The move towards plastic for Class 3 and, in some cases, Class 2 buoys results in substantial savings on maintenance costs as they do not require blasting or painting and can often be serviced at sea by smaller, more cost effective ships. It costs in the region of £15,000 to return a Class 2 steel buoy to Harwich for servicing, far more than the costs for a plastic buoy. One of the few rising costs for Trinity House is repair costs due to buoys receiving collision damage, the consequence of ships with GPS navigation using the buoys as accurate reference points and sailing at them until impact.

However, far greater sums can be saved by replacing light vessels with state of the art buoys, as will be the case with the South Goodwin light vessel this month. A diesel powered light vessel costs £250,000 to service every five years and carries the additional risk of environmental pollution should it be run into. A new Plus 1 (1S9) deepwater steel body buoy with a modular aluminium top mark costs only £20,000 to service every five years or possibly longer. The modular top mark is built to the size required to accommodate the equipment a particular buoy must carry.

Trinity House is also addressing cost issues by reducing the power consumption of all its buoys and lighthouses. For the latter, there is a development programme examining ways to maintain what are in some instances 200 year old listed buildings automatically through intelligent heating and ventilation.

Some Trinity House stations are now using up to 95% renewable energy and an active research programme into developing and enhancing renewable power systems was also shown at the Harwich Open Day. It is accepted that it is not always appropriate to deploy the technology in sites where aesthetics or perhaps nesting birds are a consideration, but at other locations a hybrid system combining wind and solar gives consistent, inexpensive, low maintenance power.

Technical Open Day also involved a visit on board THV Alert, the newly commissioned 39.3m Rapid Intervention Vessel whose purchase was prompted by the sinking of the car carrier Tricolor on the French side of the Strait of Dover . Subsequent collisions with the casualty and 100 near misses made it obvious to Trinity House that it should have a vessel capable of reaching such a wreck quickly and marking it effectively for other shipping.

Alert can be mobilised from Harwich loaded with wreck marking buoys in under an hour and reach any point in the Strait of Dover in six additional hours or less. Most of the time the DP1 vessel maintains the buoys of Trinity House and customers, conducts multibeam and sidescan hydrographic survey complete with on board processing of data, and is available for hire as a research vessel, again enhancing the Trinity House balance sheet.

MJ Information No: 22010