Lancaster Canal Lune Aqueduct

The Lune Aqueduct is a significant feature of the Lancaster Canal, considered a masterpiece of civil engineering. Built in 1797, it carries the canal for 664 feet (202.4 metres) across the River Lune, rising to a height of 61 feet (18.6 metres). The aqueduct is constructed from squared rock-faced sandstone blocks and sandstone ashlar.

Its design incorporates five semi-circular stone arches that support a stone trough, with panelled buttresses separating the arches above triangular cutwaters. The piers rest on piles of specially imported Russian timbers driven into the riverbed. The piers are hollow, built from stone and strengthened with iron bars; the cores were later filled with rubble. Parapets feature three balustraded openings over each arch.

The original stone-lined canal trough was 20 feet (6.0 metres) wide and had curving side walls 18 inches (46cm) thick, a 1-foot (30cm) deep base, and 3 feet (90cm) of puddled clay for waterproofing. A plug at the bottom of the channel allowed for draining the aqueduct into the river for maintenance. The construction involved coffer dams to hold back the river, primitive steam engines for pumping out water, and wooden scaffolding to support wedge-shaped stones used to form the masonry arches until the keystones were in place.

On the west side of the central arch is a carved keystone representing Lancaster Castle Gateway, featuring a Latin inscription that translates to "Old needs are served, far distant sites combined. Rivers by art to bring new wealth are joined,” followed by the names and dates of the engineer, John Rennies, and the architects, P. and F. Stevens: 'QUAE DEERANT ADEUNT: SOCIANTUR DISSITA: MERCES FLUMINA CONVENIUNT ARTE DATURA NOVAS. A.D. MDCCXCVII. ING. I. RENNIE EXTRUX. A. STEVENS. P. ET F.' An inscription reading 'TO PUBLIC PROSPERITY' is positioned on the east side in the same location. Below the parapet is a Doric entablature with a projecting cornice.