I recently watched a program called Voyages and in it was a clip of a steam engine scooping up water from a track pan. I got the impression that its purpose is to avoid stopping for water service. Is it normal for a steamer to use more water then fuel (coal/oil/wood)? Also did the tenders that were able to use the track pans have filters to clean up the water before it went into the boiler or is that a non issue?
Thanks for taking the time to reply to my questions.
MO
Scooping water was a really neat thing to see. The purpose was to cut time from the trip wasted for water stops. This also decreased fuel use by keeping the train moving and allowed tenders to have a larger fuel bunker proportionate to the water area. Steam locos used considerably more water than fuel hence the use of auxilliary tenders and addition of bigger tenders as engines remained in service.
I don’t recall ever hearing about any filters used in the scoop system. My grandfather worked for the Pennsy and he never mentioned anything like that. All tenders, to my knowledge, had screens at the discharge hose connections to prevent any foreign objects from clogging the lines or damaging injectors or feedwater heaters. I don’t know how small of an object they would catch. Injectors, FW pumps, check valves and boilers didn’t like anything much besides water so the screens were very important items.
Water track pans in cold areas had steam heaters installed to prevent icing. I would imagine the pumphouses had a filter or screen system to keep any debris from entering the pans. As the train passed a lot of dust, ballast and light debris would get in the pans from the spray of the water and movement of the train. Trackworkers or someone stationed at the pumphouse would watch the pans and shovel out any debris.
My grandfather told me that trains would be required to slow down to approx 50mph to scoop as going faster could cause structural damage to the tender or pans and possibly derail the tender. He said many times if engineers were trying to make up time they wouldn’t slow down enough and it would bust seams or pop rusty rivets out of the tenders. That could explain the numerous patches one sees when looking at Pennsy tenders! Most Pennsy tenders also had 2 large vents in the rear top deck corners to aid in the venting of the air in the cistern as it was compressed by the water being scooped. Often when going too fast it would be more than the vents co
When they first started this procedure, the NYC Hudsons, and later the Niagaras, were required to slow to something like 35 mph, but by the time the late 40’s came around, they had learned to do it at limited speeds of 79 mph. It was routine after that. In order to prevent nasty interactions with the shop foremen after a run due to breaking off the scoops at the fronts or the ends of the pans, the NYC placed long greased ramps up to those places. Thereby, if the fireman inadvertently lowered the scoop early or forgot to raise it in time when the tender reached the end of the trough, it would be ramped upwards and saved from damage. Neat, eh?
And yes, there is roughly a 4/1 ratio of water conversion to steam in terms of volume over fuel consumption. So the larger centipede tenders that we see in the photos are mostly water. Coaling, thankfully, was not possible on the fly, nor was it necessary.
BUT–Wouldn’t coaling on the fly have been sort of wasteful? But, Hey, a lot of fun can be had wasting something![swg][#dots][(-D] OK, nurse, I’ll go now[#dots][;)]
Scooping water had it’s advantages and dissadvantages. The biggest advantage being the fact that time wasn’t wasted on stoping for water is quite obvious. Unfortuantly, that’s the only advantage the system had. The two biggest problems were the damage it caused on tenders and the lower quality of water comming out of the pans.
Unlike water tanks, which were enclosed and could be filled with filtered and treated water without the worry of having anything contaminate it, track pans were in the worst possible place for the concern of water quality. Not only was there debris blown in by the wind, but oil dripping from the bearings, soot, coal dust and ash from the firepan, grit from brakeshoes, and a host of other contaminates were endlessly jamming up the pans. Oil was a serious problem, as it was lighter than water and floated on the surface, so every tender got a good skimming of oil with every scoop. If you had diesels running over the track pans, you could get a little bit of traction motor gear compound in the pan. Just one little glob of that could gum up your suction pipe, and you wouldn’t get any more water into that boiler until the tank was cleaned out thoroughly. Redular oil caused a similar problem, especially old lube oil, it could gel into a goopy sludge that coated the pipes and boiler, clogged filters and generally caused headaches for everyone.
Early on, wood flotsom and large debris caused serious damage to tenders and scoops as they were sucked up. With a good speed, these chunks would became heavy missiles that launched up the uptake pipe and slammed through the roof of the tender. Other times, debris would snag on the scoop and tear it off, where it could land on the rail and throw a wheel. In a short time, scoops were reinforced to reduce the risk of that happening. Also, just below the floor of the tender a grating was installed to keep objects from entering the tender. It was usually shaped in such a way as to form a ram
Never thought about the stuff floating in the pans-- wonder how BR handled that with their diesels that scooped water for their train-heat boilers.
Thanks to everyone, I learned something new today!
It would seem that track pans were both a good and bad idea. I can only imagine what the loco crew must have delt with scooping water at 60+ mph.
Look again!!! The centipede tenders New York Central used was almost all coal! Since they could pick up water on the fly Central made the tenders so that they only had to refuel once between Harmon and Chicago. The water was picked up on the fly many many times in route.
Since time seems to be the big factor, was the use of track pans mostly for passenger service?
Although water scooping was originally intended for passenger service, it was soon used for all types of trains that ran on the tracks equiped with track pans. Track pans were generally limited to high speed mainline tracks, so only trains that were of a class high enough for those tracks used track pans.
Thanks for the questions, got any more?
Matthew Imbrogno
-Mechanical Vollenteer, Arizona Railway Museum
www.azrymuseum.org
Hello. You seem to have misunderstood.
My use of the phrase “…on the fly…” suggests performing the act while on the move, and clearly that was not possible with coal. Track pans were otherwise.
And look again again - the UP centipedes were half and half - 25 tons coal, 25,000 gallons water. Since track pans in UP territory would have been a lose-lose situation (can’t install anywhere that isn’t dead level, plus massive evaporation in arid areas) they did carry more water than NYC, but had to stop for water when the bunker was still over half full.
NYC could scoop water at track speed because of their centipede tender design - a water channel which diverted the force of scooped water downward, plus very efficient vents (those little pipes sticking out of the pedestal casting.) OTOH, on the Pennsy, the Lindbergh Special had to stop for water after an attempted high speed scoop damaged the E-6s’ tender and added very little water. (They still got their newsreel footage to the Manhattan movie screens well before the people who had flown raw, unprocessed film to New York by air - which, in 1927, wasn’t that much faster than a high speed 4-4-2 pulling 2 cars.)
Chuck (who has gotten soaked by a NYC 6000 taking water on the fly)
No, I did understand. The centipede tenders held a huge amount of coal so that they only had to stop once to add another load of coal. Two full loads of coal would take a Niagara the entire distance from Harmon to Chicago! But since they were able to pick up water while moving, the tender only had to hold enough water to make it to the next track pan. And in fact the centipede tenders on the Central held very little more water than that.
Coaling in route was necessary for many 100 mile freight (and some passenger) runs for steam locomotives with “normal” tenders. For example, on the Pennsy there were between Enola and Altoona no less than 4 major recoaling facilities that could service 6 or more trains at a time. In addition there were smaller facilities at each major town that normally serviced the locals but could be used in a pinch by a mainline run. Any engineer who ran out of coal out on the road had a very unpleasant meeting when he finally made the next division point (an
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Thanks for the link to the Youtube. The clip from Voyages was an overhead shot but the youtub clip really shows the speed of the train going over the track pan.
I think I was able to make it into a hyperlink.
http://www.youtube.com/watch?v=cKx23npnYYk
Again Thanks to everyone as this has all been very informative.
I disagree. If you look at the construction of the Niagara tender, you’ll see on the side sheeting the rivet line showing the sloping rear plate of the bin that keeps the coal, about half the volume of the tender, moving forward toward the intake of the auger. That rivet line bisects the volume nicely. So, the volume, contrary to my original assertion, and yours, was roughly half-and half, quite possibly favouring coal by a 3/2 margin…not sure since I can’t find any diagrams. I regret my misstatement earlier about it being mostly water.
In any event, the coal capacity was 46 tons (per steam locomotive.com’s figures). Its reputed water capacity was 18,000 gals, which @ 8.3 lbs per gal equates to just under 75 tons…nearly twice the mass of the coal, which one would expect given its density.
Additionally, my allusion to the picking up of the coal on the fly was meant to be a joke…as it is ludicrous to envision somehow managing to refuel with coal while the train is moving at 79 mph.
I do have a few semi-related questions. In arid/desert environments did the railroads tanker water to the refilling points? If water normally ran out before fuel, how far apart were the water towers usually located?
Once again Thanks!
Remember that on a stoker locomotive the coal bin must slope toward the center. So the rivet line on the side of the tender is the high point and it slopes toward the screw which is just above the frame. Taking your numbers 18,000 gallons of water works out to 2400 cubic feet. Compare that to 26 short tons (2000 pounds per ton) of coal and using the mine run density (mixed size) of bitumenous at 40 pounds per cubit feet we see that the NYC tender had 2300 cubic feet for the coal. And since the reported capacities are usually rounded I would call the volumes even.