M2265 - Difficulties leaving port in strong winds
Initial Report
A passenger ship was due to depart port at 2150. This was the master’s first time sailing from the port, and during the master/pilot exchange, the pilot had suggested delaying departure due to the forecast strong winds of up to 25 knots. The passage plan required the vessel to reverse out of the harbour and then turn in one of 2 charted turning areas – one just outside the breakwater and the other a few miles out. The master chose the closer turning point against the advice of the pilot.
As the vessel passed the breakwater, the ferry commenced its turn with tug assistance. The wind gusted up to 50 knots, pushing the passenger vessel leeward onto a navigational buoy.
Despite the tug pushing on full power and the passenger vessel increasing speed, it was blown within 10m of the rocks before it could make headway to windward and regain the planned nav track. There were no injuries or pollution on the vessel, but the tug sustained minor damage.
CHIRP Comment
This report emphasises the need to prioritise the safety of the vessel, passengers, and crew rather than the scheduled timetable. Still, CHIRP recognises that because organisations rarely set wind guidance for vessels, masters are subject to considerable implicit commercial pressure to carry on, even in marginal conditions.
The best practice is for companies to provide weather guidance rather than limits, empowering masters to exceed the guidance if it can be justified by a risk assessment that considers local circumstances (including any advice provided by the pilot).
Pressure – A master operating on a tight schedule must never be placed in a situation where safety is compromised for commercial expediency. Does your company provide guidance to the master, especially when the master is calling at a port for the first time or during a different season?
Local practices — In this case, the pilot has experience, and their advice should have been heeded. Local knowledge can improve the interpretation of area weather forecasts.
Situational Awareness — If there was any doubt, the master should have consulted the ship’s staff and shore management. The pilot’s doubt should have been sufficient to register with the master that the departure would be challenging. Prudent overreaction should have been applied, and the vessel should have delayed departing.
Capability—The vessel’s ability to manoeuvre under high wind conditions with exposure to high sides was not assessed. The wind forces acting on the hull must be understood when designing passenger vessels with high sides. Simple rules for calculating wind force exist. Were these rules used during the master pilot exchange?
E.g. Length overall (m) x Max freeboard in (m) = windage area
An approximate wind force in tonnes per 1000 sq. m can then be calculated using:
V wind speed (meters/second) = wind speed (knots) /2
The Force (tonnes) per 1000 sq. meters = V2 / 18