Circuit Breaker
The end of a fence panel shows the triggering mechanism. The slide fence panel at left is suspended on a cable. Two large springs connect the fence panel to the fence post. A circuit box is mounted to the fence and linked to the panel by a double cable with a set amount of slack.
When a Volkswagen sized chunk of limestone comes off the bluff and thunders across this road it will run into the fence, stretching it so that the fence panel slides along the suspension cable and pulls it away from the fence post, extending the springs and pulling the slack out of the cable to the circuit box and breaking the circuit causing the block signals to drop to red and stop traffic on the RR below. Fairly simple but pretty effective safety device. March 2, 2013.
Circuit Breaker
The end of a fence panel shows the triggering mechanism. The slide fence panel at left is suspended on a cable. Two large springs connect the fence panel to the fence post. A circuit box is mounted to the fence and linked to the panel by a double cable with a set amount of slack.
When a Volkswagen sized chunk of limestone comes off the bluff and thunders across this road it will run into the fence, stretching it so that the fence panel slides along the suspension cable and pulls it away from the fence post, extending the springs and pulling the slack out of the cable to the circuit box and breaking the circuit causing the block signals to drop to red and stop traffic on the RR below. Fairly simple but pretty effective safety device. March 2, 2013.