The load line or Plimsoll mark is a permanent marker on the sides of all ships which indicates the safe freight cargo load levels for different seasons and locations. The load line is also known as the Plimsoll mark after a Liberal MP named Samuel Plimsoll called for an end to the overloading of Freight on ships. His worked brought about the Merchant Shipping Act of 1876 making load lines compulsory on all British Vessels. The First International Load Line Convention was held in London in 1930 and resulted in an international agreement for load line regulations to apply to all seagoing freight ships worldwide.