Tuesday, December 14, 2010

Westinghouse Gas Turbine - Electric Locomotive 3

Here's our final look at the Westinghouse Gas Turbine locomotive which was first operated in road service in May, 1950. Our primary source is a previously described (see older posts on this blog) specification book produced by Westinghouse in June 1952.

Westinghouse drawing number 55-J-87, described below.

It appears that in terms of test or prototype gas turbine powerplants for locomotives, Westinghouse was first out of the box with its 2000 HP prototype being operated from September 1946 until December 1948 at its plant before being shipped out to the field, modified, as a stationary plant for further evaluation (which Westinghouse of course monitored.) General Electric's prototype gas turbine plant for locomotive service operated at its plant in Erie from September 1947 until August 1948. Westinghouse indicates that its test unit operated 1500 hours; Railway Age reported in 1949 that GE's test unit operated 700 hours. Unlike Westinghouse's test unit, though, the GE unit was placed immediately in a newly-designed locomotive, lettered and numbered as "ALCO-GE 50" and placed in test operation very shortly. Extensive testing of this ALCO-GE prototype on the Union Pacific in 1949 revealed that the locomotive worked; according to Don Strack, UP had already ordered a production batch of locomotives before the end of 1950. The first was delivered in January of 1952, several months before this specification book was issued by Westinghouse covering its gas turbine locomotive.

It would then appear that Westinghouse re-issued the specification with slight revisions (the book indicates that the diagrams and line drawings supersede previous data) and put this binder out to the railroads in hopes of getting some action, as it were, before it was edged out of the gas turbine locomotive market. The fact of the matter was that all of the members of this locomotive family (Westinghouse, offering straight electric locomotives including Ignitron rectifier units, Baldwin and Lima-Hamilton, and Whitcomb) were essentially only marginal players at this point. Further, GE had an advantage with the gas turbine locomotive in simplicity and very likely in fuel economy in developing 4500 HP for traction with a single gas turbine powerplant while Westinghouse chose to use two powerplants to develop a total of 4000 HP for traction.

AS AN ASIDE, a very interesting notation appears on Westinghouse Drawing Number 55-J-87 which is included in the specification book. This drawing is labeled as "4000-4500 Locomotive Arrangement." If this carries any weight it would appear that Westinghouse was considering a 2250 HP net output for its gas turbine plant. However, Railway age reported in 1949 that while the locomotive rating ALCO-GE was publishing was 4500 HP, the gas turbine's nominal rating was 4800 SHP at highest normal altitude (for railway service) and temperature, and 5000 SHP at sea level but that the unit could possibly tolerate operation with higher turbine inlet temperature at 6000 HP and finally that in testing in cold weather the unit had actually been tested at 6400 HP. Clearly then, while it is possible that Westinghouse may have uprated slightly to match the as-built 'first generation' GE turbines, GE also had plenty of horsepower growth available - far in excess of what Westinghouse could have matched, without major redesign.

Getting back to our story line, having covered much of the operational data and the developmental story all that's left is to describe the mechanical layout of this prototype gas turbine locomotive. For that we'll use Westinghouse drawing 57-J-844 from the specification book, which is the Layout & Servicing diagram.

Starting at the left side of the drawing, we note that there are two large air brake equipment racks in the nose of the locomotive, flanking the vertically mounted front traction motor blower serving both front trucks. The blower motors are Westinghouse Y-400A units; each blower was rated 12,000 cfm air flow. Central also is the heavy fuel filler pipe, above which is a hinged door in the top of the nose. Also present in the front compartment is the UE-23 Traction Motor Blower Alarm relay, warning of blower shutdown. In the cab, the engineer's position is fairly typical for road locomotives of the time, including a pneumatic throttle. In front of the fireman's position are a remote steam generator control panel and a hand brake.

Moving into the engine room through a centerline door we find, each side, a large 5000 gallon water tank and behind these two electrical equipment cabinets. Outboard of these, and accessible are various control and indicating panels and the TS-31-D Load Regulators, part of the complex load control scheme required by the nature of the gas turbines' load profile. The front end of each powerplant is a Westinghouse 2-cylinder air compressor; inboard of these, flanking the central walkway are the operating handles for the two XC-623-H Starting Controllers. We imagine these are used only for individual powerplant startup. Outboard and below the air compressors are the YG-53-A Pilot Exciters, which have mounted on front shaft extensions A-80 Tachometers. Behind these we see the large auxiliary generators mounted directly to the front of the main traction generator groups, and on top of these are the four exciters. On top of the front end of the actual gas turbine compressor housings are turning gear motors, used to operate the turbine shafts at very low speeds (required during cooldown for prevention of rotor bowing) and alarm lights indicating dirty intake air (probably a D/P cell.) While the locomotive has three engine room ventilating fans, the larger one over the turbines is a Y-44D motor providing cooling for the turbine lube oil. Below the turbines are Y-109A auxiliary lube oil pump motors and Y-202A fuel pump motors. Overtemperature thermostats, with resets, are located in the engine exhaust pipes; under the left-side exhaust elbow is an auxiliary air compressor driven electrically by a Y-204-A motor. The unit on the left of the engine room behind the left turbine is a standard Vapor steam generator, and on the right is a Babcock & Wilcox custom exhaust heat generator; water is supplied to the exhaust steam generator by a Y-109-B motor driven pump.

Next are two further large water tanks, with the rear traction motor blower at center, sanitary facility at right rear, 75 HP auxiliary diesel left rear, and auxiliary and signal power cabinet at centerline. Item 65 on the drawing is a TK-168-A Hostling Switch, probably used to direct power from the auxiliary generator to a traction motor or pair of them for hostling moves.

The drawing indicates a total capacity of 3850 gallons of heavy fuel in main, or underbody tank, and I-beam tanks. Total diesel fuel capacity 500 gallons. Traction motors labeled as model 370K. The rear traction motor gear cases, #7 and #8 were using an experimental lubricant (Sinclair Jet Lubricant TM) in place of the normal prescribed lubricant. The cab was heated only by steam.

THAT about covers the Westinghouse 4000 HP Gas Turbine Electric Locomotive in as much detail as we need to get a good idea of its design, history, construction, and competitive position in the field at the time. I hope you've enjoyed it!

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