Weirs and Locks on The River Thames in England.
Huge violent weirs controlled by equally huge sluices to small quiet weirs some still controlled by Paddle and Rymer - The River Thames has them all.
There are several particularly impressive weirs on The River Thames - perhaps the best example is the weir at Hambleden - The Thames is fairly wide there and the weir is staggered across the water rather than straight across.
You can walk right across Hambleden's weir and whilst doing so you get a feel of really being amongst the action of the river especially if there is plenty of water flowing.
Another extremely impressive weir is located at Teddington - this weir also dog-legs it's way across the River Thames and of course at Teddington there are also the three sets of locks - including The River Thame's largest. The most violent water activity at a weir we have seen is the that found next to Abingdon Lock - the River Thames there is fairly narrow and Abingdon's weir goes almost straight across - after heavy rain the force of the water going through the sluices makes the whole structure shudder. Originally weirs were constructed by mill owners to create enough force to power their paddles - these weirs were
constructed by placing stones and boulders on the river bed and holding them in place with interwoven wooden stakes and mesh. Fishermen also took advantage of this blockade because they could easily net the eels during the migration which occurs during May and June. Before locks were introduced on the river these weirs created quite a headache for boats - if going downstream the boats waited for a head of water
to be created and then part of the weir would be removed and the boats would be "flashed" through the gap - boats heading upstream had to be pulled through manually. This breaking of the weir obviously took the flow away from the mills each time boats needed to pass through so boatmen and mill owners were not exactly the best of friends.
In many cases the weirs are situated close to the various Thames Locks and these days provide two particular functions:
The lock gates will always be closed at one end of the lock or the other and obviously the river's water has to go somewhere and the weir provides an escape route,
Secondly although The Thames is not tidal (it's subject to tides from Teddington out to the North Sea only) the volume of water in the river and the rate of flow changes all the time. This can occur for instance after heavy rain fall so the weirs have to be quite wide to cope and sometimes are staggered across the river rather than built straight across to allow for more volume control.
The water authorities can control the river's height over most of the length of The Thames and where necessary restrict water flow.
This is achieved by raising or lowering the paddles on the weirs - perhaps allowing the river to go over it's banks into water meadows in some locations upstream and protect more sensitive areas from flooding elsewhere.
Equally if there is a shortage of water perhaps during a drought the weirs are used to maintain a certain depth of water in shallower parts of the river.
There are also various locations along the Thames where the weirs are a considerable distance away from the locks - for instance the Thames at Culham enjoys one of it's frequent loops and Clifton Cut was constructed
in 1809 along with Culham lock near to Culham Bridge. The weirs themselves are actually across a water meadow from the lock at the edge of Sutton Courtney where there was once a paper mill - prior to the construction of Culham Cut the Mill owners used to charge heavy tolls for river traffic.
The following are photos of some of the Locks and Weirs which can be found on The River Thames
- starting up at the River's first and highest lock at Lechlade and heading South - plus there are several photos of one of the few remaining active Paddle and Rymer Weirs which is located at Northmoor Lock in Oxfordshire.
Access to the Weirs on the Rivr Thames:
in some cases it is possible to walk right onto the weirs and in fact cross the Thames on them such as Marsh Weir outside of Henley, at Benson and at Hambleden. This is because the weirs are parts of public rights of way (footpaths) or form part of the route of a National Trail such as the Thames Path. Where we know (as of July 2012) you can at least get onto a weir the name of it is marked in green -
(however even access to these
weirs may be stopped temorarily for various "waterways" reasons).
Lechlade - St Johns Lock
St Johns Weir
Lechlade - St Johns Weir
Grafton Lock and Weir
The River Thames and Northmoor Weir which is operated by the Paddle and Rymer System. The control of weirs by the Paddle and Rymer method has been in evidence on the River Thames since the 13th Century and is certainly part of our heritage. The paddles are fairly long posts with flat peices of wood or these days fibreglass (or rymers) attached to them - these can be dropped into a wooden cradle on the river bed and therefore block the water flow. Northmoor is one of the few remaining weirs on the River Thames which operates this system (others are at Streatley and Iffley weirs) - most weirs are now mechanical affairs. The Environmental Agency is currently destroying the
paddles at Rushey's weir and is now attempting to be allowed to destroy the system at Northmoor. This should not be permitted - the Government and it's Quango is a disgrace.
Paddles working at Northmoor Lock
Paddle + Rymer Weir
Kings Lock Weir
Clifton Cut Weir
Clifton Lock and Weir
Lock and Weir
Hambleden Lock and Weir - South Buckinghamshire in England. This area is one of our favourite places to visit along The River Thames - the lock is particularly large and has been furnished with half a dozen bench seats along it's edge.
The weir is one of the largest we have been on and doglegs it's way across the Thames from right next to the lock - the weir has 13 sluices as well as a fairly long water race - and yes it can be walked across. The couple of miles or so
stretch of the Thames Path along from Hambleden to Henley is very popular with walkers and also for cycling along as the area is edged with lots of grass areas and pretty safe for families with young children including
being quite safe for them to cycle along. Additionally there are a scattering of bench seats along the route where you can crash out for a while and watch the boats and feed the ever present ducks, swans and geese.
Boveney Lock and Weir - Dorney Common, near Windsor in England. Located on the opposite side of the River Thames to Windsor Race Course, Boveney Lock was first constructed in 1838 and may have replaced a pound lock in the area. The timber built lock was eventually converted into a boat slide in 1898 and a new lock constructed next to it - Boveney's weir was subsequently re-built in 1913. Boveney Lock is medium sized by River Thames standards with a length of just under 150 feet, 17 feet wide and the lock has a fall of 4 feet. In comparison the huge Romney lock is one of the longest on The River Thames at just under 258 feet long, nearly 7.5 feet wide and has a fall of 6 feet 7 inches.
Romney Lock Weir
Romney Lock Weir
Ham Island Weir
Old Windsor Lock
Penton Hook Lock
Penton Hook Lock and Weirs and also Penton Hook Island - River Thames, England. Penton Hook Lock is located along the Thames a mile or so south of Staines and is situated in a pleasant grassy area. Having crossed over the lock then access to Penton Hook Island is via Penton Hook Weir - the small island has quite a few paths and is completely unspoilt therefore
well worth having a wander around for half an hour. Once over the weir there is another large weir on the right which connects to the "mainland" i.e. far bank of The Thames however this cannot be crossed by the public as the land the other side is private.
Penton Hook Weir
Queen Mary Reservoir Bridge
Sunbury Lock Portage
Teddington Barge Lock
Teddington Launch Lock
The series of River Thames Locks and impressive Weirs at Teddington, England. Teddington Barge Locks is 650 feet long by 24 feet 9 inches wide and is easily the largest lock on the River Thames. The Launch Lock is the most frequently used at Teddington and is 177 feet long and 24 feet 4 inches wide. The third lock at Teddington is the Skiff Lock - this is just 49 feet 6 inches long and 5 feet 10 inches wide - it is said it's like being in a coffin when the water is dropped. All three locks of course enjoy the same Fall which is 8 feet 10 inches.
The Barge Lock is situated alongside the Thames Path - it is possible to cross the lock gates and take a look at the adjacent Launch Lock however the Skiff Lock is not usually available to take a look at by the public. Unlike other locks on The River Thames the Teddington Locks are manned 24 hours a day all year round.
Teddington Skiff Lock
Skiff Lock - lockgates
Richmond Footbridge, Lock, Barrage and Weir controlling the tidal flow of The River Thames at Richmond, England. Situated a little way downstream from Teddington Locks the three huge sluice gates at Richmond form a barrage and are designed to maintain water depth at least at half-tide levels. Each weighing nearly 33 tonnes the sluice gates are usually raised either side of high tide for around two hours during which time river craft can pass
through free of charge. Out of these times boats can either moor up and wait or can use Richmond Lock - however there is a charge if using the lock. The Grade II listed structures were constructed in the early 1890s and officially opened in 1894 by the Duke and Duchess of York.
The River Thames and it's variety of Locks.
The River Thames is navigable from Lechlade which is on the edge of the Cotswold Hills in Gloucestershire - the first of the 45 locks along the route of the Thames is St John's Lock at Lechlade - this lock is 110 feet long and just under 15 feet wide. Generally this is the average size for most of the locks as far down as Osney Lock
from where they tend to be somewhat larger, Curiously several of the locks, for instance at Mapledurham and Hambleden, are extra large within this sequence as they are around 200 feet long. These larger Thames locks were rebuilt after WW2 and according to one lock keeper they were built extra large just to create work for people. The average length and width of the locks does increase as the River Thames gets nearer to London with Teddington Barge Lock being an impressive 650 feet long and nearly 25 feet across.
Todays locks are the replacement for the original single gated "flash" locks - i.e. the
water is contained in a chamber or "pound" and held there by two sets of lock gates. The locks on The Thames between St. Johns Lock at Lechlade and Kings Lock (a little to the north of Oxford) are still manually operated but thereafter the locks are hydraulically operated. Many of the River Thames Locks are manned during the day and have lock-keeper's cottages situated beside the locks - they are generally surrounded by
beautifully kept gardens and flower-beds - for instance at Grafton Lock and Kings Lock (near Oxford) and often there are bench seats dotted around.
Sandford-on-Thames has two particular features - it boasts the lock with the greatest drop on the River Thames - the lock is 174 feet long and 21 feet 9 inches wide with a fall of 8 feet 10 inches. Sandford Lasher is the weir for Sandford
lock and a little way from the lock itself - the water at Sandford Lasher is extremely dangerous and the pools often have whirlpools - access onto Sandford Lasher is not allowed.
Using and Operating the Locks on the River Thames.
Although many of the locks on the river are manned and therefore the lock-keeper will do all or most of the opening and closing of sluices and gates for you certainly during lunch times you may find the lock is unmanned - usually indicated by a "Self Service" sign at the lock. To proceed first of all
ensure that the gates and sluices are fully closed - i.e. the red sluice indicators are in the lowest position.Filling the Lock.
Open the sluices on the the upper lock gates by winding the control wheel until the red indicators and white indicators are at the same level. When the lock is half full then you can fully open the sluices i.e. wind the wheel to
get the red indicator bar fully raised.To Empty the Lock.
Open the sluices very slowly on the lower lock gates by winding the control wheel until the red indicators are fully raised - "slowly" is important to avoid turbulence in the water.
Once the water levels are even open the lock-gates by pushing the gate beams.
Once through the lock the lock-gates
and sluices should be left fully closed
unless another boat is waiting to use the lock.