Dent Island Light
Encyclopedia
Dent Island Light is an active lighthouse
located on Dent Island, a small island off the coast of Queensland
, Australia
. Dent Island is part of the Whitsunday Group of the Whitsunday Islands
. Located on the south-west tip of the island, the light guides ships passing in the Whitsunday Passage, between Whitsunday Island
and the islands to the west, and marks the Dent Island Passage.
From its inception, the lighthouse was closely connected to Cape Cleveland Light
. Both lighthouses were recommend, approved, tendered and finally, in December 1879, constructed together.The light went through two upgrades in the 1920s replacing both the oil lamp and the fourth order lens with an incandescent gas mantle and a new lens. In 1983 the light was converted to solar power, and finally in 1987 it was demanned.
The lighthouse is a typical for Queensland, made of a timber frame clad
with galvanized iron plates. It is topped by a Chance Brothers
lantern room, and painted white with a red dome. A modern ML-300 lantern replaced the original lens.
(1868), Low Isles Light
(1877), Double Island Point Light
(1884) and Pine Islet Light
(1885). However, following personal difficulties, the contracts were transferred to John Clark and James Wiseman who completed the construction of both stations in December 1879.
The tower was constructed in the unique Queensland method of constructing a timber frame and cladding it with non-structural iron plates or iron sheets.
The original apparatus comprosed a fourth order lens with an oil wick burner
of 4,000 cd
intensity. Like other lighthouses at that time it used a clockwork
mechanism with weights, which had to be wound periodically. Due to its short height, only 6 metres (19.7 ft) from the base to the lantern, the mechanism had to be wound every 75 minutes.
In 1925, the light was upgraded to a 35mm incandescent gas mantle fueled by pressurised kerosene
, with an intensity of 225,000 cd, visible for 18 nautical miles (33.3 km). In 1927 the lens was replaced with refurbished lens from Cape Cleveland Light
.
In 1983 the light was converted to solar power
and downgraded to a visibility range of 10 nautical miles (18.5 km). It was finally demanned in 1987.
The apparatus is an ML-300 and the light source is a 12 Volt
35 Watt
Halogen lamp
with an intensity of 1785 cd.
with galvanized iron plates, painted white. Access from the entrance to the lantern is via a circular cast iron
staircase. The tower is topped by a 6 foot diameter Chance Brothers
lantern room, white painted with the dome painted red. The modern ML-300 lens is installed inside the lantern room.
The station includes two cottages, constructed in 1960, timber framed, fibro
clad, with galvanised iron roofs. One of the cottages has two storeys and a closed verandah, while the other is single leveled with an open verandah. The station also comprises a winch house, stores shed, engine room and combined workshop/radio room.
. The island is accessible only by boat. However, Dent island is privately owned, so the site is closed to the public.
Lighthouse
A lighthouse is a tower, building, or other type of structure designed to emit light from a system of lamps and lenses or, in older times, from a fire, and used as an aid to navigation for maritime pilots at sea or on inland waterways....
located on Dent Island, a small island off the coast of Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. Dent Island is part of the Whitsunday Group of the Whitsunday Islands
Whitsunday Islands
The Whitsunday Islands are a collection of continental islands of various sizes off the central coast of Queensland, Australia, situated between just south of Bowen and to the north of Mackay, some north of Brisbane. The island group is centred on Whitsunday Island, while the group's commercial...
. Located on the south-west tip of the island, the light guides ships passing in the Whitsunday Passage, between Whitsunday Island
Whitsunday Island
Whitsunday Island is the largest island in the Whitsunday group of islands located off the coast of Central Queensland, Australia. Whitsunday Island is located at...
and the islands to the west, and marks the Dent Island Passage.
From its inception, the lighthouse was closely connected to Cape Cleveland Light
Cape Cleveland Light
Cape Cleveland Light is an active lighthouse located on the northern tip of Cape Cleveland, a promontory projecting into the Coral Sea west of Cleveland Bay and about east of Townsville, Queensland, Australia...
. Both lighthouses were recommend, approved, tendered and finally, in December 1879, constructed together.The light went through two upgrades in the 1920s replacing both the oil lamp and the fourth order lens with an incandescent gas mantle and a new lens. In 1983 the light was converted to solar power, and finally in 1987 it was demanned.
The lighthouse is a typical for Queensland, made of a timber frame clad
Cladding (construction)
Cladding is the application of one material over another to provide a skin or layer intended to control the infiltration of weather elements, or for aesthetic purposes....
with galvanized iron plates. It is topped by a Chance Brothers
Chance Brothers
Chance Brothers and Company was a glassworks originally based in Spon Lane, Smethwick, West Midlands , in England. It was a leading glass manufacturer and a pioneer of British glassmaking technology....
lantern room, and painted white with a red dome. A modern ML-300 lantern replaced the original lens.
History
From its beginning, the lighthouse was closely related to the Cape Cleveland Light. The construction of both lighthouses was recommended by Commander George Poynter Heath, the Chairman of the Queensland Marine Board, in February 1878. The lighthouses were formally approved in April 1878 and tenders for the construction of both stations, each including a lighthouse and two keepers' cottages, were called in May 1878 and closed in June 1878. The tenders were awarded to W. P. Clark, who also constructed Bustard Head LightBustard Head Light
Bustard Head Light is an active lighthouse located on the southeast tip of Bustard Head, a headland, about northwest of 1770, Queensland, Australia, within the Eurimbula National Park. Built in 1868, it is the second oldest lightstation in Queensland, following Cape Moreton Light, and the first to...
(1868), Low Isles Light
Low Isles Light
Low Isles Light, also known as Low Islets Light or Low Island Light, is an active lighthouse located on Low Island, a coral cay which together with Woody Island forms the Low Isles group, about northeast of Port Douglas, Queensland, Australia...
(1877), Double Island Point Light
Double Island Point Light
Double Island Point Light is an active lighthouse located at the summit of Double Island Point, a coastal headland within the Cooloola section of the Great Sandy National Park. It is located at the southern end of Wide Bay, north of Noosa Heads, Queensland, Australia.Though the location was...
(1884) and Pine Islet Light
Pine Islet Light
Pine Islet Light, also known as Percy Isles Light, is an active lighthouse located at Pine Islet, a small islet belonging to the Percy Isles group of the Northumberland Islands, about southeast of Mackay, Queensland, Australia...
(1885). However, following personal difficulties, the contracts were transferred to John Clark and James Wiseman who completed the construction of both stations in December 1879.
The tower was constructed in the unique Queensland method of constructing a timber frame and cladding it with non-structural iron plates or iron sheets.
The original apparatus comprosed a fourth order lens with an oil wick burner
Oil lamp
An oil lamp is an object used to produce light continuously for a period of time using an oil-based fuel source. The use of oil lamps began thousands of years ago and is continued to this day....
of 4,000 cd
Candela
The candela is the SI base unit of luminous intensity; that is, power emitted by a light source in a particular direction, weighted by the luminosity function . A common candle emits light with a luminous intensity of roughly one candela...
intensity. Like other lighthouses at that time it used a clockwork
Clockwork
A clockwork is the inner workings of either a mechanical clock or a device that operates in a similar fashion. Specifically, the term refers to a mechanical device utilizing a complex series of gears....
mechanism with weights, which had to be wound periodically. Due to its short height, only 6 metres (19.7 ft) from the base to the lantern, the mechanism had to be wound every 75 minutes.
In 1925, the light was upgraded to a 35mm incandescent gas mantle fueled by pressurised kerosene
Kerosene
Kerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin or paraffin oil in the United Kingdom, Hong Kong, Ireland and South Africa, is a combustible hydrocarbon liquid. The name is derived from Greek keros...
, with an intensity of 225,000 cd, visible for 18 nautical miles (33.3 km). In 1927 the lens was replaced with refurbished lens from Cape Cleveland Light
Cape Cleveland Light
Cape Cleveland Light is an active lighthouse located on the northern tip of Cape Cleveland, a promontory projecting into the Coral Sea west of Cleveland Bay and about east of Townsville, Queensland, Australia...
.
In 1983 the light was converted to solar power
Solar power
Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as wind and wave power, hydroelectricity and biomass, account for most of the available...
and downgraded to a visibility range of 10 nautical miles (18.5 km). It was finally demanned in 1987.
Current display
The current light characteristic is a white flash every five seconds (Fl.W. 5s) visible at 335°-167°, for a distance of 10 nautical miles (18.5 km).The apparatus is an ML-300 and the light source is a 12 Volt
Volt
The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...
35 Watt
Watt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
Halogen lamp
Halogen lamp
A halogen lamp, also known as a tungsten halogen lamp, is an incandescent lamp with a tungsten filament contained within an inert gas and a small amount of a halogen such as iodine or bromine. The chemical halogen cycle redeposits evaporated tungsten back on to the filament, extending the life of...
with an intensity of 1785 cd.
Structures
The tower is 6 metres (19.7 ft) from the base to the lantern, conical in shape. It is built of an internal timber frame, cladCladding (construction)
Cladding is the application of one material over another to provide a skin or layer intended to control the infiltration of weather elements, or for aesthetic purposes....
with galvanized iron plates, painted white. Access from the entrance to the lantern is via a circular cast iron
Cast iron
Cast iron is derived from pig iron, and while it usually refers to gray iron, it also identifies a large group of ferrous alloys which solidify with a eutectic. The color of a fractured surface can be used to identify an alloy. White cast iron is named after its white surface when fractured, due...
staircase. The tower is topped by a 6 foot diameter Chance Brothers
Chance Brothers
Chance Brothers and Company was a glassworks originally based in Spon Lane, Smethwick, West Midlands , in England. It was a leading glass manufacturer and a pioneer of British glassmaking technology....
lantern room, white painted with the dome painted red. The modern ML-300 lens is installed inside the lantern room.
The station includes two cottages, constructed in 1960, timber framed, fibro
Fibro
Fibro, the shortened form of "Fibrous Cement" - or "Fibrous Asbestos Cement", FAC, is a building material made of compressed fibres cemented into rigid sheets....
clad, with galvanised iron roofs. One of the cottages has two storeys and a closed verandah, while the other is single leveled with an open verandah. The station also comprises a winch house, stores shed, engine room and combined workshop/radio room.
Site operation and visiting
The light is operated by the Australian Maritime Safety AuthorityAustralian Maritime Safety Authority
Australian Maritime Safety Authority is responsible, on behalf of the Commonwealth Government of Australia, for the regulation and safety oversight of Australia's shipping fleet and management of Australia's international maritime obligations...
. The island is accessible only by boat. However, Dent island is privately owned, so the site is closed to the public.