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.
The most violent watere 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 unlike on the canals which contain fairly static water and can get away with quite narrow sluices, although The Thames is not tidal (The Thames is subject to tides from Teddington out to the North Sea only)
the volume of water in them and the rate of flow changes all the time - 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 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
Paddles working at Northmoor Lock
Paddle + Rymer 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.
Kings Lock Weir
Clifton Lock and Weir
Lock and Weir
Hambleden Lock and Weir is easily our favourite place to visit along The 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.
The River Thames and it's 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.
Other topics we have about walking and enjoying The Thames Path:-
Thames Path walk at Lechlade
Thames Path Newbridge area walk
The Thames Path walk into Oxford
Abingdon walk on the Thames Path
Benson area The Thames Path
Thames Path Goring area walk
Reading to Maidenhead walk on the Thames Path
Beautiful Old Bridges on The River Thames
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External Link: visit The River Thames Guide
All about the River Thames and it's 215 miles of Attractions.