This is the bridge that was covered in houses for much of its life. It had 20 arches of differing sizes, a drawbridge to let shipping through. It caused enough of a barrage across the Thames that the huge volume of water held back formed a water height differential of approx. 6 feet at times and rapids between the piers and the 'starlings' that helped to protect them made navigation extremely dangerous. Taking a craft under the bridge was known as 'shooting the bridge' and was something best done by experienced 'watermen'. (Passengers often used to get out and walk round while their watermen took the boats under.)
Wikipdia offers reasonable information and there are illustrations on the 'London Bridge Experience' site. Googling Old London Bridge and London Bridge brings up a lot of sites which offer the same information in marginally different formats. There is plenty of information on the bridge prior to the medieval houses being removed (1758-1762) and plenty of information on the new London Bridge (completed 1831) but very little about the bare bridge between the removal of the houses and the demolition in 1831. A big 69 year gap in the available history!
I would really appreciate the answers to the following.
After the removal of houses from the medieval bridge in 1762 the two central arches were reconstructed to provide a single wider arch for navigation. How did that alter the basic bridge structure and the tidal flow beneath it? Specifically:
a) was there still a drawbridge to allow tall masted vessels to pass through the bridge? If so what mechanism was used to raise and lower it?
b) was there still a dangerous tidal surge of water through the arches of the bridge and was the surge as dangerous through the wider arch? What was the optimum time for a vessel to pass through the wider arch? i.e. was the surge smaller as the tide turned? Low tide? High tide?
c) if the surge altered direction with the tide, was the inward surge (east to west) less fierce than the outward surge (west to east) as the latter would include the volume of fresh water flowing down river as well as the exiting tidal water?