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By Howard C. Reese
The first and most obvious light in which the sea presents itself from the political and social point is that of a great highway; or better, perhaps, of a wide common, over which men pass in all directions...'
Alfred Thayer Mahan
The world economy runs on fossil fuels, chiefly oil, and countries with limited petroleum resources have little recourse but to import. Tankers and pipelines permit the oil-based economy to function and, in the process, oceans, coastal areas, and inland waterways become vulnerable to damage from operational and accidental pollution.
The oil-based economies are growing. In 1963, the world consumed 26,760 million barrels of oil daily.- In 1988, this consumption had expanded to 63,245 million barrels, a gain of 136%.3 Since 1973, the United States has accounted for about one-third of all oil used in the market economies.4 Since 1980, consumption has slowed because of conservation trends and more efficient petroleum use. Nevertheless, energy consumption in the major world economies is projected to grow at an average yearly rate of 1.5-2.1% through 2000.5 This means more—and larger—tankers at sea.
Tankers: Since 1939, the number of tankers has not quite doubled but their average size has increased to the extent that they now move more than 15 times the amount of oil. (See Table 1.) Also significant is the amount of tonnage operating under flags of convenience—Liberian, Panamanian, and Cypriot ships totalling 102.8 million deadweight tons, which is 43% of the tonnage of the key tanker fleets of the world.
Economies of scale influenced tanker growth but the 1956 Arab-Israeli War and the simultaneous closing of the Suez Canal had an even greater impact. The closing of the canal changed traditional navigation routes from Persian Gulf loading terminals to European and other discharging ports, making it necessary for tankers to sail around the Cape of Good Hope to European and U.S. unloading ports. Accordingly, the generation of very large crude carriers (VLCCs)—more than 200,000 deadweight tons—and ultra large crude carriers (ULCCs)—more than
- deadweight tons—came into being. With the Suez Canal impassable, tankers cruising along the East African coast became a familiar sight.6
Tankers currently plying the seas belong to eight size groups; 29% are more than 15 years old. VLCCs and ULCCs are built to meet the high construction standards of the American Bureau of Shipping, Lloyd’s, and Norske Veritas, but these criteria are no guarantee against oil outflows resulting from accidental discharge—the 214,861- deadweight-ton Exxon Valdez—built in 1986—spilled about 11 million gallons of crude oil in Prince William Sound, Alaska, in March 1989.
Oil pollution at sea: It is impossible to determine precisely how much oil goes into the sea yearly.7 Among the variables are the number of vessels at sea, their handling, and on-board procedures to control oil outflow. The post-World War II shift in refinery locations also has had an adverse impact on the marine environment. Until 1939, crude oil normally was refined near the oil fields; after the war, the oil companies moved their refineries nearer consumption centers. In the 1930s, about 80% of the seaborne transport of oil consisted of refined products and about 20% was crude, but these percentages were reversed in the years following 1945. The problem for the environment is that crude oil is more persistent than refined products and remains in the sea with adverse effects on marine animal and plant life.
Tanker operational discharges: Oil pollution at sea is the environmental price paid for the high living standard enjoyed by the industrialized countries; tanker operational pollution accounts for about 50% of the annual marine transportation losses, or about 1.45 million metric tons per year. (See Table 2.) Operational sullying of the seas is subtle and lacks the dramatic effects of accidental discharges and is generally overlooked by press and public. Nevertheless, it goes on continuously.
Tankers, like all ships, leak. Leakage stems from pipes, bilges, and bunkers and has little to do with superior or faulty tanker management. Badly managed tankers, however, are “...ceaseless polluters, and like garden snails, can often be followed by the iridescent trail of their waste.”8 The problem in 1989-90 is not as glaring as it
These ships anchored off A1 Fujayrah in the United Arab Emirates typify those traversing the "wide common. Tomorrow's ocean environment depends on today's shipbuilders and operators.
Number of
Deadweight
of Tankers
Tonnage
merit in Barrels Per Day, 1939-1987
ase, Barrels Per Day, Percent Increase)
Daily Movement In mt Barrels
Per Day
Percent
Increase
leum Facts & Figures, 1971 Edition (Washington, D.C.: f
leum Facts and Figures Centennial Edition (New York: No World Statistical Tables (London: Clarkson Research Studi
terey," June 1989, The British Petroleum Company, p.i.c
was in the late 1960s but, given the number ot tamcers at sea, it would be naive to conclude that leakage has been eliminated. Operational discharges also are an outgrowth of specific and necessary tanker procedures such as deballasting. (See Table 3.)
The 135-member International Maritime Organization (IMO)s has recommended improvements in tanker procedures but has no powers of enforcement. The International Convention for the Prevention of Pollution from Ships, as modified by the Protocol of 1978 (MARPOL 1973/1978), is one of its notable successes. The protocol recommended segregated ballast tanks, dedicated clean ballast tanks (CBTs), and crude-oil-washing systems (COWs) for tankers carrying crude oil.
Before the introduction of the load-on-top (LOT) method in the mid-1960s, tankers released cargo tank residues into the sea to cut costs, a practice that entailed pumping out one percent of the cargo.9 Concerning LOT, a distinction should be made between long- (more than 71 hours oi 1,200 nautical miles) and short-haul voyages of less duration or mileage. On long-haul trips, tankers should be
able to use LOi procedures wun nu unucunj,
that the weather is good. In contrast, ships on shorter trips
may not be able to do so. This is a shortcoming of the
regulations.
The major oil companies and the more responsible managerial organizations usually adhere to recommendations for on-board technology to preclude emitting oil residues into the sea. Unfortunately, such conformance does not extend to some of the independent owners and operators, who concentrate on the spot oil-transport market, and have little interest in adding to their operating costs by installing equipment to retain oil residues. Compounding the problem, the major oil companies frequently charter or contract for tonnage from small independent owners.
Nontanker operational discharges: Virtually all ships contribute to oil pollution at sea. As of late 1988, there were 385,900,900 deadweight tons of dry-cargo shipping at sea; any leaks from on-board machinery—lubricating oil, hydraulic fluid, fuel—inevitably flows into their bilges.
That accidents will continue to happen is a fact—but regulations now going into effect will limit the resulting pollution and damage to the environment.
Tanker accidental discharges: Terminal spills constitute a small percentage of marine pollution generally; the problem is their proximity to the shore. More sensational are the outflows from structural failures, groundings, collisions, and other causes that account for 75% of all oil lost.10
In 1988, 5,000 to 6,000 spills involving oil or other toxic substances occurred along U.S. coasts and other navigable waters. Twelve involved spills of more than
- gallons, and ten involved spills ranging from
- to 100,000 gallons. In the late 1970s, there were
- spills a year. The record is improving, but the problem remains serious."
This was confirmed on 12 June 1989, just two months after the Exxon Valdez catastrophe, when within a 12-hour period three accidents occurred along the U.S. Northeast and Gulf coasts. One tanker struck a reef, another hit a rock, and a barge collided with a cargo ship. The total spillage of number 2 and number 6 fuel and heavy crude oil was 800,000 gallons.
The record of large-scale tanker accidental discharges is replete with examples dating from March 1967 when the Torrey Canyon, a Liberian-flag tanker, grounded five miles off the Cornish coast in the United Kingdom, releasing 860,000 barrels of crude oil and becoming the first spill to attract serious public and scientific attention.
Prospects for monitoring oil spills at sea are limited. Tankers have been known to clean out their tanks near the wrecks of damaged tankers, despite the navigational risk. It is difficult to say whether this practice, which usually takes place at night, continues. With few or no surveillance ships in the vicinity, however, unscrupulous tanker masters are virtually free to do as they please. In U.S. waters, the Coast Guard checks tanker pollution out to 150 miles offshore. Until 1987, its planes maintained a routine oil pollution watch, but because of a change of priorities, i.e., the need to keep seaborne drug trafficking under increasing surveillance, the Coast Guard cut back its scrutiny of oil pollution.
The geographic distribution of petrohydrocarbons from operational and accidental discharges is uneven. Roughly one-half the transportation total stems from tanker operations and most of this loss occurs along the main tanker routes from the Middle East to Europe, to the American continents, or to the Far East. Bilge and fuel oil discharges probably reflect more or less the same pattern as tanker operations. The control of accidental pollution depends on structural and equipment standards, ship traffic management, and the technical competence of crews.
Structural and equipment standards: Can the hazards of the seaborne transport of oil be made less hazardous? The answer, or at least part of it, lies in the adoption of certain improvements and construction features, such as protective locations and segregated ballast tanks (PLs/SBTs), and double bottoms/double hulls.
Shipowners adopted PLs/SBTs after the recommenda
tions of MARPOL 1973/1978. Estimates in late 1989 conclude that all tankers in service used them. The main function of PLs/SBTs is pollution control through elimination of cargo-tank ballasting, but some protection is also afforded against groundings or collisions. The diversity within the tanker community and the absence of a policing mechanism suggest that it would be optimistic to assume that PLs/SBTs function as intended in every instance—the Exxon Valdez had PLs/SBTs.
In its study of the Exxon Valdez grounding, the National Transportation Safety Board analyzed these features and was critical of their arrangement. As prescribed by MARPOL 1973/1978, the ship was required to have 68,000 square feet of total protected shell area. She met this requirement with number two and number four port and starboard wing tanks as the staggered SBTs, which resulted in about 46,000 square feet of side protection and about
- square feet of bottom protection. This layout, however, safeguarded only about 35% of the total cargo tank side shell and about 20% of the total tank bottom areas. The latter, moreover, did not protect the bottom of any tank with cargo oil.12 The study concluded that current standards for segregated ballast and cargo tank size do not offer enough protection against oil spills resulting from groundings or collisions.13
The location of PLs/SBTs is at the ship owner’s option, as long as they cover a specified percentage of a vessel’s length, i.e., 3(M-5%. As of 1978, the Coast Guard considered them equivalent to double bottoms because they offer some protection in a grounding or collision. Naval architects generally did not concur. The primary difference is that double bottoms cover a greater part of a vessel’s length. Controversy exists among shipowners and naval architects on the real or potential advantages of double bottoms. (See “Can Double Bottom Tankers Reduce
Type of Loss
Table 2 Summary of Transportation Losses (million metric tons per annum average per vessel) Range
Best Estimate
Tanker operations Dry-docking Marine terminals Bilge and fuel oil Tanker accidents Nontanker accidents Total
0.44-1.45
.02-0.05
0.01-0.03
0.16-0.60
0.35-0.43
0.02-0.04
1.00-2.60
0.71*
0.03
0.02
0.28
0.39
0.02
1.45
—o-75 p™babie> -d °-4-‘-5 ^
range) million metric tons per annum of hydrocarbons into the sea. Ibid., p. 73
Activity
Table 3 Selective Operational Discharges by Type and by Activity
CmselSource Whop Type of Oil Ommenoeaeueee
Loading and discharging; loading new cargo Dry-docking
Ballast and tank washing water
Tank washing residue
After discharge, before taking on new cargo Every 18-24 months
Crude
Marine terminal operations
Spillages, human error, line or hose failures
Bunker
operations
"LOT—Method whereby retention-on-board steps are underscored where dirty ballast water, ta S'
discharge at terminals. Can only be used for crude and other heavy oils.
"When COW systems are fully executed, retained slops are reduced to a'°«er 'e™1 . Envjronment Update, Source: National Research Council. Steering Committee for the Petroleum n the ^ E"—c P
Sciences Board, Commission on Physical Sciences. Mathematics and Resources, 0,1 m ,he Sea mp Academy Press, 1985), p. 59
Load-on-top (LOT)a
Reduction of sludge/slop because of more efficient and crude oil washing systems (COW)b Better monitoring procedures
oily residues are held in slop tanks for
Board on Ocean Science and Policy, Ocean and Effects (Washington, D.C.: National
Pollution?” Proceedings June 1990, pages 85-88.)
Navy vessels, including half the oilers as well as chemical and liquid natural gas ships, have double bottoms. In late 1987, 400 tankers, about 13% of the world tanker fleet, met this standard. As of early 1990, 25% ot the 225 U.S.-flag tankers have double bottoms.
A double-hull vessel has a double bottom and double sides. Worldwide, 600 tankers—about 19% of all tankers in service—have double hulls. Twenty-five sail under the IJ.S. flag. The Oil Pollution Act of 1990, Public Law 101380, mandates double hulls and double bottoms on a graduated scale extending to 2015. The act requires the Secretary of Transportation to study new technologies that could improve or replace existing double bottom and double-hull construction. Retrofitting a 200,000 deadweight- ton tanker with a double bottom is estimated to cost $6070 million. Insurance charges, however, should be lower. Building a new tanker with a double bottom would add 5-10% to the basic construction cost.
On balance, however, advantages outweigh disadvantages. The benefits are to be found in a reduction ot the
tank-washing effort, lower cleaning costs, and improved pumping qualities.
In 1973 a Coast Guard Marine Board of Investigation, convened to study a mishap involving the Standard Oil of California tanker Hillyer Brown, took a pro-double-bottom position.
The Board recommended that the Commandant of the Coast Guard consider that all tankers sailing U.S waters have double bottoms under all cargo tanks and pump rooms 14 A Coast Guard study concluded from a review of 30 tanker bottom mishaps over the period mid-1969 to February 1974, “...no pollution would have occurred in 27 cases (including Hillyer Brown), if a double bottom had been installed.
The oil companies, notably Exxon, fought double bottoms on technical and financial grounds, pointing out the disadvantages and suggesting that these drawbacks did not justify higher construction costs.
Reflecting this negative response, the International Conference for the Prevention of Pollution from Ships (1973) rejected double bottoms. The Coast Guard proposed alternatives: improved ship and shore navigation aids, more realistic training of shipboard personnel, and the technical competence of crews.
There is no doubt that adoption of LORAN C (Long Range Navigation) with its impressively increased accuracy and coverage is beneficial. Few would argue against the value of simulators in imparting a sense of realism to instruction of deck and engine crews. This technology, however, is no substitute for tighter structural and equipment requirements, i.e., double bottoms and double hulls.
Nor should traffic-management schemes be overlooked. Traffic Separation Schemes (TSS) and Vessel Traffic Services (VTS) are essential in heavy shipping lanes.
Coast Guard budget cuts caused delays in upgrading the Prince William Sound Vessel Traffic Service. When the Exxon Valdez grounded in Prince William Bay, the VTS microwave system there was more than 12 years old and improvements were needed for the microwave transmission system, which is the essential link between the remote radar and communication sites and the Vessel Traffic Center. The requirement to upgrade the system was apparent, but money to overhaul it was unavailable.17.
The Secretary of Transportation is reviewing 23 U.S. ports to establish priorities for installing various levels of traffic services.
Human factors: Boredom, to some degree, has become a part of tanker operations because of tight scheduling. A tanker loads in the Persian Gulf in 12 to 18 hours before beginning its long voyage to its final destination. Tankers spend less than 10% of their time in port, and operational costs are based on a ship at sea 300 days per year. As a result, crewmen frequently remain on board ship a year or more; even longer periods are on record. Nevertheless, the principal oil companies and responsible tanker operators try to give their crews a fixed rotation of service and leave.18
Because personnel account for 30% of tanker operational costs, it is in the ship owner’s interest to reduce the size of the crew. Automation has been the usual answer. Paradoxically, tankers have increased in size, while their complement has gone down. A T-2 tanker, for example, had a crew of about 38, while a 200,000 deadweight-ton vessel has 19 or 20. The reduction has had mixed benefits on morale and efficiency.
The degree of supertanker automation varies. One-man engine rooms are common. The one-man bridge awaits approval by appropriate international conventions. A Danish product tanker, the 84,000 deadweight-ton Petrobulk Mars, claims to be the first of this type. She meets the requirement of Det Norske Veritas's new Watch 1-Ocean Areas and Coastal Waters designation. This stipulation means that one person can operate the bridge, day or night, under normal conditions. Currently, a one-man bridge is approved only during the day with the authorization of the highest ranking officer of the watch.Several maritime states are working for a night extension. The United States opposes in principle the one-man bridge concept.
Curiously, automation bears with it further tedium. While easing some work procedures, automation also isolates the individual from the challenge of hands-on tasks. There is little quarrel with the general purpose of easing the work through integrated bridges and other systems, but only as aids, not simply to replace personnel. Yet, the trend is toward more automation.
Oil pollution at sea is thus a consequence of economic growth, based on continuing access to petroleum products—and the tankers provide the access. Segregated ballast tanks and protective locations to keep oil residues on board for discharge at terminals are in general use. Double hulls and double bottoms, especially the latter, have been slower to gain acceptance. The dismal record of oil outflows caused by tanker mishaps in 1989 has led to pending congressional legislation for adoption of these features. Recommendations of the IMO regarding improved tank cleaning and deballasting methods have met with widening approval.
Despite some residual opposition, the charter party has included clean-seas clauses to ease the costs to tanker operations for retaining oil residues aboard. This practice began in 1964 when three oil companies, British Petroleum, Shell, and Exxon (then Esso) began to insert these clauses into charter parties.
However hopeful these developments may be for protecting the marine environment, an aging world tanker fleet and imperfect adherence to responsible operating procedures counter them. There can be no reliance on any one measure; corrective actions must embrace technical, economic, environmental, and political means.
'Captain A.T. Mahan, The Influence of Sea Power Upon History 1660-1783, (Boston: Little, Brown and Company, 1893) p. 25.
The British Petroleum Company, “Statistical Review of the World Oil Industry, 1963,” p. 9.
"’British Petroleum Statistical Review of World Energy,” June 1989, p. 10.
4U.S. Department of Energy, Energy Information Administration, “International Energy Outlook Projections to 2000,” Washington, D.C., March 1989, p. 19. 5Ibid, p. 23.
in 1956, boats with a maximum draft of 34 feet a maximum beam of 210 feet could use the canal. The Egyptian Canal Authority plans to deepen the draft to 88 feet. Information supplied by The Defense Mapping Agency, 15 October 1989. ’National Research Council, Oil in the Sea Inputs, Fates and Effects, (Washington, D.C.: National Academy Press, 1985), see especially pp. 56-65.
"Noel Mostert, Supership (New York: Alfred A. Knopf, 1974) p. 44.
9Daniel Behrman, The New World of the Oceans, Men and Oceanography (Boston, Toronto: Little, Brown and Company, 1969) p. 375.
IUR. Michael M’Gonigle and Mark W. Zacher, Pollution Politics and International Law Tankers at Sea (Berkeley, Los Angeles, London: University of California Press, 1979) p. 20.
"The New York Times, 29 June 1989, p. A-20.
’’National Transportation Safety Board, “Marine Accident Report Grounding ot the U.S. Tankship Exxon Valdez on Bligh Reef, Prince William Sound Near Valdez, Alaska, March 24, 1989,” PB90-916495 (NTSB/MAR-90, Washington, D.C.: March 1990) p. 163.
Tbid, p. 170.
UU.S. Department of Transportation, Coast Guard, Marine Casualty Report, “Grounding of the SS Hillyer Brown at Cold Bay, Alaska, on 7 March 1973 Without Loss of Life,” 31 March 1975, p. 19.
Tbid
'The Coast Guard furnished this information.
’’National Transportation Safety Board, op. cit., p. 160. lxMostert, op. cit., p. 29.
''"’Marine Log,” December 1988, p. 12.
Mr. Reese writes on maritime and naval affairs. He holds a doctorate in modern European history from New York University and is a retired Lieutenant Colonel, U.S. Army Reserve.