Brass Plate
From TrigpointingUK
A Brass Plate is a ground station triangulation mark.
Installed by HMS survey ships mainly around the coast of Scotland, predominantly the Western Isles, with 6 recorded in the SW of England (including 2 in the Isles of Scilly) and 2 on the South Wales coast. The total number is gradually increasing as more are found.
The inscription on the plate has minor variations. A typical example, with a central triangulation symbol, is:
HYDROGRAPHIC DEPARTMENT ADMIRALTY LONDON SW1 TRIANGULATION STATION H.M.S.COOK 1952
As at June 2025 there are 40 instances of a station with a type of Brass Plate listed in TP:UK. 38 of these have a historic use of Hydrographic Survey Station. The two exceptions are both roof stations on colliery headgear (1 unknown and the other, described as an NCB metal plate, destroyed).
