The Type 3 Diesel Locomotive album comprises over 200, mainly unpublished, full sized colour photographs of four classes of British engines, developed in the earlier years of the Modernisation Plan. The Type 3 included four classes of locomotive of medium power output, which undertook a wide range of duties from Main line and local passenger services, various freight duties and departmental work. Several are still in use on the national network, and can be seen in various parts of the country The Book has been compiled by David Cable, who has authored a range of very successful colour albums for Pen and Sword Books Ltd. The photos illustrate the many duties and colour schemes of the classes in a variety of locations and colour schemes of the classes in a variety of locations, using largely unpublished photographs from his extensive collection.