Short answers, pulled from the story.
Engineers serving Ptolemy II of Egypt constructed the device in 274 BC. This early lock was part of the Canal of the Pharaohs and represented humanity's first attempt to control river levels for navigation.
Qiao Weiyue installed two sluice-gates spaced two hundred and fifty feet apart to create a pound-lock system. A roof covered the entire structure like a building to protect it from the elements while allowing boats to enter a chamber where water could be raised or lowered safely.
Bertola da Novate designed gates that closed against each other at an 18-degree angle to form an arch shape. This geometry helped them withstand the immense pressure of water pushing against the upstream side when levels differed below.
Boaters welcome another vessel because its exit leaves the lock ready for their use immediately. This saves approximately five to ten minutes of waiting time compared to starting from an empty state.
The IJmuiden sea lock took over surface area records in 2022. The facility measures three thousand meters long and two hundred meters wide with a usable depth of fourteen point five meters.