Boulter's Lock as a pleasure boat squeezes in and under the bridge
|Maintained by||Environment Agency|
|Length||60.80 m (199 ft 6 in)|
|Width||6.47 m (21 ft 3 in)|
|Fall||2.39 m (7 ft 10 in)|
|Above sea level||77 feet (23 m)|
|31 miles (50 km)|
Boulter's Lock is a lock and weir on the River Thames in England on the eastern side of Maidenhead, Berkshire. A lock was first built here by the Thames Navigation Commission in 1772. The lock is on the western side of the river between the main (A4094) Maidenhead to Cookham road and Ray Mill Island. The name is also used for the immediate surrounding area.
The weir is some way upstream of the lock, at the northern end of Ray Mill Island. It is one of the most popular whitewater freestyle kayaking areas on the River Thames, as it has been modified to allow kayakers to use it without causing disruption to other river users.
The earliest reference to a flash lock is in the late 16th century, although a mill is known to have existed here in the 14th century. The flash lock was located in what is now the main weir, with a winch to haul the barges through it on the west bank of the river near the tip of Boulter's Island. In 1746 it was written that there was no lock downstream of this lock. The Navigation Act obtained in April 1771 did not allow the Thames Navigation Commission to build locks below Maidenhead Bridge, so the lock built here in 1772 was the furthest downstream of the eight first built by the Commission. The lock was timber-sided, and the work was overseen by Joseph Nickalls, who had designed a scheme of improvements to the river from Abingdon to Richmond, in preparation for obtaining the Act of Parliament. Originally the lock was on the Taplow side, close to Taplow Mill, and in 1773 a nearby resident complained of trespass in his woods by the barge crews who "very much misbehaved themselves by their indecent conversation and horrid oaths and imprecations". It was referred to as "Boltus Lock". A "bolter" was a miller and hence the name means "miller's lock" and originally referred to the mill at Taplow. It was exceptional that a lock-keeper's house was built in 1774. By 1780 the lock was reported as being in as bad a state as Marlow, and in 1795 Phillips Inland Navigation complained of the deep hole and subsequent shoals caused by the force of water.
In 1825 the City of London corporation complained of the condition of the lock and recommended it be rebuilt on the Berkshire side of the river. This involved creating a new lock cut, some 600 yards (550 m) long. In order to keep it drained during construction, a waterwheel was placed in the weir, which was used to operate pumps. The contract to dig the cut was given to George Gynell, at a cost of £1,630. A separate contract for the masonry and millwright's work was given to Clarke and Moss, while carpentry and general labouring was done by men employed directly by the Commission. Stone was obtained from Headington Quarry near Oxford, and because of the distance from the weir to the lock, a separate 6 hp (4.5 kW) steam engine was used to pump the lock chamber. The project was managed by George Treacher, with work beginning in December 1827 and finishing in April 1829. The total cost of the work was £11,800, and when it was completed, the lock at 151 by 19 feet (46.0 by 5.8 m) with a fall of 6 feet (1.8 m) and a depth of 5 feet (1.5 m) over the sills was the largest pound lock with masonry walls built on any of the English river navigations. In recognition of his work, Treacher was awarded £100 by the Commission in June 1829. The new lock was known as Ray Mill pound after Ray Mill Island next to it. The lock cut created Boulter's Island.
This part of the river became popular for boating parties in the late 19th century and early 20th century, as portrayed in the painting by Edward John Gregory. The lock was a popular place to visit on the Sunday after Royal Ascot when the wealthy and famous passed through the lock, often on their way to Cliveden. In 1899 an iron railing was placed round the lock to keep spectators at bay. In 1909 the Thames Conservancy purchased Ray Mill Island to provide for expansion of the lock, and it was rebuilt in 1912.
Congestion at the lock was a serious problem before World War I, and a novel solution was employed to reduce it. A moving ramp, consisting of wooden slats with chocks to prevent rowing boats from rolling over, was constructed to bypass the lock. The ramp was similar to an escalator, and small boats simply rowed towards it, and were carried up to the higher level while the occupants remained seated in their boat. The boat lift opened in 1909, and was powered by an electric motor. The date of its demise is uncertain, but its location on Ray Mill island can still be visited.
The salmon ladder opened at Boulters Weir on 19 May 2000 by the Duke of Wellington was the last of a series built on the Thames. The last salmon caught previously at the weir was landed in 1923.
Ray Mead road/Lower Cookham road (A4094) runs alongside the lock, and there is a car park with ample parking off the road. There is a track onto the lock island. An hourly bus route to the lock from Maidenhead town centre is run by Courtney Coaches.
Reach above the lock
After the long cut beside the islands the reach opens out at the head of the Jubilee River on the Buckinghamshire bank. This is followed by Bavin's Gulls on Cliveden Deep with the spectacular hanging beech woods on the escarpment above which sits Cliveden, well known for the Cliveden Set and the Profumo Affair. The river then curves round to Formosa Island and the other islands where Cookham Lock is situated.
The weir at Boutler's Lock is a popular kayaking site. A canoe/kayak flume is installed annually on the weir during the summer and there is a permanent fixed ramp in front of the third of the weir's six gates.
Literature and the media
One of the best known works of the artist Edward John Gregory (1850–1909) is his Boulter's Lock, Sunday afternoon. Nicholas Pocock, the marine artist, lived at Ray Lodge and broadcaster Richard Dimbleby had a house on Boulter's Island. John O'Farrell (author and broadcaster), grew up in 'The Weir House' opposite.
- Boulter's Lock, Sunday Afternoon, 1882–97, Edward John Gregory (Lady Lever Art Gallery)
- Boulter's Lock information for tourists and residents
- Maidenhead.net information including a 1944 postcard
- Thames Valley Freestylers weir levels
|Next lock upstream||River Thames||Next lock downstream|
3.35 km (2.08 mi)
Grid reference: SU903824
3.43 km (2.13 mi)
- "Environment Agency Dimensions of locks on the River Thames". web page. Environmental Agency. 8 November 2012. Retrieved 18 November 2012. Dimensions given in metres
- Skempton 1996, p. 176.
- Skempton 1996, p. 153.
- Skempton 1996, p. 172.
- Skempton 1996, pp. 153-154.
- Skempton 1996, pp. 170-171.
- Thacker 1968, pp. 327-328.
- McKnight 1981, pp. 45–47.
- "Ray Mill Island". Royal Borough of Windsor and Maidenhead. Retrieved 14 February 2015.
- Parliamentary debate (25 April 1972). "Thames Pollution Control and Fish Life". Hansard.
- "Environment Agency Distances between locks on the River Thames". web page. Environmental Agency. 19 November 2012. Retrieved 21 November 2012. Distances given in km
- McKnight, Hugh (1981). The Shell Book of Inland Waterways. David and Charles. ISBN 978-0-7153-8239-4.
- Skempton, Alec (1996). Civil Engineers and Engineering in Britain, 1600-1830. Variorum. ISBN 978-0-86078-578-1.
- Thacker, Fred S (1968) . The Thames Highway: Volume II Locks and Weirs. David & Charles. ISBN 978-0-7153-4233-6.