Purchased as two four-wheel carriages in 1873 from the Metropolitan Carriage & Wagon Co., Ltd., of Saltley Works in Birmingham and later allocated fleet numbers B.9 and B.14, by 1883 these two carriages had become close coupled and were later mnounted on a new steel underframe, again supplied by the Metropolitan Carriage & Wagon Co., Ltd., in 1922 to become F.70.  The carriage in this form survived in service until 1971 when it was withdrawn and stored.  The bodies were removed and scrapped in 1980 and the underframes used as a runner, retaining the fleet number.  Upon the withdrawal of Ballast Hopper No.1 which had been constructed on the underframes of F.65 in 1984, F.70 was selected to take its place and in 2011 new hoppers were fitted.  It remains in departmental use in this guise today, commonly stored on Road Zero at Douglas Station retaining the fleet number.