The Underfall Yard is a historic boatyard on Spike Island serving Bristol Harbour in England.
Underfall Yard was commonly referred to as "The Underfalls" and takes its name from the underfall sluices. The construction was completed in 1809 under the direction of William Jessop and substantially improved by Isambard Kingdom Brunel in the 1830s.
Restored in the 1990s, Underfall Yard has been designated as a scheduled monument and from the 1970s onward many of the buildings at Underfall Yard have been given Grade II Listed Building status. The harbour and its equipment are still maintained, and house a number of maritime related companies.
History
In the early nineteenth century the engineer, William Jessop was engaged by the Bristol Dock Company to create a Floating Harbour to eliminate the problem of ships being grounded at low tide. Jessop built a lock to retain the water in the harbour; this was completed in 1809, and allowed ships to remain floating at all times, unaffected by the state of the tide on the river. Part of the project included building a dam at the Underfall Yard with a weir, known as the Overfall, to allow surplus river water to flow into the New Cut, an excavation which by-passed the Floating Harbour and joined the River Avon near Temple Meads.
The docks' maintenance facility was established on the land exposed by the damming of the river to construct the harbour, and remains sited at this location to the present day. By the 1830s the Floating Harbour was suffering from severe silting and Isambard Kingdom Brunel devised the underfall sluices based on William Jessop's original plans and recommended the use of dredgers as a solution .
The Bristol Docks Company never achieved commercial success and was taken over by Bristol City Council in 1848. In 1880 the Council bought the Slipway and yard to enlarge the docks' maintenance facilities.
The 'Underfall' system was re-built in the 1880s, with longer sluices, and the yard above was enlarged. Brunel's method of silt disposal is still in operation today, but the silt is carried in mud barges or pumped to the sluices through a quayside pipe system from the more efficient modern 'Cutter-Suction' dredgers.
During the 20th century the western parts of the yard were leased to P & A Campbell Ltd, operators of the White Funnel Line of paddle steamers as a maintenance base. The yards have been little altered recently except for the replacement of the three-storey 'A' block over the sluice paddle room resulting from bomb damage in World War II.
Underfall Yard has been refurbished under the management of the Underfall Yard Trust (previously Underfall Restoration Trust).
Based at the yard are maritime academies, a scout sailing section, a blacksmith, rigging company, Omni, and three boat building businesses.
In 2015 a major restoration project was announced with the work including the development of a cafe and visitor centre. An oral history project is being conducted and school education programmes have been introduced as part of the restoration and redevelopment.
In the early morning of 6 May 2023, the yard caught fire destroying several boats and a maintenance shed.
Underfall sluices
Jessop's original designs for the harbour included a dam with an 'overfall', with the level of the water determined by the height of the dam's crest. As a result of the accumulation of mud and silt in the harbour, ships entering the narrow harbour were frequently being grounded. In 1832 Brunel was called upon to provide the solution to this problem and designed the sluice system, still in use today, to remove excesses of silt and mud.
In place of the Overfall he constructed three shallow sluices and one deep scouring sluice, between the harbour and the New Cut, together with a dredging vessel, known as a drag boat, to scrape the silt away from the quay walls. Sluices 1, 2 and 4 ('shallow') are used to control the water level, while sluice 3 ('deep') removes the silt. When the deep sluice is opened at low tide, a powerful undertow is created which sucks the silt out of the harbour and into the river. Since the original introduction of the sluices, they have been changed and renewed several times but today's sluice system was installed in the 1880s. In March 1988, the sluice control was computerised and automated.
Buildings
Most of the buildings and engineering installations at the yard were constructed between 1880 and 1890 under the direction of John Ward Girdlestone. Many of them have been designated by English Heritage as listed buildings.