This is what I was curious about, how long did the coffer dams take to erect and pump out and were they done separately or two or more at once? Still it seems

This is what I was curious about, how long did the coffer dams take to erect and pump out and were they done separately or two or more at once? Still it seems that video makes it look far simpler that it truly was. Just the carting of the stone from quarry to the job site had to be an immense undertaking