Contact Energy recently purchased a new underwater ROV (remote operated vehicle) to complement their gate inspections.
A test drive was undertaken at Clyde Dam to train operators in its use before deploying the ROV to a more risky deep dive to the sluice gates at Roxburgh Dam. However the operators accidentally managed to tie the umbilical cord in a knot at 20m depth around a beam in front of unused intake No.6. This was confirmed by the ROV video! Unable to untie the knot divers were required the following week to safely salvage the ROV.