Hauling loads of anthracite coal from mine operations deep in Pennsylvania as well as long strings of freight, the green and gold striped midnight black FT's helped Reading handle the increased load of Wartime traffic. Lashed in A-B-B-A units, the FT plied the rails in places like the Catawissa Branch eliminating much of the costly helper service that was cutting into the companyNULLs bottom line. Reading bought 20 units that served the line until they were fazed out of service for GP-30NULLs by 1964.