Measuring clearances in Whittier Tunnel: The special gondola shown is called the "Chipper Car" and was sometimes run through tunnels during the winter to knock down ice that had grown on the ceilings and walls of the tunnels on the Seward and Whittier Subdivisions. In 1978 it was decided that the Whittier Tunnels needed an updated clearance envelope and the car was used to take measurements by stopping every 100' at a station that was already painted on the walls and a rod pushed to the inside of the tunnel to take the measurement.