Hugh said:



If the system in question was indeed the Hancock Turbo system, it is a true feedwater heater and not an ESI. It uses three stages of pumping to produce high enough pressure to lift the boiler check valve, and does not use momentum in the steam/water mixture as in an injector. I think much of the confusion regarding the system is that people see the name "Hancock Turbo-Injector" and conclude (wrongly, I think) that it must be an ESI.


Here is the description of how to run the system from the PRR fireman's manual of 1949:

Hancock Turbo Feed Water Heater

This device delivers heated water to the boiler when the locomotive is working, drifting or standing. The
principal parts of the heater are:

1. Operating valve.
2. Centrifugal pumping unit.
3. Condenser.
4. Control valve.
5. Automatic heating valve.
6. By-pass valve

The operating valve is used to start and stop the pump and to regulate the amount of water entering the boiler.

The centrifugal pumping unit pumps cold water from the tender to the condenser and hot water from the condenser to the boiler.

The condenser receives cold water from the pump, passes it through a series of jets, condensing the heating steam, and returns the heated water to the pumping unit for delivery to the boiler.

The control valve allows exhaust steam from the locomotive cylinders to enter the condenser. It also prevents water from passing into the locomotive cylinders when the system is not in operation.

The automatic heating valve arranges for live steam to enter the condenser when the locomotive is standing or drifting, and for exhaust steam to heat the water when the locomotive is working.

The by-pass valve assists in regulating the amount of water being fed to the boiler and also prevents hot
water from flashing into steam on its way back to the pumping unit from the condenser.

The water is heated and delivered to the boiler in the following general manner:

Water comes from the tender through the suction pipe to the first stage of the pump and is then delivered to the nozzles of the condenser. It then passes through the tubes of the condenser, forming a jet where exhaust from the locomotive cylinders enters and heats the water. The heated water is then delivered from the condenser back to the first stage of the hot water pump and in three hot water stages has its pressure built high enough to lift the boiler check. Part of the hot water being delivered from the condenser is by-passed back to the hot well in the tender which is built around the tank valve. When the locomotive is standing or drifting, the feed water is heated by live steam from the operating valve through the automatic heating valve.

This feed water heater is operated in the following manner :

1. Open the regulating wheel wide.

2. Pull handle of operating valve to priming position and let it stay there until some steady
pressure is indicated on the delivery pressure gauge.

3. Pull handle of operating valve wide open. The delivery pressure gauge will then indicate a pressure slightly higher than the boiler pressure, showing that water is being fed to the boiler. If the system does not start after following the above instructions, put the operating handle to priming position, open the sprinkling hose valve and wait until a steady pressure is indicated on the delivery pressure gauge and a steady flow of water is coming through the sprinkling hose. Then pull handle to pumping position. If the locomotive is standing, open drain cock in control valve, condenser and suction pipe before placing handle in priming position.

The two ball bearings of the pumping unit are the only points in the system that require lubrication. The
oil cups on these bearings are filled with SAE oil by shop forces. The engine crew should see that these
cups are properly filled before leaving enginehouse territory. Engine or valve oil must not be used in these cups.


Here is a drawing from the N&W archives that shows the general layout of the pump:

That's it, Robert. I'd never seen any details on the unit or its operation previously. As stated earlier, the C&O removed the unit and replaced it with a Nathan non-lifting injector when the engine was brought out of retirement for coal train service in 1955. Perhaps replacement parts for the units weren't available by that time.

I didn't realize the N&W had tried one. IIRC the New Haven 4-6-4's used them as well as the Pennsy T1 4-4-4-4's. Any others?