Obstacles in the part of the cable carriers can cause serious problems on harbour cranes. The cranes are so heavy that they will take a few seconds to stop. If the cable carrier is caught on an obstacles, the crane will tear the carrier to pieces before it shuts down. This stops the crane working, and can cause huge losses to harbour owners.
In the new system, the main carrier is fitted with a second emergency cable carrier (ECC). If the main carrier is caught on an obstacle, the ECC is detached. Rather than damaging the main carrier, the crane pulls the ECC free. The ECC can be dragged along behind the moving crane, until it comes to a stop. Once the obstacle is removed the crane can easily be restarted, without serious damage or delay.
