Forty plus years after its introduction, people are still fascinated by the Isetta. They marvel at its size and simplicity. And when they see that door open, especially for the first time, they are absolutely amazed! Children will watch that door open and close repeatedly....... like a magic show.
The design of the Isetta has fascinated me just as much. Italians are masters of design, so I figured that Pretti or Rivolta created the one-door-in-front concept. Pretti was a glider designer and worked on some Italian Air Force gliders. The US had some that opened in front. A sort of clamshell thing, I believe. And there was at least one Italian car in the 30's with two front doors.
Some time ago, a friend pointed out an American car by James V. Martin that
was listed on the IOCGB site under unusual microcars. The patent drawings were
included. Recently, the Gazette has published these drawings. There are some
remarkable similarities between the 'Martinette' and the isetta. Could the Martin
3-wheel design of 1928 have been the inspiration of the ISO Isetta 20 years
Compare these cross sections. At left is the patent drawing of the Martin 3-wheeler, also called 'Martinette' and 'Autoette'. At right is the bubble window BMW Isetta, nearly identical to the ISO. The initial ISO prototype was a three wheeler, more similar yet to the Martin design and had a small rear window, not the wrap around design that came with the production ISO.
Look at the original patent drawings of the Martinette on this web site, under 'rare bubbles', 'Autoette'. Although the Isetta has a steel frame, the Martinette had an aluminium panel floor with two panels spaced a couple of inches apart to form a rigid lightweight hollow base for the body.... like aircraft construction or an aluminium painter's scaffold. The Martinette is laid out much like the Isetta; single front door, engine behind the firewall, chain drive rear axle, teardrop body style. The patent drawings show a two cylinder opposed air cooled engine. BMW would, no doubt, have preferred one in the Isetta. I wouldn't be surprised if the Martinette influenced the Isetta.
Martin was an aircraft designer interested in aerodynamic design, as were Paul Arzens (who designed the ultimate bubblecar in 1942) and Ermenegildo Pretti (who designed the Isetta). Martin preceded them, having been very active in aircraft design before, during and after WW1. It is very likely his aircraft and automobile designs were seen in Europe.
James Vernon Martin was born in Chicago in 1883. He joined the Merchant Marines at age 17 and had his Mariners Certificate ten years later. As Captain James V. Martin, he enrolled in Harvard in 1908 to study astronomy, but became interested in flying. He soon organised the Harvard Aeronautical Society, helped design, build and fly the Harvard-1 Biplane, an aircraft with a pusher propellor and no tail, similar to some modern ultralights. He also built the world's first glider to leave the ground on skids.
Martin organised a Harvard-Boston flying competition and attracted fliers from all over the world. He became friends with Claude Graham-White, who walked off with most of the prize money from that event. Martin went to England in 1911, enrolled in the Graham-White flying school at Hendon, and learned to fly Farman and Bleriot planes. He soon became a flight instructor at the London Aerodrome and trained many of the men who would later become Britain's aviators in WW1.
He married a lady from England in that year, the attractive Lily Irvine, taught her to fly, and she became the first woman in England to do so. On March 11th Martin became the first man to fly over London, and to great acclaim.
He and his wife came to America that spring and Martin flew in competitive flying events on the East Coast and Chicago. By October he was test flying a Queen-Martin biplane with a 14 cylinder 100hp Gnome engine. He smashed it whilst making an emergency landing in a Nassau backyard. He switched to a Kirkham engine and was flying again by November.
Early in 1912 Martin was in the Seattle area doing flying exhibitions in a Gage biplane with an 8 cymindrer Hall-Scott engine. This plane was equipped to land on water or land. In 1913 he flew it to alaska and made the first flying exhibition tour, startling crowds of natives and miners. He and Lily spent the winter of 1913/14 in San Fransisco.
Martin invented a rubber strap landing gear suspension that he later incorporated in a truck suspension design. He designed a special aileron, an automatic stabiliser, a lightweight wheel of cast aluminium, patented a design for a self levelling bomber and a retractable landing gear system.
Martin partnered with Miles Carpenter about 1926 to build a small car called 'The Dart'. It featured an ohv 4 cyl air cooled motorcycle engine. The suspension utilised rubber aviator cords that were said to be good for 25000 miles and easily replaced for 25 cents each. These small cars were to be sold by mail order and shipped in a wooded crate by train. The crate was designed to later serve as the garage.
In the late 1920's Martin designed and patented a 2 passenger 3-wheel Martinette automobile with one door at the front. He built a prototype of this 'aerodynamic' Martinette in 1932 and also a larger 4 wheel 'Aerodynamic' with side doors at the same time for Capt. Billy mitchell. Both cars had aviator cord suspension and engines in the back. The 3-wheel Martinette was reputedly capable of 75mph with its 4 cylinder Austin 7.5hp engine. The front suspension within the wheel left little room for brakes, so braking was handled by the single rear wheel in this 800Ib car. Our Isetta's may not be so fast, but braking is probably superior.
Other than these prototypes, these cars never went into production. Martin began sueing a great many aircraft companies in the 1930's for patent infringement, law suits that lasted until WW2, when he served as the Captain of a troop transport. Although he contributed many clever inventions to the advancement of flying, his aircraft days were ending. He invented an airless tyre during the war and used it in 1948 on an up-graded version of his 1932 3-wheel Martinette with 'magnetic fluid drive'. He also designed a massive 6 engine bomber with a twin hull for landing on water. It is said to be the fore runner of Howard Hughes' Spruce goose.
Col. James Martin died in obscurity in 1956, fortunate to have survived the early air age. His prototype four wheel Aerodynamic sedan is at the Prostman Museum in Stone Mountain, Georgia, not far from Atlanta. The 3-wheel Martinette can be seen at the Cradle of Aviation Museum at Garden City, Long Island, not far from New York City. His small fighter aircraft, the 'Kitten K-III' is dispayed at the Silver Hill facility of the Smithsonian. There are many 3 wheel cars that preceded the isetta, but this may be the only one one-front-door car. Captain J.V.Martin is due some credit for that.
Here is a view of the Martinette prototype built in 1932 and now at the Cradle
of Aviation Museum. It is finished handsomely as a two tone, white on top and
red below, with a black bumper all around. The front wheels are very large to
incorporate the special suspension system within the wheel itself. There are
louvered panels on each side near the engine for venting, something like the
The flat underside no doubt provides far less turbulence for better fuel economy and more speed, something that could have benefitted the Isetta a great deal. The Martinette is a larger car, but only weighs a bit more due to the extensive use of aluminium. The wraparound windows are an interesting feature. I wonder if a good designer, having seen this car, might have been stimulated to design a Dymaxion, a Messerschmitt, or even an Isetta?