Controls the water level change so that boats can navigate up and down different water levels.
the port lock
The longest lock on the River Thames is Teddington Lock. Teddington Lock also contains the smallest lock on the Thames, which is located in England.
Lock
One long blast on the boat's horn or whistle indicates to the river lock attendant that you wish to go through the lock.
A flashing green light indicates that you can proceed into the river lock. This signal means it is safe to enter and that the lock is ready for you. Always ensure to follow any additional signals or instructions from lock personnel for a safe passage.
Tides as far up river as Teddington Lock and heavy rainfall in the rest of the river.
commercial;)
To alert a river lock attendant that you wish to go through the lock, you usually sound your horn or whistle in a specific sequence as defined by the lock operation rules. Typically, this involves a series of long and short blasts to communicate your intention to pass through the lock.
The river Thames is tidal as far upstream as Teddington Lock which is in a suburb of West London.
Green
Green
Max Lock has written: 'The Hartlepools' 'Bedford by the river' -- subject(s): City planning