- Written by webmin
In the year-plus since we discovered the photos of the first-ever Symposium on Low Pollution Power Systems Development, we’ve teased out more information on a couple of the attending vehicles: the McKee-built Sundancer and the GM 512-series micros. Next up, the Lear-built steam bus.
While we only see evidence of one Lear steam bus, a GMC, at the Symposium, thanks to the Los Angeles County Metropolitan Transportation Authority’s Flickr stream, we see that Lear built at least two other steam-powered buses for a California-based federally-funded alt-fuel transit bus project, including the Flxible and the unidentified bus in the photo above. According to LACMTA, the project ran from 1973-1974 (neatly overlapping the October 1973 date of the Symposium, which took place in Ann Arbor, Michigan) and placed one bus each on the streets of Los Angeles (through the Southern California Rapid Transit District), Sacramento, and San Diego.
The Lear behind the Lear steam buses would be William P. Lear, the originator of the Lear Jet (and, incidentally, the automotive eight-track tape player). After selling his jet business in 1967, Lear relocated to the old Stead Air Force base outside of Reno, Nevada, where in about 1968 he began work on his steam turbine engines with the ultimate goal of downsizing them enough to place them in passenger cars.
As we see in this second photo from LACMTA showing the Flxible’s steam engine, it differs significantly in appearance from the engine shown in the Symposium photos, suggesting that Lear and his engineers hadn’t yet finalized the design of the engine. Indeed, his initial announcements on the steam engines proclaimed he had invented a substitute for water – something up until then only theoretically proposed – with idealized thermal conversion properties. He called it Learium, but by 1972, he abandoned Learium and reverted to water after finding that Learium was not as chemically inert as he believed. Lear received a number of patents on his design, including Combustor for Vapor Power Generators (U.S. Patent 3,812,826) and Vapor Generators with Low Pollutant Emission (U.S. Patent 3,846,065).
Both Popular Science and Popular Mechanics sent reporters to Nevada to take exhibition rides on Lear’s prototype GMC in early 1972 and came back with a good number of statistics: The turbine would spin up to 60,000 RPM, producing about 220 horsepower and resulting in a top speed of about 55 MPH. Zero to 30 took 16 seconds – or 12 seconds faster than a diesel-powered bus – and noise levels were about half that of a diesel. Fuel consumption was double that of a diesel, however, though they duly noted that steam turbines can theoretically run on any combustible fuel with far lower emissions. Interestingly, PopMech noted that the GMC was scheduled to undergo testing in San Francisco.
The buses were not the extent of Lear’s steam visions by far. We know that Lear built a steam-powered Chevrolet Monte Carlo, as well as a steam-powered race car designed to compete at Indianapolis, and he allegedly built 26 steam cars for the California Highway patrol around this time. According to LACMTA, the steam engines were removed from the three buses after the test, and one was later used in a land-speed record attempt. That would be the Jim Crank/Barber-Nichols Steamin’ Demon, which ran Bonneville in the late 1970s and 1980s and is now on display in the National Automobile Museum in, of all places, Reno.