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Nent Force Level
along the River Nent between Alston and Nenthead, Cumbria
Nent Force Level
associated engineer
John Smeaton
date  1776, 1777, 1810, 1842
era  Georgian  |  category  Drainage System  |  reference  NY719468
ICE reference number  HEW 398
photo  ICE R&D Fund
Nent Force Level is an 8km access and haulage tunnel — a kind of underground canal — that follows the line of the River Nent. It was begun in 1776 and designed to transport ore and waste from underground workings at a time when lead mining was a thriving industry in the North Pennines.
In 1776 the original excavation of Nent Force Level resulted from an exploratory and drainage tunnel supervised by engineer John Smeaton. Smeaton was one of the receivers of the Greenwich Hospital Estates, owners of considerable areas of land in the North Penines and much involved in lead mining there. It was hoped that the excavation would reveal hitherto unknown veins of ore, though nothing significant was found.
The tunnel was driven from a single face, with six intermediate shafts constructed along its length. It was initially intended to be 2m high and less than 1m wide. After discussions between John Gilbert, who was involved with the Duke of Bridgewater at Worsley and a lessee of lead mines in the Alston area, and Smeaton, it was decided that the dimensions should be increased to just over 2m by 2m, so that boats could be used to convey the ore and waste. A water depth of just over a 1m was envisaged.
Work on the level temporarily ceased in 1842, after some 80,000 had been spent. It was extended again between 1870 and 1904, though no new ore bodies were discovered.
In the 19th century, part of Nent Force Level was opened as a tourist attraction. However, it is now inaccessible, except with extreme difficulty via the ventilation shafts. As it is not maintained in any way, further damage is likely to be caused by natural rock falls, etc. The nearby lead mines, which can be visited, are England's largest and highest.
A similar tunnel, the Blackett Level, was later built some 13km to the northeast. It was engineered by Thomas Sopwith and Thomas John Berwick to a slightly smaller cross section, although never intended to be an underground canal. Work began in 1855 with tunnel driving from 5 shafts, though it was abandoned uncompleted in 1903.
Research: Pd and AJD
"Nenthead Mines Heritage Centre: An adventure in silver and lead
North Pennines Heritage Trust, information leaflet, 2006
reference sources   CEH North

Nent Force Level