Hillmorton Bottom Lock (Locks 2 And 3), Former Oxford Canal

Locks 2 and 3, known as Hillmorton Bottom Lock, form a pair of twinned narrow locks on the Oxford Canal at Clifton upon Dunsmore. They were built in 1840 on the site of an original single lock constructed between 1769 and 1774.

The locks are lined in red and blue brick, with heavy stone capping at the northern end. The remainder is capped with later bull-nosed concrete and blue brick. The two locks run parallel to each other, allowing traffic to pass through both simultaneously. Lock 2 retains its original cast-iron gates installed in 1840; the remaining gates are later timber replacements. A paddle positioned between the two locks allowed water to pass from one chamber to the other to conserve water; the gearing mechanism remains in place at ground level between the locks. The quadrants on either side have been recently resurfaced in modern red and blue brick.

The Oxford Canal was constructed over more than twenty years following an Act of Parliament in 1769, intended to link the industrial Midlands to the River Thames and London. The distinguished engineer James Brindley oversaw the project until his death in 1773, when his assistant Samuel Simcock took over. The first phase, from near Coventry to Napton, was completed by 1774. A second Act in 1775 enabled further construction. The canal reached Banbury by 1778, though financial difficulties delayed the final stretch until 1786. This last section was built economically and the canal opened formally on 1 January 1790. Initially successful for commercial traffic, the canal's business declined after the Grand Junction Canal opened in 1805, offering a more direct route between the Midlands and London.

The canal was originally constructed as a contour canal to avoid steep level changes and extensive locks. From the 1820s, facing competition from the Grand Junction Canal and railways, plans emerged to straighten sections and reduce travel time. In May 1834, a shortened stretch opened south of Hawkesbury Junction, greatly increasing traffic. This immediately strained the capacity of the three-lock flight at Hillmorton, the first locks south of Hawkesbury's stop lock. To resolve congestion, the existing locks were duplicated, creating three pairs of parallel narrow locks to double capacity. The work was completed on 25 August 1840 at considerable expense of approximately £4,200. Each lock was fitted with large cast-iron gates rather than the more usual timber ones. The narrower design also reduced operating time; test runs achieved operation in as little as one minute and twenty seconds. The locks functioned as mutual side ponds, with a paddle enabling water transfer between adjacent chambers to conserve water. These improvements substantially increased traffic, with 20,859 vessels passing through Hillmorton Locks in 1842.

The northern canal stretch to Napton remained an important trunk route, principally carrying Warwickshire coal towards London, sustaining heavy freight traffic until the 1960s. Like most canals, profitability declined sharply from the 1950s onwards. The canal now primarily serves leisure rather than commercial use. The Hillmorton locks have undergone significant restoration since the 1980s. All cast-iron gates have been replaced with timber examples except those in Lock 2.