1GL Bolt: Thirsk Bridge   

Bolt in West pier of East arch of Thirsk Bridge ; 3.84 ft. above surface [1GL, Selby to Newcastle-upon-Tyne, Mark No. 82] - estimated location.

Location
Grid reference: SE 4317 8210.
Landranger 99: Northallerton & Ripon, Pateley Bridge & Leyburn.
Structure: Bridge.
Waypoint: BT0781.

Neighbouring Bench Marks

BM	Thirsk Bridge 10.00m to the north.
RIVET	Thirsk Bridge 20.00m to the west.
BM	Thirsk, Long Street 480.83m to the north.
BOLT	Thirsk, Church 505.67m to the northwest.
BOLT	Sowerby, St. Oswald's Church 743.30m to the south.

The nearest fundamental bench mark is Northallerton, 11.53km to the north.

First Primary Levelling, England & Wales (1840-60)
This bench mark was used during the First primary levelling, England & Wales, and was levelled with a height of 99.0730 feet [30.1975 metres] above mean sea level (Liverpool datum). It was included on the Selby to Newcastle-upon-Tyne levelling line. The surveyor's description was Bolt in West pier of East arch of Thirsk Bridge ; 3.84 ft. above surface.