Two large ships’ sterns broke away from their berths when a common bollard holding their stern lines failed, damaging a rail bridge and a third vessel.
On 17 August 2014, Grand Pioneer (Figure 1) and AAL Fremantle (Figure 2) broke away from their berths when a thunderstorm passed across the Port of Fremantle. A bollard on the wharf holding both ships’ stern lines failed, most likely after Grand Pioneer’s vehicle ramp contacted it. AAL Fremantle contacted a ship at an adjacent berth, and parts of the Fremantle Rail Bridge nearby.
The ships were berthed again with tug assistance. The ships had suffered minor damage. The rail bridge, however, was closed for 3 weeks for inspection and repairs to track alignment and other non-structural damage.
Figure 1: Grand Pioneer
Source: Marcus, Shipspotting
Figure 2: AAL Fremantle
Source: Australian Transport Safety Bureau
The ATSB investigation concluded that Grand Pioneer moved off the berth slightly as the tension in its mooring lines increased, in response to the high winds associated with the passing thunderstorm. It is likely that its vehicle ramp then made contact with the bollard that held the stern lines of both ships. As a result of the contact, the bollard broke away from the wharf.
The investigation found that Fremantle Port Authority’s (Fremantle Ports) examination of the risks associated with a ship contacting the rail bridge contained limited analysis on keeping ships alongside in adverse weather, particularly at berths 11 and 12 where the wind is predominantly on ships’ beams. There was also no analysis of the means to assist a ship that got close to Wongara Shoal and the rail bridge.
The ATSB also found that Fremantle Ports’ adverse weather procedures were triggered only by specific Bureau of Meteorology (BoM) forecast categories and terms. There was no guidance for vessel traffic service (VTS) officers to take action based on actual weather conditions, or other weather terms used in BoM forecasts.
Another investigation finding was that BoM’s marine forecast at the time of the incident did not describe expected wind speeds using recognised marine terms, such as ‘gale force’. Further, the forecast title understated the wind speeds expected.
Fremantle Ports has put into service 12 ShoreTension devices in the inner harbour. These devices maintain a constant tension in a mooring line to assist keeping a ship alongside its berth.
The port has subscribed to a customized weather prediction service for its area, and upgraded its weather station and VTS equipment to enhance monitoring. The VTS officers have been trained to use the new and upgraded equipment. The port has updated its ship weather warnings to include a broader range of meteorological terms and descriptions.
Fremantle Ports has also revised its weather warning distribution list to include the manager of the rail bridge, the Public Transport Authority (PTA). The port and the PTA have established direct, high level, points of contact with communication processes in place to manage any emergencies that could involve the rail bridge.
The BoM safety action includes undertaking to use standard terminology in marine forecasts and implementing a formal process to consult stakeholders to better identify and meet their needs.
Safety message
When analysing the risks to a port’s operation, its operator needs to consider the risk controls to avoid a serious incident as well as the recovery controls in case an incident does occur.
Read the report: Breakaway of Grand Pioneer and AAL Fremantle, at Fremantle, Western Australia, on 17 August 2014