According to its extensive entry published in Jim Crank’s definitive work, The Doble Steam Car, chassis F-30 is a most unusual Doble. As the realities of the Depression took hold, Doble executives realized that the magnificent E-Series was simply too expensive to be a viable product going forward, and the decision was made to adapt existing components from established manufacturers and install Doble’s steam system.

Such was to be the case with F-30, which was built for – and substantially by – Doble’s patent attorney Marcus Lothrop, who was determined to own a Doble by any means possible, in spite of his limited budget. Numbered F-30 – simply due to the car being constructed largely in 1930 – it sat on an E-Series chassis with an E-Series engine and was equipped with an F-Series steam generator, steam water pump, and draft booster. Mr. Lothrop ordered a new LaSalle convertible coupe body and new Cadillac V-16 fenders and bumpers from Fisher. Completed in 1931, F-30 was the very last Doble automobile to leave the Emeryville, California plant and it served Mr. Lothrop and his wife very well for about five years and 35,000 miles. It was their primary vehicle for both errands around the Bay Area and longer excursions, which often included hill climbs – that were challenging even for internal combustion cars of the day – as well as a journey into hot and dry Baja California.

Eventually, the Lothrops sold their faithful Doble to William Besler, who had by then assumed control of the Doble company. From there, F-30 was in the custody of a series of owners who did the car no favors. Beginning with Nevada resident Roland Giroux, the components of the Doble system that were designed to function harmoniously in the hands of a knowledgeable operator were individually re-engineered and modified until the car could not function efficiently, if at all.

Thankfully, Doble F-30 survived its most vulnerable years outwardly intact. In the 1970s, it came into the ownership of the noted Southern California collector Barry Hon, who entrusted it to the capable hands of Cal Tinkham and Peter Scott-Brown. A new set of Doble cylinders and ancillary components from other manufacturers including Caterpillar and Chrysler were installed, and the Doble became an operable automobile for the first time in perhaps decades. In 1985, F-30 was sold to the famed collector J.B. Nethercutt, and before long passed to Stan Lucas, where it joined the largest modern-day assemblage of Dobles. Mr. Lucas then retained Tinkham, Scott-Brown, and Len Campbell to further refine the car – although it has never been fully brought back to its original mechanical configuration. The next chapter for this Convertible Coupe, the final Doble built on a Doble chassis, may just include its return to the road in the hands of its next caretaker – a most rewarding undertaking.