Theme : Materials – Stretch-Fit

There’s a paucity of new materials being used. Does an old construction technique have a future?

"Blue Train Bentley" - image : bentleymotors.com
‘Blue Train’ Bentley Speed Six – image : bentleymotors.com

Early aeroplane construction made use of fabric stretched over a lightweight frame. Ex test pilot Charles Weymann adapted this technique for car bodies, patenting his construction method, selling patents and opening factories in France, Britain and the USA in the early 1920s. Using flexible joints for the underlying timber stopped unseemly squeaking, hidden wires held the doors in shape, and the ‘fabric’ comprised layers of chicken wire, muslin, cotton and, finally, self-coloured synthetic leather. Despite the fragility of the structure in the event of an accident and the risk of rotting fabric, the system was well-received and used extensively by coachbuilders. However, as metal body technology improved, by the early 1930s, demand had declined drastically although the technique continued to be used on bus bodies in the UK and the name Weymann continued on until the end of the 80s, when one-time transport manufacturing giant MCW (Metro Cammell Weymann) was broken up. Continue reading “Theme : Materials – Stretch-Fit”

Theme : Shutlines – Now You See It …

… Now You Don’t. We look at the GINA, BMW’s attempt to produce a literal shutline

Gina 03

However much he might have railed, an engineer of Dr Piech’s standing knew that, even by calling it a shut line, it would always be, in reality, a shut gap. Expansion, engineering tolerances, sag and the possibility of damage means that the shutlines of a solid bodied car will always be measured in millimetres, not microns. Even those uniformly narrow gaps on modern VAG products must have been an irritation to him until the end. Continue reading “Theme : Shutlines – Now You See It …”