Post grouping the 4F 0-6-0 tender locomotives were generally regarded by non Midland Railway crew and locomotive cognoscenti as pretty feeble, especially compared with some of the similar LNWR and Scottish versions, which they ran alongside. They also tended to run hot, and their frames crack. In this masterful tome Adrian Tester offers a considerable defence of what was, by any reckoning, a large class, and of the modifications to them. You may not always agree with him, but this is a interesting and technical look at the class and the design philosophy of Derby. 274 A4 format pages, full of diagrams, graphs, drawings and some B&W photographs. Paperback.