Raffles Lighthouse is a lighthouse located on

Pulau Satumu Pulau Satumu ( Chinese: 沙都姆岛) is an islet to the south of the main Singapore island, and the southernmost island of Singapore. The Raffles Lighthouse is located on the island. The island's name means "One Tree Island"Victor R. Savage an ...

in the Singapore Strait, about south of the main island of Singapore.

History

The Raffles Lighthouse was first mooted in 1833, but the

foundation stone A cornerstone (or foundation stone or setting stone) is the first stone set in the construction of a masonry Foundation (engineering), foundation. All other stones will be set in reference to this stone, thus determining the position of the entir ...

was only laid in 1854 when William John Butterworth was the Governor of the Straits Settlements from 1843 to 1855. The stones on which Raffles Lighthouse stands come from the granite quarries on Pulau Ubin. The lighthouse was named after Sir

Stamford Raffles Sir Thomas Stamford Bingley Raffles (5 July 1781 – 5 July 1826) was a British Colonial Office, colonial official who served as the List of governors of the Dutch East Indies, governor of the Dutch East Indies between 1811 and 1816 and lieut ...

, who founded modern Singapore in 1819. The lighthouse was erected on a rocky island called

, the southernmost island off the main island of Singapore. Pulau Satumu means "one tree island" – ''sa'' refers to ''satu'' ("one") and ''tumu'' is the Malay name for the large

mangrove A mangrove is a shrub or tree that grows mainly in coastal saline water, saline or brackish water. Mangroves grow in an equatorial climate, typically along coastlines and tidal rivers. They have particular adaptations to take in extra oxygen a ...

tree, '' Bruguiera confugata''. The light source was a wick burner which was replaced in 1905 by a pressurised vapour

kerosene Kerosene, or paraffin, is a combustibility, combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in Aviation fuel, aviation as well as households. Its name derives from the Greek (''kērós'') meaning " ...

mantle burner to increase the light intensity for a greater visible range. A 2nd Order optic was mounted on a roller carriage to allow for smooth rotation. (The Order is a system of classifying the type of lenses used based on the

focal length The focal length of an Optics, optical system is a measure of how strongly the system converges or diverges light; it is the Multiplicative inverse, inverse of the system's optical power. A positive focal length indicates that a system Converge ...

of the lens). This roller carriage was a weight-driven machine which had to be rewound manually to lift the weight whenever it reached the base. The rewinding was done hourly. A crew of seven men was required to man the lighthouse. Raffles Lighthouse locator map

In 1968, the installation of a 4th Order electrically operated revolving optic replaced the original 2nd Order optic with a pressurised vapour kerosene "Hood" mantle burner. The light source was changed to a 100-volt/1,000-watt

incandescent bulb An incandescent light bulb, also known as an incandescent lamp or incandescent light globe, is an electric light that produces illumination by Joule heating a filament until it glows. The filament is enclosed in a glass bulb that is either ...

producing 350,000

candela The candela (symbol: cd) is the unit of luminous intensity in the International System of Units (SI). It measures luminous power per unit solid angle emitted by a light source in a particular direction. Luminous intensity is analogous to radi ...

s of light intensity with a visibility range of . The power supply came from one of the three generators installed in a generator room built close to the keeper's room. As the rotation was electrically driven by motors, the crew was reduced to four men. In 1988 the 4th Order optic was replaced by a rotating beacon. This comprised an array of

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...

halogen lamp A halogen lamp (also called tungsten halogen, quartz-halogen, and quartz iodine lamp) is an incandescent lamp consisting of a tungsten filament sealed in a compact transparent envelope that is filled with a mixture of an inert gas and a small ...

s in aluminium

parabolic reflector A parabolic (or paraboloid or paraboloidal) reflector (or dish or mirror) is a Mirror, reflective surface used to collect or project energy such as light, sound, or radio waves. Its shape is part of a circular paraboloid, that is, the surface ge ...

s mounted on a gearless revolving pedestal. The lamps require only one-fifth of the energy required to produce the same intensity as incandescent lamps. These low-power lamps therefore allow

solar power Solar power, also known as solar electricity, is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV) or indirectly using concentrated solar power. Solar panels use the photovoltaic effect to c ...

to be used in place of generators. In addition, the operation of the light is controlled by a

photocell Photodetectors, also called photosensors, are devices that detect light or other forms of electromagnetic radiation and convert it into an electrical signal. They are essential in a wide range of applications, from digital imaging and optical c ...

. The manning of the lighthouse was further reduced to two men. The use of

solar energy Solar energy is the radiant energy from the Sun's sunlight, light and heat, which can be harnessed using a range of technologies such as solar electricity, solar thermal energy (including solar water heating) and solar architecture. It is a ...

which is freely and readily available has resulted in a reduction of operating and maintenance cost.

Present-day lighthouse

The present lighthouse equipment consists of a main and standby rotating beacon, each producing 117,000 candelas with a nominal range of . A radar beacon ( racon) was also installed at the lighthouse which provides additional navigational information to ships by emitting a

Morse code Morse code is a telecommunications method which Character encoding, encodes Written language, text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code i ...

on the ship's radar screen. In 2005, an Aids to Navigation

Automatic Identification System The automatic identification system (AIS) is an automatic tracking system that uses transceivers on ships and is used by vessel traffic services (VTS). When satellites are used to receive AIS signatures, the term ''Satellite-AIS'' (S-AIS) is ...

(AIS) was installed to broadcast additional positioning information to ships.

Coral reef surveys

The National Parks Board, National Biodiversity Centre, Blue Water Volunteers and volunteers from the public started a

coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in group ...

surveying programme in 2005 to monitor the status of hard corals (''

Scleractinia Scleractinia, also called stony corals or hard corals, are marine animals in the phylum Cnidaria that build themselves a hard skeleton. The individual animals are known as polyps and have a cylindrical body crowned by an oral disc in which a mo ...

''), mobile

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

s and

coral reef fish Coral reef fish are fish which live amongst or in close relation to coral reefs. Coral reefs form complex ecosystems with tremendous biodiversity. Among the myriad inhabitants, the fish stand out as colourful and interesting to watch. Hundreds ...

at several locations around five southern islands, including Pulau Satumu on which Raffles Lighthouse is located. Internationally recognised techniques developed by Reef Check and the Global Coral Reef Monitoring Network were adopted for this programme..

References

Notes

Citations

External links

Raffles Lighthouse on the Lighthouse Depot website
(with photograph)

Satellite image of Raffles Lighthouse and Pulau Satumu on Google Maps

Singapore on the Amateur Radio Lighthouse Society World List of Lights (WLOL) website
{{Authority control Islands of Singapore Lighthouses in Singapore Lighthouses completed in 1855 Western Islands Planning Area 19th-century architecture in Singapore