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Oman Today - Adventures in Oman
maritime
Under a minara
 
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The light above Didamar island

How Oman’s lighthouses continue to show mariners the way.
By Stephen Bennett

The Sultanate of Oman has a long and proud maritime history. Seafarers have passed along its ruggedly beautiful 1,709 nautical mile (3,600km) coastline for centuries. The waters through which they have navigated are generally deep and free from offshore dangers, except along the Arabian Sea coast between the Halaaniyat Islands and Masirah where coral reefs and dangerous rocks lie just below the surface. Early mariners relied on their position by looking out for landmarks during the day and by their ability to recognise stars at night. Being shallow draft vessels, their principle navigational hazard was from the wind and sea.

Towards the end of the 19th century, the coast of Oman had been charted and trade was increasing. Until then, ports and anchorages had been identified by flags on headlands or islands, such as Jazirat Sirrah (known locally as Cat Island) off Bandar al Rowdha. The khwar or cove at Muscat (in Arabic, the place of letting down anchors) has sheltered mariners for centuries. The island, Jazirah, which forms the eastern side of the khwar, had long been crowned with a watchtower and fire-beacon. With the size and number of vessels using Omani waters growing, there was a clear demand for improved aids to navigation to guide mariners safely.

The Arabic for lighthouse is minara, from which was derived ‘minaret? a structure which provides direction and guidance. The first lighthouse in Oman was built on the island of Didamar in the Strait of Hormuz in 1914. This is one of the three islands lying about ten miles off the Musandam coast. European seafarers called the two wedge-shaped outer islands Great and Little Quoin after the quoin or wedge that was used to elevate ship-borne cannon. The most northerly and largest island is called Salamah, which is an Omani female name. The Shihuh tribe living in Musandam speak Kumzari. This is a form of Arabic-influenced early Persian with other dialect words thrown in. The Shihuh named the two outer islands Mumar and Didamar; ‘mother?and ‘daughter?and the central rugged island Fanaku.

Tidal flows between the mainland and the islands, the historic course of the ancient river that flowed to the sea when the Gulf was above sea level, run at up to five knots; the strongest tidal streams in Oman. Winds are unpredictable. Sudden squalls and shamal (strong northerly) winds can be experienced throughout the year making navigation through the area difficult. These effects were detailed in the first Persian Gulf Pilot published in 1864. The Committee of Enquiry on Lighting and Buoying of the Gulf, which met in 1909, recognised that a major light should be established to guide vessels through the strait. Given the curvature of the earth, a lighthouse needs to be placed at a high elevation above sea level so that it can be seen over the horizon. Salamah was precipitous and inaccessible, but Didamar, though barren, was conveniently flat-topped. Plans were therefore made to construct a suitable steel tower, lantern house and light-keepers?accommodation on the island. The optic, that is the huge lens that focussed the light into a narrow beam, would be lit using kerosene lamps and rotated by a clockwork mechanism driven by lead weights running down the central pillar of the open framework cast steel tower. The whole installation was first assembled in the UK, each component being given its unique identification mark, before disassembly and shipment to Oman.

The construction was not without difficulty. Apart from the short tidal window at high and low water in which components could be unloaded, a number of the construction team died during the two years it took to complete the installation and are buried on the Island. Another, Albert Wood, was a Chance Brothers engineer. He was taken ill and carried to Muscat in the Royal Indian Merchant Ship Elphinstone, where he died and was buried in Cemetery Bay in August 1912.

Didamar Light was operational by 1914. The giant optic, comprising of three sections with two lenses in each, rotated every 30 seconds and gave off two intense white flashes every ten seconds. This ‘characteristic?gave the light a unique identity which told mariners that they were in sight of the entrance to the Gulf, where Didamar was, and how to navigate past it safely. The clockwork mechanism driving the lantern rotation required rewinding every six hours by a team of seven watch-keepers. The responsibility for its operation was transferred from the Indian Marine Service to the Persian Gulf Lighting Service in 1951. PGLS was later renamed the Middle East Navigation Aids Service (MENAS). One problem faced by all maintenance authorities was, and remains, earth tremors caused by the tectonic movement of the Arabian Plate as it slides inexorably beneath its Eurasian neighbour. While the structure has withstood the shocks, including during the great Makran earthquake of November 1945, the glass lozenges of the lantern house have not. Fortunately spare glass diamonds and triangles were included in the original shipment and have been used when required.

In the mid 1930s Oman’s second lighthouse was commissioned on the northern summit of Jazirat Masqat to guide mariners to the safety of Muscat cove. It is accessible by a rock and concrete path leading from the sheltered khwar below. In the middle of the last century Oman was served by just these two lighthouses. Then with the renaissance in the early 1970s, the demand for new harbours grew again. Lighthouses, shore beacons and buoys would be needed to guide ships into Port Sultan Qaboos and Mina Raysut in Salalah.

Each light or buoy must conform to standards set by the International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA). The atmosphere absorbs light energy. Long range can only be achieved by increasing the intensity of the light. White light is the least affected and is therefore used for the lighthouses and harbour beacons. Green, red and amber light is absorbed more rapidly and is used for buoys or lights at the end of harbour breakwaters. Buoys marking channels into ports are painted either red or green and carry lights of the same colour. Vessels entering the harbour pass red buoys on the port (left-hand) side and green buoys to starboard. The light on each buoy must be given a different flashing characteristic so, like the light at Didamar, it can be distinguished clearly at night from the others. Other buoys, painted with red and white vertical stripes, mark safe water at the outer approaches to a port. These Fairway buoys, such as the one off Mina al Fahl, carry white flashing lights. Buoys that mark isolated dangers such as the wreck off Seeb airport are painted black and yellow, while yellow buoys with amber lights mark dredged limits within harbours or restricted coastal areas. These steel buoys look small in the water, but weigh up to seven tonnes each and are tethered to a three tonne sinker on the seabed by a heavy mooring chain. Each buoy attracts a colony of marine life and needs to be lifted once every two years for inspection and cleaning and it must be replaced by a new buoy every five years.

In the last few years, advances in technology such as GPS have enabled ships to navigate far more accurately. However the majority of vessels using Oman’s waters are small and do not carry sophisticated navigational suites. These small trading dhows, fishing vessels and recreational craft are just as important to an authority supplying aids to navigation service as are LNG carriers and container ships. The international maritime community recognises that the need to provide accurate, well-maintained aids to navigation is essential, and will remain so for the foreseeable future.

As the sultanate’s maritime infrastructure develops so will its requirement for aids to navigation. For example the new port at Duqm will require 15 buoys, six harbour lights and new lighthouses on the south end of Masirah, Ras Madrakah and on the Halaaniyat Islands. For as long as people go to sea, they will require the security that modern aids to navigation supply. Here’s wishing all mariners both large and small safe passage in Omani waters. As they say in Arabic, ma salamah ?go with safety; fare well.

AMNAS

In late 2003, the government of Oman granted Arabian Maritime and Navigation Aids Services ?AMNAS ?a private limited company under the clear guidance provided by the chairman, His Highness Sayyid Shihab Bin Tariq al Said, the exclusive right and privilege to provide an Aids to Navigation service throughout Oman’s waters. As part of its service to mariners, AMNAS commenced a programme of refurbishment and upgrade of the existing aids to navigation. This included Muscat Light and the famous lighthouse at Didamar (26° 28?7N 056° 32?3E) which has just been refurbished at a cost of RO135,000.

The number of aids to navigation that AMNAS services in Oman has grown from two in 1950 to 70 in 2004 to over 100 today. Further details of this and other company activity, including the installation of a major new lighthouse on the headland above the Port of Salalah can be found at www.amnas-oman.com.

The author is the operations and development manager for AMNAS.

Behind the lighthouse

An aid for navigation and pilotage at sea, a lighthouse is a tower, building or framework sending out light from a system of lamps and lenses. Lighthouses also provide coordinate location for small aircraft travelling at night. More primitive navigational aids were once used such as a fire on top of a hill or cliff.

Because of modern navigational aids, the number of operational lighthouses has declined to less than 1,500 worldwide. Lighthouses are used to mark dangerous coastlines, hazardous shoals away from the coast and safe entries to harbours.

Perhaps the most famous lighthouse in history is the lighthouse of Alexandria, built on the island of Pharos in ancient Egypt, built in the 3rd century BC (between 285 and 247BC) to serve as that port’s landmark, and later, its lighthouse. With a height variously estimated at between 115 and 135m it was among the tallest man-made structures on Earth for many centuries and was identified as one of the Seven Wonders of the World by classical writers.

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