Railroad Vehicle Glazing Standard Development

Abstract The American Public Transportation Association’s (APTA) Passenger Railroad Equipment Safety Standard (PRESS) Task Force initiated a testing program to develop a new railroad vehicle glazing standard. The program was coordinated and funded through the Federal Railroad Administration (FRA). This paper presents the procedures and results of this testing program. The test program used an air cannon to project various sizes of steel balls at speeds between 30 and 125 miles per hour and a 24-pound cinder block at 30 miles per hour to impact different glazing samples (glass laminates and polycarbonates) in the vertical position with the impactors striking at 90 degrees to the samples. With the cinder block, the impacts had to occur between the corner of the block and the samples. A pendulum system was used to impact the samples at slower speeds. The ballistic tests consisted of a 0.22-caliber long rifle, 40-grain bullet at speeds between 960 and 1163 feet per second. The pass/fail criteria were dislodgment of the glazing from the frame, or spall penetrating one mil aluminum foil witness plate placed 6 inches behind the samples. Based on this test program and input from the rail industries, a new glazing standard was developed.