Lighthouse
Raffles Lighthouse
(
Chinese
:
?佛士?塔
;
Malay
:
Rumah Api Raffles
;
Tamil
:
????????? ??????? ????????
) is a lighthouse located on
Pulau Satumu
in the
Singapore Strait
, about 14 kilometres (8.7 mi) south of the main island of
Singapore
.
[1]
History
[
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]
The Raffles Lighthouse was first mooted in 1833, but the
foundation stone
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
, who founded modern Singapore in 1819.
The lighthouse was erected on a 1.3-
hectare
(3.2-
acre
) rocky island called
Pulau Satumu
, 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
tree,
Bruguiera confugata
. The light source was a wick burner which was replaced in 1905 by a pressurised vapour
kerosene
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
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.
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
producing 350,000
candelas
of light intensity with a visibility range of 22
nautical miles
(41 km; 25 mi). 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
halogen lamps
in aluminium
parabolic reflectors
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
to be used in place of generators. In addition, the operation of the light is controlled by a
photocell
. The manning of the lighthouse was further reduced to two men. The use of
solar energy
which is freely and readily available has resulted in a reduction of operating and maintenance cost.
Present-day lighthouse
[
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]
The present lighthouse equipment consists of a main and standby rotating beacon, each producing 117,000 candelas with a nominal range of 20 nautical miles (37 km; 23 mi). A radar beacon (
racon
) was also installed at the lighthouse which provides additional navigational information to ships by emitting a
Morse code
on the ship's radar screen. In 2005, an Aids to Navigation
Automatic Identification System
(AIS) was installed to broadcast additional positioning information to ships.
Coral reef surveys
[
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]
The
National Parks Board
,
National Biodiversity Centre
, Blue Water Volunteers and volunteers from the public started a
coral reef
surveying programme in 2005 to monitor the status of hard corals (
Scleractinia
), mobile
invertebrates
and
coral reef fish
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.
[2]
See also
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]
References
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]
External links
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]
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Operational
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Historical
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