A marine foghorn gives an audible navigational signal to warn vessels of dangers, hazards and the presence of other vessels in fog conditions. The foghorn signal is a series of long and short sounds with short or long pauses between them. These common signals conform to a code called the International Regulations for Preventing Collisions at Sea and provide such information as whether the vessel is under sail or motor, large or small, aground or at anchor. The designs of foghorns vary but they all use a column of air to make a loud sound. Some use vibrating plates or metal reeds, others force air through holes in a revolving cylinder or disc, sounding like a siren, and some use a clockwork mechanism to open the valves that let the air into the horn. They are usually built to meet particular specifications e.g. U.S.C.G. (US Coast Guard). This Tyfon plunger foghorn has a horizontal handle attached to a vertical rod that moves up and down inside a cylinder. When the handle is plunged down, in a similar way to a bicycle pump, the air is forced out of the bottom of the cylinder into a pipe with a bell-shaped horn on the end, making a loud, low sound. The wider base of the cylinder helps to keep it stable. The original type Tyfon foghorns were manufactured in about 1910 by Kochums Mechanical Workshop (Kockums Mechanical Werkstad, Ltd.), Malmo, Sweden. The company was established in 1840, became a Limited company in 1866, and established a shipyard at the Port of Malmo, Sweden, in 1870. The civilian ship production in Malmo ceased in 1987. As well as building ships the company built large industrial and agricultural machinery and maritime goods.this replica foghorn represents the design of a Swedish, Tyfon model 1910. It is an example of the type of safety equipment used on marine vessels to signal other vessels and signal to land. Replica foghorn; portable marine, plunger operation. It has a brass cylinder and adjustable brass horn. The plunger handle and base are wooden. Inscriptions are on the plaque on the horn and moulded into the air intake. Facsimile of a Kockums of Malmo, Sweden, Tyfon model 1910 Fog Horn.Impressed into the attached plaque "KOCKUMS MLK. VERKSTAD / MALMO SWEDEN" and "TRADE TYFON MARK" Also added to the plaque individually "288938" Molded around the circumference of the air intake "TYFON PATENT"flagstaff hill, warrnambool, shipwrecked coast, flagstaff hill maritime museum, maritime museum, shipwreck coast, flagstaff hill maritime village, great ocean road, foghorn, fog horn, tyfon foghorn, kockums mlk verkstad, malmo sweden, replica, warning signal, safety equipment, ship's equipment

Defence Instruction (Air Force) AAP 7832.002-4-3