Volume Eight - Pre-Victorian to the present day - more aspects - A brief history of Trinity House lightvessels . .

Lee Chadwick goes on to describe the relief of lighthouse and lightship crews aboard the T.H.V. Mermaid. The description of the danger and risk to the crew during the periodic inspection and servicing of coastal buoys situated around the entire coast and river estuaries of the British Isles provides a link to the work undertaken by myself and Martin, my son, by our company on behalf of Trinity House some years ago.

A major problem with conventional steel fabricated buoys, as Mr. Chadwick points out and is clear from the image on the previous page, are barnacles, other sea creatures and plant life which adhere to the buoy below the waterline and make the shell its home. If left to build up, the encrustations would cause the buoy (or lightvessel) to become unstable and less buoyant; the buoy would eventually sink below the waves under the sheer weight of this encrustation. We at Rota Design Limited were contracted to design a series of buoys which did not suffer this phenomenon. The answer was to use polyethylene (PE) flotation chambers which were then filled with closed cellular foam. A simple steel frame connects together all the component parts into a strong and practical solution which is extensively used in coastal waters, not only around the British Isles but has found favour from the Baltic Sea to the Persian Gulf and beyond.

Very little sticks to PE and the rotational moulding process is a great way to produce the complex geometric shapes necessary and these factors are a specialty of the design expertise at Rota Design Limited.

The saving in monetary terms was in the order of several thousand pounds per annum per buoy and the saving in health and safety terms is more difficult to quantify, but lets just say that it is significant!