The third volume in the series describing the industrial railways and locomotives of County Durham, written by the late Colin Mountford. Colin continued to work on this volume during his final illness, and almost completed it. The Industrial Railway Society published it as a tribute to Colin. The book comprises 280 pages, with extensive descriptions of the sites covered and locomotive lists, well illustrated (many of the photos being in colour), and with a set of maps.

The book is divided into four sections.

• Section 1: The Fluorspar Industry in Weardale
• Section 2: Locomotives used by Contractors
• Section 3: Dealers and Repairers
• Section 4: Locomotive and Railway Preservation (including 15” gauge lines)

There are also full indices of locomotives, owners and locations