A LPG tanker of 30.000 tonnes dwcc may, in the case that cargo explosion occurs, have an effect of 11 times more than that of the atomic bombs dropped onto Hiroshima and Nagasaki.
AbstractShipping accident is a term generally used for any accident results in financial loss, either in life or property or both. The reasons for shipping accidents are many and complex. Bigger size brings corresponding increases in cargo and passenger capacity; hence when an accident occurs, the risk of life and property immediately becomes higher. Reduced ship maneuverability in connection with larger scale is another contributing factor in shipping accidents.
Several crucial causes play a role in shipping accidents. Natural conditions, technical failures, route conditions, ship-related factors, human errors, cargo-related factors are the striking ones.
Shipping accidents by types are quite many and their impacts on marine environment differ from one another. Collision or contact, capsize, foundering, breaking up, grounding, stranding, breakdown of the ship underway, and fire or explosion are examples of common shipping accidents.
Groundings and shipboard fires are the dominant types of shipping accidents worldwide.
Torrey Canyon disaster has been the cornerstone for the protection of marine environment. The first 20 major oil spills of all time reveal that nearly 2.4 million tones of oil entered the sea due to accidental and operational oil pollutions.
Shipping is and always will be full of risks despite high and ever increasing safety standards. Nevertheless, improved standards for ships, seafarers and shipping management by way of internationally adopted measures have all made and will make a major impact on shipping safety for safer shipping and cleaner oceans.
Shipping accidents and marine environment
1. A crucial problem of shipping activities: oil pollution Often, a shipping incident or a series of incidents provides a spark for a new regulatory framework of international character. For example, the Titanic disaster prompted the first SOLAS Convention; the disastrous grounding of Torrey Canyon made its mark and was instrumental in providing the impetus for the MARPOL Convention; the Estonia case accelerated the thorough review of the safety of roro ferries; the Prestige incident led to increases in the amount of compensation available to the victims of oil spills; both the
Prestige and Erika incidents however caused the regulations surrounding single and double-hull tankers to be reviewed.9 Hence, the ever growing technical, operational and administrative profiles of shipping are shaped to a great extent by the outcome of such or similar incidents.
Oil pollution from ships was first recognized as a problem during the First World War, but there was no attempt to introduce effective measures concerning accidental and operational oil pollutions, nor to deal with pollution by other substances until the Torrey Canyon disaster occurred in 1967.
The grounding and sinking of the Torrey Canyon off the SW coast of
England, which ended up with spilling 120.000 tonnes of oil into the sea, was the worst and biggest oil pollution ever at the time, and for the first time the general public were made aware of the dangers and profound consequences that the carriage of oil posed to the marine environment.
Therefore, the Torrey Canyon incident has been the cornerstone for the protection of marine environment. Before this shipping accident however pollution was regarded as a relatively minor problem.
Marine pollution, particularly by oil, is of great importance because the major pollutant in terms of tonnage is oil. Oil is a general expression to designate a viscous liquid having a density less than that of water. It can include crude oils varying in proportion, and refined oils (such as diesel oil, heavy fuel oil, lubricating oil, kerosene and gasoline). Some oils are toxic to marine life; others are harmful partly due to their smothering effect when deposited. (Smith, 1971)
Oil pollution incidents are caused mostly by shipping activities; either by ship operations such as loading or discharging of oil, bunkering, oil transfer etc.(operational pollution) or ship accidents, mostly by tankers, such as collision, grounding, hull failures, fire and explosion (accidental pollution).
The consequences of an accident can have negative impacts on the affected area, particularly if the accident occurs close to the coastal area. A large oil spill resulting from a shipping activity, or a series of activities, does not hurt only the people directly involved. Neighbouring economies may also be badly affected as a result of a pollution incident occurred in other state’s territorial water. A seaside vacation, swimming, water sports, fishing and fish farming could be ruined by oil pollution. Seafood could be more difficult to find; even harm to fish and wildlife could be immeasurable; the freight of goods carried onboard large ships can increase due to applicable liability compensation(s) after a costly ship accident.
Increasing the dimensions of ships to an incredibly larger size for the good sake of economies of scale has brought in higher risks and ultimately more costly actions in case of emergency.
The implementations of such internationally accepted rules and regulations reduced operational and accidental pollutions considerably.
2. How about if a LPG casualty occurs?
Dangers and environmental threats did not exist long ago; but it does today.
A LPG tanker of 30.000 tonnes dwcc may, in the case that cargo explosion occurs, have an effect of 11 times more than that of the atomic bombs dropped onto Hiroshima and Nagasaki.
Nothing is impossible; it may be argued that a LPG tanker whatever the size is secure enough and petroleum gases carried in cargo tanks in liquefied form do not explode easily; but it can not be measured beforehand how physical or environmental changes can give rise to a violent collision ending up with a very serious threat or how a large fire affects the gas leaking or escaping from a cargo tank…
Another aspect of LPG in case of gas escaping or leakage is the toxicity. As specified in the relevant safety guide, petroleum gas produces narcosis on human being. “The symptoms include headache and eye irritation with dizziness similar to drunkenness. At high concentration these lead to paralysis, insensibility and death”. (ICS, OCIMF and IAPH, 1984)
The human body can tolerate gas concentrations up to 0.2 p.c and irritation of eyes occurs. When the concentration reaches to a level of 0.7 p.c however, drunkenness within 15 minutes takes place and immediate death happens when the concentration is of 2 p.c or 20.000 ppm. (ICS, OCIMF and IAPH, 1984)
3. A study area: The Bosphorus with high accident rate
The Strait of Istanbul, or the Bosphorus, is one of the major and busiest seaways in the world linking the Black Sea to the Sea of Marmara. It is a narrow “S-shaped” channel, open for international shipping. It is also one of the most critical passages in the world for vessels particularly because of its narrowness, its shape with several sharp turns and headlands which limit the opportunity to maintain to a proper look-out and the complex nature and changes of its currents.
Geographical and oceanographic conditions as well as navigational constraints are the main parameters making the navigation through difficult and risky. Additionally, since passage through the Strait entails a run by about 17 nautical miles all the way and takes almost two hours, utmost vigilance is necessary in order to maintain safe standards of navigation and to conduct vessels.
Shipping accidents ended up with mostly oil pollution, large or medium scale, have also occurred in the Bosphorus Region and around 200.000 tons of oil spilled into the sea. The Independenta disaster, one of the majors in the world, besides its fire and explosion threats to the Istanbul area and Istanbuller also added a new but serious dimension to the environmental performance, namely the air pollution. The emission of SO2 NOx and particles given to the atmosphere were equal to the daily emission of the whole city in winter. In the six days period almost 480 tons of SO2 and 104 tons of NOx were emitted to the atmosphere in that area. It is clear that emissions had an impact on the acidic rains measured regionally, as a consequence of emissions and particles being carried to quite remote distances. (Erturk, 1994) Safe navigation in the
Bosphorus is a matter of vital importance to Turkey as well as to all nations using the Strait. Therefore, the dangers posed by ever increasing shipping traffic to the surrounding inhabited areas and to the environment have compelled.
Turkey to take immediate action and to reinforce existing regulations of maritime traffic in the Strait Marine casualties occurring in the Bosphorus involves local factors and are mostly of international interest. Therefore, having studied the casualty cases in-depth one may deduce either one or some of the following reasons are
Major factors and suggest possible solutions:
Factor possible solution(s)
Ships proceeding without a pilot compulsory pilotage / VTS orVTMIS
Bad weather conditions delay passage
Dense marine traffic VTS
Technical inadequacy of ship –
Complex and day-to-day changing nature of current navigation advisory; take pilot
Lack of adequate knowledge about region take pilot; VTS
Loss of alertness and caution impeding delay passage
The safe passage
Existence of areas with sharp turns take pilot; VTS
Darkness and background shore lightings exercise extreme caution
Improper conduct of vessels within the TSS VTS; take pilot
Conclusion
1. Safer shipping ahead Shipping accidents of today have become more “environmental” and the issue has been though than ever for all parties concerned, as those may end up with huge financial losses. Shipping accidents are also a threat to smooth flow of shipping trade and damage to the environment.
Ships are exposed to various external hazards such as darkness, different visibility conditions, bad weather, and currents, which one way or another, may contribute to shipping accidents like collisions, strandings or groundings. Bad look-outs, not taking the proper action until a very late stage, close presence of a third ship which prevents taking early action and a late proper maneuver as against the crossing, overtaking and meeting end-on rules, etc. also constitute the internal threats of such incidents.
Discussion about this post