“Lothal” Proof For Dravidian maritime knowledge!
They meticulously designed the water way for desilting. The automatic desilting was achieved by allowing excess water to flow through the spillway and some more grooves were provided at regular intervals in the sidewalls as weep holes. To make the ships float in the low tide the construction of abutments to the wall at the entrance of the dock. To counteract the water thrust in the closed enclosure the walls were buttressed from the outer side with more than twelve meters wide platform with bricks.
As a conclusion The Harappans were the early users of tidal phenomena and they utilized the tidal phenomena solely for the sluicing and berthing of ships in the dockyard at Lothal.