to the problems at this site

http://findarticles.com/p/articles/mi_q ... 63588/pg_4

Also it is highly doubtful that any injector device can deliver boiler water at 350 degrees. The Worthington system could only deliver water around 260 degrees.