These 40' standard box cars with single doors, tall ladders and no roofwalks are painted red with white billboard logos and lettering. They were built in November and December 1954 (respectively), serviced in July 1971 and run on Roller Bearing trucks. MKT owned an ammunitions plant located on-line in McAlester, OK; the rebuilt cars were assigned to this plant, connecting with US Naval and Army storage facilities in Northern California. The extra large billboard “MKT” paint scheme was intended to alert all railroads of their dangerous load from great distances.