Laminated plywood construction

Laminated plywood construction /lam-i-nay-tid ply-wʊd kuhn-struk-shuhn/ noun (uncountable)

Laminated plywood construction is a method of building a vehicle chassis where multiple layers of plywood are bonded together to form a strong and lightweight monocoque structure. This was the startlingly innovative, if slightly worrying, practice of building a high-performance sports car out of the same material as a cheap wardrobe. It was a technique borrowed from the aviation industry, where the de Havilland Mosquito bomber had proven the immense strength of bonded wood. For the British car maker Marcos, the plywood monocoque was a stroke of genius, creating a chassis that was incredibly light, stiff, and cheap to produce. It did, however, come with the nagging fear of woodworm and what might happen if you left the car out in the rain for too long.

The Full Story of Laminated Plywood Construction

The inspiration for a wooden sports car came, fittingly, from the sky. During the Second World War, the de Havilland Mosquito, nicknamed the "Wooden Wonder," proved that a structure made from bonded plywood could be both immensely strong and exceptionally light. One of the engineers who worked on this project was Frank Costin, an aerodynamicist who would later apply his aviation knowledge to motor cars.

In the early 1960s, Costin, together with Jem Marsh, founded the Marcos car company. Their first cars were bizarre-looking racers, but their engineering was radical. The chassis was not made of steel, but of laminated marine plywood. It was a true monocoque, constructed from over 300 individual wooden pieces meticulously bonded together over a jig to form the entire central tub of the car. The engine, suspension, and a swoopy fibreglass body were then attached to this wooden core.

The most famous wooden Marcos arrived in 1964, a beautiful, low-slung coupe that would define the brand's image. For the first five years of its life, every one of these cars sat on a plywood chassis. The benefits were remarkable. The wooden structure was exceptionally light and torsionally very stiff, giving the cars brilliant handling, even when they were powered by humble four-cylinder engines from Ford or Volvo. It was a genuine piece of left-field engineering brilliance.

For all its technical merit, building a car out of wood had its challenges. The process was incredibly labour-intensive, and repairing crash damage was a highly specialised job requiring skills closer to cabinet making than panel beating. And while the marine-grade plywood was highly resistant to rot, the perception that your expensive sports car might one day succumb to damp was a difficult one to shake in the showrooms.

By 1969, Marcos decided that in order to increase production, a switch to a cheaper and much faster-to-produce welded steel chassis was necessary. The era of the production plywood sports car was over, leaving it as a fascinating and uniquely British engineering cul-de-sac.

For The Record

Was the entire car made of wood?

No, just the chassis. The chassis formed the main structural tub of the car, including the floor, sills, and bulkheads. The complex, curved bodywork that was placed on top was made from fibreglass.

Did the wooden chassis actually rot?

Not if it was properly maintained. The chassis was made from high-quality marine plywood and was well-sealed when it left the factory. Rot was only a significant problem if the car was neglected or poorly repaired after crash damage allowed water to penetrate the bonded layers.

Was it inspired by Morgan?

No, this is a common misconception. The Morgan has a traditional steel ladder chassis. Its body frame, the non-structural part that the panels are attached to, is made from ash wood. The Marcos was completely different: the wood was the chassis, a fully stressed monocoque structure.

Why did Marcos stop using plywood?

Primarily for cost and production speed. As demand for their cars grew, the slow, labour-intensive process of bonding hundreds of individual wood pieces together became a major bottleneck. A welded steel chassis was much quicker and cheaper to produce in larger numbers.

Were any other cars built this way?

It is an extremely rare technique for production cars. Some earlier racing cars and prototypes used wood, and some amateur one-off "specials" have been built this way, but Marcos is the only significant manufacturer to have put a plywood monocoque chassis into series production.