Think sliding doors in the automobile industry, and you automatically think ugly old space wagon. But actually sliding doors are used in a range of vehicles from vans to sports cars and have a variety of uses.
A sliding door is a type of door that opens usually horizontally (but sometimes vertically) through a sliding motion that is enabled by a track system. These doors are not usually used on small vehicles, because their most useful application is when large loads, or a large number of passengers need to enter a vehicle. For this reason, they are most often utilised in commercial settings, such as large wheel based vans or minibuses.
The most common type of sliding door has a three-point suspension with outward opening to run alongside of the vehicle. This was first conceived by Volkswagen in 1964. Another type is the pocket door, which slides along the length of the bodywork and then disappears although this type is rarely used in the automobile industry more so in architecture and design.
Vertical sliding doors also slide on a rail or a track. BMW’s first utilised these in the automobile industry, and its Z1 model used a vertical sliding door that slid down into a compartment within the body of the car and so was technically a pocket door in an unconventional sense. What was clever about this design was that the windows could operate independently of the doors.
Inner track sliding doors operate in the same way as external which are most commonly used in commercial vans, only here the track is on the inside of the van as opposed to external. These are less common than external systems and are usually only utilised where there is no space to have the track mechanism externally.