Hornby OO R30038 Railroad PO, T. Brown Distilleries, 0-4-0T, No. 3 - Era 3

Small industrial locomotives like this have been used by companies with large amounts to move for as long as railways have existed. Their small size means that they can traverse smaller radius corners, enter factories, and require less infrastructure to maintain. Often they would be used to shunt goods, preparing them to be collected by another locomotive which would then take them further afield.