Abstract: The center locks of a bascule or other type of double leaf movable bridge are fitted on bearings mounted upon the main bridge girders, so that the center lock bars may be moved, when the bridge is in the lowered position, along a horizontal axis parallel to the axes of rotation of the leaves of the bridge, effecting a shear connection at the meeting point of the two leaves of the structure so that, when the bridge is in the lowered position and the center lock bars are engaged rigidly with respective rotating sockets, the tips of the leaves at a vertical lateral plane containing the center locks are forced to deflect equally while the center locks accommodate longitudinal movement and rotational deflection of the protruding ends of the two leaves via components that are permanently engaged, optionally including capacity of independent rotation of the main bridge members on axes parallel to the longitudinal axis of the bridge.

Abstract: Sections of a highway crossing over the rail road are raised completely clear of the rail road to form a barrier preventing automobile traffic from entering the rail road when a train is at or nearing the crossing. When the train has passed, the barrier sections are lowered, reforming the grade crossing so that automobile traffic may cross the rail road at near grade. The ends of each barrier transverse to the centerline of the roadway are shaped and positioned so that a continuous surface is formed when the barrier sections are in the lowered position, partly resting on the rail road or nearby supports, allowing automobiles to continue over the rail road by means of driving on the upper surfaces of the lowered barriers, with only small gaps at the joints where the sections adjoin each other or meet the approach roadway.