These 60' Centerbeam Flat Cars are painted Burlington Northern green with white lettering.  These cars were built by the Thrall Car Company in May of 1983.  Centerbeams are freight cars designed to carry bundled building supplies such as dimensional lumber, wallboard and fence posts.  They are essentially bulkhead flat cars that have only been reinforced by a longitudinal I-beam.  They must be loaded symmetrically to avoid tipping over.