While a UK marine aggregate dredger was undertaking a turn during dredging operations, it became apparent that the pipe had touched the bottom as the draghead wire was seen to veer away from the ship. This was due to the draghead and intermediate wires not being hauled away from the bottom far enough in advance of the turning manoeuvre.
Initially, the gear was quickly hauled clear, but before operations were re-commenced, the ECR reported an air leak in the system. The gear was then immediately recovered and the pump stopped.
On recovery, it was discovered that the intermediate wire was tangled on the winch drum. This is believed to have been caused by an initial riding turn as the pipe and gimble had touched the bottom. This had also resulted in the recovery wire to come free from its secure eye plate fixings causing the plug on the draghead angle sensor to be pulled free from the connection and the air pipe feed to be pulled from one of the pipe joints.
Given these circumstances, the dredge wires could have parted and the dredge pipe could have been lost. The intermediate wire becoming tangled confirmed that the wire slackened because the intermediate section of the dredge pipe also touched the seabed on the swing.