The Frindsbury Lock, Strood, Kent
AOC have recently completed a built heritage survey on the remains of the Frindsbury Lock Chamber where the Thames and Medway Canal once met the River Medway. The work was commissioned by SKM Enviros on behalf of Strood Sustainable Transport.
The work was to record the remains of the structure before its burial to allow construction of a new sustainable bus and cycle transit route along the Medway riverside. The main body of the lock chamber and landward gates were infilled in the 1980s. The lock basin was originally known as the Frindsbury Basin. The record comprised a photographic, drawn and written survey. Early architectural drawings were also researched.
The Thames and Medway Canal was originally proposed by the Engineer Ralph Dodd in 1799 at the height of the Revolutionary and Napoleonic Wars with France. The scheme would provide a route safe from predatory French privateers for coastal trade and especially military ordnance lighters plying between the Royal Dockyards and naval arsenals of Woolwich and Chatham.
Work started at the Gravesend end of the cut in 1800 but rising costs and attendant delays meant that the canal was not completed to its Strood end (Frindsbury) until 1824, by which time its principal reason for existence had ended. In addition, the canal also suffered from extreme water loss due to being cut into porous chalk and having locks opening into tidal waters at both ends. Soon after completion the coming of the railways also made the canal largely obsolete.
At the time of building, the tidal locks at Gravesend and Frindsbury were amongst the largest in the world; the Frindsbury Lock having the capacity to pass vessels of 300 tonnes.
The lock chamber was a relatively rare example of a barrel chambered lock in having been designed with a curved base to conform with the hulls of sea going vessels, such as the ubiquitous Thames Spritsail Barge, a feature it shares with the tidal lock at the Gravesend end of the canal.
Plan of the Frindsbury Lock by William Strickland (1824) (Courtesy of the British Library)
Photograph of the seaward approach to the lock showing the curved base to allow passage of Spritsail Barges
The lock itself was constructed of brick, with stone coping and quoins. The survey identified that the lock chamber was built on a raft resting on timber piles, exactly as shown by Strickland’s 1824 drawings.
View of the base of the seaward approach to the lock showing remains of timber raft
The original gates as depicted by Strickland were constructed with a curved design and were moved by chains at their base powered by lockside capstans. By contrast the two sets of surviving gates at the seaward end of the lock were of a more recent straight design and date to the late 19th or early 20th century. The inner pair was constructed around a timber frame, the outer around a steel frame, and was of a later date. Most of the fittings of the gates were in poor condition or absent.
The seaward gates of the Frindsbury Lock, dating to the late 19th or early 20th century
The Frindsbury Lock c. 1912
A more complete, although slightly smaller tidal lock still survives at the Gravesend end of the Thames and Medway Canal and is Grade II Listed.
Associated Links:
English Heritage Listing for the more complete but smaller Lock at Gravesend:
http://www.britishlistedbuildings.co.uk/en-508409-barrelled-lock-chamber-sea-walls-swing-b
Thames and Medway Canal Association:
http://www.thamesmedway.co.uk/
