A Brief History Of Car Trailers And Their Construction

Box trailers have been a key component in the transportation of classic cars and race cars throughout the 20th and 21st Century. The early construction methods were far removed from those of the sleek, streamlined heavy duty trailers of today. While the innovations in technology have led to changes and improvements in material and cost-efficiency, the original design has hardly changed. The torpedo shape and rounded roof remain the same throughout, whether we are looking at the latest model or a relic from the 1930s. The restoration of such a trailer by a collector uncovered the secrets of how it was made all those years ago. The chassis was constructed from steel tubing, with wooden boards forming the floor. This was no heavy duty car trailer. Originally, the sides of the trailer would have been covered by canvas, providing little protection for the car within.

Corner-mounted jacks allowed the trailer to be tilted at a steep angle, so the car could be winched in without the need for a ramp. Later, an aluminium canopy was added to replace the canvas covering. This served two purposes: affording the car a more substantial roof and creating a surface on which to present sponsor’s logos. It is so interesting, looking at this early design of a box trailer, how little has changed aesthetically.

Obviously, the place where the most significant changes and improvements have been made in heavy duty car trailer design is in the materials. Today, most trailers are constructed out of fibreglass. The lightweight, extremely resilient material is surprisingly made of one of the most fragile substances: glass. The process refines the glass and makes it suitable for the construction of aeroplanes, racing bikes, clothing and in this case, heavy duty trailers. The glass is heated until completely molten, then forced through miniscule holes creating glass filaments. These fibres are then woven into larger structures or left in an unstructured form and used as insulation or soundproofing. Following this, various resins are added to increase strength or malleability.

Fibreglass is very popular in the manufacturing of custom-made components for cars as it can be so intricately moulded. It can also be made using foam templates. The foam prototype is coated in a layer of fibreglass resin which hardens to the shape of the mould. This method is used to make custom automobile parts or modifications as well as a box trailer.

The material is incredibly lightweight, but sturdy, making it the substance of choice in the manufacturing of a high-end box trailer. In the case of modern trailers, the bodywork is made of high-quality fibreglass, ensuring flexibility and structural integrity. The fibreglass is then coated in specialised resin, with UV Stability to protect the trailer from and damage due to sunlight. The heavy duty trailers also keep their condition due to an Anti-bio formula within the resin, preventing the growth of moss or algae from being kept outdoors or in damp conditions. The resin is made using recycled polyester, helping the temperature resistance of trailers during winter. These are typically heavy duty car trailers but can be used to transport boats, professional sports equipment, quad bikes and go-karts. Smaller, lighter trailer options are also available for the transportation of motorcycles and bicycles.

Comparatively, the trailers of today are worlds apart from the trailers of the 1930s, but the purpose and shape remains the same. Modern trailers have a hard-outer shell and generally come in bright, glossy colours with logos and labels decorating the outside. The older models often had canvas covering the car, stretched across a steel ribcage. However, the canvas was still emblazoned with sponsors and logos as if to prove how little has changed in the world of racing trailers. The advent of new technology may have changed the way these box trailers are constructed but the look of these trailers has survived the test of time.