Horizontal and vertical survey control information

Traditional horizontal control stations, triangulation or 'trig' stations (pillars and other survey marks) and vertical control (bench marks) have been the mainstay of control information in Great Britain for many years. They provided the means to link surveys to the national horizontal and vertical datums as well as providing structure to a survey. To do this it was necessary to physically occupy either the triangulation station or bench mark with survey equipment and purchase the control coordinates from Ordnance Survey.

Ordnance Survey has made a commitment to continue to offer traditional control information to surveyors who do not use methods such as the Global Positioning System (GPS) to provide control. However, due to the quantity of traditional stations and the expense of their survey, tied in with the greater accuracy and uniformity that new satellite-based survey techniques provide, it is neither sensible nor realistic for Ordnance Survey to maintain the triangulation and bench mark network.

These pages are your free resource to access all the Ordnance Survey traditional horizontal and vertical control survey information.

Virtually Level Guide

A useful guide from the Royal Institute of Chartered Surveyors (RICS) and Ordnance Survey® on the transition from the familiar bench mark to heighting using the Global Positioning System (GPS). The RICS Geomatics Mapping and Positioning Practice Panel (MAPPP) have been working in close collaboration with Ordnance Survey to produce the newly released client guide 'Virtually Level'. The guide outlines the do's and don'ts of heighting with GPS and is a must read for all surveyors using GPS and/or traditional methods of levelling. The Virtually Level guide is the latest in a new series from the RICS MAPPP.

Disclaimer

The data and information accessible on and via this website (the Data) has not been updated, nor will it be maintained in the future. Ordnance Survey has taken all reasonable steps to ensure that the Data is accurate at the time of publication. However, Ordnance Survey cannot guarantee that all or any of the Data is complete or error free. Furthermore, in no event shall Ordnance Survey be liable to any party or person for any direct, indirect, incidental, consequential, special or exemplary damages or loss of profits resulting from the use or misuse of any of the Data.