Lines operated by locomotives shedded at St Blazey are mainly the branches from Par to Newquay and associated freight lines and the two lines to Fowey. This resulted in an allocation of locomotives designed for hauling freight trains, and with the tight curves encountered on some of the branches, types with a short wheelbase suitable for such lines were usual. The smallest engine allocated to St Blazey was the tank used for the Lostwithiel to Fowey branch, which was usually four-coupled. Under the GWR a Metro tank was usual but under British Rail an ex-GW 1400 class was used.