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Union Pacific M-35
From Rail & Wire Issue 172, July 1998

by Dan Mulvihill

Eleven years ago, M-35 was captured on film on IRM trackage crossing Seemann Road on one of its rare outings. Photo by Victor Humphreys

Union Pacific M-35 is a gasoline-electric motor car built in 1927. Motor cars, often referred to as "Doodlebugs," were primarily used for passenger service on light traffic branch lines during the steam era. In this type of service they proved to be less expensive to operate than a steam locomotive pulling only one or two coaches. As a result many railroads purchased motor cars, which were offered by several builders. M-35 was built by the Electro-Motive Corporation, the predecessor to the Electro-Motive Division of General Motors, Corporation, the largest and most influential builder of diesel-electric locomotives.

The car became part of the Illinois Railway Museum Collection in 1975, when it was donated by the Stuhr Museum of the Prairie Pioneer, located in Grand Island, Nebraska. The Museum's restoration of M-35 began in the spring of 1978. The biggest obstacle to making the car operational was the condition of its original Winton gasoline engine. When taken out of service by the UP in 1955, the car was stored for approximately 15 years before being acquired by the Stuhr Museum. Apparently, at some time after the car was taken out of service and before IRM acquired it, the water was not drained out of the cooling system during cold weather. When the water froze, it expanded and caused the engine block to crack. Since it would have been very difficult, not to mention expensive, to repair the Winton, it was decided to replace it. Fortunately, Sperry Rail Service donated a Roiline gasoline engine, along with a generator, that was similar to the Winton.

To make removal and replacement of the engine and generator easier, the roof (made mostly of wood and covered by canvas, just like an interurban car of the same vintage) over the engine room/cab section of M-35 was removed. Nobody felt too bad about taking part of the roof off, since it was in poor condition and would need to be replaced as part of the restoration. While the engine and generator were being exchanged, the wood tongue-and-groove floor in the engine room/cab was replaced. After a few years of additional work, M-35 was made operational again.

Motor car M-35 on Train 544 at Marysville, Kansas, in October 1948. The train ran between Grand Island, Nebraska to St. Joseph, Missouri. Photo by Albert C. Phelps, collection of Francis G. Gschwind

I became interested in the car during 1994. To my knowledge, it had not operated since 1987. Those who had previously worked on the M-35 were no longer able to spend much time at the Museum or had turned to more pressing projects and responsibilities. Given this, I thought the Doodlebug would be a good project to adopt. That year for the annual Diesel Days celebration, the cooling system was filled with water and an attempt was made to start the engine. It fired for a few revolutions, began to backfire, then died. This was as far as we got that summer. Over the coming winter the water pump (which was leaking) and the oil cooler were removed and sent out for rebuilding.

In the spring of 1995, the water pump and oil cooler were installed, using new hoses for the water connections. The cooling system was again filled and another attempt at starting the engine led to the same result as the previous year. A couple of months of Sundays were spent investigating various possible causes. The condition of the gasoline was checked and found to be satisfactory. The fuel delivery system was checked and the few minor problems that were found were corrected. The carburetor was removed, disassembled, and cleaned. Next, the oil filter was changed and the accumulated sludge was cleaned out of the filter housing. The batteries were also carefully checked and more than two gallons of distilled water were added to the cells before they were hooked up to a charger. All of this paid off, as the engine was started and the car successfully operated in July of that year.

The author takes a break from checking and topping off battery cells on the UP Doodlebug. Photo by Peter Schmidt
M-35 spends most of its time inside Barn 2 with other pieces of the Internal Combustion collection. Photo by Peter Schmidt
During 1996, many other items were attended to. Two cooling system drain valves (that were leaking) were repaired. The exhaust stacks, which were fabricated when the Roiline engine was installed, would not clear the entrance to all of our car barns. They were originally made longer than it was thought necessary to make sure they would be long enough when everything was put together. Some research was done and it was determined that the stacks were protruding seven inches higher than the originals. The stacks were subsequently taken down and cut to the correct length.

An air horn was located and installed, but before it could be used, another problem had to be resolved--a leaking feed valve in the line that supplied the air to the horn. Since it isn't necessary to have a feed valve for the air horn, the problem was temporarily fixed by bypassing the valve until it can be repaired. In July, the car's exterior was washed while some of the loose paint chips and dust were swept up inside. The brake cylinder was disassembled, cleaned, inspected, and reassembled with clean AAR brake cylinder grease. Shortly thereafter, damaged brake rigging on the rear truck was repaired. At the end of the season, while the weather was still warm, the traction motor support bearings, gear cases, and traction motor armature bearings were inspected for proper lubrication.

Last year work continued at a steady pace. Some miscellaneous hardware was replaced and the engine room/cab was cleaned. The battery charging ammeter was repaired, and the controller was cleaned and lubricated. Before the Motor Car was taken out of storage and the engine started, the lube oil and oil filter were changed. During the middle of the summer quite a bit of time was again, devoted to the braking system. The centrifugal dirt collectors in the air system were cleaned out. Two of the steel brake lever supports had the wood "wear strips" replaced. One of the supports was discovered to be bent, so it was heated with an acetylene torch and straightened. With this done, the brake cylinder piston travel was checked and adjusted.

The M-35 has made a few appearances on the Museum's railroad, most recently on Diesel Day in July 1998. However, several more years will be required to fully restore this car. In 1998, plans are to continue to improve the mechanical condition of the M-35, as well as continue attending to the missing details of the carbody. Hopefully, in a couple of years or so, we can begin the complete replacement of the roof As with all other museum projects, funds will be needed to continue the work. Any donations to the M-35 would be welcomed and appreciated.

Thanks to all of the members of the Internal Combustion Department who have worked on the M-35, and also to members of the Electric Car Department and Steam Department for their help and assistance.

Union Pacific M-35 was painted in UP's streamliner colors (yellow, silver, and red) shortly before it was retired. Here it is in storage at Grand Island, Nebraska on August 19, 1955. Photo by Richard L. Rumbolz, collection of Francis G. Gschwind

From the Rail & Wire Issue 172, July 1998

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