Plimsoll Line

Plimsoll Line, a mark painted on the sides of British merchant ships which indicated the load line to which a ship might be loaded with cargo for varying conditions of season and location. Load lines are now controlled by an International Convention adopted by the International Maritime Organization.

The Plimsoll Mark was made compulsory in Britain under the conditions of the Merchant Shipping Act 1876, passed after a long and bitter parliamentary struggle conducted by Samuel Plimsoll MP (1824–98), a champion for better conditions for seamen. After an early life of hardship, which he later claimed introduced him to the wretched conditions under which the poor lived, he became aware of what were known as ‘coffin ships’, those vessels which were unseaworthy and overloaded, heavily insured against loss, in which many shipowners, under the existing law, were permitted to risk their crews. After eventually succeeding in business, Plimsoll entered Parliament in 1868 and began his campaign to improve the lot of British seamen. He wrote a book called Our Seamen which aroused so much interest that in 1873 a royal commission was appointed which recommended changes. The government introduced a Bill in 1875 but this was abandoned due, so it was said, to the political pressure from shipowners. However, the depth of public feeling on the matter forced the government to reintroduce the Bill which became the 1876 Merchant Shipping Act.