Maritime flag signalling
Encyclopedia
Maritime flag signalling, generally flaghoist signalling, is the principal means other than radio by which ships communicate to each other or to shore; distinguished from flags showing nationality, ownership, or (for naval vessels) organizational status. Virtually all signalling by non-naval vessels (whether by flaghoist, semaphore
, signal lamp
, or other means) is now organized under the International Code of Signals
, which specifies a standard set of flags and codes; naval vessels generally use an extended set of flags and their own codes. This article will touch on the historical development of maritime flag signalling.
By 1653 the Royal Navy had issued instructions by which an admiral could signal various orders by hoisting flags in various locations on his ship. Modern use of naval code signaling begun with the invention of maritime signal flags in the mid-17th century by the Duke of York who was created Lord High Admiral
after the Restoration
. A ship's message had to be approved by the Officer of the watch, and his system was augmented and changed in various ways over the following century. In 1790 Admiral Lord Howe issued a new signal book for a numerary system using numeral flags to signal a number; the number, not the mast from which the flags flew, indicated the message. Substitute flags were also instituted to indicate repeated numerals, and there was consideration of making the flags more distinct. In 1799 Captain Sir Home Popham
published his first list of words and sentences which could be referenced by a number (or "code"); three subsequent editions added letter flags, with the 1801 edition numbering 2994 codes.
A Code of Signals for the Merchant Service, published in 1817. This consisted of six parts of large numbered lists:
Different flags indicated which list was referred to. As an example, flying the Rendezvous (RE) flag (indicating Lighthouses, Ports, etc.) over the numerals 1537 indicates the ship's home port is Amsterdam. Flying Rendezvous under the number indicated the ship is sailing from Amsterdam, and flying it at some other mast-head indicates she is bound for that port. Numbers alone indicate a sentence: "4576" means "I mean to keep sail set, and carry on all night, as I am anxious to get into port." Quite a mouthful for only four flags, and expeditious. Marryat's code was an immediate success, was translated into several other languages, and because of its widespread usage the 1854 edition was renamed The Universal Code of Signals for the Mercantile Marine of All Nations. The last edition was published in 1879, two decades after the publication of the code that was to supplant it; there are reports it was still being used as late as 1890.
(ICS). A significant development was the addition of letter flags to make the code alphabetic. (Although the vowels were initially left out to avoid formation of any objectionable words.) During World War I there was an unprecedented need for ships, merchant as well as naval, to communicate, but the ICS was found wanting: "It was not international. It was found that when [signalling] word by word, the occasions upon which signaling failed were more numerous than when the result was successful." This led to major revisions in 1931. Additional changes in 1969 greatly reduced the Code (dropping the Geographical and Vocabulary sections), and more narrowly focused it on communications related to safety of navigation. An indication of the success of the ICS is that most navies now use the ICS flags for representing letters.
Semaphore
A semaphore telegraph, optical telegraph, shutter telegraph chain, Chappe telegraph, or Napoleonic semaphore is a system of conveying information by means of visual signals, using towers with pivoting shutters, also known as blades or paddles. Information is encoded by the position of the...
, signal lamp
Signal lamp
A signal lamp is a visual signaling device for optical communication . Modern signal lamps are a focused lamp which can produce a pulse of light...
, or other means) is now organized under the International Code of Signals
International Code of Signals
The International Code of Signals is an international system of signals and codes for use by vessels to communicate important messages regarding safety of navigation and related matters. Signals can be sent by flaghoist, signal lamp , flag semaphore, radiotelegraphy, and radiotelephony...
, which specifies a standard set of flags and codes; naval vessels generally use an extended set of flags and their own codes. This article will touch on the historical development of maritime flag signalling.
Early developments
In the Middle Ages the use of signals to communicate between ships was primitive, as seen by one admiral's instructions to his fleet in 1530:
"Whensoever, and at all tymes the Admyrall doth shote of a pece of Ordnance, and set up his Banner of Council on Starrborde bottocke of his Shippe, everie shipps capten shall with spede go aborde the Admyrall to know his will."
By 1653 the Royal Navy had issued instructions by which an admiral could signal various orders by hoisting flags in various locations on his ship. Modern use of naval code signaling begun with the invention of maritime signal flags in the mid-17th century by the Duke of York who was created Lord High Admiral
Lord High Admiral
Lord High Admiral can refer to:* Lord High Admiral of the United Kingdom * Lord High Admiral of Scotland* Lord High Admiral of the Wash* Lord High Admiral of Sweden-See also:...
after the Restoration
Restoration (1660)
The term Restoration in reference to the year 1660 refers to the restoration of Charles II to his realms across the British Empire at that time.-England:...
. A ship's message had to be approved by the Officer of the watch, and his system was augmented and changed in various ways over the following century. In 1790 Admiral Lord Howe issued a new signal book for a numerary system using numeral flags to signal a number; the number, not the mast from which the flags flew, indicated the message. Substitute flags were also instituted to indicate repeated numerals, and there was consideration of making the flags more distinct. In 1799 Captain Sir Home Popham
Home Riggs Popham
Admiral Sir Home Riggs Popham KCB was a British Royal Naval Commander who saw service during the French Revolutionary Wars and the Napoleonic Wars...
published his first list of words and sentences which could be referenced by a number (or "code"); three subsequent editions added letter flags, with the 1801 edition numbering 2994 codes.
Marryat's Code of Signals
Previous systems were primarily naval. The first general system of signalling for merchant vessels was Captain Frederick Marryat'sFrederick Marryat
Captain Frederick Marryat was an English Royal Navy officer, novelist, and a contemporary and acquaintance of Charles Dickens, noted today as an early pioneer of the sea story...
A Code of Signals for the Merchant Service, published in 1817. This consisted of six parts of large numbered lists:
- A list of English Men of War.
- A list of foreign Men of War.
- A list of the English Merchant Vessels (from Lloyd's List).
- A list of Lighthouses, Ports, Headlands, Rocks, Shoals, Reefs &c.
- A selection of Sentences.
- The Vocabulary.
Different flags indicated which list was referred to. As an example, flying the Rendezvous (RE) flag (indicating Lighthouses, Ports, etc.) over the numerals 1537 indicates the ship's home port is Amsterdam. Flying Rendezvous under the number indicated the ship is sailing from Amsterdam, and flying it at some other mast-head indicates she is bound for that port. Numbers alone indicate a sentence: "4576" means "I mean to keep sail set, and carry on all night, as I am anxious to get into port." Quite a mouthful for only four flags, and expeditious. Marryat's code was an immediate success, was translated into several other languages, and because of its widespread usage the 1854 edition was renamed The Universal Code of Signals for the Mercantile Marine of All Nations. The last edition was published in 1879, two decades after the publication of the code that was to supplant it; there are reports it was still being used as late as 1890.
International Code of Signals
Various other codes were also published, but all these were eventually supplanted by the Commercial Code of Signals published by the British Board of Trade in 1857; what eventually became the International Code of SignalsInternational Code of Signals
The International Code of Signals is an international system of signals and codes for use by vessels to communicate important messages regarding safety of navigation and related matters. Signals can be sent by flaghoist, signal lamp , flag semaphore, radiotelegraphy, and radiotelephony...
(ICS). A significant development was the addition of letter flags to make the code alphabetic. (Although the vowels were initially left out to avoid formation of any objectionable words.) During World War I there was an unprecedented need for ships, merchant as well as naval, to communicate, but the ICS was found wanting: "It was not international. It was found that when [signalling] word by word, the occasions upon which signaling failed were more numerous than when the result was successful." This led to major revisions in 1931. Additional changes in 1969 greatly reduced the Code (dropping the Geographical and Vocabulary sections), and more narrowly focused it on communications related to safety of navigation. An indication of the success of the ICS is that most navies now use the ICS flags for representing letters.
See also
- Flaghoist signalling
- International Code of SignalsInternational Code of SignalsThe International Code of Signals is an international system of signals and codes for use by vessels to communicate important messages regarding safety of navigation and related matters. Signals can be sent by flaghoist, signal lamp , flag semaphore, radiotelegraphy, and radiotelephony...
- Naval flag signallingNaval flag signallingNaval flag signalling covers various forms of flag signalling, such as semaphore or flaghoist, used by various navies; distinguished from maritime flag signalling by merchant or other non-naval vessels or flags used for identification.-History:...
External links
- Excerpt from Brown's Signalling (1916), showing earliar version of ICS.
- International Code of Signals , United States edition (1969) (pdf download)
- International Code of Signals , United States edition (1969) Alternate source, courtesy of Sea Scouts.
- Sea Flags (Joseph McMillan)
- Commander H. R. Mead's article on Captain Marryat
- Captain Howeth: Historic Modes of Naval Communication
- Flags of the World: Maritime Signal Flag History