Vessel management techniques to provide safe navigation

Much is made in the literature about the consequences of collision, grounding and the increased risks resulting from higher traffic levels. The truth is that major incidents involving environmental side effects are rare, although where they do occur they receive major publicity. Any skipper risks his job if he acts in an unsafe manner, and shipowners expect safe operation if only to minimise maintenance and insurance costs. These are powerful motivators.

Ports are investing in more sophisticated traffic management measures accommodating ever-higher traffic densities. Some of the techniques used are summarised in Box 14. Even where these provisions are in place, problems can arise where different types of user share the same water. Yachts, fishing vessels, water skiers and other leisure users can cause problems. Regulation through byelaw should be used as a last resort, if only because it is costly to enforce and does not motivate users to comply.

Other examples exist where alternative, shallower channels have been marked so that small craft can choose to stay clear of large vessels, and will usually do so for their own peace of mind. At the narrow entrance to Portsmouth Harbour, where tides can be strong, small craft are recommended to use engines, if fitted, and to stay to one side of the channel, clear of ferries that cannot risk losing steerageway in the entrance. This approach works, however it may not be effective on every occasion, and the likely required approach to management will be a combination of the voluntary approach with a degree of supporting regulation.

Vessel management techniques to provide safe navigation

• Use of pilots, or qualified masters holding pilotage exemption certificates.
• Creation of ‘sole occupancy’ channels for large or unmanoeuvrable vessels, especially those carrying hazardous or polluting cargoes.
• Development of passage planning procedures, including pre-agreed ‘abort’ actions to be used in the event of difficulties developing.
• Introduction of effective VHF communications.
• For very large tankers, the use of escort tugs where it can be demonstrated these are effective (although refineries or their customers usually insist on such provision before the harbour deems it to be required).
• For harbours with dense traffic, including vessels carrying hazardous cargoes, modern VTS facilities with digital signal processing and display are generally employed.

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