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WonderMaritime safety design fact

The Plimsoll line, a circle with a line through it painted on a ship's hull, marks how deep a loaded ship may safely sit in the water. Extra lines beside it allow for fresh water, tropical water and winter seas, where the safe limit is different.

Plimsoll line

EngineeringDesignOceanTradeTechnologyHistory

The story behind the card

The mark is named after Samuel Plimsoll, a British member of parliament who campaigned in the 1870s against “coffin ships”: vessels sent to sea overloaded and often over-insured, so that owners could profit even if the ship sank and its crew drowned. His 1873 book Our Seamen stirred public anger, and the Merchant Shipping Act of 1876 made the load-line mark compulsory on British ships. International conventions in 1930 and 1966 extended load lines to ships worldwide. The letters beside the mark stand for tropical fresh water (TF), fresh water (F), tropical (T), summer (S), winter (W) and winter North Atlantic (WNA). Canvas plimsoll shoes are said to take their name from the band where the upper meets the sole, which recalls the line.

Türkçe oku
Plimsoll işareti, gemi gövdesine boyanan ve ortasından yatay bir çizgi geçen dairedir; yüklü bir geminin suya en fazla ne kadar gömülebileceğini gösterir. Yanındaki ek çizgiler, tatlı suda, tropik sularda ve kış denizlerinde güvenli sınırın farklı olduğunu hesaba katar.

İşaret, adını 1870'lerde “tabut gemiler”e karşı mücadele eden İngiliz milletvekili Samuel Plimsoll'dan alır. Bu gemiler aşırı yüklenerek ve çoğu zaman değerinden yüksek sigortalanarak denize gönderilirdi; gemi batıp mürettebat boğulsa bile sahipleri kâr edebiliyordu. Plimsoll'un 1873'te yayımlanan Our Seamen (Denizcilerimiz) adlı kitabı kamuoyunu ayağa kaldırdı ve 1876 tarihli Ticaret Gemileri Yasası, İngiliz gemilerinde yükleme çizgisini zorunlu kıldı. 1930 ve 1966'daki uluslararası sözleşmeler bu kuralı bütün dünyadaki gemilere yaydı. İşaretin yanındaki harfler tropik tatlı su (TF), tatlı su (F), tropik (T), yaz (S), kış (W) ve Kuzey Atlantik kışı (WNA) anlamına gelir. İngilizcede kanvas spor ayakkabılara “plimsoll” denmesinin, sayanın tabanla birleştiği yerdeki şeridin bu çizgiyi andırmasından geldiği söylenir.

Sources and further reading

Background reading: Plimsoll line
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