The Malacca/Singapore Straits

The Europe-Far East shipping route that traverses the Malacca and Singapore Straits and the South China Sea is one of the busiest in the world. Some 90% of Japan’s oil imports move through this region as do most of the oil imports of the Republic of Korea and Taiwan. Oil moving to China along this route is also increasing. Eastbound tankers proceeding along the Malacca/Singapore Straits through the South China Sea are generally loaded with crude oil from the Middle East and bound for East Asia. They also carry crude oil from Nigeria and Algeria3. The United States Navy also values these straits as well as the archipelagic sealanes through the Philippines and Indonesia as options increasing the mobility and flexibility of its Seventh Fleet. The United States also retains the option of using these straits to transport crude from the Middle East to its west coast.

If the Malacca/Singapore Straits were to be closed – – completely, or to certain vessels – – the principal link between the Indian and the South Pacific Oceans would be either the Sunda Strait to the South China Sea or the Lombok Strait to the Sulawesi Sea. For example, the alternative route for very large crude carriers(VLCCs), 200,000 – 300,000 gross registered tonnes(grt), and ultra large crude carriers(ULCCs), greater than 300,000 grt, with drafts too deep for the Malacca-Singapore Straits, is through the Lombok-Makassar Straits and the Sulawesi Sea south of Mindanao, through the Surigao Strait and on through eastern Philippine waters. VLCCs could save about 1,000 miles or 3 days by using the Malacca/Singapore Straits, and ULCCs coming from the direction of South Africa could save 200 miles4. But the real problem of alternative routes is that most of them pass through either Indonesian or the Philippine archipelagic waters and these countries could, in the worst scenario, seek to close not one but a series of alternative straits at the same time.

Shipping Traffic

Total ship traffic through the Malacca and Singapore Straits of all types and sizes averages more than 150 vessels per day, of which half are ships with sizes of more than 5,000 grt, while those exceeding 30,000 grt make up over 10% of the total. In 1994, 1995 and 1996, the number of vessels passing the One Fathom Bank Lighthouse was 34,446, 30,251 and 31,672 respectively, excluding vessels stopping at Port Klang and fishing vessels5. About 35% of these were oil tankers, i.e., 11,069, 8,915, and 9,815 respectively(Table 1). Thus, an average of 30.3, 24.4 and 26.9 oil tankers per day passed through this section of the Straits in 1994-1996. More than 60% of these tankers were larger than 200,000 grt6. Traffic in and out of the port of Singapore is particularly heavy. A ship either enters or leaves Singapore harbor on an average of every two minutes. In 1996, 117,723 vessels called at Singapore for an average of 9,000 vessels per month. Traversing Singapore Strait to enter or leave the port is like crossing a busy intersection without traffic lights.

Users Of The Straits

In 1993, crude oil accounted for 58% of the interregional cargo tonnage flowing through the Straits of Malacca and Singapore7. Most of it came from the Middle East and went to Japan, with Southeast Asia as a secondary source and the newly industrializing economies as the number two destination. Finished goods, including automobiles, machinery and consumer products, accounted for over 60% of the value of cargoes passing through the Straits.

Japanese interests owned 27.6 % of the tonnage passing through the Straits in 1993, four times more than any other nation. Greece was second with 6.5%, and the United States was third with 6.2% of the tonnage. The rest of the top ten owning nations are divided between maritime nations, such as the United Kingdom and Norway, and Asian nations, such as Singapore and the Republic of Korea. The majority of owners in large states, e.g., Japan, Greece and the United States, use flags of convenience. As much as 90% of the Malacca/Singapore Straits shipping traffic is purely foreign flagged. Norway, Taiwan, and Malaysia are exceptions.

Accidents and Responses

The current common concern of littoral straits states everywhere regarding shipping is oil discharged during routine passage, and accidental oil spills. Although marine casualties are the most dramatic source of oil pollution, routine discharge of bilge water, cleansing of ballast and oil tanks, and leaks are also important sources of oil pollution. Oil spill incidents in the 1970s stimulated agreement on an Under Keel Clearance(UKC)of 3.5 metres for vessels with a draft of more than 15 metres, and the establishment of a Traffic Separation Scheme(TSS)in three critical areas in the straits. The TSS was adopted by the International Maritime Organisation(IMO) – the present recognized arbiter in such matters – and came into effect in May 1980. It was supplemented by a Japan-supplied US$3 million Revolving Fund for the payment of compensation and damages arising out of pollution of the marine environment caused by oil spills. The TSS was initially very effective in reducing accidents in the straits.

However, between 1977 and 1992, there were 72 shipping casualties in the Malacca/Singapore Straits, with 60% occurring since 19878. Collisions and groundings were the most common types of maritime casualties(Table 2). Although general cargo vessels account for the largest percentage of casualties, it is the number of tanker casualties(17%)that is of greatest concern to the littoral States because of their potential to cause serious pollution damage to the environment. There have been 54 such oil spill incidents in the Straits since 1975(Table 3). Major incidents resulting in large oil spills include the Showa Maru, which prompted the imposition of the UKC and TSS; the Diego Silang; and the Nagasaki Spirit. The combined spill from these three incidents alone was more than 26,000 metric tons of oil.

At the end of 1992, two major accidents occurred at the northern entrance of the Straits re-alerting the Straits States to this very real hazard. The response was a series of activities including Malaysia’s convening of a National Conference on the Strait of Malacca on 11 November 1993 and an international conference on the same subject from 14-15 June 1994. Then in mid-October 1997, the Straits suffered from the largest oil spill to date—about 28,500 tonnes of heavy marine fuel—from the loaded eastbound tanker Evoikos which collided with the empty westbound tanker Orapin Global9. This spill was about the same size as that from the Amoco Cadiz. A 20.5-mile long slick drifted into Malaysian and Indonesian waters. Some 16 agencies, 60 vessels and a team of Japanese experts were engaged in the round-the-clock battle to fight the oil spill10.

At the time of the incident, visibility at 8 km was good, the shipping lane was not congested, and the port’s navigation equipment was functioning perfectly. The Vessel Traffic System had warned the westbound empty tanker Orapin Global that it was in the wrong lane and warned both ships three times that they were on a collision course. The managers of the Thai-registered Orapin Global claimed that the eastbound Evoikos cut across the lane for westbound traffic at a narrow angle, rather than at a right angle as required by the TSS. The captains of the two tankers were arrested by Singapore authorities and charged with reckless navigation and endangering human lives(failure to take appropriate action to avoid the collision and failure to reduce speed to prevent serious damage)11. And the Orapin Global was impounded by Malaysian authorities when it was found illegally anchored in its waters. But the litany of disaster continues. In early October of 2000, the tanker Natuna Sea ran aground in Indonesian waters about 8 km southeast of Singapore spilling at least 7000 metric tons of oil12.


Although Malaysia and Indonesia advocate the use of the alternate route east of Bali and Borneo via the Straits of Lombok and Makassar for laden supertankers, very few, if any, follow this advice13. Indeed, almost all supertankers on the main oil route from the Arab Gulf to Northeast Asia use the Straits of Malacca and Singapore because it is the shortest route and, if necessary, they can use the facilities of the Port of Singapore, which is a significant logistical and operational advantage. Larger vessels within the range of 160,000 to 250,000 DWT are definitely testing the “officially” recommended draft limit of 18.5 meters when fully laden. Most tankers of the largest size observed in the region, over a quarter million DWT, operate well in excess of any official guideline when fully laden. However, many of the larger supertankers light load, i.e., take cargoes of less than maximum size, to reduce their draft when they sail through the Straits.

A significant percentage of vessel operators face a close judgment call regarding draft restrictions14. Loading too deep may ultimately contribute to an accident, while loading too light reduces profits. The decision is a trade-off between cost and safety. Supertankers may take as much as ten miles to stop, and they have little control at very slow speeds due to loss of steerageway. The watch officer may be forced to choose between the risk of a collision in the channels and the risk of running aground by leaving the channel.

The dramatic increase in marine casualties in the Straits of Malacca and Singapore since 1992 has prompted angry statements from important political figures in Malaysia and Indonesia. In particular, it has been suggested that the current system is no longer adequate and needs to be revised or at least reviewed15. Suggestions have also been made to either levy a toll on ships passing through the Straits or to make pilotage compulsory for ships passing through the narrowest portions.

However, closer examination of the problem revealed that many marine casualties could not be ascribed to a flaw in the TSS or its obsolescence. Statistics provided by all three Straits States revealed that over 90% of the casualties were caused by collisions–not groundings. The underlying reason for the marine casualties was therefore not hazards to navigation but poor seamanship. Apparently, most accidents were caused by ignorance of the basic rules of road such as “the right of way” of ships passing in opposite directions. Some collisions were also due to the inability of the crewmember at the wheel to understand English. This may be due to the hiring of sub-standard crews by “flag of convenience” vessel owners. This cost saving measure is employed because of continuing low world scale shipping rates and the increased costs of operating oil tanker fleets produced by the strict construction and other standards set by the IMO.