Company:Roberts Motor Company
Roberts Motor Company was an American manufacturer of lightweight, high-speed engines for aircraft, boats, stationary, and automobiles, based in Ohio during the early 1900s.[1][2][3][4]
Company history
1905 - 1914 (Roberts Motor Company)
The company originated in 1905 in Clyde and moved to Sandusky, both in Ohio, in 1908.[1] It was cofounded by Benjamin Leacock "B. L." Roberts and his brother, Edmund Willson "E. W." Roberts, a mechanical engineer, engine designer, inventor, patent agent, and prolific author of gas engineering books.[5][3] E. W. Roberts was known for being chief assistant to Hiram Maxim in his 1894 'flying machine' project in Kent, England and a designer of a large wind tunnel for Maxim.[6][7][8][9] Prior to founding his company, Edmund Roberts was chief engineer at the Elmore Manufacturing Company.[1] He was one of the top leading gas engine designers from the 1900-1915 period.[4]
According to the Smithsonian Institution, which has a few Roberts engines in its collection, the Roberts Motor Company produced more engines during this pre-WWI period than Hall-Scott and Curtiss Motor Company put together.[10]
1914 - 1917 (Roberts Motor Manufacturing Company)
Roberts left the company in 1914 when the company faced financial trouble, and became editor of The Gas Engine magazine before starting a private consulting practice for engine design.[11][3] According to an Early Bird of Aviation from Sandusky, Reinhardt Ausmus, "the company spent more in national advertizing than they took in on sales."[12] William H. Burke took over as president and the company produced several automobiles in 1915, powered with the company's engines.[1] The name of the company also changed to Roberts Motor Manufacturing Company, and not much was heard from the company after 1915.[4]
1918 - 1935 (Roberts Motors)
The Roberts Motor Manufacturing Company ceased operations upon the tragic death of Thomas Benoist in 1918, who had been affiliated with the company.[13] Earl Johnston, who had taken over as superintendent in 1915, purchased the company in 1918.[9] Subsequently, the company shifted its focus to engines for boats rather than aircraft, and began to operate under the name, Roberts Motors.[8] In 1935, the company became a new incorporation with a new name, the Johnston Motor Co.[14][9]
Products
Aircraft engines
| Model name | Configuration | Power | Bore x Stroke | Weight | Year |
|---|---|---|---|---|---|
| Roberts Model 4-X[8] | I4 | 50 hp @ 1400 RPM | 4.5"x5" | 170 lbs. | 1911-1912 |
| Roberts Model 4-X | I4 | 65 hp @ 1200 RPM | 5"x5" | 230 lbs. | 1912-1916 |
| Roberts Model 6-X[8] | I6 | 75 hp @ 1200 RPM | 4.5"x5" | 243 lbs. | 1911-1912 |
| Roberts Model 6-X[8] | I6 | 100 hp @ 1200 RPM | 5"x5" | 330-350 lbs. | 1911-1917 |
| Roberts Model 6-X[8] | I6 | 100 hp @ 1200 RPM | 5"x5.5" | 368 lbs. | 1916 |
| Roberts Model 6-XX | I6 | 125 hp @ 1100 RPM | 5.5"x6" | 390 lbs. | 1912 |
| Roberts Model 6-XX | I6 | 165 hp @ 1200 RPM | 6"x6" | 650 lbs. | 1917 |
| Roberts Model 6-XX[8] | I6 | 200 hp @ 1400 RPM | 6.5"x6" | 690 lbs. | |
| Roberts Model E-12[8] | V12 | 350 hp @ 1200 RPM | 6"x6.5" | 990 lbs. | 1916-1917 |
Boat engines
| Model name | Configuration | Power | Bore x Stroke | Weight | Year |
|---|---|---|---|---|---|
| Roberts Model A | I1 | 25 hp @ 950 RPM - 35 hp @ 1450 RPM | 4"x5" | 1925 | |
| Roberts Model H | I1 | 1.5 hp @ 750 RPM - 2 hp @ 900 RPM | 3"x2.5" | 50 lbs. | 1909 |
| Roberts Model 2-H | I2 | 8 hp @ 1000 RPM | 3.75"x4" | 163 lbs. | 1919-1921 |
| Roberts Model J | I4 | 8 - 16 hp | 3.75"x4" | 1922-1926 | |
| Roberts Model O | I1 | 2.5 @ 750 RPM - 3 hp @ 900 RPM | 3.5"x3" | 95-100 lbs. | 1909 |
| Roberts Model 2-O | I2 | 6 hp @ 900 RPM | 3.5"x3" | 128-135 lbs. | 1911 |
| Roberts Model 3-P | I3 | 30 hp | |||
| Roberts Model 4-P | I4 | 40 hp @ 1000 RPM | 4.5"x5" | 525 lbs. | |
| Roberts Model 6-P | I6 | 60 hp | |||
| Roberts Model R | I1 | 16 - 20 hp | 3.78"x4" | 1925 | |
| Roberts Model S | I1 | 8 hp @ 300 RPM - 10 hp @ 400 RPM | 6"x6.5" | 300 lbs. | 1917 |
| Roberts Model M | I1 | 20 hp | |||
| Roberts Model 2-M | I2 | 10 hp @ 900 RPM | 4"x_ | 240 lbs. | |
| Roberts Model 3-M | I3 | 15 hp @ 900 RPM | 293 lbs. | ||
| Roberts Model 4-M | I4 | 20 hp @ 900 RPM | 450 lbs. | ||
| Roberts Model 6-Z | 100 hp | 1925 |
Automobile engines
| Model name | Power | Bore x Stroke | Weight | Year | Notes |
|---|---|---|---|---|---|
| Roberts 6-X[1][3] | 60 hp | 4.5"x5" | 700 lbs. | 1912-1915 | racing engine |
Other
| Product | Specifications | Weight | Significance | Year |
|---|---|---|---|---|
| Engine-compressor unit[4] | 30 CFM @ 100 PSI | 40 lbs. | Progenitor portable air compressor | 1910 |
Significance
The Roberts engines were designed to be as lightweight as possible by using Germany-imported aluminum and magnesium alloys for the cylinders, pistons, and crankshaft, an alloy which the company called 'aerolite,' as well as a hollow crankshaft.[10][8][15] All the Roberts engines operated on a two-stroke cycle for parts reduction and thus lighter weight, though four-stroke cycle engines were introduced after WWI.[3][8][10] Despite being two-cycle, they were known for never backfiring due to a cellular by-pass in the crankcase designed by E. W. Roberts.[9][8]
Some of the Roberts engines were used by prominent exhibition pilots, including Tom Benoist, Willie Haupt, Joseph Richter, Clifton Hadley, and Weldon Cooke.[16]
| Engine model | Power | Roberts engines in early aviation history | Date |
|---|---|---|---|
| Roberts 4-X | 50 hp | Powered one of the first Bleroit XI aircraft built in the United States.[10] | 1911 |
| Roberts 4-X | 50 hp | Powered the aircraft built by the first South Dakotan pilot, Saxe Pitts Gantz.[17] | March 9, 1911 |
| Roberts 6-X | 50 hp | Powered the Ecker Flying Boat which is on display at the Smithsonian Institution.[18] | 1911-1912 |
| Roberts 6-X | 75 hp | Powered a Benoist biplane used in the first parachute jump from an aircraft, performed by Captain Bert Berry and piloted by Anthony Jannus in St. Louis, Missouri.[19] | March 12, 1912 |
| Roberts 6-X | 75 hp | Powered the Benoist Type XIV during the first commercial passenger airplane flight, flown by Jannus, in St. Petersburg, Florida.[9] | January 1, 1914 |
Gallery
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E. W. Roberts (right), founder of Roberts Motor Co., once chief assistant to flying machine inventor, Hiram S. Maxim (left)
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Roberts Engine for Ecker Flying Boat –1911
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Roberts Hydroplane Engine – 1911
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Engine used by Oscar R. Solbrig to power a Curtiss-type pusher aircraft he built in 1911-12.
-
Roberts Motor Co. at the May 1912 New York Air Show
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Roberts Motor Company - Advertisement
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Roberts Motor Company: Parachute Achievement Advertisement
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Beverly Rae Kimes , Henry Austin Clark Jr.: Standard catalog of American Cars. Krause Publications, Iola 1989, p. 1255.
- ↑ George Nicholas Georgano (ed.): The Beaulieu Encyclopedia of the Automobile. band 3 : P–Z . Fitzroy Dearborn Publishers, Chicago 2001, ISBN 1-57958-293-1 , p. 1342.
- ↑ 3.0 3.1 3.2 3.3 3.4 Grayson, Stan (1999). Engines Afloat, from Early Days to D-Day: The Gasoline Era. 1. Devereux Books. ISBN 0964007045.
- ↑ 4.0 4.1 4.2 4.3 Wendell, C. H. (1983). American Gasoline Engines Since 1872. Crestline Pub Co.
- ↑ "Engine Designer Succumbs; After Distinguished Career; Son of Civil War Surgeon". The Cincinnati Enquirer. March 14, 1947. p. 14. Retrieved July 7, 2025.
- ↑ Underwood, Paul (July 18, 1942). "Engineer Recalls Experiment with Steam-Powered Plane, Once Hiram Maxim Helper". The Cincinnati Enquirer. Cincinnati, OH. p. 16. Retrieved July 6, 2025.
- ↑ Knue, Paul F., ed. (October 27, 1987). "Bicentennial Capsule: Prince Hill Inventor's Ideas Soared". The Cincinnati Post. p. 10. Retrieved July 7, 2025.
- ↑ 8.00 8.01 8.02 8.03 8.04 8.05 8.06 8.07 8.08 8.09 8.10 Angle, Glenn D. (1921). Airplane Engine Encyclopedia. Dayton, Ohio: The Otterbein Press. pg. 427 - 429
- ↑ 9.0 9.1 9.2 9.3 9.4 Harmon, Mel (January 6, 1967). "Flying Very Popular Here; Pioneers Started in 1909". Sandusky Register. p. 8. Retrieved July 7, 2025.
- ↑ 10.0 10.1 10.2 10.3 "Roberts 4X, In-line 4 Engine | National Air and Space Museum". https://airandspace.si.edu/collection-objects/roberts-4x-line-4-engine/nasm_A19350049000.
- ↑ "Roberts, Edmund Willson". Rutherford B. Hayes Presidential Library & Museums. Retrieved June 28, 2025.
- ↑ Reinhardt, Ausmus (1969). "Reinhardt Ausmus Speech on Aviation in Sandusky". ohiomemory.org. p. 7. Archived from the original on 2022-06-21. Retrieved 2025-07-06.
- ↑ Roos, Frederick W., "The Brief, Bright Aviation Career of St. Louis's Tom Benoist," American Institute of Aeronautics and Astronautics, Inc., 2005.
- ↑ "Sandusky Listed With Pioneers in Aviation". Sandusky Register. November 24, 1947. p. 82. Retrieved July 8, 2025.
- ↑ Von Muffling, E. Adrian (June 1912). "The New York Aero Show". Fly Magazine: The National Aeronautic Monthly 4 (8): 13. https://ia802801.us.archive.org/35/items/fly4v1v12/fly4v1v12.pdf.
- ↑ Hankins, Hobart Bishop (December 1911). "The Latest Engine Product of E. W. Roberts". Fly. The National Aeronautics Monthly. 4 (2). Philadelphia, PA: Aero Publishing Co.: 20–22 – via Internet Archive.
- ↑ Kraemer, Norma (2010). South Dakota’s First Century of Flight. Arcadia Publishing Inc..
- ↑ Ogden, Bob (2007). Aviation Museums and Collections of North America. Air Britain Historians Ltd.
- ↑ Mason, Paul B. (September 16, 1945). "Along Aviation Lanes". The Cincinnati Enquirer. p. 13. Retrieved July 7, 2025.
External links
| Wikimedia Commons has media related to Category:Roberts Motor Co.. |
Roberts Motor Company Aircraft Engines
Smithsonian Collection of Roberts Aircraft Engines
Ohio museum: E. W. Roberts collection
Ohio museum: Reinhardt Ausmus collection - Roberts Motor Company catalogs
