I recently purchased a B-mann “Consolodation”, which is a sweet running loco. I am amazed at its pulling power for a smaller steam loco. But having been mainly an early Diesel person I know only the basics of steam power.
My question revolves around the two pipes on each side of the engine that hang down facing rearward from around the firebox area that have knobby things on the end of them.
Please inform me as to what they are and their purpose.
Not a newbie, but still uninformed in some areas. [:^)]
Those pipes that run along the boiler or running board surface, and that turn and enter the front of the boiler are the inlet pipes for the boiler. There are two injectors on the backhead, one for each crew member. When an injector is opened, water is forced along the pipe at high pressure, sufficiently high to overcome the preventative pressure of the check valve located where the pipe you see turns at 90 deg and enters the boiler just behind the smoke box.
Thanks for the reply, but you misunderstood my post. These pipes come from around the firebox on each side and point down and to the rear actually going now where. Too far above the tracks to be sanders. They are on an angle of approx. 45 degress to the rear and have a bulb type end on them down below the cab in the free air.
Click on pix to enlarge, you can see them below the cab on a 45 degree angle to the rear on both sides.
Crandell is thinking about the other end of the same pipes you’re discussing. They do lead to the injectors. The “knobby end” on the pipes are actually where the hoses from the tender fed the injectors on each side. These hoses are usually omitted from models, as they could cause binding. So you’re left staring at pipes that go nowhere on the model.
Sounds like you are talking about the pipes running down about 45 degrees right by the corner of the cab. With can like things on the end. Those are blow-off or blow-down pipes. To catch loose and floating crud in the boiler water, rust, boiler scale, whatever, there are skimmers and screens and catchers of various kinds mounted inside the boiler. Periodically the engine crew would open a blow off cock and steam pressure would blow the captured crud, some boiler water, and a good deal of live steam out the pipes. The can like thing on the end is a diffuser, to break up the jet of boiling hot water and keep it from washing the ballast away. Blowing down would create a great cloud of steam enveloping the cab.
Well, Dave’s got a picture and I believe he is right about these being blowdown pipes on this model. I suspect that’s what you’re seeing here.
More generally though, what Crandell and I mentioned are frequently found on models and appear similar to the blowdown arrangment on this loco. Usually ithere’s a 90 degree elbow up, rather than a long sloping pipe. Basically, on the prototype the hose acts like the elbow on the kitchen sink – keep it full of water, since it’s the low spot – and everything is happy. Since it’s the low spot in the water supply it acts as the sump for the injectors to pull water from.
I used the same pipes from the Bachmann Consolidation on my Ten-Wheelers (and the same cabs, too). The pipes are part of the lifting-type injectors mounted on the side of the boiler. The rearmost pipe on each side is to bring water from the tender to the injector. This is done by passing live steam (high pressure) through an opening inside the injector, which creates a vacuum, thereby sucking the water up the pipe (the “lifting” part of the name). It’s then force-fed (by the steam pressure) to the check valves on the sides of the boiler of the Consolidation. (I use a top-feed check valve on my Ten-Wheelers.)
The other pipes, one on each side, are overflow pipes for when the injectors are cut-out, and they simply empty the residual water onto the ballast.
In the photo below, the water delivery pipes appear to have hoses from the tender connected to them:
…but it’s only an optical illusion, as you can see in this photo. The “hoses” are actually wires feeding power to the motor, as the tender is equipped with all-wheel pick-up (DC operation):
Okay, I see what you are referring to, and Wayne is correct. The injectors draw water past a venturi, but the venturi effect does not take place immediately. It takes sometimes several seconds before the effect begins to draw tender water down into the compression chamber and along to the checkvalves. Meanwhile, all that water has to go someplace, so it just drops down the pipe you see and onto the ground.
Blowdown ports are almost always just below the boiler, facing sideways.
We haven’t discussed feedwater pumps. They’ll have piping leading from the tender through a flexible coupling below the cab, and more piping from the pump, usually slung just forward of the cab on the fireman’s side, or else just below the running board. They continously feed water into either the boiler directly or into a feedwater heater mounted just in front of the smokestack.
Selector and Wayne have it right. Some further info: All steam engines are required by law to have at least two means of delivering water to the boiler, as redundant safety features. If one goes out on you, the other one can still keep your crown sheet from blowing out and killing you and your engineer. Older engines will usually have two injectors, as the Bachmann Connie does, but more modern ones will have a feedwater heater/pump arrangement and an injector as backup.
On the Connie, the rearmost pipe of the two running diagonally acrossthee firebox side is the supply pipe from the tender - the other is usually called the overflow pipe and more often runs straight down from the injector to near the rails. Their operation is as Selector has noted.
Blowdown valves are located low on the side of the firebox, and on freight engines have a short pipe pointing straight out. Passenger locomotives will often have the blowdown directed downward with a muffler down near the trackside. This reduces the possibility of blasting a passenger on the platform with a shot of superheated steam, boiling water and scale debris from the boiler, which, to say the least, would not be a good thing.[xx(]
