Until about 1886, lightvessels were of wood construction. Later they were chiefly composite, followed by iron, and after 1936 the new builds were all of steel.
The vessels ranged in size from 84’ to 137’ overall length and from 20’ to 26’ in width. The last Trinity House lightvessel was built in 1967.
Moving on from crude elevated ship’s lanterns, the navigation light in older vessels consisted of a grouping of oil wick burners focussed in silvered copper reflectors mounted on a frame, and rotated by a weight-driven clock.
By rearranging the reflector groupings, angling the reflectors and changing the speed of rotation, different light characters could be achieved, a very important identification measure at night in areas with several lights.f.
The Trinity Buoy Wharf boat – Lightship 95 – a former Trinity House lightvessel – was built in 1938 in riveted steel, she is 134ft long (just over 40m) with a breadth of 25ft.