The First Oil Tanker, the Zoroaster, Built in 1878.

The hull was built with steel, which became available in the last half of the nineteenth century as a result of Henry Bessemer’s development of a method to produce large quantities of steel from pig iron. The ship contained iron tanks to hold the oil. This innovation was the brainchild of Ludvig and Robert Nobel. They developed an oil pipeline to carry the oil from its source to the ship’s tanks. They developed a system of ballast to stabilize the ship. They subsequently built additional tankers to carry oil across the Caspian Sea and up the Volga and Don rivers. The ships, built in Sweden, could reach the Caspian Sea by sailing the Baltic Sea, the canals, and smaller rivers leading to the Volga river, which entered the Caspian Sea, a route suitable for tanker travel during high water levels after the winter thaw. These tankers pioneered the method of carrying liquid cargo by ship.