Raffles Lighthouse
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| Raffles Lighthouse | |
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| Location: | Pulau Satumu, Singapore |
| Coordinates | 1°09′33″N 103°44′27″E / 1.15917°N 103.74083°E |
| Year first constructed: | 1855 |
Raffles Lighthouse (Chinese: 莱佛士灯塔; Malay: Rumah Api Raffles) was built in 1855 on Pulau Satumu (‘One Tree Island’ in Malay). Named after the founder of colonial Singapore Sir Stamford Raffles, the foundation of the lighthouse was laid in 1854 by the late Colonel W. J. Butterworth who was then the Governor of the Prince of Wales Island, Singapore and Malacca.
The light source was by 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 100-volt/1,000-watt incandescent bulb producing 350,000 candelas of light intensity with a visibility range of 22 nautical miles (about 40 km). 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 4 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 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 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.
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 (about 37 km). 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.
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