Pannier Tanks were used almost exclusively in Britain by the GWR. They were brought into service to replace earlier built and designed saddle tank locomotives. Their design offered the locomotive a low centre of gravity, reasonable range and easier access to the workings of the locomotive. In all, 863 were built between 1929 and 1950 and sixteen survive into preservation. Eleven 5700 saddle tanks were bought by London Transport for use on shunting duties on the London Underground network. These were numbered L89 to L99 and continued in service until 1971. The locomotive's durability and functionality is attested to in the fact that the last locomotive in service was used well into the 1970s by the National Coal Board at the Deep Duffryn Colliery at Mountain Ash.

The Dapol 57xx features:

Finely moulded body with many separately added fine details

Prototypical cab styles and water tanks available

DCC Ready - 6 pin decoder socket

DCC Fitted available

Cast wheels with fine relief and appropriate colouring

Heavy metal chassis and all wheel pick up

Accessory bag with spares and other added detail