The Oil Companies International Marine Forum (OCIMF) recently issued guidelines in an effort to help the development of company risk assessments for vessels operating in Turkish Straits.
It is known that the Turkish Straits are some of the busiest waterways in the world, as they are the only waterway connection between the Black Sea and the Mediterranean Sea. However, those straits present a unique navigational challenge.
Therefore, the paper considers new and updated regulations and traffic systems, outlines risks of, and recommendations for, transiting the Turkish Straits to safety of navigation.
In light of the situation, OCIMF Managing Director Robert Drysdale said:
It’s difficult to imagine a more congested stretch of water with the potential to cause serious environmental impact in the event of an incident. Preparation and implementation of a robust transit plan is critical for the Turkish Straits. These updated guidelines will provide some assistance to operators in planning their transit.
Among others, OCIMF members have assessed the risks of transiting Turkish Straits. From the assessments, the following conclusions have been drawn:
- The current combination of the TSS, traffic rules and the VTS means that a casualty in the Straits involving tankers over 200 metres long is now much less likely.
- While vessels 200 metres or longer can cause the largest oil spills, casualty data shows that the number of incidents that they cause and their overall pollution risk are both significantly lower than for smaller vessels. This is likely because of the current rules requiring one-way traffic.
- Analysis of incident data shows that spills are caused more often by tankers that are less than 200 metres long. Tankers of this length are less rigorously restricted and are often treated like non-dangerous/hazardous cargo vessels. Their casualty rate is about the same as that of non-dangerous/hazardous cargo vessels. Although they only account for about 10% of the transiting population, they make up 80% of the oil spill risk.
- There may be vessels transiting the area that may not be double-hull ships. Some of them may have a double-bottom cargo area but bunker tanks may not be in a protected location. This remains an area of concern.
- Tankers transiting in ballast, mainly northbound, have a much lower risk of pollution. This is partly because northbound tankers have very little cargo on board, as well as their added manoeuvrability and ease of anchoring when navigating against the prevailing currents.
According to OCIMF, experience shows that the Turkish Straits can be transited safely. However, because of their topography and marine traffic density, the Straits have unique navigational challenges. The risks can be minimized by selecting the appropriate vessel and good navigational planning.
Recommendations for transiting the Turkish Straits
- Senior Navigating Officers should have suitable experience and knowledge of transiting Turkish Straits.
- Vessel tonnage and carriage capacity should be optimized to reduce the total number of transits and lower overall risk.
- Conventional Suezmax class tankers 275-300 metres LOA is the maximum size that can safely navigate the Istanbul Strait with acceptable margins under normal circumstances. Tankers greater than 300 metres in length pose additional risks when transiting the Istanbul Strait. These may, however, transit through the Straits subject to strict application of additional restrictions by the administration and risk assessment by the company.
- Qualified pilot should be utilized for north and southbound transits of the Istanbul and Çanakkale Straits.
- Embarkation and disembarkation of pilots should be undertaken at IMO-designated pilot transfer locations.
- Vessels should be suitably trimmed to optimize manoeuvrability during transit. While laden, this generally means using a slight stern trim, when squat at transit speed is considered.
- Navigational best practices should be followed with particular focus on bridge manning and proper position fixing.
- Cargo and ballast operations such as ballast transfer, tank cleaning or gas freeing should not be undertaken during transit and all cargo tank lids should be secured.
- Anchoring in Istanbul anchorage should be avoided unless it is specifically needed or if calling into port.
