Teddington Lock
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Information on the Lock and Weir.

The town of Teddington has been around (in one form or another) for at least a thousand years. It is first mentioned in the year 960AD , and was known as 'Tudinton - the settlement of Tudda's people' . A lot of people mistakenly believe the name Teddington derives from Tide End Town , and while this is a nice story , unfortunately, it is untrue. Before the first lock was built here , the tide used to go as far as Walton , and sometimes as far as Staines. The tide only started ending at Teddington in the early 19th Century.

The very first lock at Teddington was built in 1810 and was made of timber, this quickly became dilapidated and was replaced in 1856/7 with basically the launch lock that you see today (although it was refurbished in 1950)  In 1904 the barge lock was added making Teddington Locks the largest lock system on the non-tidal Thames. Everything about Teddington Locks is big, we have the largest weir on the Thames , 20 electrically operated gates capable of letting 12 billion gallons (54.50 billion litres) of water through a day at peak flow. We also have the largest lock (The Barge Lock) which is 650 feet (198.12 metres) long and holds 1.75 million gallons (8 million litres) of water.

Rebuilding the launch lock in 1950 .....

Some facts about the Locks.

Teddington Locks are 14 feet (4.2 metres) above sea level.

  • Barge Lock dimensions :- (L) 198.12m (W) 7.54m (D) 2.10m

  • Launch Lock dimensions :- (L) 54.22m (W) 7.41m (D) 2.10m

  • Skiff Lock dimensions :- (L) 15.08m (W) 1.77m (D) 2.10m

Teddington Locks have both the largest and the smallest locks on the river , as you can see from the figures above. The smallest, which is the skiff lock, is rarely used and is sometimes referred to as the ‘coffin lock’ - as when you are inside it , it is like looking up out of a coffin !

  • The Launch lock is roughly 1/3rd of the size of the Barge lock and holds 479 thousand gallons (2.2 million litres) of water.

Some facts about the Weir.

Largest weir on the Thames – 20 gates (other weirs have more gates, but none are as big as ours)

  • Largest gate is 4.5m x 15m ( Roller Sluice ) Smallest is 0.75m x 0.75m ( Fish Pass )

  • Peak flow 12 billion gallons (54.50 billion litres) a day

  • Summer flow usually about 131 million gallons (600 million litres) a day

Floods at Teddington in 1894 .... this should never happen again due to better understanding of the river, flood defences and modern technology ..... There seems to be a big flood every 50 years or so , this was 1894 , the next big one was 1947 and we had another flood event in 2000 ...

How locks work and why we have them.

Simply speaking, a lock lets us raise or lower a very small section of the river to allow passage of boats up and down stream.

To let a boat upstream , the lock-keeper would open the tail (bottom) gates by using the tail controls, the boat would enter the lock and put its ropes around a bollard (it wouldn’t tie them off , as the ropes need to be kept tight as the boat rises or falls with the water) .

Then the lock-keeper would go to the head (top) controls and open the sluices (these are small doors underwater at the bottom of the gates), this allows water to flow into the lock. You can see the if the sluices are opening or closing by watching the black and white rods on top of the gates …… if they are going up, the sluices are opening, if they  are going down, the sluices are closing.




All the while he is doing this, the lock-keeper is keeping a very close watch on the boats inside the lock, to make sure they are keeping their ropes tight and the moving water is not bouncing the boats around too much. Safety is very important in the lock chamber and on the lock side.

When the water level in the lock is the same as the water level upstream, the lock-keeper will open the gates and the boats will continue their journey upriver. The lock-keeper will then shut the head sluices ready for the next lock.

In order to let a boat downstream, the procedure described above is reversed.

Before locks (like you can see at Teddington) were built, the river level was controlled by ‘flash weirs’ these were basically a dam built across the river with a removable section to allow boats through. They were quite dangerous as the boat either had to fight the ‘flash’of water going upstream or ride the ‘flash’ downstream!

The locks and weirs you see today allow us to monitor and control the level of the water above it (each lock is responsible for the stretch of water above it , as far as the next lock)  without the locks and weirs, the river would be a raging torrent in winter and a small stream in the summer. A weir is effectively a dam across part of the river, which allows us to keep the water at a constant level , by holding it back or letting it go, so that everyone can enjoy the river; boaters , canoeists and fishermen to name a few. The lock is there so that boaters do not have to ride the ‘flash weirs’ any more. Most of Londons drinking water comes from the Thames, so we also have to make sure there is enough in it for the water companies to take.



Some Fun Facts about Teddington Locks.

  • If you were going to empty the Launch Lock by drinking the water in it, at the recommended daily rate of 2 litres of water a day, it would take just over 3,000 years to drink it dry !!

  • If you ran up and down the Barge lock 115 times, you would have run a marathon.

  • If you wanted to fill the Barge lock up with cans of cola you would need 24 million of them.

  • If you earned a pound for every litre of water the weir at Teddington let through at peak flow , you would be the worlds richest person after just 8 hours !

  • You could drive 2 double decker buses side by side through the largest gates on Teddington weir.

Monty Python and Teddington Lock.

Monty Python's Fish Slapping Dance was filmed at Teddington Lock in the early '70's , it culminates with Michael Palin being whacked into the lock by John Cleese with a huge fish and is enormously funny. You can see it here :-

Click Here To See The Video !

At the reunion , some years ago, the lock-keepers were given an unofficial 'blue plaque' which is displayed in the window of the gauge house. We also received a signed thank you photo which is displayed in the entrance hall to the lock office. 

Teddington Lock Wildlife.

We have a huge diversity of bird life at Teddington Locks as well, some species that can be seen regularly at Teddington include :- Canada Geese, Egyptian Geese, Mallards, Grebes (Great Crested and Little), Coots, Moorhens, Grey Herons, Cormorants, Kingfishers, Great Black Backed Gulls, Herring Gulls, Black Headed Gulls, Mute Swans, Wood and Feral Pigeons, Crows, Jackdaws, Magpies, Jays and Ring Necked Parakeets.

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