Wednesday, November 24, 2010

"Samuel Plimsoll"

"Samuel Plimsoll"
1824 ~ 1898
During the 19th century, British trade with the rest of the world was growing rapidly. The large number of ships being wrecked each year caused greater and greater concern. For example, in the year 1873-4, 411 ships sank around the British coast, with the loss of 506 lives. Overloading and poor maintenance made some ships so dangerous that they became known as 'coffin ships'. One of the first attempts to force ships to carry loading marks for safety was made in 1835 by Lloyd's Register, a large company that insured ships. They introduced rules about loading, but these only applied to those ships registered with the Lloyd's company itself. Other ship-owners could still do as they liked when they loaded their ships. If they chose to disregard safety, no one would stop them.

Seamen worried about the dangerous condition of ships, and many refused to go to sea. In 1855, a group of seafarers calling themselves 'The seamen of Great Britain' wrote to Victoria the then Queen, complaining that courts had found them guilty of desertion when they complained about going to sea in dangerous ships. Around the same time, an inspector of prisons reported that nine out of twelve prisoners in the jails of south-west England were seamen, imprisoned for twelve weeks for refusing to sail in ships they considered to be un-seaworthy, or without enough crew. In one case in 1866, the whole crew was jailed, when they refused to set sail on an old ship.
Different attempts, like that of Lloyd's Register, were made over the years to ensure that only safe amounts of cargo were loaded, but there was still no compulsory system to force ship owners to act to protect their ships. In 1870, Samuel Plimsoll MP, who was a coal merchant, became interested in the subject. He began to write a book about the disastrous effects of overloading ships. When he began to investigate, Plimsoll found the problem was even worse than he had expected. He began to campaign in parliament with the aim of improving safety at sea. Many ordinary people became very interested in his book and his campaign. In 1872, a Royal Commission on Un-seaworthy Ships was set up to look at evidence and recommend changes. Plimsoll was defeted several times in parliament, but he continued in his fight until load lines became compulsory. He became so famous that several popular songs were written about him.

The Merchant Shipping Act of 1876 made load lines compulsory, but the position of the line was not fixed by law until 1894. In 1906, foreign ships were also required to carry a load line if they visited British ports. Since then, the line has been known in the U.K. as the Plimsoll Line. To this day, it still carries the name of the MP who fought such a long struggle in parliament to win better safety conditions for ships crews. Together with other important changes made to ships in the Victorian period, load lines helped to preserve the lives of ships crews and passengers.

The Plimsoll Line was painted on the side of merchant ships. When a ship was loaded, the water level was not to go above the line. However, the water could reach different parts of the line (see drawing) as its temperature and saltiness varied with season and location. The basic symbol, of a circle with a horizontal line passing through its centre, is now recognised worldwide.   Samuel Plimsoll"



It has been recognized that limit on drafts to which a ship may be loaded make significant contribution to her safety. The first official loading regulations are thought to date back to maritime legislation originating with the kingdom of Crete in 2,500 BC when vessels were required to pass loading and maintenance inspections. Roman sea regulations also contained similar regulations. In the Middle Ages the Venetian Republic, the city of Genoa and the Hanseatic league required ships to load to a load line. In the case of Venice this was a cross marked on the side of the ship and of Genoa three horizontal lines. The first 19th century loading recommendations were introduced by Lloyd's Register of British and Foreign Shipping in 1835, following discussions between shipowners, shippers and underwriters. Lloyds recommended freeboards as a function of the depth of the hold (three inches per foot of depth). These recommendations, used extensively until 1880, became known as "Lloyd's Rule". In the 1860s, after increased loss of ships due to overloading, a British MP, Samuel Plimsoll, took up the load line cause. A Royal commission on unseaworthy ships was established in 1872, and in 1876 the United Kingdom Merchant Shipping Act made the load line mark compulsory, although the positioning of the mark was not fixed by law until 1894. In 1906, laws were passed requiring foreign ships visiting British ports to be marked with a load line. It was not until 1930 (The 1930 Load Line Convention) that there was international agreement for universal application of load line regulations. In 1966 a Load Lines Convention was held in London which re-examined and amended the 1930 rules. The 1966 Convention has since seen amendments in 1971, 1975, 1979, 1983, 1995 and 2003.
The waterline is an imaginary line marking the level at which a ship or boat floats in the water. To an observer on the ship the water appears to rise or fall against the hull . Temperature also affects the level because warm water provides less buoyancy, being less dense than cold water. Likewise the salinity of the water affects the level, fresh water being less dense than salty seawater. For vessels with displacement hulls, the hull speed is determined by, amongst other things, the waterline length. In a sailing boat, the length of the waterline can change significantly as the boat heels, and can dynamically affect the speed of the boat

The purpose of a 'load line' is to ensure that a ship has sufficient freeboard and thus sufficient reserve buoyancy. The freeboard on commercial vessels is measured between the lowest point of the uppermost continuous deck at side and the waterline and this must not be less than the freeboard marked on the Load Line Certificate issued to that ship. All commercial ships, other than in exceptional circumstances, have a load line symbol painted amidships on each side of the ship. This symbol must also be permanently marked, so that if the paint wears off it remains visible. The load line makes it easy for anyone to determine if a ship has been overloaded. The exact location of the Load Line is calculated and/or verified by a Classification Society and that society issues the relevant certificates. This symbol, also called an international load line or Plimsoll line, indicates the maximum safe draft, and therefore the minimum freeboard for the vessel in various operating conditions

 Example of load lines

The original "Plimsoll Mark" was a circle with a horizontal line through it to show the maximum draft of a ship. Additional marks have been added over the years, allowing for different water densities and expected sea conditions. Letters may also appear to the sides of the mark indicating the classification society that has surveyed the vessel's load line. The initials used include AB for the American Bureau of Shipping, LR for Lloyd's Register, GL for Germanischer Lloyd, BV for Bureau Veritas, IR for the Indian Register of Shipping, RI for the Registro Italiano Navale and NV for Det Norske Veritas. These letters should be approximately 115 millimetres in height and 75 millimetres in width. The Scantling length is usually referred to during and following load line calculations.

The letters on the Load line marks have the following meanings:
  • TF – Tropical Fresh Water
  • F – Fresh Water
  • T – Tropical Seawater
  • S – Summer Temperate Seawater
  • W – Winter Temperate Seawater
  • WNA – Winter North Atlantic