7F-073-034 O Gauge 7 Plank World Best MumThe 7 plank wagon was the standard coal wagon up to the 1930s when steel mineral wagons were developed. In 1923 the RCH produced a standard plan for the 7 plank wagon, as up to this time there were many variations depending on the builder and region. However, even after the standard was applied, many non standard wagons were still used. Dapol Model two variations of 7 plank wagon, the internally braced variant with a 9 foot chassis with no end doors