Site Records

Site Name: Greywell Tunnel - Basingstoke Canal

OS Grid Ref: West Portal SU708517, east portal SU719515

Sub Brit site visit April 1975, March 1976 & September 2004

[Source: Nick Catford]

The last recorded regular commercial traffic through Greywell Tunnel was to and from the Nately Brickworks which opened in 1898 producing 2 million the following year. Traffic must have been considerable but the venture was short lived with the works closing in 1901.

The last boat to navigate through the tunnel was probably the 'Basingstoke' owned by Mr. A. J. Harmsworth. Having left Ash Vale with 10 tons of sand on 16 November 1913, it finally arrived at Basingstoke Wharf in February 1914. The time taken indicates the poor state of the canal.

Following a serious roof fall in 1932 when the crown of the roof gave way, the tunnel was closed and the remaining five miles of canal was abandoned. The first 800 yards of the tunnel are in stable chalk, beyond this, the tunnel runs through clay; this is where the collapse occurred. Subsequent subsidence has caused the west portal to collapse and although the tunnel is open at this end all the brickwork has gone and the portal is now securely gated for safety

A J Harmsworth poling into Greywell Tunnel in 1913

Greywell Tunnel - the west portal about 1920

There are now five ponds above the western end of the tunnel; it is the pressure of water from one of these that caused the collapse; a tree fell through and was left standing upright through the roof of the tunnel. The blockage was initially only partial and the tunnel was still passable for canoeists until the early 1950's. A further collapse has now left the tunnel blocked with soil up to the roof although the material appears to be soft and could, in time, be cleared and the roof repaired. Despite the collapse the brick lining between the collapse and the western end appears to be in sound condition.

At the eastern end, the tunnel can be navigated for 800 yards up to the collapse and each summer there is a boat trip along the tunnel to check the condition of the brick lining. At other times there is no access following the discovery of bats hibernating in 1995. It has now been declared a Site of Special Scientific Interest (SSSI) and a locked gate has been installed inside the east portal to conserve the tunnel as a winter hibernation and breeding habitat and stop unauthorised access.

Photo:Greywell Tunnel - the east portal in 2004
Photo by Paul Naylor

The present limit of navigation is the winding hole (a wider piece of canal where boats can perform the equivalent of a three point turn in order to go back the way they came. An indentation in the bank allows the bows of a narrowboat to be held whilst the prevailing wind blows the boat round. Hence the unusual pronunciation - ‘winding hole’.) immediately west of the Whitewater aqueduct although the 600 yards up to the eastern portal was been dredged in 1987 to clear the spring heads and improve the water supply. The portal was renovated by Hampshire County Council in 1975 to mark European Architectural Heritage Year.

Click here for a full account of A J Harmsworths last trip along the Basingstoke Canal and through Greywell Tunnel.

See also: Little Tunnel - Basingstoke Canal


East Portal 1974

East Portal 1975

East Portal 1975

Looking along
tunnel from west end

East Portal 1976

East Portal 1976

West Portal 1976

Internal gate to
prevent access 2004

Looking along the
tunnel from east end


Click on thumbnail to enlarge


[Source: Nick Catford]

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Last updated: 04 01 2011
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