Guernsey’s Hanois Lighthouse – Pioneer In Lighthouse Engineering

The Hanois Lighthouse rises from a reef on the south west side of the Island of Guernsey, and takes its name from the group of rocks – Les Hanois. The lighthouse marks the western end of the Channel Islands indicating the shoals and reefs to the west of Guernsey and providing a position fix for vessels entering the Channel Traffic Separation Scheme.


Guernsey (2000) 5 Pounds (back) – Hanois Lighthouse

Hanois Lighthouse is important in the development of lighthouse engineering, because not only all the stones in each course but also all the courses were dovetailed together, both laterally and vertically to form one solid mass. The cement mortar in the joint formed between the faces so locked the dovetails that the stones cannot be separated without being broken. This method was first employed at the Hanois Lighthouse, and it became the pattern for all sea rock towers.