Flag signals
Encyclopedia
Flag signals can mean any of various methods of using flags or pennants to send signals. Flags may have individual significance as signals, or two or more flags may be manipulated so that their relative positions convey symbols. Flag signals allowed communication at a distance before the invention of radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...

 and are still used especially in connection with ships.

Flaghoist signalling

Flaghoist signalling is one or more flags (or pennants) simultaneously flying from a fixed halyard
Halyard
In sailing, a halyard or halliard is a line that is used to hoist a sail, a flag or a yard. The term halyard comes from the phrase, 'to haul yards'...

, and generally any method of signaling by such means. Each of the flags has a distinct shape and color combination. Each flag or combination of flags has a preassigned meaning or "code". 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...

 defines a standard set of flags and associated alphabet suitable for international use, as well as a set of standard codes. Flaghoist is also used in boat racing
Racing Rules of Sailing
The Racing Rules of Sailing govern the conduct of yacht racing, windsurfing, kitesurfing, model boat racing, dinghy racing and virtually any other form of racing around a course with more than one vessel while powered by the wind...

, to warn of impending severe weather, and other specialized applications.

Maritime flag signalling
Maritime flag signalling
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 organizational status...

 has a long history, especially prior to the advent of radio, and remains the preferred means of signaling in many situations. In naval flag signalling
Naval flag signalling
Naval 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:...

, additional flags and an expanded list of signals are used for identification and commands, as well as the mercantile uses. Many navies have their own proprietary or secret codes, and use additional flags. A designator flag is used to indicate if a flaghoist signal is meant to be interpreted as an ICS signal or as a naval signal. The U.S. Navy uses a set of 68 flags, including flags for each letter of the alphabet and each numeral to convey messages of tactical or administrative nature..

Semaphore

Flag semaphore
Flag semaphore
Semaphore Flags is the system for conveying information at a distance by means of visual signals with hand-held flags, rods, disks, paddles, or occasionally bare or gloved hands. Information is encoded by the position of the flags; it is read when the flag is in a fixed position...

 signalling uses two flags, held in specific positions to signify letters. This method requires simple equipment but can be obscured by bad weather. A permanently installed chain of semaphore stations is a semaphore line and before the invention of the electric telegraph, was the fastest means of communication over moderately long distances.

Wig-wag flags

In the 1850s, U.S. Army Major
Major
Major is a rank of commissioned officer, with corresponding ranks existing in almost every military in the world.When used unhyphenated, in conjunction with no other indicator of rank, the term refers to the rank just senior to that of an Army captain and just below the rank of lieutenant colonel. ...

 Albert J. Myer
Albert J. Myer
Albert James Myer was a surgeon and United States Army officer. He is known as the father of the U.S. Army Signal Corps, as its first chief signal officer just prior to the American Civil War, the inventor of wig-wag signaling , and also as the father of the U.S...

, a surgeon by training, developed a system using left or right movements of a flag (or torch or lantern at night). Myer's system used a single flag, waved back and forth in a binary code conceptually similar to the Morse code
Morse code
Morse code is a method of transmitting textual information as a series of on-off tones, lights, or clicks that can be directly understood by a skilled listener or observer without special equipment...

 of dots and dashes. This is sometimes called the wig-wag method of signaling, or "wig-wagging". More mobile than previous means of optical telegraphy, as it only required one flag and a 6–8 feet platform on which to stand the signal corpsman, this code was used extensively by Signal Corps
Signal Corps in the American Civil War
The Signal Corps in the American Civil War comprised two organizations: the U.S. Army Signal Corps, which began with the appointment of Major Albert J...

 troops on both sides in the American Civil War
American Civil War
The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...

. (Its first use in battle was by Confederate
Confederate States Army
The Confederate States Army was the army of the Confederate States of America while the Confederacy existed during the American Civil War. On February 8, 1861, delegates from the seven Deep South states which had already declared their secession from the United States of America adopted the...

 Lieutenant
Lieutenant
A lieutenant is a junior commissioned officer in many nations' armed forces. Typically, the rank of lieutenant in naval usage, while still a junior officer rank, is senior to the army rank...

 Edward Porter Alexander
Edward Porter Alexander
Edward Porter Alexander was an engineer, an officer in the U.S. Army, a Confederate general in the American Civil War, and later a railroad executive, planter, and author....

 at the First Battle of Bull Run
First Battle of Bull Run
First Battle of Bull Run, also known as First Manassas , was fought on July 21, 1861, in Prince William County, Virginia, near the City of Manassas...

 in 1861.)

In this code, alphabet letters were equated with three positions of a single flag, disk, or light. The flags measured two, four, or six feet (60, 120 or 180 cm) square and were generally either red, orange or black banners with white square centers or white banners with red or orange square centers. The disks were 12 to 18 inches (30 to 46 cm) in diameter and were made of metal or wood frames with canvas surfaces. Somewhat easier to handle than the flags, they provided a different method for daylight communications. The lights were kerosene lanterns attached to a staff. A second "foot torch" was placed on the ground before the signalman as a fixed point of reference, making it easier for the recipient to follow the lantern's movements.

Each letter consisted of a combination of three basic motions. All began with the flagman holding his device vertically and motionless above his head. The first motion was initiated by bringing the device downward on the signalman's right side and then quickly returning it to its upright position. The second motion brought the device down on the left side and then returned it to the starting position. The third motion lowered the device in front of the signalman, then restored it to its vertical position.

See also

  • Maritime flag signalling
    Maritime flag signalling
    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 organizational status...

  • International maritime signal flags
    International maritime signal flags
    The system of international maritime signal flags is one system of flag signals representing individual letters of the alphabet in signals to or from ships...

  • Signaller
    Signaller
    In the armed forces, a signaller or signaleer is a specialist soldier or seaman or airman responsible for military communications. Signallers, aka Combat Signallers or signalmen or women, are commonly employed as radio or telephone operators, relaying messages for field commanders at the front line...

  • Substitute flag
  • Naval flag signalling
    Naval flag signalling
    Naval 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:...

  • Flag semaphore
    Flag semaphore
    Semaphore Flags is the system for conveying information at a distance by means of visual signals with hand-held flags, rods, disks, paddles, or occasionally bare or gloved hands. Information is encoded by the position of the flags; it is read when the flag is in a fixed position...

  • Racing Rules of Sailing
    Racing Rules of Sailing
    The Racing Rules of Sailing govern the conduct of yacht racing, windsurfing, kitesurfing, model boat racing, dinghy racing and virtually any other form of racing around a course with more than one vessel while powered by the wind...

  • England expects that every man will do his duty
    England expects that every man will do his duty
    "England expects that every man will do his duty" was a signal sent by Admiral Horatio Nelson, 1st Viscount Nelson from his flagship HMS Victory as the Battle of Trafalgar was about to commence on 21 October 1805. Trafalgar was the decisive naval engagement of the Napoleonic Wars...

    (a famous flag signal).
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