The OHE portion is disconnected. You can see in pic 3 that there is a cable from the OHE wire to the three wires above. After that connection, the OHE wire terminates at the bridge. In pic 4, the OHE wire ( the one that contacts the pantograph) is terminating at the bridge. Basically, on both sides of the bridge, a small portion of the OHE is neutral. And the three wires passing under the bridge sort of bypass the neutral section and connect the OHE on both sides of the bridge.