TP1070 - Barton Heights

Not far from this hide, if you look carefully - you can just see the Barton Heights (TP1070) triangulation station hidden in the hedge. (See reference waypoint)

Grid reference : SE 71814 72806 

Height : 115.97 M

On 18 April 1936, a group of surveyors gathered around a white concrete pillar in a field in Cold Ashby, Northamptonshire, and began the retriangulation of Great Britain.

The triangulation pillar, most often known as a "trig pillar" or "trig point" and a welcome sight to many a walker as they reach the peak of their walk.

There were once about 6,500 trig pillars, built by the early surveyors at OS.

The pillar was devised by Brigadier Martin Hotine to provide a solid base for the theodolites used by the survey teams and to improve the accuracy of the readings obtained.

Though the OS no longer uses the trig pillars, maintaining them is still its responsibility; about 6,000 remain.