Locks and weirs on the River Thames
The
History
From ancient times there were many obstructions across the Thames, for fish-pounds and millers' weirs. They are referred to by
Originally these were
On the lower section, the river was tidal as far as Staines until the beginning of the 19th century and was under the control of the City of London. The City's jurisdiction was marked by the London Stone. The principle of lock/weir combination, which maintained the depth of water for navigation and reduced the danger of flooding, was extended over the tidal section as far as Teddington in a series of locks built after 1810.[2]
The first authority charged with managing navigation and lock building was the
Operation
Management
From the head of navigation at Cricklade to the start of the
Most of the Environment Agency's locks and weirs are staffed by a lock keeper, who often lives in a house adjacent to the lock. The lock keeper's duties involve both operating the lock, and managing the river levels above the lock by adjusting the weir openings.
Locks
Most locks are operated by their keepers between 9 a.m. and 7 p.m. from June to August, with progressively shorter hours as the hours of daylight reduce, and they are not operated during the lock-keeper's lunch hour between 1 p.m. and 2 p.m. During the summer months Assistant Lock Keepers and volunteers are employed to deal with the heavy traffic and avoid the lunch-time closure. However
The locks at the upper end of the river, from St John's Lock to King's Lock, are manually operated. All other locks on the Thames are hydraulically operated. All locks, except Teddington, can be operated by boat crews outside manning hours, using the adapted system of "public power", which allows boaters to use the hydraulic machinery at reduced power, except during the hours of darkness.
Locks are popular visitor attractions, and many serve refreshments. Locks were often built adjacent to islands and therefore many are situated in remote locations, hard to find and can only be reached on foot. Many locks also have moorings that can be used overnight, and some include electric charging points for electric powered boats.
All the locks have obvious access from the Thames Path, except for Whitchurch Lock which is within an island and only accessible by boat; Cookham Lock requires a 1km diversion from the Thames Path; and Marlow Lock requires a short diversion.
Weirs
The Environment Agency has the responsibility of managing the flow of water along the length of the river to prevent flooding on particular reaches and to maintain navigation depths. The volume and speed of water down the river is managed by adjusting the gates at each weir. Occasionally this can result in a fast stream rendering navigation more hazardous. These conditions are indicated by yellow or red warning boards on the lock gates and the status of all locks is published by the Agency.[4] The Agency cannot legally stop navigation when the red boards are out, but continuing to travel is inadvisable and may invalidate a boater's insurance.
Occasionally flooding is unavoidable, and the Agency issues Flood Warnings with three levels of severity - Flood Alert, Flood Warning, and Severe Flood Warning.[5]
In recent years the Salmon Conservancy has been installing fish ladders at weirs to allow salmon to travel up river.
Today some weirs are often used recreationally by
sanctioned modifications made to them for such use.Reaches
The locks and weirs, in effect, break the river up into 44 lakes or lock reaches. Each lock controls the reach above it and thus identifies it. Each reach has its own character and points of interest.
Many reaches host
When the boats were horse drawn, a towpath was needed on the bank side. This towpath has formed the basis for the Thames Path which runs between the source and mouth of the river. The path runs between locks and is therefore often the main means of access on land. Where the towpath changes from one side of the river to the other ferries were once provided. These have now almost all disappeared and the Thames Path has to be diverted to the nearest bridge, often a considerable distance, to cope with this.
Foot crossings
All of the Thames locks have walkways on top of the lock gates, so except at Whitchurch Lock one can cross to the lock island from the adjacent bank. Upstream of Wallingford, many locks also have walkways on top of the weir to cross the whole river. Downstream of Wallingford,
List of locks and weirs
The list of locks, weirs and ferries is given in upstream to downstream order, from source to sea. for catching eels.
Lock | Date | Recorded date of flash lock | Fall | Distance from next lock up | Earlier weirs in this reach | Ferries |
---|---|---|---|---|---|---|
St John's Lock | 1790 | 1775 | 0.85 m (2.8 ft) | |||
Buscot Lock | 1790 | 1.69 m (5.5 ft) | 1.85 km (1.15 mi) | |||
Grafton Lock | 1896 | 1762 (Day's/Lower Hart) | 1.11 m (3.6 ft) | 5.37 km (3.34 mi) | Farmer's, Harts | |
Radcot Lock | 1892 | 1746 (Beck's, Clare's or Buck's) | 1.48 m (4.9 ft) | 2.98 km (1.85 mi) | Old Eye | |
Rushey Lock | 1790 | 1.82 m (6.0 ft) | 4.23 km (2.63 mi) | Old Nan's | Rushey | |
Shifford Lock | 1898 | 1762 | 2.23 m (7.3 ft) | 6.92 km (4.30 mi) | Tadpole (Kent), Thames, Ten foot, Shifford Upper, Duxford | Duxford |
Northmoor Lock | 1896 | (Hart's Weir) | 1.24 m (4.1 ft) | 7.63 km (4.74 mi) | Limbre's | Ridge's (Hart's) |
Pinkhill Lock | 1791 | Pre-1791 | 1.05 m (3.4 ft) | 6.21 km (3.86 mi) | Ridge's (Langley), Ark, Skinner's | Bablock Hythe |
Eynsham Lock | 1791 | 0.84 m (2.8 ft) | 2.38 km (1.48 mi) | |||
King's Lock | 1890? | 1541 | 0.77 m (2.5 ft) | 4.37 km (2.72 mi) | Clay | |
Godstow Lock | 1790 | 1.57 m (5.2 ft) | 1.81 km (1.12 mi) | |||
Osney Lock | 1790 | 1227 | 1.89 m (6.2 ft) | 3.87 km (2.40 mi) | Medley (Binsey) | |
Iffley Lock | by 1632 | 1585 | 0.81 m (2.7 ft) | 3.73 km (2.32 mi) | Folly | Iffley |
Sandford Lock | 1632 (enlarged 1793) | 2.69 m (8.8 ft) | 2.7 km (1.7 mi) | |||
Abingdon Lock | 1790 | 1316 | 1.89 m (6.2 ft) | 7.38 km (4.59 mi) | Nuneham | Thrupp |
Culham Lock | 1638 (moved 1809) | 1580 | 2.41 m (7.9 ft) | 4.15 km (2.58 mi) | Culham old (1638 on Swift ditch), Swift | |
Clifton Lock | 1812 | 1.03 m (3.4 ft) | 4.52 km (2.81 mi) | Culham | ||
Day's Lock | 1789 | 1580 | 1.58 m (5.2 ft) | 4.8 km (3.0 mi) | Dorchester, Clifton | |
Benson Lock | 1788 | 1746 | 1.87 m (6.1 ft) | 6.37 km (3.96 mi) | Shillingford, Keen Edge | |
Cleeve Lock | 1787 | 1580 | 0.89 m (2.9 ft) | 10.46 km (6.50 mi) | Pollington's, Chalmore Lock, Moulsford (lock) | Leather Bottle, South Stoke, Littlestoke , Chalmore, Benson
|
Goring Lock | 1787 | 1538 | 1.77 m (5.8 ft) | 1 km (0.62 mi) | Streatley | |
Whitchurch Lock | 1787 | 1580 | 1.01 m (3.3 ft) | 6.55 km (4.07 mi) | Hart's lock | Gatehampton |
Mapledurham Lock | 1777 | 1300 | 2.05 m (6.7 ft) | 3.67 km (2.28 mi) | ||
Caversham Lock | 1778 | 1493 | 1.44 m (4.7 ft) | 7.08 km (4.40 mi) | Chawsey | Purley (2) |
Sonning Lock | 1773 | 1580 | 1.63 m (5.3 ft) | 4.23 km (2.63 mi) | Breach's | |
Shiplake Lock | 1773 | 1746 | 1.55 m (5.1 ft) | 4.68 km (2.91 mi) | Wargrave, Bolney | |
Marsh Lock | 1773 | 1580 | 1.33 m (4.4 ft) | 4.8 km (3.0 mi) | Beggar's Hole (Bolney), Lashbrook, Wargrave | |
Hambleden Lock | 1773 | 1338 | 1.44 m (4.7 ft) | 4.59 km (2.85 mi) | Aston | |
Hurley Lock | 1773 | 1580 | 1.05 m (3.4 ft) | 5.89 km (3.66 mi) | Mednam | Medmenham |
Temple Lock | 1773 | 1580 | 1.23 m (4.0 ft) | 1.03 km (0.64 mi) | Temple | |
Marlow Lock | 1773 | 1585 | 2.16 m (7.1 ft) | 3.13 km (1.94 mi) | ||
Cookham Lock | 1830 | 1.3 m (4.3 ft) | 6.44 km (4.00 mi) | Cookham Upper, Spade Oak | ||
Boulter's Lock | 1772 (moved 1828) | 1580 | 2.39 m (7.8 ft) | 3.35 km (2.08 mi) | My Lady, Hedsor | |
Bray Lock | 1845 | 1328 | 1.46 m (4.8 ft) | 3.43 km (2.13 mi) | ||
Boveney Lock | 1838 | 1375 | 1.47 m (4.8 ft) | 5.1 km (3.2 mi) | Boveney | |
Romney Lock | 1797 | 2.01 m (6.6 ft) | 3.75 km (2.33 mi) | Gill's bucks | Windsor | |
Old Windsor Lock | 1822 | 1300 | 1.74 m (5.7 ft) | 4.83 km (3.00 mi) | Datchet | |
Bell Weir Lock | 1817 | 1300 | 1.82 m (6.0 ft) | 4.94 km (3.07 mi) | Magna Carta Island | |
Penton Hook Lock | 1815 | 1.22 m (4.0 ft) | 4.33 km (2.69 mi) | Savory's | Tims', Egham | |
Chertsey Lock | 1813 | 1.22 m (4.0 ft) | 3.13 km (1.94 mi) | Laleham | ||
Shepperton Lock | 1813 | 2.03 m (6.7 ft) | 3.32 km (2.06 mi) | |||
Sunbury Lock | 1812 | 1623 | 1.87 m (6.1 ft) | 4.75 km (2.95 mi) | Ballinger's | Shepperton Church, Weybridge |
Molesey Lock | 1815 | 1.87 m (6.1 ft) | 4.79 km (2.98 mi) | Hampton | ||
Teddington Lock | 1811 | 2.68 m (8.8 ft) | 7.74 km (4.81 mi) | Kingston | Surbiton, Ravens Ait , Thames Ditton
| |
Richmond Lock |
1894 | 2 m (6.6 ft) | 4.9 km (3.0 mi) | Hammerton's, Twickenham |
Additionally, Blake's Lock is located on a reach of the River Kennet that is administered by the Environment Agency as part of the River Thames, and is often counted as a Thames Lock. It is the only manual Thames lock below Oxford.
The tide flows as far as Teddington Lock: the weir at Richmond Lock is only used at low tide, to maintain the water level above it.
Chalmore Lock (1838) was removed in 1883.
See also
- Thames Barrier
- Crossings of the River Thames
- Islands in the River Thames
- Tributaries of the River Thames
References
- ^ Dix, Frank L. (1985), Royal River Highway, David & Charles, Newton Abbott, p. 12
- ^ a b Thacker, Fred S. (1968a) [1914]. The Thames Highway: Volume 1 General History. David & Charles.
- ^ Environment Agency, EA Winter Lock Closures and Repairs
- ^ Environment Agency River Thames River Conditions Archived 16 January 2009 at the Wayback Machine
- ^ "Check for flooding in England - GOV.UK".
- ^ See River User Groups Archived 4 August 2009 at the Wayback Machine
- ^ Thacker, Frederick S. (1968b) [1920], The Thames Highway, vol. II: Locks and Weirs, David & Charles, Newton Abbott
- ^ 2012-13 Cruising Guide to the River Thames and Connecting Waterways, British Marine Federation
- ^ Thacker 1968a, p. 156