in 1925. GWR 3700 Class No. 3705 Mauritius LSWR S15 class No. 515 Built in 1921. Dartmoor branch On the ground floor of the museum, a model representing a Great Western Railway branch line on Dartmoor, originally built in 1955 to showcase the trains being built for the Vale scene, is operated for visitors. The main focus of the Dartmoor scene is a model of Brunel's timber viaduct at Walkham in Devon built by R. Guy Williams, who also built many of the model locomotives at the museum. Locos on the layout include: GWR 2900 Class No. 2921 Saint Dunstan Built in 1907. GWR 2800 Class No. 2844 Built in 1912. LSWR M7 Class No. 30 Built in 1904 Madder Valley The museum includes displays of individual models, modelling methods and railway artefacts. It also displays Madder Valley, a pioneering model railway built by John Ahern. Models The model trains are hand built, to represent individual locomotives, carriages, and wagons as exactly possible, based on surviving records and photographs. Operation consists of a sequence of trains, showing what one could have seen passing by on a summer day and night, in the mid-1920s. This sequence is based on timetables of the period. They are all modelled in 4 mm to 1 foot scale (1:76), and run on track of 18mm gauge, a combination known as EM gauge. References External links Pendon Museum official website Museums with year of establishment missing Museums in Oxfordshire Railway museums in England Model railroads Scale modeling