Case Histories - T

TANIO (France, 1980)

TANIOOn 7 March 1980 TANIO, carrying 26 000 tonnes of No. 6 fuel oil, broke in two during violent weather conditions off the coast of Brittany, France. As a result approximately 13,500 tonnes of cargo oil was spilled. The stern section, with about 7,500 tonnes of cargo oil aboard, remained afloat and was towed to Le Havre; the bow section, carrying 5,000 tonnes of cargo oil, sank to a depth of 90 metres. Strong northwest winds at the time of the incident moved the oil towards the Breton coast (which had already received major oil impacts from the TORREY CANYON spill in 1967 and the AMOCO CADIZ in 1978). Due to the high viscosity of the oil and severe weather conditions, neither chemical dispersal nor containment and recovery techniques at sea were possible. The spilled oil began to be washed ashore on 9 March, and eventually contaminated about 200km of coastline to varying degrees. Many of the worst affected areas could not be boomed effectively because of the nature of the coastline, the extremely large tidal range (9m) and the severity of the weather at the time of the accident.

As tourism is of major importance in Brittany, the main emphasis of the cleanup operation was to return amenity areas to a usable condition as quickly as possible. In severely contaminated areas, bulk oil was removed by the use of tractor-drawn vacuum trucks, but this technique could not be used on cold, cloudy days when the oil became too viscous. Owing to concern that a forthcoming high tide would extend the shoreline contamination, it was decided that a more rapid removal of the bulk oil was required. Heavy earth-moving equipment (bulldozers and front-end loaders) was therefore used despite the well-known detrimental effects of driving heavy equipment over severely oiled beaches. While much oil (and a considerable amount of beach material) was removed within a short time, the underlying sediments at a number of sites were heavily contaminated and required extensive restoration work at a later stage. Where access was difficult or where the deposits of oil were thin or well spread out, men with shovels were employed to pick up the oil and to put it into sacks or tractor-drawn trailers. Oil collected during the cleanup operation was taken to a tanker deballasting station for treatment. The removal of bulk oil was followed by the cleaning of the rocks in the tourist areas, using hot water washing machines and high pressure cold water jets. Released oil was collected using granular mineral sorbents and dispersants were used in cases of severely contaminated rocks. By the time the cleanup operation was completed at the beginning of July most of the beaches and accessible rocks had been restored to something approaching their pre-spill state.

The TANIO spill presented considerable cleanup problems to which there was no easy solution, but the low toxicity of the oil meant that the environmental effects were limited. Approximately 1,700 dead birds, primarily guillemots and other auks, were recovered during the incident, and there were some localised effects - such as contaminated oyster beds and disrupted seaweed harvests - caused by the smothering of intertidal life and by the extensive cleanup operations at the worst affected areas.

Selected Bibliography

Ganten, R.H. (1985). The Tanio spill: A case history illustrating the work of the International Oil Pollution Compensation Fund. Proceedings of the 1985 Oil Spill Conference, 135-139. API Publication No.4385. American Petroleum Institute, Washington DC, USA

Brac, C. (1981). Operation Tanio. La Nouvelle Revue Maritime. July, 363, 10-25.

Links

CEDRE - Case History
http://www.cedre.fr/en/spill/tanio/tanio.php

 

TASMAN SPIRIT (Pakistan, 2003)

TASMAN SPIRITThe Maltese tanker TASMAN SPIRIT (87,584 DWT) grounded at the entrance to Karachi Port, Pakistan in the early hours of Sunday 27 July 2003. The vessel was carrying 67,800 tonnes of Iranian Light crude oil destined for the national refinery in Karachi. There were also 440 tonnes of heavy fuel oil in aft bunker tanks. The condition of the grounded tanker deteriorated as she was subjected to continuous stress from the heavy swell of the prevailing south-west monsoon and the vessel subsequently broke in two. In total, it is estimated that some 30,000 tonnes of oil was spilled from the TASMAN SPIRIT.

In the course of inspections on board the TASMAN SPIRIT it became apparent that most of the cargo tanks had been ruptured, whilst the bunker tanks remained intact. The owners appointed salvors and also hired a succession of small tankers and barges for the purpose of shuttling and storing oil lightered from the casualty. During the next few weeks roughly half of the crude oil cargo and most of the bunker fuel was successfully transferred from the casualty.

On 11 August the tanker began to show signs of breaking up and eventually broke in two overnight on 13/14 August, spilling several thousand tonnes of crude oil. Much of the spilled oil quickly stranded on Clifton Beach, the main tourist beach in Karachi, but significant quantities remained afloat both inside and outside Karachi port. Dispersants were applied offshore from a Hercules C-130 aircraft equipped with an aerial dispersant spraying system (ADDS Pack) in response to two distinct pollution events involving the progressive break-up of the tanker. Approval for large scale dispersant use was given by the Karachi Port Trust (KPT) and the Pakistan Environment Protection Agency.

Oil entering the port of Karachi was confined by deploying booms at suitable collection sites, and in total some 140 tonnes of oil were recovered by skimmers. KPT also deployed vessels to apply dispersant on oil drifting through the port entrance.

The severe pollution of Clifton Beach created very strong oil vapours causing considerable discomfort to local residents and clean-up personnel. Local hospitals reported many cases of headaches, nausea and dizziness and seventeen schools in the vicinity were closed for about a week. The beach was cleaned by a combination of manual and mechanical means, but work was hampered by a lack of suitable disposal sites for collected oily waste. Agreement was eventually reached for disposal at one of the municipal waste sites serving Karachi City. Clifton Beach was re-opened to the public in the middle of October.

Given the low persistence of Iranian Light crude oil and the high mixing energy in the many damaged cargo tanks generated by the incessant heavy swell, it is likely that most of the spilled oil dispersed naturally. Field surveys conducted showed little or no impact on mangroves, salt pans and other sensitive resources in the vicinity. The geographical extent of shoreline oiling was limited to a ten-mile radius around the grounded tanker.

Whilst there were few reports of repercussions of the oil on fisheries, a three-month fishing ban was imposed by the Marine Fisheries Department along the coastline directly affected by oil, extending five nautical miles offshore.

Links

CEDRE - Case History

http://www.cedre.fr/en/spill/tasman_spirit/tasman_spirit.php

 

TORREY CANYON (United Kingdom, 1967)

TORREY CANYONTORREY CANYON ran aground on Pollard Rock on the Seven Stones Reef, near Lands End, Cornwall on 18 March 1967. Thousands of tonnes of oil were soon spilling from the stricken vessel's ruptured tanks and during the next 12 days the entire cargo of approximately 119,000 tonnes of Kuwait crude oil was lost.

A wide variety of methods to mitigate the spill were tried. Burning the slick proved unsuccessful, and eventually the British Government gave orders for TORREY CANYON to be destroyed by aerial bombardment in the hope that all the oil still remaining on board would be burnt off. This operation was partially successful, but did not prevent escaping oil from polluting many parts of the south west of England, causing the deaths of thousands of seabirds and threatening the livelihoods of many local people in the forthcoming summer tourist season. Later the drifting oil polluted beaches and harbours in the Channel Islands and Brittany.

A distinguishing feature of the TORREY CANYON response operation was the excessive and indiscriminate use of early dispersants and solvent based cleaning agents, which caused considerable environmental damage. The dispersants were generally successful at their task of reducing the amount of oil arriving ashore and subsequently expediting onshore cleanup operations, but they were considerably more toxic than those used today and were applied in far greater concentrations, often being poured undiluted on slicks and beaches. Many of the detrimental impacts of the spill were later related to the high volume, high concentration and high toxicity of the dispersant and detergents used.

The TORREY CANYON was the first major tanker disaster to be brought to the notice of the general public due to enormous media coverage, and drew universal attention to the dangers of dispersants. The spill triggered the international Conventions, which form the basis for compensation for damage caused by tanker spills, and interim voluntary agreements to bridge the gap before the Conventions entered into force and became widely accepted.

Selected Bibliography

Zuckerman, S. (1967). The Torrey Canyon. Report of the Committee of Scientists on the Scientific and Technological Aspects of the Torrey Canyon Disaster. Departments of State and Official Bodies. Cabinet Office, London, UK

Petrow, R. (1968). The black tide: in the wake of Torrey Canyon. Hodder & Stoughton, London, UK

Southward, E.C.& Southward, A.J. (1978). Recolonization of rocky shores in Cornwall after the use of toxic dispersants to clean up the Torrey Canyon spill. Journal of the Fisheries Research Board of Canada 35 (5) 682-706

Links

CEDRE - Case History

http://www.cedre.fr/en/spill/torrey/torrey.php

 

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