These two diagram books contain copies of over 180 engine diagrams for locomotives designed, modified or owned by the LNER from 1923, including the final designs which came out after nationalization. The Gresley diagrams for NER locomotives are headed ‘SECTION D’; the D stands for Darlington. The other pre-grouping companies’ locomotives, not reproduced here, were covered by Sections; B for North British, E for Great Eastern, C for Great Central, N for Great Northern and S for Great North of Scotland.
The earlier Gresley diagrams, headed ‘SECTION LNE or SECTION D’, were drawn at 3/16 inch to one foot, but the Thompson diagrams, with no heading, were 1/8 inch. The original Gresley diagrams were 18 x 8.5 inches over binding, and the Thompson were 11.5 x 5.65. The Gresley diagrams were split into two books; one for tender engines and the other for tank. It was probably the intention to replace all the Gresley diagrams by Thompson ones, but it is not known if the task was completed. The gilt lettering on the green binders referred to them as ‘Engine’ not ‘locomotive’ or ‘weight’ diagrams, and the LNER title is retained here.
For ease of reference the diagrams in these books are arranged in class order regardless of whether they were tank or tender or from Gresley or Thompson originals. This leads, for example, to the A1 and A2 classes, introduced in 1922, being reproduced ahead of the later Thompson and Peppercorn types.
The diagrams should be of considerable value to modellers, and with the aid of decent photographs could even lead to an accurate model being built. However, there are pitfalls as they are only diagrams. The top of the firebox on a class V2 does slope down towards the cab, unlike that shown on the diagram and reproduced in a well-known model.