Design British Railway Milk Tank Wagon

preserved united dairies three-axle milk tank wagon @ bluebell railway, based on sr chassis

the initial milk tank wagon designs based on 12-foot (3.7 m) 2 axle railway wagon chassis. there ladder either side allow filling via industrial rubber hose flip-top dome casing, while steel pipe exited @ bottom of tank tap either end of chassis between buffer beams extraction. designs unlike typical goods wagons used vacuum braking, due high-speed deployment. various designs railway companies used followed common pattern, @ stage differences appeared making them easy spot. while gwr designs used flat-strip metal bracing, lms , sr designs used rounded steel bracing. sr designs had additional v-shaped support bracing either end, , had additional wooden packing behind each of buffers. lms designs had catwalk around filling dome.

the first tanks labelled externally being glass-lined (they vitreous enamel), meaning wagons unauthorised loose or hump shunting, reminder of applied in large capital letters chassis. tank design had no baffles, meaning milk self-churned during journey, , made wagon highly unstable. after required improvement in milk quality not gained, , number of derailment accidents, 13 feet (4.0 m) three-axled six-wheel wagons introduce 1931, , baffles became standard practise. last of two-axle design withdrawn pre-world war ii, while three-axle designs continued in production under british railways 1950s, stainless steel linings.

later, limited production twin-tank designs introduced, based on triple-axle chassis. more common on gwr, used sr transport of dairy products channel islands came in via southampton docks. twin-tanks allowed easy collection smaller dairies of both premium gold-top, other silver-top products.

in total, across 4 railway companies, 600 three-axle milk tank wagons produced.