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Doble steam car
The Doble steam car was an American steam car maker from 1909 to 1931. Its latter models of steam car, with fast-firing boiler and electric start, were considered the pinnacle of steam car development. The term "Doble steam car" comprises any of several makes of steam-powered automobile in the early 20th century, including Doble Detroit, Doble Steam Car, and Doble Automobile, severally called a Doble because of their founding by Abner Doble.
The Doble Detroit incorporated key ignition, doing away with the need for manual ignition of the boiler system. John Doble also constructed a flash boiler with rectangular casing in which atomized kerosene fuel was ignited with a spark plug, in a carburetor-type venturi and used forced draft provided by an electrically driven fan. This rapidly heated the feedwater contained in vertical grids of tubes welded to horizontal headers. The steam-raising part of the boiler was partitioned off by a wall of heat-resisting material jacketed with planished steel from a smaller compartment in which were similar grids of tubes for feedwater heating. There seem to have been at least two versions of this boiler, the first with the burner and combustion chamber at the bottom, the other with them at the top of the casing; this led to the subsequent counterflow monotube boiler arrangement. Boiler operation was fully electro-mechanically automated: the bottom of the boiler housed a metal tray with a row of quartz rods. As heat increased, the tray expanded, pushing the rods forward and shutting off the burner. As the system cooled, the quartz rods receded, engaging the burner.
A two-cylinder double-acting uniflow engine was mounted under the floor driving the back axle; double slide valves were driven by a Joy valve gear. The car had only four controls: a steering wheel, a brake pedal, a trip pedal for variable cut-off and reversing, and a foot-operated throttle. The layout of the chassis put the boiler at the front end of the car under the hood, the engine and the rear axle forming an integrated unit. The even weight distribution and low center of gravity contributed much to the ride and handling of all Doble cars.
The only defect sometimes noted throughout the Doble car era was less than perfect braking, which was common in automobiles of all types before 1930. Typically, a car of 1920s only had two rear-mounted mechanical drum brakes, although those fitted to Dobles were of larger than usual proportions. Dobles achieved reliability by eliminating most of the mechanical items that tended to malfunction in conventional automobiles: they had no clutch, no transmission, no distributor, and no points. Later Doble steam cars often achieved several hundred thousand miles of use before a major mechanical service was necessary
During WW1 Doble's Detroit steam motors were used in two prototype tanks. One was the Holt Manufacturing Company steam-powered tank. This tank underwent trials in February 1918, but no further models were made. The other was a Steam Tank project by the Corps of Engineers. The Corps had created a successful flame-thrower in November 1917 and decided to mount it on a tank. Funding for the project was made by the Endicott and Johnson Shoe Company. The tank was similar in design to British heavy tanks of the period. It weighed 50-tons and was powered by two Doble steam engines.
The outcome was a complete redesign, the Model D of 1922. The uniflow engine, perceived as the root of the troubles with the Doble Detroit, gave place to a two-cylinder compound type, still with Joy's valve gear, but with piston valves. Another crucial development was a coiled monotube once-through vertically mounted cylindrical boiler following the thinking behind the later version of the Detroit boiler, the most distinctive feature of which was the placing of the burner at the top of the boiler. This plus a copious amount of insulation was meant to cause the hot gases to reside within the boiler casing for an optimum length of time giving up the maximum amount of heat to the feedwater. There was a forced-draft burner at the top of the boiler and an exhaust flue at the bottom. The venturi was placed horizontally at the top of the vertical boiler barrel and oriented in such a way as to avoid direct contact with the monotube while inducing a swirl motion to the gases. It was thus a counterflow design with water entering the lower end of the coiled monotube and progressing upward toward the burner, which meant that the hottest gases gave superheat to the steam at the top of the coil whilst the cooler gases preheated oncoming the feedwater at the bottom. The distinctive hand-operated "miniature steering wheel" rotating a throttle control rod that passed down the middle of the steering column can be observed in D2 which still exists (in the UK) at the present time. Photographic evidence shows that D1 retained the foot throttle pedal, so when the wheel throttle control was first applied is not clear. The latter probably gave more precise adjustment.
No more than five of the D model appear to have been built, if that. It is said that the two-cylinder compound engine sometimes gave difficulty in starting.
The Model E had been developed by 1922; this could be said to be the "classic" Doble, of which the most examples have survived. The initial monotube boiler design was perfected into the "American" type. This produced steam at a pressure of 750 psi (52 bar) and a temperature of 750 °F (400 °C). The tubing was formed from seamless cold-drawn steel 575 ft 9 in (175 m) in total length, measuring 22 in (560 mm) in diameter by 33 in (840 mm) in height when coiled and assembled. The boiler was cold water tested to a pressure of 7,000 psi (480 bar). Two 2-cylinder compound cylinder blocks were in effect placed back to back as the basis for a 4-cylinder Woolf compound unit with high-pressure cylinders placed on the outside. A piston valve incorporating transfer ports was fitted between each high-pressure and low-pressure cylinder in an arrangement similar to Vauclain's balanced compound system used on a number of railway locomotives around 1900. Stephenson's valve gear replaced the previous Joy motion. Like all steam vehicles it could burn a variety of liquid fuels with a minimum of modification and was a noticeably clean-running vehicle, its fuel being burned at high temperatures and low pressures, which produced very low pollution. Price ranged from $8,800 ($134,000 in 2020) to $11,200 ($170,000 in 2020) in 1923. The Model E ran on a 142 in (3,600 mm) wheelbase. Twenty-four E's were made between 1922 and 1925 with a variety of body types from roadsters to limousines. Owners included Howard Hughes and the Maharajah of Bharatpur. One of the Hughes cars, a roadster engine number 20, is currently owned by Jay Leno. Abner Doble owned the last one—number 24, which McCulloch later acquired in the course of developing the Paxton steam car.
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Doble steam car
The Doble steam car was an American steam car maker from 1909 to 1931. Its latter models of steam car, with fast-firing boiler and electric start, were considered the pinnacle of steam car development. The term "Doble steam car" comprises any of several makes of steam-powered automobile in the early 20th century, including Doble Detroit, Doble Steam Car, and Doble Automobile, severally called a Doble because of their founding by Abner Doble.
The Doble Detroit incorporated key ignition, doing away with the need for manual ignition of the boiler system. John Doble also constructed a flash boiler with rectangular casing in which atomized kerosene fuel was ignited with a spark plug, in a carburetor-type venturi and used forced draft provided by an electrically driven fan. This rapidly heated the feedwater contained in vertical grids of tubes welded to horizontal headers. The steam-raising part of the boiler was partitioned off by a wall of heat-resisting material jacketed with planished steel from a smaller compartment in which were similar grids of tubes for feedwater heating. There seem to have been at least two versions of this boiler, the first with the burner and combustion chamber at the bottom, the other with them at the top of the casing; this led to the subsequent counterflow monotube boiler arrangement. Boiler operation was fully electro-mechanically automated: the bottom of the boiler housed a metal tray with a row of quartz rods. As heat increased, the tray expanded, pushing the rods forward and shutting off the burner. As the system cooled, the quartz rods receded, engaging the burner.
A two-cylinder double-acting uniflow engine was mounted under the floor driving the back axle; double slide valves were driven by a Joy valve gear. The car had only four controls: a steering wheel, a brake pedal, a trip pedal for variable cut-off and reversing, and a foot-operated throttle. The layout of the chassis put the boiler at the front end of the car under the hood, the engine and the rear axle forming an integrated unit. The even weight distribution and low center of gravity contributed much to the ride and handling of all Doble cars.
The only defect sometimes noted throughout the Doble car era was less than perfect braking, which was common in automobiles of all types before 1930. Typically, a car of 1920s only had two rear-mounted mechanical drum brakes, although those fitted to Dobles were of larger than usual proportions. Dobles achieved reliability by eliminating most of the mechanical items that tended to malfunction in conventional automobiles: they had no clutch, no transmission, no distributor, and no points. Later Doble steam cars often achieved several hundred thousand miles of use before a major mechanical service was necessary
During WW1 Doble's Detroit steam motors were used in two prototype tanks. One was the Holt Manufacturing Company steam-powered tank. This tank underwent trials in February 1918, but no further models were made. The other was a Steam Tank project by the Corps of Engineers. The Corps had created a successful flame-thrower in November 1917 and decided to mount it on a tank. Funding for the project was made by the Endicott and Johnson Shoe Company. The tank was similar in design to British heavy tanks of the period. It weighed 50-tons and was powered by two Doble steam engines.
The outcome was a complete redesign, the Model D of 1922. The uniflow engine, perceived as the root of the troubles with the Doble Detroit, gave place to a two-cylinder compound type, still with Joy's valve gear, but with piston valves. Another crucial development was a coiled monotube once-through vertically mounted cylindrical boiler following the thinking behind the later version of the Detroit boiler, the most distinctive feature of which was the placing of the burner at the top of the boiler. This plus a copious amount of insulation was meant to cause the hot gases to reside within the boiler casing for an optimum length of time giving up the maximum amount of heat to the feedwater. There was a forced-draft burner at the top of the boiler and an exhaust flue at the bottom. The venturi was placed horizontally at the top of the vertical boiler barrel and oriented in such a way as to avoid direct contact with the monotube while inducing a swirl motion to the gases. It was thus a counterflow design with water entering the lower end of the coiled monotube and progressing upward toward the burner, which meant that the hottest gases gave superheat to the steam at the top of the coil whilst the cooler gases preheated oncoming the feedwater at the bottom. The distinctive hand-operated "miniature steering wheel" rotating a throttle control rod that passed down the middle of the steering column can be observed in D2 which still exists (in the UK) at the present time. Photographic evidence shows that D1 retained the foot throttle pedal, so when the wheel throttle control was first applied is not clear. The latter probably gave more precise adjustment.
No more than five of the D model appear to have been built, if that. It is said that the two-cylinder compound engine sometimes gave difficulty in starting.
The Model E had been developed by 1922; this could be said to be the "classic" Doble, of which the most examples have survived. The initial monotube boiler design was perfected into the "American" type. This produced steam at a pressure of 750 psi (52 bar) and a temperature of 750 °F (400 °C). The tubing was formed from seamless cold-drawn steel 575 ft 9 in (175 m) in total length, measuring 22 in (560 mm) in diameter by 33 in (840 mm) in height when coiled and assembled. The boiler was cold water tested to a pressure of 7,000 psi (480 bar). Two 2-cylinder compound cylinder blocks were in effect placed back to back as the basis for a 4-cylinder Woolf compound unit with high-pressure cylinders placed on the outside. A piston valve incorporating transfer ports was fitted between each high-pressure and low-pressure cylinder in an arrangement similar to Vauclain's balanced compound system used on a number of railway locomotives around 1900. Stephenson's valve gear replaced the previous Joy motion. Like all steam vehicles it could burn a variety of liquid fuels with a minimum of modification and was a noticeably clean-running vehicle, its fuel being burned at high temperatures and low pressures, which produced very low pollution. Price ranged from $8,800 ($134,000 in 2020) to $11,200 ($170,000 in 2020) in 1923. The Model E ran on a 142 in (3,600 mm) wheelbase. Twenty-four E's were made between 1922 and 1925 with a variety of body types from roadsters to limousines. Owners included Howard Hughes and the Maharajah of Bharatpur. One of the Hughes cars, a roadster engine number 20, is currently owned by Jay Leno. Abner Doble owned the last one—number 24, which McCulloch later acquired in the course of developing the Paxton steam car.
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