Steam & Excursion > Thirsty large locomotives

I watched an older video of UP's Challenger 4-6-6-4 3985 when it ran a multi-state tour several years ago. That machine could travel; never saw side rods moving so fast. As mentioned in this board, large steam engines often pulled auxiliary water tenders. Engine 3985 had two in the consist. My question is how much water does a large locomotive use when at speed (could one say equivalent to diesel run 8?). I imagine the data might be gallons per minute, or per mile. What diameter hose delivers water to the locomotive? Is auxiliary tender water gravity fed to the locomotive tender?

box8513 Wrote:
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> My question is how much water does a
> large locomotive use when at speed ?

Who's the engineer? Some will use 50% OR MORE water than others for a similar train on the same route! Firemen hate them.

-LD

Well, Mr. Doyle does have a valid point,but that was never an issue on the UP steam crew. Surprisingly, 3985 doesn't really use THAT much water "at speed", probably only about 150 t0 200 gallons per mile at 60MPH or faster. However, at 20 or 30MPH, with a heavy throttle while ascending steep grades with a heavy passenger train, 3985 will generally exceed 300 to 500 gallons per mile water consumption.

Bob and Jack,seems like I remmember the ratio about 10 to 1. 200 gals of water and 20 gals fuel oil per mile at full tilt.Is that close. And what Jack says would make sense under extreme load at low speeds.So with each water bottle 28000gals and the tender 23500 for 844 and 25000 for 3985 the range should be atleast 400 miles.
Is that close.
Steve

I love this board...

Posted from iPhone

wpjones Wrote:
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Bob and Jack,seems like I remmember the ratio
about 10 to 1. 200 gals of water and 20 gals fuel
oil per mile at full tilt.Is that close. And what
Jack says would make sense under extreme load at
low speeds.So with each water bottle 28000gals and
the tender 23500 for 844 and 25000 for 3985 the
range should be atleast 400 miles.
Is that close.
Steve

That pretty well covers it, under normal conditions. A complete opposite "event" was we, Bob and I, had to push/help a stalled 12,000 ton manifest train, westbound, on Archer Hill with 844. I dipped the oil tank prior to the "push", and Bob dipped it again upon arrival at Cheyenne. As I recall 844 was using about 30 gallons of oil and 2500 to 3000 gallons of water, PER MILE! However, I don't thing we ever got to 20MPH either!

T&P 2-10-4's would average using 13 gallons of oil per mile. With a 14,000 gallon water capacity, with a "normal" train it would consume 13,000 gallons of water in 70 miles which included a grade 13 miles long at 1.35% and another at 8 miles of 1.35 where speed dropped very low. That would average out 185 gallons of water per mile.

Sounds reasonable, with the barrel valve open, a top fuel dragster is running 120-140 gpm fuel rate and
we talk about steam wasting thermal energy.

rehunn Wrote:
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Sounds reasonable, with the barrel valve open, a
top fuel dragster is running 120-140 gpm fuel rate
and
we talk about steam wasting thermal energy.

To put this into perspective about a top fuel dragster, or funny car since they both use the same design engine:

The top fuel, super charged, 500 cubic inch, "hemi" design engine burns one and a half GALLONS of Nitro Methane per SECOND! For example, a fully loaded 747 consumes jet fuel AT THE SAME RATE, with 25% LESS energy being produced. The cylinders in a top fuel engine operate at a virtual hydraulic lock during a successful under 4 second run.

Well I recall we used 54 gallons 0f oil per mile shoving from Burns to Archer Wyoming up the hill. Jack took the figures with him back to the EMD number crunchers and they figured we were putting out about 44oo hp. Drifting 844 would average around 7 miles per gallon oil and working depending on the grade at 20-24 gallons per mile and that wss based on the tonnage trains we would get. 3985 would drift at 11-12 gallons of oil per mile and working could be upwards of 30-35 gallons per mile. Up the steeper grades would use up to 45 miles per gallon. Yes, you can figure 10 to 1 water to oil.

Bob Krieger
Cheyenne, WY

rehunn Wrote:
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> Sounds reasonable, with the barrel valve open, a
> top fuel dragster is running 120-140 gpm fuel rate
> and
> we talk about steam wasting thermal energy.

I crewed on a NTPA 4 engine Grand National Modified Tractor depending on temp/humidity for a 300 ft track we would burn approx 11-15 gallons of methanol. The methanol also acted as the coolant which is why runs of all 4 motors where less than 30 seconds max ideally from start up to kill switch at the end. Sorry if OT but blown high performance engines are another hobby of mine.

That sort of engine is an interesting definiton of "efficiency". It seems to be a very good producer of power, but only for a few seconds before you have to shut it down and spend a couple of months pretty much rebuilding it from scratch. Wouldn't be very useful for plowing the farm, even though it could pull a whopping big plow. For a few seconds.

It does make me idly wonder where the tradeoff point is on size vs power. How big an engine would you need to develop that sort of power on a constant basis, that could go months without a major rebuild, or possibly years?

Very interesting thread guys, thanks. I know what our little live steamers do, but it's interesting to hear it scaled up. We don't pay much attention to efficiency and often run in the corner to make it sound better. :D At full size it becomes a major issue.

Throwing those numbers around, suddenly a 200,000 gallon tender does not seem unreasonable.

lwilton Wrote:
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> It does make me idly wonder where the tradeoff
> point is on size vs power. How big an engine would
> you need to develop that sort of power on a
> constant basis, that could go months without a
> major rebuild, or possibly years?

It's easy to make something more powerful by making it bigger, rather than smaller but tuned within an inch of its life. There is definitely an inverse correlation between performance and longevity when you start pushing the design tolerances.

Just scale it up for the job at hand. If you want X horsepower and want it to last for Y time, you can design for that but it's going to get bigger. Dragsters are a special case though. They need to be small, light AND powerful. but they're not concerned with longevity, so that's the big tradeoff.

Mike Massee
Tehachapi, CA
Photography, Railroading and more..

A 200,000 gallon tender??? Uh, just the water in that beast would weigh approx 1,600,000 lbs!

I hope that was a typo! ;-)

I thank you all for a great discussion. Now back to my 1" scale 0-6-0....

Posted from iPhone

If I recall correctly on the SP 4449 treks to and from Minneapolis, the longest day was about 450 miles, from Havre MT to Minot ND. The engine had one auxiliary tender, for a total of 53,500 gallons water. It was pulling 10-11 cars plus a P42, and rolled along at a fairly constant 60-65 mph. It made no intermediate water stops.

"Smokebox" or some other crew person told me they did use the diesel a bit to stretch out the water supply on long days.

filmteknik Wrote:
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"Smokebox" or some other crew person told me they
did use the diesel a bit to stretch out the water
supply on long days.

The Amtrak diesel was used VERY little, since both Engineers on 4449, Doyle and Bill Stettler, really know how to set the throttle and reverse gear for maximum efficiency. Simply having the diesel push you around is NOT why we do this, and actually is harmful to the running gear on ANY steam locomotive. Over the years that we have had the big aux tender, we have done some pretty long runs with 4449 WITHOUT diesels, and we still have gotten EXCELLENT mileage on water AND fuel.

I'm not so foolish as to question what did or did not happen since I was not aboard, but as a general question why would using a bit of diesel power necessarily mean that the diesel would be pushing the steamer? Is it not possible for them to share the load if the engineer desires it? Naturally for every mile the steam locomotive's pistons are going to make the same strokes either way but one would presume if the load is shared (whether the other engine is steam or diesel) one could reduce the cutoff and the steam (and fuel/water) consumption. I ask questions because I don't know and enjoy learning.

Steve

OK. The diesel can be used to help accelerate the train, and THAT saves LOTS of water & fuel. However, when up to "cursing speed", the diesel is dialed back to run 1, while the throttle on 4449, or 844 for that mater, can be placed at about 25% or 35% with a valve gear setting only hooked up about 1/3. That gives a nice crack, or "pop", to the exhaust, which means you are "running on the heat" of the superheated steam. Water consumption and fuel consumption is optimal, and the diesel is only barely powering its own weight.

On the other hand, if you try to "ease back" too far on the throttle and let the diesel due more, or too much, work then you have a situation where the wheels and rods are pushing the pistons, which creates overheated rod bearings. The machinery on a steam locomotive does NOT like, nor was it designed to, be operated under reverse thrust conditions, i.e. the pistons do NOT like to be pushed and pulled in and out. That is also why it is VERY important to have SOME steam going through the valves and pistons, with the proper full stroke valve gear setting, when defending long grades. Steam locomotives like 4449 and 844 have NO drifting valves, so throttle and valve gear settings are critical when drifting down long grades.