Self Propelled Passenger Cars

Motor Coach, Self-Propelled

In 1922 Service Motor Truck Company, located in Wabash, Indiana had possibly found a way so that truck building possibilities could be realized with the substitution of a modern gasoline rail car for steam locomotives in light local passenger service. The gas engine was beginning to attract a wide range of attention from designers and users of rail equipment and it appeared quite clear that further development of light railway equipment was now to come. Recent developments in gasoline motor rail cars now offered competition to the steam locomotive as the adaption of motor trucks to rail use had been very satisfactory. These new cars, built by the Service Motor Company could accommodate forty-six passengers and operate at speeds of up to fifty miles per hour. As built each car weighed approximately fourteen tons.

Link to image of Self-Propelled Cars 198-199
Self-Propelled Cars 198-199 sitting out their final years on the WP at Sacramento, California in 1937.
Frank Brehm Collection.

This new type of passenger equipment was self-powered and of the four-wheel driving truck type. The most distinctive feature though was found in the driving mechanism, which provided for a four-wheel driving truck under the front end of the car. All propeller shafts were of alloy steel while all wearing parts were hardened and ground. All stressed parts, such as yokes, crosses, etc., were manufactured by the drop forging process and then heat treated. The driving axles on the forward truck were provided with a beveled gear, driven by a pinion through the secondary propeller shaft extending from the auxiliary transmission in the swing bolster. All gears and shafts were made from carbonized and oil-tempered steel and nickel steel and carried on Timken Taper Roller Bearings.

The gears in the main transmission were 1¼ to 1¾ inches wide and the clutch was of the multiple dry disk type. The motor was mounted in the forward end of the car and in such a position that it could be easily disconnected and removed as a unit from the car by sliding forward when repairs were of such a type that they could not be made from inside the car by raising the hood over the engine. The engine itself was a four-cylinder, four-cycle valve in head, heavy duty type with a 4¾ inch bore and six-inch stroke, the crankshaft was three inches in diameter and carried on three main bearings, with the total bearing length being 10¼ inches. The connecting rod bearings were 3 inches by 2¼ inches long. The engine was provided with a full pressure oiling system with a geared pump supplying oil under pressure through the crankshaft to all main crank and cam shaft bearings. The oil pressure was regulated by automatic control from the intake manifold so that the oil pressure varied with the load. The horsepower of this engine at various speeds were as follows:
800 R. P. M. 41.8 H. P.
1000 R. P. M. 51.3 H. P.
1200 R. P. M. 59.1 H. P.
1400 R. P. M. 65.8 H. P.
1500 R. P. M. 68 H. P.

The safe constant speed for the motor was 1600 R. P. M. and the maximum speed was 1800 R. P. M.

This car measured 42 feet 6 inches long with a baggage compartment of 70 square feet in length, in addition to space for light parcels along the side of and above the engine hood. The width of the car was eight feet, four inches and the height from the rail to the top of roof approximately eleven feet.

The truck centers were twenty-two feet two inches apart. Construction of the car body was similar to the standard light weight steel frame electric cars of the time with steel plates extending to the belt rail, continuous steel tee posts and car lines and with a roof rail just above the letter-board. The driver's seat was placed on the left of the engine hood in the forward end of the baggage compartment. Control from this position was by means of a foot-operated clutch, hand-operated gear shift and hand-operated spark and throttle control with foot auxiliary throttle with the brake operated by a hand wheel in front of the driver and by an air brake valve. The entrance to the car was at the rear, through a standard type of vestibule.

The accompanying illustrations serve to indicate the general arrangement of the car body and character of appointments. The expanding use of automotive vehicles for both passenger and trucking service had now resulted in a wide knowledge of automotive design, construction, and operation, thereby making less difficult the adaptation of this equipment to railroad service. Many railroad men though had been extremely doubtful about the success of operating these motor rail cars at speeds necessary for passenger service. However sufficient time had now elapsed which allowed the proper demonstration of these cars and the doubts began to diminish.

Western Pacific had no doubts concerning this type of passenger equipment and ordered two of the self-propelled cars, numbers 198 and 199. They were built in November 1922 and were received by the WP at Sacramento, California on December 7, 1922 and placed in service on the San Jose Branch beginning January 5, 1923. This service though was discontinued in 1927 although I could not find an exact date. In 1927 or 1928 they were tried on the Reno Branch but found unsuitable for this service. They were then returned to Sacramento and placed in storage from 1929 until retired and sold to the Georgia Car & Locomotive Company in December 1939.

WP’s designation for them was Motor Coach, Steel, Combination Coach and Baggage, Model 55. According to a diagram of the cars they had 30” wheels, a Midwest Model 399 4-cylinder motor, 50-gallon gasoline tank and Westinghouse air brakes. Seating capacity was 42 and weight of the body and trucks was 26,000 pounds.

BUDD Rail Diesel Car RDC-2 375-376

Western Pacific, on January 25, 1950 became the first railroad to place an order for one of the new Budd rail diesel cars, when the passenger and express model, technically referred to as the RDC 2, was purchased for delivery in May, at a cost of about $130,000. WP’s order for the first car was followed very quickly by C&NW, PRR, B&O, and the NYS&W. The Board of Directors then authorized purchase of a second car for delivery in June 1950.

Before placing an order, WP had used the RDC-1 demonstrator from Portola to Salt Lake City in trial revenue service from January 18-27, 1950. With BUDD approval WP shop forces temporally modified the car with a head-end compartment for baggage use and ran it as numbers 1 & 2. BUDD, at their expense, also applied pilots at each end. This gave WP the distinction of being one of the first railroads to use the RDC in revenue service.

Link to image of RDC 375
One of WPs BUDD cars, number 375, on an excursion at Niles Canyon on March 31, 1951.
Arthur Lloyd.

Proclaiming it was a “Revolution on Rails” the Budd rail diesel car closely resembled the California Zephyr vista dome coaches in appearance, although the “dome” contained the engine cooling system rather than observation seats. Mounted under the car floor were two six cylinder, 275-h.p General Motors diesel in line engines with the power drive provided by Allison torque converters, developed for heavy tank use during the war. Even with this mounting arrangement, all clearance requirements were met with no intrusion on revenue space. Moreover, this placement contributed to a low center of gravity only 52.6 inches. The installation was designed with special consideration for simplifying normal maintenance, preventive maintenance, and ready replacement when overhaul schedules required.

The principle of the torque converter, which was being widely employed in automotive transportation, was applied to the power transmission. It operated during acceleration up to a designated speed, at which point the transmission automatically locked into direct drive. In addition to providing high efficiency and reliability, the torque converter saved tons of weight, was appreciably lower in price than other drives, and gave unsurpassed flexibility and smoothness in operation. Only the inside axle of each truck received power.

Seldom did these cars lack for power. In direct drive, cruising speed was 70 miles per hour at 55 percent of available horsepower while in torque conversion the maximum speed was 55 miles per hour. On the one percent grade a maximum speed of 62 miles per hour was obtainable. In 6,000 miles of test service the car averaged 2.8 miles per gallon of diesel fuel at a cost of slightly more than 3 cents per mile. Fuel cost for steam locomotives used in similar service averaged 22 cents per mile.

The Budd Railway Disc Brakes, model CF, operated in conjunction with the Budd Rolokron anti wheel slide device, could stop a fully loaded car, under service application, from 85 miles per hour in 2,330 feet. The disc for each brake was bolted to the inner face of the wheel. To increase rail adhesion the car was equipped with both automatic and manual sanding devices. Delivered with 33” wheels these were replaced with 34” wheels in 1953 by the railroad. At the time these two RDC cars were the only “locomotive” type equipment on the railroad equipped with sealed beam headlights.

The car was fully insulated against heat, cold and noise, and completely air conditioned by seven ton, electromechanical equipment especially designed for railway car use by the Frigidaire Division of General Motors. This model of Rail Diesel Car had a seventeen-foot baggage section and its foam rubber seats provided a comfortable ride for 70 passengers at speeds up to 83 miles per hour.

Traffic wise, the Budd car presented an attractive appearance. Constructed throughout of stainless steel, it made a fitting supplement to the California Zephyrs, and for this reason, Western Pacific dubbed its new cars "The Zephyrette’s."

Before being placed in service, the cars were set up at the Sacramento Shops. Many modifications followed over the years. These included electric water coolers as well as additional toilet and hot water facilities. Photomurals depicting scenes of the Feather River Canyon were placed in each car as were reclining seats in the center section for use by through passengers. Exterior modifications included two number boards at each end of the car and a red Gyralight at the rear of the car with a white Gyralight being mounted at the front. Additional air horns were installed at each end of the car and mounted so as to sound toward the opposite end of the car. One interesting addition was the installation of special fish racks in the baggage section for the handling of iced fish shipments.

After being declared surplus by WP, the cars were sold to the Northern Pacific who in turn sold them to Amtrak. Both cars have since been scrapped.