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The Turkish Straits Vessel Traffic Service

Answering the kind invitation of its Director, we publish the visit report carried out by a member of Afcan with the Istanbul strait VTS.


A brief history

      As of highest antiquity, the straits of Dardanelles and Bosphorus were a first importance maritime passage, and their control the object of severe conflicts, Trojan War until the landing of Dardanelles at the time of the First World War. Several treaties marked out this history, corresponding to the interests of the dominant power of the moment, until that of Montreux signed in 1936 by Bulgaria, France, Greece, Japan, Romania, Turkey, the United Kingdom, and the former USSR, Yugoslavia.

      This Convention lays down the rules of passage for the warships, subjected to a preliminary declaration and several restrictions, and stipulates, in its first article that the signatories parts " recognize and affirm the principle of freedom of passage and navigation in the straits " and in its second article that " in peacetime, the trading ships of all states have the complete freedom of navigation in the straits, day and night, and that pilot and tug remain optional "

      Are added to the Montreux Convention the Turkish Maritime Regulations of 1994/1998, and the I.M.O. rules and recommendations which expressly recommends the use of a pilot and for the large ships, of an escort tug boat. This article 2 relates however only to the trading ships proceeding without stopover or anchorage. For the ships bound for a port or an anchorage in the straits area, the access is subjected to the Turkish regulations, and pilot is thus compulsory.

Nautical characteristics of the Turkish straits

      The passage from the Black Sea to the Aegean Sea is carried out in 164 nautical miles by the Istanbul strait, the Marmara Sea, and the Çanakkale strait. These straits are very sinuous, often narrow, and flowed by strong and complex currents.

        The strait of Istanbul is subjected to strong northerly winds, rain and dense fogs particularly during spring and autumn. The weather conditions can change so quickly that a ship entering the strait by cloudy sky can be suddenly in a thick fog, with no visibility.

      Several currents combine their effects in the straits :

The basic current is due to the difference in density between the Aegean Sea and the Black Sea. The surface current is the consequence of the difference in level between these two seas, and can reach 6 to 8 knots. This reduces as much the rate of water flow on the rudder for a ship navigating with the current, and affects widely its manoeuvrability. Furthermore, there are counter-currents, eddy currents and the current of ORKOZ.

      All this explains why the Turkish authorities and I.M.O. strongly recommend to have a pilot on board, even for medium size vessels, with results as follows :

year Total
with pilot
1995 46954   17772   37,8  
1996 49952   20317   40,6  
1997 50942   19752   38,7  
1998 49304   18881   38,3  
1999 47906   18424   38,4  
2000 48078   19209   39,9  
2001 42637   17767   41,6  
2002 47283   19905   42,1  
2003 46939   21175   45,1  
2004 54564   22318   40,9  
2005 54794   24449   45,0  
2006 (9 months) 40988   19913   49,0  
year Total
with pilot
1995 35459   8292   23,4  
1996 36198   10307   28,4  
1997 36543   11047   30,2  
1998 38777   11448   29,5  
1999 40582   10002   24,6  
2000 41561   11130   26,7  
2001 39249   10703   27,3  
2002 42669   12164   28,5  
2003 42648   13020   20,5  
2004 48021   14404   29,7  
2005 49077   15661   32,0  
2006 (9 months) 36609   12605   34,4  

Maritime traffic in the Turkish straits

Over the period 1994-2002, an average of 132 ships are proceeding each day through the Turkish straits, which equals nearly 6 per hour.

Statistical figures about vessels proceeding through Turkish Straits :
     If taking account of the local traffic, it is necessary to add approximately 2000 passages per day (nearly 85 passages per hour), which allows to consider that all day long, a hundred ships of all sizes are navigating simultaneously in the straits. Another comparative data, the annual traffic of the main canals of the world over the period 1999-2000:

passage annual transits
Panama canal
Suez canal
Kiel canal
Istanbul strait
Malacca strait
12 755   
13 552   
23 945   
48 000   
100 000   

Annual tonnage of dangerous cargo passing through the Turkish straits :

       The Turkish straits are the only maritime passage between the Black Sea and the Mediterranean sea. The recent development of oil and natural gas exploitation in the countries close to the Caspian Sea transformed the straits into a first importance hub of energy.

Daily average of tankers
proceeding through the straits

year Istanbul

Casualties in the Turkish straits

amount of casualties
year Istanbul
1995 4   12  
1996 7   10  
1997 11   5  
1998 20   7  
1999 9   7  
2000 9   8  
2001 20   9  
2002 13   9  
2003 13   4  
2004 26   4  
2005 42   20  
         Introduction of a Traffic Separation Scheme in 1994, then the beginning of a Vessel Traffic Service in 2004, strongly influenced the occurrence of casualties. But the traffic density, the increasing size of the ships, and some reduction in the qualification of the crews masked part of the beneficial effects of the means introduced to improve safety of navigation in the straits.

       The 608 accidents which occurred in the Bosphorus during years 1982-2003 were caused by:
  • Human factors :
  • Bad weather :
  • Breakdowns :
  • Violents currents:
  • Fire :
  • Sabotage :
  • Topographic conditions :
  • Others :
       If taking account of the 246 cases for which the reasons remain unknown, and without the material events such as fire or sabotage, approximately 84% of all the accidents of period 1982-2003 can be awarded to the human error.

For the same period, the accidents are
  • collisions :
  • groundings :
  • fires-explosions :
  • others :
Lastly, during this same period 1982-2003, out of the 608 accidents which have occurred, 564 ships did not have a pilot on board (92,8%), and 44 had a pilot on board (7,2%).

Vessel Traffic Services in the Turkish straits

Incoming :

       The idea of a VTS for the Turkish straits occurred in the years 1980, on the initiative of the Turks pilots. As almost everywhere else, the pilots and the pilot station used to assume a number of the VTS functions. But that could not be really effective at that time, because of the lack of modern equipment, and the weak use of the pilot services in the Bosphorus and Dardanelles straits.

       The NASSIA casualty on March 13th 1994 is during the same year, the starting point of introducing in urgency the Maritime Regulations of the Turkish Straits and the Traffic Separation Scheme (TSS). This TSS was approved by I.M.O. in May 1994, as well as the "Rules and Recommendations" recognizing to the Turkish authorities the right to suspend the one-way or two way traffic in order to provide safe passage for "large ships".

       If the number of accidents were strongly reduced, the number of ships waiting at the entries was clearly increased, causing complaints from Black Sea countries and some Mediterranean ones. These States voiced their complaints to I.M.O. in 1997. However, in 1999, I.M.O. came to the conclusion that the I.M.O. Rules and Recommendations had resulted in an increase in safety of navigation through the Turkish straits, and recommended the installation of a modern VTS. The manufacturer of the VTS system was selected in October 1999, and on December 30th, 2003, the VTS began operations.

       But remains however some constraints for the VTS in such narrow waters. The width of the navigation lane is reduced sometimes to less than 100m in some places. In case of incident, few seconds are enough for a ship to violate the borders of the Traffic Separation Scheme, and this ends with a collision or a grounding. The VTS operator must inform the ship of a wrong trajectory, while avoiding giving an excess of data which may saturate ship's bridge decision makers, and be counter-productive in the efforts to provide more efficiency.

Organization :

         The competent authority of Turkish Straits Vessel Traffic Service (TSVTS) is the Minister of Transportation, and the General Director of Coastal Safety and Salvage Administration, appointed by the Turkish Government, is the TSVTS Authority. In addition to the safety of navigation, the TSVTS applies the emergency plans, and coordinates all the means to be used in accordance with these plans (towing, fire fighting, antipollution, S.A.R., medical care). But its domain of responsibility is limited by “the fact that the ultimate decision relating to the safety of navigation is given by the Master, and that any information, any warning, any instruction or recommendation given by the VTS does not affect in any way the responsibility of managing the vessel, the professional ability and the knowledge of the Master”. All the VTS operators are Captains with at least two years of command experience, and received a specific formation in conformity with the IALA standards.

       There are currently two VTS areas in the Turkish straits : the Istanbul VTS (55Nm), and the Çanakkale VTS (78Nm). The Marmara Sea TSS (71 Nm) is under works, and will be integrated into the TSVTS at the end of 2007.


Furthermore, all sector operators should have a commanding influence over their respective sector.


         Information on the vessel traffic situation is obtained from 8 towers on the Istanbul strait, and from 5 towers on the Çanakkale strait. Each tower is fitted with a X band radar and a remote-controlled TV camera sending datas to the area's VTS center. Three towers in each VTS area are equipped with VHF devices. Six AIS base stations are established in the Turkish straits, and the straits pilot station has 50 portable AIS transponders units, enabling each pilot to obtain a whole image of the vessels proceeding through the straits.

       The VTS lay out in addition Doppler sensors for the currents, salinity and temperature profilers, automatic weather stations, DGPS reference stations, VHF direction finders stations, and communication equipments (VHF, HF, MF, INMARSAT C) fitted with record and replay units.

The TSVTS renders three different services:
  • Information Service about maritime traffic which gives the relative positions of the ships, the intended movements of other vessels, the notices to mariners, the weather reports, and any other information considered necessary by the VTS operators.
  • Navigational assistance for the ships experiencing difficulties due to navigation equipment failures or bad weather.
  • Traffic organization service, which provides operational information to the ships before entering in the straits, in accordance with the Turkish Straits Maritime Traffic Regulations.

Extracts of the procedures for the transit through the Turkish straits

General regulations :

  • Submission of SP 1 and SP 2 reports to the TSVTS in accordance with The Turkish Straits Reporting system (TUBRAP).

  • Call Point Reports shall be given by ships during entry and exit of the TSVTS area and at the time of changing sectors.

  • VHF R/T channel of the TSVTS Sector shall be listened to at all times during passage or anchorage when inside the TSVTS area.

  • TSVTS should be informed at all times when vessels are leaving the TSVTS area.

  • Vessels navigating within the Turkish Straits, for safety of navigation, protection of life and the environment, should continuously monitor all TSVTS broadcasts and take heed of information, advices, warnings and instructions given by the TSVTS.
  • Masters of vessels navigating within the Turkish Straits should report to the TSVTS all perils to safety of navigation observed.

  • Vessels navigating within the TSS through the Marmara Sea, whether in stopover or non stopover passage, in case of any deviation from the TSS, berthing or mooring to buoys, dropping anchor, turning back or emergencies and similar exceptional circumstances and any delays on their ETA's exceeding 2 hours should report to the concerned VTSC.

  • Vessels engaging in non-stopover passage through the Turkish Straits should hoist the signal flag "T" during the daytime and at night time exhibit a green light that can be observed from all points in the horizon, both during passage or while at anchor.

  • All communications concerned with pilotage service should be performed via VHF R/T Channel 71.
Capt. F.X. Pizon

sources :
- Turkish Marine Research Foundation publication 25
- Turkish Straits Vessels Traffic Service

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