TDI have been working on London Underground projects since 1990 when first retained (then as Warwick Design Consultants) by LUL to develop new interiors, cabs and front end designs for Jubilee, Piccadilly and Northern Line tube stock. TDI also manufactured full size mock-up for each of the train interiors as well as developing the driver's desks and Jubilee 'M' door detrainment system.
Notably, TDI undertook comprehensive ergonomic studies for all driver and passenger interfaces including integration of the first wheelchair spaces on the Underground and the definition of a universal seat profile which could be used across all new stock. This led to TDI's research and illustrations being used as the foundation for the London Underground 'Train Interior Guidelines' first published in 1996.
Most recently, TDI has assisted Bombardier with the engineering of various cab and interior systems for the new VLU and SSL stock.