Several MSs and CUs of diesel locomotive shunting box cars, moving along track by itself or with string of cars, of brakemen at work signalling, switching. MSs of box cars, locomotive coupling. CUs of locomotive, boxcars passing very close to camera, of points of switch moving, of wheels rolling over switch. Shots of brakemen riding cars on ladder. Several other shots of diesel locomotive and box cars, flat cars, vans, moving about hump yard , overcast skies. Montage shot of markings on sides of box cars. Shots of cars shunting at Canadian National Railways freight station in Saint-Laurent near Sainte-Croix Avenue. TILT UP from track to crossing, cars passing as locomotive approaches. ZOOM IN on locomotive as it crosses crossing. Shots of train moving by camera, vans. Shots of track crew moving up on speeder, shifting speeder from one track to another, tower of Saint-Laurent College visible in background. Interior shot of engineer in locomotive cab, of his hands on controls. MS or railroad dispatcher at his desk, speaking into microphone, looking at papers.