History Mystery: “Lothal” Proof For Dravidian maritime knowledge!

      The maritime activities of India were very much old as that of Bronze Age (i.e. of between early third and mid second millennium BC). The excavation of Lothal at Gujarat coast constructively gives evidence for the maritime activities of the Dravidians. The Gujarat coast is with several creeks and rivers that provide a natural environment for the harbor along the coast. The Gujarat coast is rich in marine wealth such as conch and shells which were exported during those days. Since from the prehistoric period the Harappan people aware of the behavior of the tidal waves and they were the first who used the ebb and neap flow of the water effectively in berthing and moving the ships from the dockyard. They constructed a harbor at the coastal city Lothal in Gujarat. The early works of Tamil and the later works in Sanskrit illustrate, the ancient’s have the thorough knowledge in the tidal waves and they were also aware how the tides changes its behavior according to the position of moon. Sadly there is no physical evidence to show that they had a thorough knowledge in astronomy.

      In the early historic period the Harappans had a clear understanding about the coastal tidal features and their special importance for maritime navigation. The Indus valley Dravidian people have a very close trade contacts with Sumeria, Srilanka and others both by the land and sea. This was supported by the finding of a seal and a pot - sherd portraying a ship. It is further substantiated by the discovery of the Lothal, a Harappa civilization site in Ahmadabad district in Gujarat. The Harappans constructed a dock for berthing and servicing the ships near the mouth of the river Sabarmati (But the river Sabarmati’s course was shifted later years).This is the earliest structure based on the knowledge relating to the ebb and the neap tides in the world. And the remains of the Lothal port prove the sound knowledge of the Dravidian in the maritime engineering and the hydro-graphic. They have the better understanding in the effects of tidal water on the brick build structure also. They have constructed the walls of the dock with the kiln burnt bricks. The ships were allowed through the flood gate into the dock through the river estuary flooded by an inlet channel at high tide from the Sea. Similarly the ships have to leave the yard during the high tide and the buttress walls were constructed either side of the inlet near the embankment to avoid the erosion and scouring of the tidal waves.

     The selection of Lothal for the construction of a dock yard is a cleverly selected one and this reflects the knowledge of the Dravidian of those days. Why because, even now the Cambay reason is the only region with highest tidal range in India. Even now the Spring tides in the Cambay Gulf rise and fall as much as 33 feet with a velocity of more than six knots and the neap tide raise more than 23 feet with more than 5 knots wind speed. In the first century AD an anonymous Egyptian navigator wrote “Periplus Maris Erithrei” in it he gives a detailed descriptions of the harbors, the kings and the people of that period anchorages and about the climate, prevailing wind and also he recorded his observations about the tides in the Arabian sea and the part of Indian ocean and he mention that In India the seas ebb and neap with tides of extra ordinary strength. Lothal site is now silt laden but excavations carried out by the archaeologists and they found 5 phases of structural activities so far. And the first four phases belongs to Harappa culture and the fifth one represents the late or degenerate phase. The dockyard is in the eastern side of the mound with trapezoidal plan. The western and eastern embankments of this dockyard had the facility for berthing and handling of cargo of length 218 meter and 38 meters with the height of more than 4 meters constructed with the kiln burnt bricks. The inlet channels are of 7 meter height and 2.5 kilometers long.

       The Ships has to enter the harbor were sluiced through the inlet channel at the high tide and when the water level is about the inlet sill. They are well aware of scouring effect of the tidal waves and so constructed two buttress walls on either side of the inlet walls. The second channels runs towards south embankment and right angle to it. In the either sides of the junction of the embankment was provided with the vertical grooves to inserting the wooden door to close the spill way for maintain the maximum water level in the water way.

    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.