Tucker 48
Automobilhersteller :  |
Tucker |
---|---|
Modell: |
48 |
Jahr: |
1948-1949 |
Art: |
Sedan |
The Tucker 48 (named after its model year) was an advanced automobile conceived by Preston Tucker and briefly produced in Chicago in 1948. Only 51 cars were made before the company folded on March 3, 1949, due to negative publicity initiated by the news media, a Securities and Exchange Commission investigation and a heavily publicized stock fraud trial (in which allegations were proven baseless in court with a full acquittal). Speculation exists that the Big Three automakers and Michigan senator Homer S. Ferguson also had a role in the Tucker Corporation's demise.
Even before the War's end Preston Tucker began working on plans for his new automobile. In the summer of 1944, he hired noted car designer George S. Lawson to style his new automobile. Lawson worked on the project for over a year-and-a-half before his design debuted publicly, beginning about February 1946 and found as late as a year later in March 1947. Lawson was named the Tucker Corporation's "chief stylist" in February 1946, immediately upon the Corporation's formation.
In December 1946, Lawson resigned from the Corporation after a disagreement with Preston Tucker, and shortly thereafter, now-famous stylist Alex Tremulis of local Chicago design firm Tammen & Denison, was hired and furthered the development of the Lawson design. Tucker gave Tammen & Denison and Tremulis a three-month contract, which expired in March 1947 and was not renewed. The culmination of Tremulis' efforts during this phase of design development was featured in a full page advertisement run in numerous national newspapers in March 1947. Tremulis' design was based directly upon the work of George Lawson, but incorporated his own artistic flair.
Simultaneous to Tremulis' departure, Preston Tucker hired a team of five designers (Read Viemeister, Budd Steinhilber, Tucker Madawick, Hal Bergstrom and Phillip Egan) from the New York design firm J. Gordon Lippincott, who updated Tremulis' design just as Tremulis had done with Lawson's. After a month's absence, Tremulis was rehired and the two independent design groups developed full-size clay models side by side in direct competition. Surviving photographs of the two models reveal that Tremulis' clay design remained unchanged from his March 1947 advertisement proposal and was not chosen for production. The passenger side of the Lippincott team's clay model (they submitted two designs), which incorporated the side profile developed by Tremulis prior to their arrival, was chosen virtually intact for the production automobile's styling.
The Tucker '48's evolving appearance in the Corporation's press releases and other promotional materials, combined with suggestive statements such as "15 years of testing produced the car of the year"—despite no running prototype existing at the time—were instrumental in the SEC filing mail and conspiracy fraud charges against Preston Tucker. The SEC, however, failed to prove their case, and Tucker was acquitted of all charges in January 1950. The Corporation never recovered.
Tremulis, like George Lawson, was eventually named the Tucker Corporation's "chief stylist," although the first reference to him holding this position does not appear until 1948, after the Tucker '48's exterior styling was completed.
The Tucker automobile was originally named the "Torpedo," but was changed to "Tucker '48" around the time of Lawson's departure and Tremulis' arrival, reportedly because Tucker did not want to remind the public of the horrors of World War II. Alex Tremulis has claimed responsibility for dubbing the first prototype automobile the "Tin Goose," which is presently used in a loving manner but at the time was considered derogatory.
Some components and features of the car were innovative and ahead of their time. The most recognizable feature of the Tucker '48, a directional third headlight (known as the "Cyclops Eye"), would activate at steering angles of greater than 10 degrees to light the car's path around corners. At the time, 17 states had laws against cars having more than two headlights. Tucker fabricated a cover for the cyclops center light for use in these states.
The car was rear-engined and rear wheel drive. A perimeter frame surrounded the vehicle for crash protection, as well as a roll bar integrated into the roof. The steering box was behind the front axle to protect the driver in a front-end accident. The instrument panel and all controls were within easy reach of the steering wheel, and the dash was padded for safety. The windshield was made of shatterproof glass and designed to pop out in a collision to protect occupants. The car's parking brake had a separate key so it could be locked in place to prevent theft. The doors extended into the roof, to ease entry and exit. Each Tucker built differed somewhat from the previous car, as each car built was basically a “prototype” where design features and engineering concepts were tried, improved, or discarded throughout the production cycle. The door releases on the interior of the Tucker came from the Lincoln Zephyr. The steering columns used in the Tucker were donated by Ford and are from the 1941 Lincoln. Preston Tucker held a patent for a collapsible steering column design. A glove box was added to the front door panels instead of the more conventional location in the dash to provide space for the “crash chamber” that the Tucker is now famous for. This is a padded area ahead of the passenger seat, free from obstructions, providing the front seat passengers an area to protect themselves in the event of an accident. The engine and transmission were mounted on a separate subframe which was secured with only six bolts. The entire drivetrain could thus be lowered and removed from the car in minutes. Tucker envisioned loaner engines being quickly swapped in for service in just 30 minutes.
Tucker initially tried to develop an innovative engine. It was a 589 cubic inches (9.65 L) flat-6 cylinder with hemispherical combustion chambers, fuel injection, and overhead valves operated by oil pressure rather than a camshaft. An oil pressure distributor was mounted inline with the ignition distributor and delivered appropriately timed direct oil pressure to open each valve at the proper interval. This unique engine was designed to idle at 100 rpm and cruise at 250-1200 rpm through the use of direct drive torque converters on each driving wheel instead of a transmission. These features would have been auto industry firsts in 1948, but as engine development proceeded, problems appeared. The 589 engine was installed only in the test chassis and the first prototype.
Tucker had promised 150 hp (112 kW), and his innovative 589 engine was not working out. The large 589 cu in (9,650 cc) engine functioned, but the valvetrain proved problematic and the engine only produced approximately 88 hp (66 kW). The high oil pressure required a 24 volt electrical system and long cranking time at start-up. Having wasted nearly one year trying to make the 589 work, Tucker started looking for alternatives.
The company first tried the Lycoming aircraft engine but it would not fit in the car's rear engine compartment. A Franklin air-cooled flat-6 engine, the O-335 made by Air Cooled Motors (and originally intended for the Bell 47), fit, and its 166 hp (124 kW) pleased Tucker. He purchased four samples for $5,000 each, and his engineers converted the 334 cubic inches (5,470 cc) engine to water cooling (a decision that has puzzled historiographers ever since). The Franklin engine was heavily modified by Tucker's engineers, including Eddie Offutt and Tucker's son Preston, Jr. at his Ypsilanti machine shop. Using an aircraft engine in an automotive application required significant modification; thus, very few parts of the original Franklin engine were retained in the final Tucker engine. This durable modification of the engine was tested at maximum power for 150 hours, the equivalent of 18,000 miles (29,000 km), at full throttle.
Tucker quickly bought Air Cooled Motors for $1.8 million to secure the engine source, then canceled all of the company's aircraft contracts so that its resources could be focused on making automotive engines for the Tucker Corporation. This was a significant decision, since at the time of Tucker's purchase, Franklin held over 65% of post-war U.S. aviation engine production contracts. The loss of income was substantial.
Suspension designs, especially the front suspension, had to be changed throughout development. Rather than springs, Tucker used an elastomeric (rubber) 4-wheel independent suspension similar to that which was used on the race cars he developed with Harry Miller at the Indianapolis 500. The rubber elastomers were developed with assistance from the Firestone Tire Company and used a special Vulcanization process to produce a specific spring rate.
Tucker's suspension designs were plagued by severe stiffness throughout development which, while good for handling, caused front wheel corner lift when cornering on uneven surfaces. The test bed and the prototype had a double-rubber disc type front and rear suspension, similar to Miller's race cars, which was too weak for the weight of a passenger car. On cars #1001 and 1002 the rear wheels could not be removed without removing the fender or suspension due to the stiffness of the suspension and the rear wheel arch fender design. On cars #1003-on the rear fender shape was changed so the tire could be removed easily. Aside from the fender changes, the rear suspension remained the same from car #1001-on.
The front suspension was installed in 3 versions on the car (aside from the rubber-disc style used on the prototype). Cars #1001–1002 used a rubber torsion tube design which suffered from severe toe-in during heavy braking. Tucker then switched to a rubber sandwich-type suspension (with a rubber block sandwiched between upper and lower A-arms) on cars #1003–1025, however this type was severely stiff. On cars #1026-on Tucker finally settled on a suspension design with a modified version of the rubber torsion tube with the toe-in braking problem corrected.
The front bumper of the car was lengthened from car #1003-on to prevent the center headlight from being the forwardmost point on the car. The lengthened bumper protected the center headlight from being crushed if the car were pulled too close to a wall or barrier.
To solve the transmission problems with a new design, Warren Rice, creator of the Buick Dynaflow transmission, was consulted. A unique continuously variable automatic transmission called the "Tuckermatic" was designed, which was strong enough to handle the Franklin O-335's power and torque. It was a simple but effective design with double torque converters and only 27 parts, about 90 fewer than normally required for an automatic. The double torque converters allowed a continuously variable drive ratio with only one forward gear and one reverse gear which used the torque converters to vary the transmission ratio based on load and engine speed.
Three versions of the Tuckermatic were made, the R-1, R-1-2, and R-3, (R for Warren Rice, its designer). The first version, the R-1, was not installed on any of the final cars. It required the engine to be off in order to select a gear. The R-1-2 was improved by adding a layshaft brake to allow gear selection while the engine was running. This version was installed on cars #1026 and 1042 only. The R-3 version had further improvements including a centrifugal clutch to help shifting between forward and reverse even further, but it was never installed in any of the final cars.
Because the two torque converters on the Tuckermatic made the engine/transmission unit longer, the fuel tank in the Tucker '48 had to be moved from behind the rear seat to in front of the dashboard for all Tuckers from car #1026 forward, even though only two of them actually had the Tuckermatic installed. This had the added advantage of improving weight distribution on the car.