The caissons' vertical guillotine gates created a watertight seal. edit

"The caissons' vertical guillotine gates created a watertight seal."

Is that it? How did that work? How did the boats warp into the caissons? There are four sets of rails, so were there four guillotine gates? How were they sealed when the caisson wasn't present? How was the gap sealed when the caisson was present? Was there some mechanism to pull the caisson in tight to the fixed (shore) part of the system? Does "guillotine" mean that the gates rose high above the boats to let them enter? If so there must have been a massive framework to carry that. I didn't see it in any of the photographs at the museum. Or did they lie flat in the water to let the boat pass over them?

This important engineering feat deserves better. I'm sorry that I don't know enough about it to answer these questions myself. Afterbrunel (talk) 16:37, 8 June 2022 (UTC)Reply