Thank you ever so much for the additional photos.
As for the upper lock gates I'm possibly more confused than ever.
The arm that intruded into the photo is normally the bit that you push on, to open the gates. It looks like you would need very long legs indeed to achieve this here. Are the gates motorised if so why keep the arms, if not how do you push?
Don't suppose you will see a great deal of lock action at the moment it looks like it has been completely drained.
Half of my questions were about the first photo. [You must be registered and logged in to see this link.]
The lock gates looked odd as if the were the wrong way round, but also there looked to be more gate than is normal.
I've seen enough to realise that each end of the lock has double gates.
The ones further down stream (sic?) the ones in your present photo are closed because the height of the tidal section can become too high. Or presently because the lock is drained.
The photo re hosted by myself shows the other set in action where it's the level of the canal thats being preserved.
If you look you can see the lower level of the tidal section. The ring of mud flat just visible below the grass.
The gates that protect an area from a rise in sea level are much rarer.
Looking at the height of the upstream (sic?) gates I was thinking the length the area to be protected must be very short.
At this point I realise I'm forgetting it's a very flat area and that we might be far enough down the east cost to be subject to the surges of tide caused by the winds affect on the North Sea.
This affect that raises tides while the North Sea tries to funnel itself through the constriction of English Channel is the reason that the Thames Barrier was built.
What are they doing to the lock to cause them to drain it?