2024年11月10日 · The bench mark database contains records of survey bench marks in Great Britain, Ireland, the Isle of Man, the Channel Islands and Gibraltar.

There were over 500,000 benchmarks created. On the map you will see that they are largely concentrated in urban areas and mostly along roads or on the side of buildings and walls. …

They are domed metal bolts about 1" (50-60mm) in diameter fixed to horizontal surfaces engraved with OSBM and the benchmark symbol. By far the most common type. Used and made from …

Bench marks are the visible remains of height measurements made by the Ordnance Survey. When used in conjunction with older Ordnance Survey maps they indicate the height above …

The datum for mainland Great Britain is mean sea level at Newlyn; the Ordnance Datum (OD). The first primary levelling across England, Wales and Scotland, was carried out 1841-60.

2019年10月8日 · In this way hundreds of thousands of bench marks were sited all around the UK & Ireland from the mid 19th to late 20th centuries. There are several distinct types of bench …

2025年3月27日 · OSBM Flush Bracket S6818 - Coppingford TP. Ordnance Survey Benchmark (OSBM) used for levelling height above Ordnance Datum (OD). Height (1966): 50.9357m OD …

2018年5月1日 · Here at OS, we have created a map of all the benchmarks in Great Britain. Find out more about the different types of benchmarks and have a read of our archive. Sharing the …

2025年4月4日 · The bench mark database contains records of survey bench marks in Great Britain, Ireland, the Isle of Man, the Channel Islands and Gibraltar.

The Ordnance Survey formed in 1791 is the national mapping agency for Great Britain and is both a self-funding government department and one of the world’s largest map producers. The …