The boat, nb Dizzy, was entering Lock 9w from the short pound above, which was very low. The stern of the boat became stuck on the wooden cill that abuts the top gate. The water in the lock continued to drain away until the bow of the boat took on water and sank.
It is believed that one of the hydraulic tail gate paddles was obstructed and would not fully close. BW say this had not been reported to them by other boaters, although one boater has said he reported it a week earlier. In addition, the lock has considerable leakage around the tail gates. It is understood that the lock drained so rapidly that the crew were not able to rectify the situation in time. Fortunately, no-one was hurt in the incident.
The boat owner arrived and assisted BW ground staff in re-floating the boat. This was done by sealing the front doors and vents and carefully re-filling the lock. The well deck took on water but the boat floated as the levels rose.
Nb Dizzy in Lock 9w.
Nb Dizzy lives up to its name, pivoting on the lock cill.
The pounds above and below the lock were drained to facilitate the recovery.
Doors and vents sealed, the water level is carefully raised.
Nb Dizzy afloat once more, although low in the water, having taken on water.
The excessive leakage around the tail gates may have contributed to the incident.