Monument record MHG24616 - Lybster Hill, US Naval Communication Unit

GR corrected to above - HAW 12/2002

ND06NW 131 022 698

A photographic record was made of the remains of the former United States Naval Communications Base. At Lybster Hill.

The extant structures amount to the transmitter building for the main mast (centred on ND 0230 6985) and concrete foundations and cable tracks. These structures are all that remains of the plethora of antenna arrays of differing geometries and phases of construction that once covered the site.
The foundations are largely of two kinds, antenna bases and anchors for the associated wire stays that stabilised the antenna masts. The conflation of antenna arrays of different periods at a single locus makes it difficult if not impossible to reconcile a particular set of anchors with its associated set of mast bases.

Several antenna configurations were encountered across the site. The steel main mast is thought to have been mounted on a single insulator the mast itself forming the antenna. The concrete mast base appears to have been completely copper clad, as was the internal surface of the associated building.

Early phases of masts appear to have included single masts, linear arrays and right-angular arrays apparently oriented on cardinal geographical axes. These structures appear to have employed largely timber masts. These arrays were supplanted by later hexagonal arrays of six masts with a central cable junction; steel masts replacing timber. This type of array tended to be located around the periphery of the site. Each hexagonal antenna array had, at its centre, a rectangular area delineated by a timber fence inside which was a gravel area surrounding a central junction box. <1>