This is a companion volume to the book by Rowland Abbott published by The Oakwood Press in 1989. This new volume brings the original book up to date and includes much new information gathered from original historical research. Whilst much of the book provides revised and expanded data about the principal builders and discussion of many of the more obscure builders. Amongst the larger builders covered is Atkinson Walker and their locos are fully discussed with many new illustrations. The histories of the locos built by Alexander Chaplin have been expanded upon as have those built by DeWinton. For the section on Sentinel there is a new construction list.