Union Pacific Motor Cars

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This page was last updated on October 16, 2023.

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A railroad Motor Car is a self-propelled railroad passenger car, at times known as a "Doodlebug." Union Pacific was a pioneer in the design and use of motor cars with the introduction of the McKeen motor car in 1905. The McKeen cars were gasoline-powered, with a mechanical transmission. Previous "motor cars" were steam-powered. General Electric became involved in 1906 with its electric transmission car, which became much more successful than McKeen's mechanical design.

The first internal-combustion rolling stock on UP was a series of self-propelled McKeen passenger cars, powered by small gasoline and distillate-fueled engines. These motor cars were designed by UP's superintendent of motive power and machinery, William McKeen, and were built beginning in 1905 by UP in the railroad's Omaha, Nebraska, shops. In 1908, UP organized the McKeen Motor Car Co. as a subsidiary to sell McKeen cars to other railroads, and production continued in the Omaha shops. With their distinctive wedge-nosed front ends, these cars were designed and operated as self-contained passenger trains, but by 1909, they were powerful enough to pull a trailer.

The design of the McKeen car was for a mechanical transmission, and its early success in the 1908-1910 period got the attention of other builders, including GE, and they started competing with their electric transmission designs. World War I and the USRA diverted everyone's attention, and by the time the war was over, McKeen had built his last cars; two in 1916 and two in 1917, including the unique Southern Utah no. 100, a 300 hp, six-wheel truck design that was a failure on the road's grades in Utah.

Competition for McKeen's mechanical-transmission motor cars came in 1911 when General Electric released its own design for an electric-transmission motor car. McKeen's largest vehicle, a rounded-front 300-horsepower car with a three-axle power truck, was completed in 1916 as a demonstrator for Southern Utah Railroad in Utah's Carbon County coal fields (it was delivered on January 1, 1917). The last McKeen cars were completed in 1917, which was also GE's last year for motor-car production. The production of motor cars ceased with the United States' entry into World War I.

After the war, the market for rail motor cars improved, with builders by the name of Brill and St. Louis taking the lead, and EMC coming to the market in 1924. McKeen's mechanical designs could not compete.There are stories that Union Pacific continued to support McKeen and his motor cars after Harriman's death in 1909 because Harriman's widow wished it, based on Harriman's own support of McKeen. That changed when Carl Gray became UP president in January 1920. Production formally stopped in March 1920 when Union Pacific bought out McKeen's interest in his McKeen Motor Car Co. Union Pacific completed several motor cars for itself during mid-1923, using the remaining McKeen bodies.

A growing interest for electric-transmission motor cars after the war led to the formation of Electro-Motive Corp. in 1922 to again market gas-electric motor cars to America's railroads, taking advantage of better and more powerful engines and better electrical control. In 1927, UP began buying Electro-Motive motor cars, receiving 15 cars during 1927 and 1928. Also in 1928, UP acquired two motor cars from Brill, and another two came from Brill in 1930. Several of the mechanical McKeen cars were converted to gas-electrics during the 1920s, and the last mechanical McKeen cars were retired in 1942. Electric-transmission motor cars with both gasoline engines and distillate engines remained in service on UP throughout the 1940s and 1950s, with the last one being retired in 1961.

Between 1920 and 1932, the number of passenger-miles for America's railroads had dropped by two-thirds, inversely matching the tripling of automobile registrations during the same period. The public wanted faster schedules and more comfort. To furnish faster schedules, Union Pacific needed either lighter trains or more powerful locomotives. UP chose to pursue a lighter train, based on its experience with self-propelled motor cars, with their electric transmissions and increasingly powerful distillate engines during the late 1920s. Lighter trains would also spring from developments in lightweight metals during the post-World War I years, and from aerodynamic designs for rail equipment (specifically, Pullman's Railplane of March 1933). More comfort, especially for business and upscale pleasure travelers, would come with new, more modern designs. These developments led Union Pacific in 1933 to ask for the development of the lightweight, articulated passenger train, which became known as The Streamliner. Union Pacific saw The Streamliner as the answer to what the traveling public wanted, and the first Streamliner was M-10000.

June 15, 1918
McKeen Motor Car Company lost its appeal before the Nebraska Supreme Court for an injuries and damages suit filed by a former employee. The award was $11,860. (Lincoln Star, June 15, 1918)

(The $11,860 amount awarded by the court in damages in 1918, is approximately equivalent to $193,000 in 2018 dollars. This was likely the final blow to its finances that the McKeen company suffered. Then, McKeen's name was in the newspapers following an affair, and supposedly Mrs. Harriman gave instructions that Union Pacific cut all connections with McKeen, including buying his interest in the McKeen Motor Car company. McKeen and his wife were divorced in December 1921. By 1923, McKeen was a resident of Santa Barbara, California.)

March 1920
Union Pacific purchased full control and interest of the McKeen Motor Car Company in March 1920. (Associated Press, Kingsport Times, September 5, 1922)

September 1, 1920
"Old Company Passes Away -- Omaha, Aug. 31. -- The McKeen Motor Car company, manufacturers of gasoline driven railway carriages many of which are used in foriegn countries, will go out of existence today following incorporation of the McKeen Works as part of the shop organization of the Union Pacific, it was announced at the offices of the latter company today." (The Nebraska State Journal [Lincoln], September 1, 1920)

Roster Listing

Motor Car Roster -- A roster of Union Pacific's motor cars, including the McKeen cars, the EMC cars, the Brill cars, and the cars that UP itself built.

System Repair Shop

A new engine house was constructed at Grand Island, Nebraska in 1910, and at that time, Grand Island "became the major system repair point for a growing fleet of passenger motor cars. The motor cars continued to be repaired at Grand Island until the last of them were retired." (The Streamliner, Volume 2, Number 2, April 1986, page 21)

Miscellaneous Notes

Randy Heese wrote on October 16, 2023, on the subject of couplers on McKeen cars.

The Master Car Builders (MCB) association fixed the size of the coupler at 9" tall (at the face) in 1889. That would stay the size while the contour was adjusted to become the "D" coupler in 1918. In 1932 the standard would be changed to the type E coupler, with an 11" face.

McKeen cars would have been built with a type D coupler. For modelers, the Kadee No. 5 couplers are a bit oversize for a type E and way oversize for a type D. You need to find a scale coupler if you want it to look right. Also, McKeens had conventional couplers at both the front and rear, not streetcar style drawbars.

Letter to the editor, concerning a photo in an issue of The Streamliner (Volume 14, Number 1, Winter 2000, page 10):

The photo shows a view of McKeen motor car M-23. The caption suggests that the photo was taken during a run to evaluate some device mounted to the front truck. That may be true, but I think that what it really shows is M-23 on its first trip west. Notice how shiny the car and trailer are (sticky fresh, as some would say). The photo is dated May 17, 1915. Available records show that M-23 was built in May 1915.

This photo is unique because it shows the first use of the M prefix to the motor cars, since M-23 was the first car built after the 1915 renumber plan was put into place. All of the cars built before that time, from UP 1 (in 1905) to UP 22 (in 1909), were later renumbered to their M series numbers.

In the Spring 2001 issue of The Streamliner, Don Lodge wrote a letter to the editor:

"The McKeens were gas mechanical and thus cannot be considered direct predecessors of the early Streamliners. In fact, the McKeen cars might be thought of as one of a number of dead ends in the history of self-propelled rail cars."

"The first Union Pacific gas electric cars came in 1927. These were M-29 and M-30, built in the company shops from unused McKeen parts, and M-31 to M-35, built by St. Louis Car for EMC. According to Keilty, the shop-built "McKeens" utilized four unused car sides, Hall-Scott gas engines, and electrical components from General Electric. It was the electrical parts from GE that were critical to these cars' success."

"GE's pioneering work in designing a method of tieing together the control of a gasoline engine and an electric generator led to the modern day diesel locomotive."

Mr. McKeen Meets Dr. Diesel

Chris Baer wrote to the R&LHS discussion group on December 18, 2014:

There is a story concerning the movements of Rudolf Diesel on his U.S. tour. A local journalist wrote an account of him visiting some small town to check out a McKeen car. This story was printed many years later in Railroad Magazine and then reprinted almost whole as a chapter in a Diesel biography, the journalist still being alive as an old man. The problem is, when you check the New York Times as to when Diesel actually left Hamburg and arrived in New York, he would have either had to time travel or teleport to get to whatever transmississippi state to make the visit at the stated time. Either the dates were erroneous, or the whole thing was a journalistic fabrication. The fact that the same book had Diesel returning to Europe on the Berengaria, a German liner given to Cunard as reparations for the Lusitania well after Diesel's death, and which did not yet exist even in its original German form, calls the whole thing into question. It would require access to St. Louis papers, which I don't have, to get a contemporary tracking of Diesel's movements, but clearly something is amiss.

Kyle Wyatt wrote to the R&LHS discussion group on December 19, 2014:

The story goes that Dr. Diesel met E. H. Harriman at the St Louis fair 1904 opening. Reportedly after leaving St Louis, Dr Diesel visited the Southern Pacific, including the Sacramento Shops, as a guest of Harriman. We'd need to cross-check timing on McKeen car development and Dr. diesel's travel schedule, but it is possible he might have seen one of the first Union Pacific McKeen prototype cars while en route to or from California. McKeen car #1 was completed in March 1905; #2 in September 1905; and #3 in November 1905. #1 was 31 feet long; #2-3 were 55 feet long. #2-3 seem unlikely, but depending on timing Dr. Diesel might have seen #1 - maybe while under construction in Omaha - to the national press, Omaha might have been considered a "small town", I suppose.

Also note that in 1904-05 Southern Pacific had a diesel-electric locomotive under construction by American Locomotive Company and General Electric. Dr. Diesel would very likely have visited that, or at least had discussions about it, since he advocated using diesel engines in locomotives and had ideas on the subject. Perhaps it was confused with the McKeen car in news accounts. Some articles refer to the locomotive as a "rail car". The SP diesel loco was ultimately unsuccessful - it was never placed in service, and disappeared from news accounts in the Spring of 1905.

William R. McKeen, Jr. was Union Pacific's superintendent of motive power and machinery from July 1902 to July 1908, succeeding Samuel Higgins.

The first McKeen motor cars were completed in 1905, and the McKeen Motor Car company was organized in 1908.

Using Distillate Fuel

Union Pacific and its subsidiary companies used gasoline in their motor cars until the mid 1920s. After that time, distillate fuel replaced gasoline as the fuel of choice due to much lower costs.

(Read more about the use of distillate fuel.)

Motor Cars In Utah

(incomplete; more to be added)

May 4, 1905
Mckeen motor car no. 1 made a trip from Evanston to Ogden on May 4, 1905, then proceeded on to Salt Lake City, where addition test runs were made. The car was not large enough to carry passengers, and was intended solely to demonstrate the deisgn to local railroad management. After operating in and around Salt Lake City for two days, the car was moved to Portland for exhibition during the Lewis and Clark Exhibition. (Ogden Standard, May 4, 1905)

August 24, 1909
OSL no. 480 was the first motor car in Utah, and made its trial run in Utah, between Salt Lake City and the Saltair resort on the south shore of Great Salt Lake. The car entered regular service on the OSL on Monday August 30, 1909 between Ogden and Malad, Idaho. (Salt Lake Telegram, August 25, 1909, "yesterday") (Read the transcribed text for the newspaper article.)

July 1911
OSL began using a 100-passenger motor car for service on the Cache Valley branches. To connect with through trains that ran through Cache Junction, one round trip was made between Cache Junction and Preston, Idaho, each day, and two round trips were made between Cache Junction and Logan each day. The motor train operation was in addition to regular steam trains which continued to make their scheduled truns. (Box Elder County News [Brigham City], July 27, 1911)

W. R. McKeen Biographical Information

William R. McKeen -- Biographical notes for W. R. McKeen, as part of the story of the men who led UP's mechanical department.

McKeen Patents

William Riley McKeen held several patents for designs used on his motor cars.

McKeen also filed a patent for a weed cutter for railway equipment, Patent 830,163, dated September 4, 1906.

More Information

Carter, Clive. "Union Pacific Self-Propelled Cars" Mainline Modeler, June 1998, Volume 19, Number 6, pages 20-27. (link to text)

Keilty, Ed. "Union Pacific" Doodlebug Country (Interurban Press, 1982), pages 169-178. (link to text)

Keilty, Ed. "McKeen Motor Car Co." Interurbans Without Wires (Interurban Press, 1979), page 48 (link to text)

Keilty, Ed. "Electro-Motive Corp." Interurbans Without Wires (Interurban Press, 1979), page 109 (link to text)

Kratville, William, and Harold E. Ranks. "Meet Mr. McKeen" Motive Power of the Union Pacific (Barnhart Press, 1977) page 123. (link to text)

Wikipedia, McKeen Motor Car Company

McKeen Motor Car Co. -- An online bibliography of McKeen Motor Car information, at Mid-Continent Railway Museum.