Wednesday, October 27, 2010

ALCO-GE "1600"

Here we'll show the cover of an ALCO-GE sales brochure originally printed February 1950 and reprinted August 1950; both dates appear on the rear.

As we can see, the model being advertised is the ALCO-GE 1600. No model number for this locomotive is used anywhere in this brochure.

The locomotive in the airbrushed view on the front cover is an Alton & Southern locomotive, which normally would be classed by railfans as an "RS-2" considering that its fuel tank is mounted underneath its cab, its battery box is under the frame, and the locomotive was built rated 1500 HP. However, according to ALCO-GE sales literature and operating manuals this properly was a "1500" and the cover illustration is clearly being reused from an earlier edition.

While most of the illustrations in this brochure show the belt-driven auxiliary generator and exciter commonly associated with the 1500, the illustration shown by the heading "Main Generator" shows end-mounted auxiliaries. Further, the speed-tractive effort curve in the brochure gives a continuous rating of 52,500 lbs, commonly associated with the 1600 or "RS-3."

Of course, all that the curve really assures is that it's accurate as of 8/50 and not that any of the illustrations inside would match. With careful analysis, then, it's pretty safe to say that the previous cutoff of model numbers, RS-2 vs. RS-3 correlates with the change in fuel tank location, change in main generator model, change in mounting style of aux. generator and exciter, and change in rated continuous tractive effort. The increase in rating of the engine to 1600 HP happened briefly before all these other items were altered.

All that aside, the illustration is still impressive!

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.

Sunday, October 24, 2010

GE FDL engine designations 1

Letter designations for EMD engines in the 567 and 645 range are commonly used in all venues, as they have been published widely by Electro-Motive from the beginning. Actual designations for other makers' diesel engines aren't so easy to find; they're buried in technical manuals. Luckily, we have lots of those.

One of the best is a manual from a set issued to Conrail by General Electric in April 1979, covering all GE locomotives that Conrail owned including all those from all predecessor roads. The latest locomotives covered by this manual are the B23-7 and C30-7 units. This large manual is GEK-30130A, Volume IIIA, Diesel Engine Maintenance Manual. In this book are the some of the secrets of GE diesel engine designation. It's complicated.

Let's make some simple statements first off. The U25 materials in our collection, including a locomotive overhaul manual published for the NYC covering its first two orders of U25B units and a number of sales brochures, often did mention the designation 7FDL-16A for the diesel engine employed in those units. Following this, for most U25 production and U28 production GE sales materials are silent on model designation. With the release of advertising material for the U30, the designation 7FDL-16D appeared. Following this, the model designations disappear from sales materials again for good.

The fact of the matter is that there were subletter designations for the GE engine all the way from A through F, and there were sub-designations in each range as well. Let's first just cover the basic models and ratings - and remember that this covers domestic (that is, US railroad) Universal Series locomotives only.

FDL-16A U25 2500 HP for traction / 2750 HP gross
FDL-16C U28 2800 HP for traction / 3080 HP gross
FDL-16D U30 3000 HP for traction / 3300 HP gross*
FDL-16E U33 3300 HP for traction / 3600 HP gross
FDL-16F U36 3600 HP for traction / 3940 HP gross

*Earlier manuals give 3250 HP gross for the FDL16D.

This basic sequence held true in designation, even though, for example, the U30 continued in production alongside higher rated models.. and yes, features that appeared on the E engine did get applied to D engines concurrently so that D engines began immediately to resemble E engines in fitted parts if not in rating, fuel rack travel, or governed speed.

The old hack line that GE engines were just uprated by fuel rack setting is totally untrue. Many significant alterations were made over time. These were fitted to lower-rated engines still in production, and in many cases backfits were possible to older engines. For example, the steel-head cylinder assembly introduced with the C series engine could be backfitted to A engine locomotives so long as a proper depth existed in the engine block all around for clearance; instructions are given that some interference had been noted on old blocks and that minor grinding on crank and cam bosses inside the block would allow fitting of this new assembly to old engines. In this way, old GE engines could receive new leases on life with new parts even if they weren't uprated.

That's all for now- in later posts I'll go into vastly more detail on the progression of GE FDL engines in the U-series locomotives.

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!