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!

Westinghouse Gas Turbine - Electric 2

Our first post on this prototype locomotive gave some basic information and characteristics. Let's take a look this time at the powerplants used in this locomotive.

Here is a drawing of the gas turbine powerplant as shown in a Westinghouse sales brochure from 1947. At left are the two DC traction generators, coupled together; to the right is the reduction gearbox; the drive shaft enclosure seen running into the turbine compressor is actually at the center of the concentric air intake. The combustion chambers are individual, and expansion bellows can be seen placed between the chambers and the exhaust elbows. The exhaust elbows direct the hot combustion gas to the turbine, and finally the exhaust stack angles 90 degrees to direct exhaust gases through the roof.

According to the materials in the specification book, work on the Westinghouse Gas Turbine Locomotive project began in 1945, and rapid progress led to a test unit of the configuration seen here on this blog being constructed, with testing of this unit beginning in September, 1946. This test set was operated at Westinghouse until December, 1948 at which time it was modified and shipped to Arkansas to be used as a test and prototype natural gas pump. This modification was not a removal from the locomotive testing program; rather, the test imposed greater stress on the "hot" parts of the turbine from which Westinghouse could extrapolate data and develop modifications for locomotive service.

Each turbine contained a 23 stage axial compressor, 12 combustion chambers, and an 8 stage turbine. Combustion temperature was approximately 1350 degrees F. The turbine itself developed roughly 6000 HP, but roughly 4000 HP of this power was needed to drive the axial compressor, leaving 2000 HP available for propulsion and auxiliary needs on board the locomotive. The turbines burned Bunker C oil, as did the General Electric turbines built for the Union Pacific for freight service.

The March, 1947 edition of "Westinghouse Engineer" details some of the features, development, and problems with the prototype turbine set. Mentioned is the fact that the turbine sets had to endure fairly rapid combustion temperature changes ranging from 700F to 1350F in railroad locomotive conditions, that is, no load to full load. Westinghouse did not apparently tackle all of the problems associated with very rapid temperature and pressure changes, and the control system applied to the prototype locomotive (pneumatic throttle in cab, incidentally) was designed to limit the rate of increase of load to an acceptable value. Idle speed of the turbines was roughly 60 percent of the speed at full load. Our sources do not give a speed for the turbine rotors, although Westinghouse Engineer gives a generator armature speed of 1200 RPM at full load while the specification states 1150 RPM.

Starting of the turbines began with rotation of the whole machine by use of one of the traction generators as a motor. Test results in the lab indicated that 80 KW of cranking power (battery power) would bring an engine to operating speed in one minute, while 50 KW would do it in 1-1/2 minute. Operating experience with the prototype showed that total starting time for one turbine set was about 3-1/2 minutes.

Each turbine set drove, in addition to two traction generators, a 50 KW auxiliary generator, an exciter, and a 2 CDB Westinghouse air compressor. Westinghouse used a sophisticated combination of components including main exciters and YG-53A pilot exciters to match desired load characteristics (for train handling) to the peculiar speed-torque characteristics of gas turbine engines; the pilot exciters were belt driven like the aux generators / main exciters but mounted on the floor. One electrically driven auxiliary air compressor was also fitted on board, which could be either powered from the battery or from the auxiliary diesel.

At left, one of the two turbine sets manufactured for locomotive service. Note the application of lagging (insulation) and shielding to the production machines to be placed side by side in close proximity in a locomotive.

Next time, we'll cover the general construction of the locomotive and describe the overall equipment layout with the help of some large and never-seen diagrams from the specification book.

Westinghouse Gas Turbine - Electric Locomotive 1

One of the most interesting pieces in our collection is an original specification book issued by Westinghouse Electric Corporation covering its experimental 4000 HP Gas Turbine locomotive. This book has an issue date of June 9, 1952 and includes a few photographs, diagrams, a specification section dated April 1, 1952 and a number of drawings, as well as some reprinted material originally produced by Westinghouse for publication in Railway Mechanical and Electrical Engineer in 1950. Let's take a look at some of the pictures and information contained in this unusual book. Click pictures to enlarge.

At left, the front cover. The title page clearly states that the book was produced by "Westinghouse Electric Corporation - Baldwin Lima Hamilton Corporation," and this with statements in the book and the two photographs clearly show that BLH was involved with the locomotive, contrary to some published assertions.


Here is the first photo, cropped to show detail. This is the completed 4000 HP Gas Turbine locomotive. According to the introduction the locomotive was completed in May, 1950 and from that date until production of this book in 1952 the unit had tested on Union Railroad, Bessemer & Lake Erie, Pittsburgh & Lake Erie, Pennsylvania Railroad and at press time was testing on the Missouri-Kansas-Texas. The locomotive was configured and geared for passenger service, although of course as with diesel-electric locomotives, a freight version would have been practically identical, with omission of train heat equipment and a change in traction motor gear ratio.


Here is the Westinghouse Gas Turbine Locomotive shown backing express cars onto the head end of a passenger train prior to departure. The photo was taken during testing on the Pennsylvania Railroad, and the location is PH Tower, Pittsburgh.





At left, a simple diagram of the completed locomotive. As can be seen, the locomotive contained two generator sets; each set was comprised of one 2000 HP gas turbine engine, a reduction gearbox, two close-coupled DC generators, and at the rear end an exhaust elbow. The right side turbine exhausted through a Babcock & Wilcox waste heat boiler, providing steam at 2000 lb/hr when the turbines were running; a Vapor-Clarkson OK-4625-130 steam generator also being fitted, rated 2500 lb/hr. At left rear is a small 75 HP diesel used for battery charging and hostling.

Basic ratings for this locomotive were as follows - and these are given as provided by Westinghouse with 2/3 of full load of fuel and water on board.

Total Weight: 494,000 lbs (all on drivers)
Rated Starting Tractive Effort: 115,000 lbs
Continuous Tractive Effort: 52,800 lbs
Maximum Speed: 100 MPH
Gear Ratio: 22:57 (Westinghouse 370)
Length: 77' 10"

The truck arrangement, officially AAR class B-B-B-B, used a novel and patented Westinghouse design that allowed 2.5 inches lateral motion in each direction on the end trucks and 7.5 inches each direction on the center trucks. An identical style of design was used on two prototype Ignitron rectifier locomotives built for operation on the PRR which used a B-B-B wheel arrangement.

At left, speed-tractive effort performance curve for the 4000 HP Gas Turbine locomotive. A direct comparison is made in the published material to two 2000 HP A1A-A1A wheel arrangement passenger diesel-electric locomotives; the Gas Turbine exhibits identical horsepower, higher weight on drivers, shorter overall length and lower total locomotive weight.

This concludes our first installment on the Westinghouse Gas Turbine Electric locomotive. Future installments will cover the gas turbine powerplants in detail, the locomotive internal arrangement in more detail, and operational and design aspects of the whole locomotive system as well as developmental details on the turbines themselves. Be sure to check back!