Unused trigpoints
From TrigpointingUK
The following trigpoints were constructed by the Ordnance Survey, but never surveyed.
Hey Edge TP7322
This trigpoint is not displayed on the 1:50K map, and is marked on the 1:25K map simply as "pillar", without the blue triangle symbol. It was constructed in 1939 as a result of the original reconnaissance, but operations were severely curtailed during WWII and when the retriangulation was commenced after the war it is thought that this station was unnecessary in a revised control network.