Carriage, Mark II D Carriage No. 5669 built at Derby Carriage works and completed in October 1971.

An example of the first regularly in service air-conditioned coach on Britain's railways – the Mark II D has been called ‘the coach that launched Inter City’. Design for the coach was partly done using Vitry testing station and computer modelling, and the Wilkes and Ashmore archive has details of seat design development.