Automobile History: body & chassis


Unlike the first engine and chassis builders, who had no precedents to follow, the first auto body engineers represented an old established craft. It mattered little to them whether vehicles were to be propelled by a gasoline engine, electric power, or steam. Their task was the same as in the days of chariots: to construct a conveyance that would carry people.

The body builders contended that if carriages were good enough for horses, they were good enough for engines. They were even given carriage names — phaeton, brougham, tonneau, landaulet, and wagonette.

Don’t get the idea that early body engineers were a stodgy conservative bunch. When it came to trying new structural concepts and materials, they were as radical as the engine and chassis guys — so much so, in fact, that practically every body structural technique in use today had been tried by 1920, even gluing bodies together.

In 1984 Volvo announced the use of epoxy to tack-weld body parts together, thus reducing the number of conventional spot welds from 4000 to 500. But Volvo is not No. 1 in the use of glue for this purpose. Body engineers used casein to hold early wooden body members together on the Cadillac, Columbia, Locomobile, and Peerless of 1898 to 1904 among others.

If we had to pick the two most revolutionary events in the development of the auto body, we would select the transition from wood to metal and the development of quick-drying lacquer — events that occurred 25 years apart.

The wooden body panels of those early cars restricted body designers. Wood can only be steamed and bent into simple curves. When applied to wooden frames, the body panels of one make of car looked pretty much like those of any other make.

When sheet steel and aluminum came along in 1900, this sameness in appearance started to change. New metalworking techniques were perfected — drop-hammering and power-hammering in the 1900 to 1910 era, hydraulic stretching around 1920, and drawing and stamping around 1935. As each occurred, metal panels began taking on new, novel shapes. The first U.S.-built auto to sport a steel body was the 1901 Eastman Steamer, the first to have an aluminum body was the 1902 Marmon. Both were built with all-wood frames to which metal panels were pinned.

The wood frame/metal panel arrangement lasted about 10 years. Then, wood frames reinforced with steel to give the car body greater rigidity came along. Called armored wood, it saw its first use as framing to hold the steel body panels of the 1911 Hupmobile. Built by Edward Budd, the Hupp body was the traditional design for the day — a touring (open) car.

Closed cars were available from about 1900 on, but they found few takers since they cost about 20 percent more than open vehicles. To protect passengers in open vehicles, several automobile accessory companies made lots of money selling folding, cape and canopy tops.

The closed car, or sedan, became less expensive and more attractive soon after World War I thanks to Budd, who devised ways to cut the manufacturing cost. In 1919, Dodge brought out the first closed car with steel frame members and body panels.

The development of quick-drying lacquer that could be sprayed on occurred in 1924. It, more than any other development, ushered in the era of mass auto production. Until then most auto bodies were finished with paint and varnish, which took weeks to dry. Some old timers remember the days when new cars were lined up for miles along Detroit’s Woodward Avenue waiting for “that damn varnish to lose its tackiness.” Meanwhile, the production lines slowed to a crawl. There was just no more room to put cars.

Lacquer cut the drying time first to days — then to hours. Developed by Duco, its first use was on the 1924 Oakland. Oakland was the original division of General Motors that later became Pontiac.


On a late October afternoon in Detroit in 1915, an auto body engineer by the name of H. Jay Hayes was presenting a talk before the annual conference of the Society of Automobile Engineers. Hayes represented the Ruler Auto Co., and recounted in rather humdrum fashion the development of the auto body.

During a pause in his speech, a voice boomed, “What do you think about the moot theory of combining the body and frame into one unit?”

The voice got attention of everyone in the audience. They waited with interest to hear Hayes’ response. The combined body-frame theory had been bandied about for almost 10 years, but no car company had developed a cost-effective way to turn theory into reality.

Hayes presented a 15-minute dissertation on the virtues of unitized body construction — what we call today unibody or unit body construction. He explained to his fellow engineers how, by making the car smaller and lighter, it was possible to overcome the two main disadvantages of combined body and frame construction: excessive cost and body vibration.

Hayes then dropped a bomb by announcing that the following week his company was going to put on sale 3000 vehicles with unitized bodies. The car was called the Ruler Frameless.

As Hayes had promised, the vehicles appeared on the market without framing. Instead, body members were fashioned into tubular form to give metal the rigidity it needed to do without a frame. The engine and suspension members rested on a platform.


Here are some highlights in body evolution:

  • In 1897, a car named the Hugot hit the street with a wicker body. The nameplate and body soon became basket cases.
  • Aluminum and steel started vying to replace wood body panels as early as 1900. At the time, sheet aluminum was more expensive than steel, and cast aluminum brackets more expensive still. Thus was born the first car caste system. Cars having sheet steel body panels were manufactured for the masses, while those with aluminum body panels were made for the rich.
  • The first ever Cadillac, the 1902 model, sported patent leather fenders.
  • In 1903, a car that was called the Bates seemed to offer significant improvement in the way the body was attached to the frame rails. Engineers fitted the transverse rear frame girder with hinges, so the body could be attached with two slip-on security bolts. By slipping out the bolts, the body could be swung back easily so mechanics could have better access to the under parts of the vehicle.
  • Hinged side doors — two of them — became popular in 1905; four of them started to become popular in 1913, although they were available in 1910.
  • In 1922, the Auburn came out with the first X-member frame. The structure provided a major stride in torsional stiffness and cut down on vibration.
  • Some called it J.J.’s joke — the patent acquired by John Joseph McGuire of Yonkers, New York, on Oct. 24, 1922. But it turned out to be one of the most unique body ideas in automotive history. Based on the 1903 Bates idea of a bolt-on-bolt-off body, McGuire’s vehicle was an all-in-one car. Within minutes, whatever body was on the chassis could be unbolted, lifted off and replaced with a different body — limousine, 4-door closed sedan, 4-door open touring sedan, 2-door coupe, or 2-door roadster.
  • The first production wood-body station wagon was the 1923 Star. The first all steel-body production model was the 1935 Chevy.
  • Called pants at first, fender skirts were first used by Frank Lockhart in a 1928 Stutz racer.
  • Credit for the first modern hardtop convertible goes to Chrysler — with a 1946 model. But the first hardtop retractable convertible was invented by B. B. Ellerbeck in 1931.
  • The Kaiser Darrin and Chevy Corvette share the honor of being the first production sports cars with fiberglass bodies — in 1953 — but Ford built a fiberglass prototype as early as 1938.
  • Lotus introduced its “backbone” chassis on the 1962 Elan. A central steel box section carried the engine, drive shaft, and suspension. The fiberglass body was bonded (glued) to this steel frame.
  • Lotus was first to build a unit body structure using the lightest and strongest materials available — a combination of Kevlar and carbon fiber-reinforced resins. This structure significantly reduced noise and vibration.

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