What are thos tanks and equipment on the front of these locomotives and why do some have them and others don't?
https://www.dropbox.com/s/oxp3zt0ffz1q9g4/File%20Mar%2022%2C%208%2019%2054%20AM.jpeg?dl=0
https://www.dropbox.com/s/ikfd94tnmhxdsj7/File%20Mar%2022%2C%208%2025%2010%20AM.jpeg?dl=0
Gary
In the first photo, the cylindrical tank sitting on top of the boiler is the Feedwater Heater. As the name implies, it pre-heats the boiler water before it is injected into the boiler. Feedwater heaters were produced by different manufacturers and were of different designs. Some were located inside the boiler smoke box.
In the second photo, the objects mounted on the front of the locomotive are air pumps for the compressed-air brakes.
Assuming you're talking about the object on top the boiler, behind the stack. It's a feedwater heater (Elesco I think, but not sure). It warms the water before it's injected into the boiler, which improves the efficiency of the loco.
The objects atop the pilot are shields for the air pumps mounted there.
Feedwater heaters are reletively late additions to steam locos, IIRC after WWI (but don't quote me on that one), so many steam locos did not have them. There were also other versions that were more "stealthy" and not so obvious, but I'll defer on the details to someone with more expertise in steam than I.
Mike Lehman
Urbana, IL
Here are a couple of photos showing some of the components of that Elesco feedwater heater system:
The Elesco and Coffin systems used waste steam from the cylinders and from other steam-powered appliances on the locomotive to pre-heat the water being fed into the boiler. Both of those were closed-systems, where the water and steam didn't come into direct contact.Worthington feedwater heaters also used exhaust steam, but mixed it with the feedwater, and that system used two pumps, one for the cold water and another for the hot.
Wayne
Feedwater heaters were not on every steam locomotive. They were a "modern" appliance generally installed on the latest and best. Or sometimes retro-installed. They were quite rare on switchers and smaller engines.
There were different kinds of feedwater heaters and their various "bits" looked different. In this case, the main component of the Elesco is particularly noticeable. If you do a search for "feedwater heater steam locomotive", you can learn pretty much all about them.
About the other thingys, the air compressors. If steam locomotives hauled trains that had air brakes, they had to have an air compressor. And they had to be put somewhere. The most common location was on the side of the boiler, usually the left side. There might be one, two, or three. And they might be "single" or "compound". They all looked very similar. Anyway, someone realized that the compressors didn't HAVE to be on the side. By moving them up front, they could transfer a lot of weight in that direction. Which could better ballance the weight distribution. The two locations were on the face of the smokebox, or down low, ahead of the cylinders. BUT, if you DON'T seem them in these two locations, they definitely are somewhere else. Except perhaps on a teeny little steam critter working in a quarry.........
Ed
Appliances and piping on steam locomotives could be mounted in many ways. The Mechanical Departments of the various railroads had their own ideas about such things.
Feedwater heaters were developed to preheat the water before it was injected into the boiler, for greater efficiency. Not all steam locos had them. "Late" steam engines were usually built with feedwater heaters, and older engines were sometimes upgraded with them, and there were several different types with different characteristics. The Erie engine shown was a K-5A 4-6-2, built in 1923 as a copy of the USRA heavy 4-6-2. At some time after delivery, she had an Elesco bundle-type feedwater heater installed ahead of the stack. The pump to feed it is on the left side, under the running board, about midway between the cab and smokebox. On many engines, this is the location of the air pump because the weight of the air pump on the left side is somewhat compensated for by the weight of the power reverse gear on the right. In this case, the Elesco pump fills that balancing role.
On this Erie K-5A, the railroad decided to install a second air pump some time after installation of the Elesco heater. The pumps were placed on the pilot deck at the front of the engine behind shields, one on each side. If they had been left in the traditional location, there could have been a balance issue. Some PRR Decapods received a second air pump, and had the second one installed on the right side to maintain a semblance of balance. Other obvious improvements to this K-5A included Boxpok drivers and a Delta trailing truck instead of the standard USRA Cole truck.
The Erie put the air pumps on the front for two main reasons: First, that helped maintain a better weight distribution, placing more weight on the front to help the engine track better as it entered curves; and second because fresh air entering the air pumps was cleaner if it came from the front, as opposed to a location farther back, where road grime could accumulate. The pumps were moved to the front on a lot of railroads. B&O did that on its EM-1 2-8-8-4's and T-3 4-8-2's of the 1940's, as well as P-7b, c, d, and e Pacifics rebuilt in that same era. For the many B&O engines that did not have their air pumps moved, the INTAKE was often moved to a position at the front, just below the smokebox.
The air pumps on the Great Northern 4-8-4 in the lower photo were placed high on the front for much the same reasons: better balance and cleaner air intake. Great Northern was one of several roads that liked this high placement of air pumps. Others were C&O, Seaboard, etc.
Santa Fe was another railroad that liked Elesco bundle type feedwater heaters, but they usually mounted the transverse bundle heater down on the pilot deck.
If you don't know just what you are looking at, it can be confusing. Many people see a pilot mounted air tank, as used by PRR and others, and confuse it with a bundle-type heater, and vice versa.
These Erie K-5's and K-5A's had a lot in common with Southern Railway's Ps-4's, but had taller drivers. Because of the nicely balanced look of the air pumps on the front, I have always preferred the Erie engines over the Southern. The green paint on the Southern engines is the thing that makes them distinctive --- not the overall design. Now I'll duck. I can feel the brickbats about to fly from a Southerly direction.
Tom
The first part of Linn Westcott's Model Railroader Cyclopedia, Vol 1 STEAM LOCOMOTIVES is a detailed explanation of the various parts of a steamer's guts and plumbing, what they do and how they interconnect. Well worth the price if you're into detailing or kitbashing steam.
The Erie Pacific (basically a USRA heavy Pacific with upgrades) has an Elesco feedwater heater. The cold water pump is located back where an air compressor would be expected. with the heater bundle ahead of the stack. Having the bell in front of the heater made it easier to hear from the front while keeping a lot of the 'CLANG' out of the cab.
The big tank in line with the sand dome is one of the air reservoirs. There's another on the other side, and plumbing connecting the two, the pilot deck pumps and the cab brake stands (one for train brakes, the other for independent brakes on the locomotive itself.) In front of the visible tank, hard to see, is a mechanical lubricator box that pumped oil to places that needed continuous lubrication.
I could easily write a treatise on steam locomotive systems, which started dead simple in the 1830s and grew steadily more complex right up to and beyond the end (The Withuhn system for eliminating dynamic augment, which was never built, and the Lima double Belpaire boiler, which only reached a 1:6 scale 'proof of concept' model). But then, my first 'live fire' line drawing involved three boilers, main propulsion turbine, a turbine powered AC generator and about three dozen steam-powered pumps, all of which exhausted into a single condenser. You can't stop a ship at a mid-ocean water tank to replenish, and the evaporators could only keep up with drinking and wash water needs. As cadet engineers we had to make complete line drawings of every system, every fitting and every valve. The reasoning? In case of disaster we had to be able to cope with problems in the pitch darkness of a compartment with no natural light...
(And now you know why I retired from the Air Force...)
Chuck (Modeling Central Japan in September, 1964)
Doctor Wayne:
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Thank you for those well identified photographs. You asnwered a few questions I had but never asked.
-Kevin
Living the dream.
tomikawaTT the Lima double Belpaire boiler, which only reached a 1:6 scale 'proof of concept' model. Chuck (Modeling Central Japan in September, 1964)
Yes, the Lima double belpaire model was donated to the Museum of Transport in St. Louis and should still exist, although I haven't heard it discussed in a long, long time. There were also airbrushed photos showing what a loco would look like with the double belpaire boiler installed. They were based on builders photos of a Lima C&O Greenbrier 4-8-4.