Skip to main content
Advanced Search
Signal flag from the tug ILUKA, Q
Signal flag from the tug ILUKA, Q

Signal flag from the tug ILUKA, Q

Maker
Date1950s
Object number00006738
NameSignal flag
MediumLinen, canvas, brass
DimensionsOverall: 740 x 950 mm, 0.25 kg
ClassificationsVisual communication
Credit LineANMM Collection
DescriptionPlain yellow linen signal flag representing the letter 'Q', from the tug ILUKA. The plain yellow 'Q' flag, once referred to as Yellow Jack, when visible on a vessel off shore, indicates 'my vessel is healthy and I request free practique'. Practique is license for a ship to enter port on assurance from the captain to authorities that the ship is free from contagious disease. The clearance granted is commonly referred to as 'free pratique'. HistoryThe Commercial Code of Signals was first published in 1857 by a Committee set up by the British Board of Trade. It contained 70,000 signals and used eighteen flags. It was adopted by most seafaring nations to would become known as the International Code of Signals (ICS). An amended Code was completed in 1897 and was distributed to all maritime powers but WWI exposed a number of flaws in the system of ship to ship communication and in 1931, the system was revised. This new ICS was officially brought into force worldwide in 1934 but was still found cumbersome in some ways and in 1969 a more modern and reduced Code was proposed, dropping the geographical and vocabulary sections, and placing more focus on communications related to safety of navigation. The ILUKA was built in 1944 by Central Bridge Company, Ontario and arrived in Sydney in April 1945 as deck cargo aboard the LEWIS HENNEPIN to be part of the Royal Navy Pacific Fleet. In May, ILUKA was declared surplus and offered for sale by the Commonwealth Disposable Commission. After two years in Port Moresby, ILUKA was purchased by the NSW Department of Public Works and stationed on the Clarence River until 1972towing barges used for construction work on the river entrance breakwaters at Iluka and Yamba. In 1973, ILUKA arrived in Sydney after passing into private hands. The vessel, fitted with a Kelvin diesel engine and stern gallows for fishing, was based at the fisherman’s wharf, Black Wattle Bay.SignificanceThe signal flags of the International Code of Signals are used by ships at sea to spellout short messages, or used individually or in combination, have special meanings.