Grimsby Haven Lock And Dock Wall 58 Metres Long Adjoining To West

Grimsby Haven Lock and Dock Wall

A lock basin and adjoining dock quayside wall, approximately 58 metres long, built in 1798-9 by John Rennie, engineer, for the Grimsby Haven Company. This Grade II* listed structure represents the earliest modern dock at Grimsby and showcases an important engineering innovation of its time.

The lock pit measures 145 by 37 feet (44.2 by 11.3 metres). Although later infilled, both ends and wing walls remain visible beneath the later material. At the inner southern end, on the south-east corner of the lock passage approximately 15 metres from the lock-gate recess, stone steps descend to the water level. The lock pit is constructed in ashlar.

Adjoining the lock on the west side is a section of dock quayside wall extending approximately 40 metres from the lock entrance. This wall is built with ashlar piers and segmental-arched brick vaults between stepped piers, creating an arcade effect.

Historical Context

The bill for improving Grimsby Haven was passed in 1796, with work beginning in 1797. In 1798, John Rennie was brought in to rescue the struggling scheme. The lock served a dual purpose: as the dock entrance and as a device to assist in scouring the harbour entrance and keeping it clear of silt.

Rennie devised a distinctive construction method using vaulted or "hollow" walls to address the challenge of building retaining walls in soft ground. These hollow walls provided greater base area and greater strength than solid walls containing the same quantity of material. He subsequently employed this method in other pier and harbour works, including the Humber Dock at Hull (1803-9). The same construction principle, on a much larger scale, was later used by James Rendel for the Royal Dock at Grimsby, built approximately 50 years later.

The lock created the first dock at Grimsby, the Haven Dock, which opened in 1800 and was later incorporated into the Alexandra Dock. The lock was largely superseded as a dock entrance by the Union Dock to the east, which in 1879 linked the Alexandra and Royal Docks. The lock was closed in 1917 and subsequently mostly infilled, although it still carries a culverted outfall between the dock and the estuary.

The structure is significant as a survival of the earliest modern dock at Grimsby and for representing the first use of vaulted quayside walls, a major technical innovation by one of Britain's foremost harbour engineers. The quayside construction forms an important comparison with the same system built on a much larger scale at the nearby Royal Dock.