Quote from their website:
The purpose of this site is to bring together varied and disparate sources of data including books, webpages, magazines and personal records and present this data in a homogeneous manner, allowing the user to search for data in context, i.e. not in just a 'dry' statistical manner. However, to achieve this 'grand' aim, I need your help! Data sources, anecdotes, photographs, trainspotting logs etc... will all be welcome.