The changing face of tow truck design

The vehicle that is credited with being the world’s first tow truck was built by Ernest Holmes, of Chattanooga, Tennessee, back in 1916.

Ernest Holmes was faced with increasing demands to recover stuck vehicles. The procedure was to use ropes, blocks and tackle, men, horses or tractors and he just knew there had to be a better way.

Holmes, the inventor, modified a 1913 Cadillac by fitting a pair of swinging booms, chains, hooks and pulleys to the back of it and the first tow truck was born. The booms could swing through 90-degrees on each side of the Caddy, to recover vehicles that had run off the road and then the booms joined together, to form a crane jib, so that the stranded vehicle could be towed behind the Cadillac.

An early Holmes wrecker in action. Pic courtesy of Edmonton Towing.Technically, the modified vehicle was a twin-boom ‘wrecker’, not just a ‘tow truck’, because it could recover vehicles that weren’t sitting on a formed road surfaces.

Holmes filed for a patent for his idea in 1917 and then founded the Ernest Holmes Company that built and marketed tow trucks. The company survived the Great Depression and built wreckers for the American war effort in WWII. In 1974, Holmes’ grandsons, Gerald Holmes and Bill Holmes, founded the Century Wrecker Corporation, to build affordable hydraulic towing equipment now used widely in the industry.

Tow trucks and wreckers remained essentially unchanged in principle until the rise in popularity of plastic front and rear bumper bars, independent suspension, automatic transmissions, front-wheel-drive and all-wheel-drive vehicles. All these innovations forced tow truck design to adapt.

Before then, nearly all vehicles were manual-transmission designs, with beam front axles and rear-wheel-drive. Towing them was simply a matter of hooking a chain under the front axle to lift the steer wheels off the ground and putting the transmission into ‘neutral’, so the prop shaft and gearbox could rotate without turning the engine.

Chains didn’t work well with independent front suspension, plastic bumpers and front wheel drive, because bodywork and mechanical damage was inevitable, so ‘towies’ adapted, using hydraulic booms with dual ‘forks’ that fitted under the tyres, not the chassis or suspension.

Even then, some automatic-transmission vehicles and SUVs couldn’t be towed with two wheels rolling, without the risk of transmission damage. A solution was a dual-wheel ‘dolly’ on each side of the front or rear wheels. These dollies were clamped in place and raised by means of a long lever, lifting the vehicle wheels off the ground. Thus the stranded vehicle could be towed without its own wheels rotating.

This ability to lift and tow a locked vehicle proved a boon for ‘repo’ (repossession) truck operators.

Meanwhile, at the heavy end of the tow truck business, three-, four- and five-axle vehicles dominated, fitted with heavy-duty hydraulic booms and drum winches.

Because nearly all prime movers retained beam front axles and transmissions with ‘neutral’ gearing it was still possible to tow them by lifting the front wheels clear of the road and leave the drive wheels rolling. Thus, it was also possible to tow a broken-down prime mover and semi-trailer or B-Double combination.

The most recent development in passenger and light commercial recovery is the tilt-tray tow truck.

This design employs a tilting tray that becomes a ramp, up which the stranded vehicle can be driven or winched. The tray surface is usually steel plate, providing minimal friction resistance if the stranded vehicle wheels cannot rotate and a hydraulic winch is need to load it onto the tray.

Some tilt-trays have swivelling ability, so they can parallel double-park and load a kerb-parked vehicle.

Many tilt-tray tow trucks are crew-cab types that can accommodate up to five occupants from the stranded vehicle. Also, this design allows the tow truck to hook up a caravan or other trailer that the stranded vehicle may have been towing.

The truck that we encountered over the Xmas break was well specified, starting with a tilt tray that had a hinged aft section. This design allowed the approach angle to be as low as three degrees, making it possible to load vehicles with ground-hugging front spoilers.

It had more chrome and stainless than a custom Peterbilt – even a polished spare wheel cover – as well as trick lighting to make its roadside presence more than obvious. Thanks for the slick service, Craig!