Semaphore & Signals

Semaphore is the use of an apparatus to create a visual signal transmitted over distance. A semaphore can be performed with devices including:

Fire,

Lights,

Flags,

Sunlight

Moving Arms

Sign Language

Semaphore Flag Training Course

A signal lamp (sometimes called an Aldis lamp or a Morse lamp) is a semaphore system using a visual signaling device for optical communication, typically using Morse code. The idea of flashing dots and dashes from a lantern was first put into practice by Captain Philip Howard Colomb, of the Royal Navy, in 1867. Colomb's design used limelight for illumination, and his original code was not the same as Morse code. During World War I, German signalers used optical Morse transmitters called Blinkger�t, with a range of up to 8 km (5 miles) at night, using red filters for undetected communications.

Modern signal lamps produce a focused pulse of light, either by opening and closing shutters mounted in front of the lamp, or by tilting a concave mirror. They continue to be used to the present day on naval vessels and for aviation light signals in air traffic control towers, as a backup device in case of a complete failure of an aircraft's radio.

The railway semaphore signal is one of the earliest forms of fixed railway signals.[20] These signals display their different indications to train drivers by changing the angle of inclination of a pivoted 'arms'. A single arm that pivots is attached to a vertical post and can take one of three positions. The horizontal position indicates stop, the vertical means all clear and the inclined indicates go ahead under control, but expect to stop. Designs have altered over the intervening years and colour light signals have replaced semaphore signals in most countries.

The Phryctoriae were a semaphore system used in Ancient Greece for the transmission of specific prearranged messages. Towers were built on selected mountaintops, so that one tower, the phryctoria, would be visible to the next tower, usually twenty-miles distant. Flames were lit on one tower, then the next tower would light a flame in succession.

The modern English alphabet coding system as follows:

	1	2	3	4	5
1	A	B	C	D	E
2	F	G	H	I	J
3	K	L	M	N	O
4	P�	Q	R	S	T
5	U	V	W	X	W
6	Z

When wanting to send the letter "O" (omicron), fire five torches on the right side and three torches on the left side.

In the early 1800s, the electrical telegraph was gradually invented allowing a message to be sent over a wire. In 1835, the American inventor Samuel Morse created a dots and dashes language system representing both letters and numbers, called the Morse code. In 1837, the British inventors William Fothergill Cooke and Charles Wheatstone obtained a patent for the first commercially viable telegraph. By the 1840s, with the combination of the telegraph and Morse code, the semaphore system was replaced. The telegraph continued to be used commercially for over 100 years and is still used by amateur radio enthusiasts. Telecommunication evolved replacing the electric telegraph with the advent of wireless telegraphy, teleprinter, telephone, radio, television, satellite, mobile phone, Internet and broadband.

A heliograph is a semaphore that signals by flashes of sunlight using a mirror, often in Morse code. The flashes are produced by momentarily pivoting the mirror or by interrupting the sunlight with a shutter. The heliograph was a simple but effective instrument for instantaneous optical communication over long distances during the late 19th and early 20th century. The main uses were for the military, survey and forest protection work. Heliographs were standard issue in the British and Australian armies until the 1960s and were used by the Pakistani army as late as 1975.

Sign languages (also known as "signed languages") are languages that use the visual-manual modality to convey meaning. Sign languages are expressed through manual articulations in combination with non-manual elements. Sign languages are full-fledged natural languages with their own grammar and lexicon. Sign languages are not universal and are usually not mutually intelligible with each other, although there are also similarities among different sign languages.

Phone: 206-780-6885 E-mail: fwarc@usa.com