BUILDING THE BOULEVARD RIDE
A smooth ride was not on the menu for most passenger cars of the late twenties and early thirties except perhaps for limousines, whose long wheelbases and prodigious sprung weight masked many sins. The gradual adoption of low-pressure tires and shock absorbers had helped a bit (the latter hadn’t even been offered on many cars of the twenties, including the original Chrysler Six), but solid axles, stiff semi-elliptical springs, and substantial unsprung weight still made for less than cloud-like comfort. On relatively smooth roads, the driver and front passenger didn’t fare too badly, but back seat passengers, perched above or behind the heavy rear axle, were not so fortunate.
Breer discovered that the packaging changes of the streamlining project did much to improve that sorry situation. First, for rear passengers, sitting within the wheelbase proved far more comfortable than sitting atop the axle. Second, moving the engine forward put about 55% of the car’s static weight on the front wheels, compared to perhaps 40-45% for conventional sedans of the era. With less weight on the tail, the rear springs could be substantially softer. By lengthening (and thus softening) the front springs to match, it was possible to avoid a pendulum effect while also reducing the overall frequency of the ride motions by about 25%, which, as Breer often noted, put it closer to a natural walking pace. Chrysler advertising christened it the “Floating Ride.”
Surprisingly, this was achieved without independent front suspension, although Chrysler was then developing a double-wishbone layout for Plymouth, Dodge, and conventionally engineered six-cylinder Chryslers. While the production Airflow’s tubular front beam axle might seem a retrograde step in an otherwise sophisticated car, Breer decided that IFS simply wasn’t necessary. It’s important to remember that a major rationale for Detroit’s adoption of independent suspension in this era was not better handling, but a smoother ride. The revised spring rates and altered weight distribution achieved that without the added cost, complexity, and maintenance headaches of early IFS systems.
BRIDGE AND TRUSS
Since the streamlined car was already laid out very differently than conventional models, Breer decided it was also a good candidate for new techniques in body construction.
Most passenger cars of the early thirties used body-on-frame construction with a heavy, rigid ladder-type frame. The body itself was usually steel or aluminum panels over a wooden framework, although all-steel bodies were becoming increasingly common. The Dodge Brothers had adopted them early on; Plymouth went all-steel in 1930, followed by Ford in 1932. For the streamlined Airflow, however, Breer and Clark opted for something far more advanced: a steel monocoque.
Like streamlining, monocoque construction dated back to the end of World War I. Although it was gaining popularity in aviation in the late twenties and early thirties, Italian engineer Vincenzo Lancia had applied for a patent on self-supporting automobile bodies in 1919, likely inspired by shipbuilding practice, and the first unit-bodied Lancia Lambda went into production in 1922. Thanks to its greater weight and space efficiency, monocoque construction gradually found favor in Europe, but American automakers remained wary. In 1931, for example, Joseph Ledwinka and William Mueller of the body supplier Budd had found no takers for their unit-bodied FWD prototype, although historian Michael Lamm believes their car was the inspiration for the unit-bodied Citroën 11CV ‘Traction Avant,’ which debuted in early 1934; Budd developed the tooling for the Traction.
Chrysler’s approach, also developed in partnership with Budd, was not quite a monocoque. Commonly described as “bridge-and-truss” construction, it used stressed exterior panels welded to a cage-like steel structure that included the frame, the cowl and windshield frame as well as vertical members through the roof pillars and horizontal rails above the door openings. While the structured looked some like a tubular space frame, it was not self-supporting, relying on the exterior panels for its torsional stiffness. The bridge-and-truss system was bulkier and heavier than true monocoque construction, but it simplified production, allowing the engine and running gear to be installed before the exterior panels were attached, much like a body-on-frame design.
When the Airflow was introduced, there were some ugly rumors that its metal framework, with no wood bracing, was unacceptably flimsy. It was true that the framework itself was not very rigid, but it wasn’t intended to be. When the sills and exterior panels were welded in place, the unitized structure was extremely strong, and Chrysler boasted that it had 40 times the torsional stiffness of a body-on-frame design. Chrysler eventually laid the rumors to rest in dramatic fashion by demonstrating that the Airflow remained drivable even after being pushed off a 110-foot (33-meter) cliff. In the summer of 1934, they also hired Barney Oldfield’s “Hell Drivers” racing team to roll Airflows in a sand pit as part of an hourly demonstration at the Chicago World’s Fair.
The downside of that strength was added weight. Breer said that ideally, unitized construction would have saved up to 200 lb (90 kg) over a body-on-frame design, but as the development process continued and exterior design and trim were refined, the cars grew progressively heavier. The production Airflows weighed substantially more than the body-on-frame cars they replaced, in some cases by more than 250 lb (115 kg). Later models, with different grilles and stouter bumpers, would be heavier still.
THE TRIFON SPECIAL
The first true Airflow prototype was built in great secrecy in the summer of 1932. Powered by a DeSoto straight six, it had bridge-and-truss construction, relocated engine, a repackaged interior layout, and Floating Ride suspension. It had no grille and carried no Chrysler badges or identification of any kind. When the company registered and licensed it with the state of Michigan for road testing, the prototype was identified as the 1932 Trifon Special, taking its name from test engineer Demitrion Trifon.
Because the company did not yet have its own proving grounds, Chrysler arranged to test the cars on land owned by two farmers outside Grayling, Michigan, north of Detroit. To avoid attracting attention, test crews did not drive the prototype on public roads and engineers and executives heading up to Grayling were asked to drive non-Chrysler vehicles.
The first Trifon was an awkward-looking beast with curious proportions: the work of engineers, not stylists. Even the production Airflows were developed with little input from either Chrysler’s fledgling in-house styling department or Briggs Mfg. Company, which provided much of Chrysler’s exterior design work in those days. Chrysler’s Art & Colour section, founded in 1928, still focused primarily on detailing, upholstery, and trim; its chief, Herbert V. Henderson, had previously been an interior designer. Both Henderson’s group and Briggs designers contributed to the nicely detailed, Streamline Moderne interiors of the production cars, but their involvement in the exterior design was limited to details like the rear fender skirts. For better or worse, the Airflow’s shape was primarily the work of Carl Breer, Oliver Clark, and Chrysler’s body engineers.
Aesthetics aside, the Trifon Special drove quite well, with excellent ride quality even on bumpy country roads. After months of testing, Breer and his team finally invited Walter Chrysler himself up to Grayling for a test ride. Chrysler was extremely impressed and said he wanted to put the car into production. He was not daunted by its radical design; he thought it would serve as a new corporate flagship, demonstrating how far the Chrysler Corporation had come in ten years and setting a new direction for the future.