Signal lamp

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.

During World War I, German signalers used optical Morse transmitters called Blinkgerät, with a range of up to 8 km (5 miles) at night, using red filters for undetected communications.

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.

[2] The idea of flashing dots and dashes from a lantern was first put into practice by Captain, later Vice Admiral, Philip Howard Colomb, of the Royal Navy, in 1867.

[5] In 1944, British inventor Arthur Cyril Webb Aldis[6] patented a small hand-held design,[7] which featured an improved shutter.

The lamps were usually equipped with some form of optical sight, and were most commonly used on naval vessels and in air traffic control towers, using colour signals for stop or clearance.

The Commonwealth navies and NATO forces use signal lamps when radio communications need to be silent or electronic "spoofing" is likely.