As CI continued its programme of rolling stock renewal under the tenure of Oliver Bulleid, Inchicore Works turned its attention to the construction of a humble but useful flat wagon with a 12-ton capacity. Utilising a version of Bulleids patented triangulated chassis developed as the basis for a variety of CI wagons, a total of 79 were turned out between March and April 1958. Later, a number of withdrawn H Vans were repurposed as flat wagons for the Permanent Way Department which were use for transporting materials and machinery