Ticari gemilerde gmdss tehlike alarmlarının etkinliği üzerine bir i̇nceleme

Abstract

Deniz ortamının potansiyel tehlikeleri ve zaman unsurunun ticaretteki önemli rolü denizde haberleşmeyi deniz taşımacılığının en önemli unsurlarından biri haline getirmiştir. Gemilerde haberleşme cihazlarının ilki olarak karşımıza çıkan telsiz telgrafların yirminci yüzyılın başlarından itibaren kullanıldığı görülmektedir. 15 Nisan 1912 tarihinde yaşanan Titanic kazasının trajik sonuçları, ilk kez yetkili otoritelerin dikkatini gemilerin sınırlı haberleşme imkânlarına ve bu durumun sonuçlarına çekmelerine neden olmuştur. Bu olay üzerine 5 Temmuz 1912 tarihinde Londra Konferansı gerçekleştirilmiştir. Londra konferansında telsiz vardiya saatleri düzenlenmiştir ve 500 kHz öncelikli gemi haberleşme frekansı olarak belirlenmiştir(London, 1912). Uluslararası Denizcilik Örgütü'nün(IMO) 1979 yılında gerçekleştirmiş olduğu bir toplantıda denizde can emniyetini arttırmak için Arama ve Kurtarma(SAR) altyapısına sahip bir Küresel Deniz Tehlike ve Emniyet Sistemi (GMDSS) kurulmasına karar verilmiştir. GMDSS sistemi gereksinimleri Denizde Can Güvenliği Sözleşmesi (SOLAS) Bölüm 4'e eklenerek SOLAS'a tabi gemiler için zorunlu hale getirilmiştir. Gemilerin sefer yaptıkları deniz alanlarına göre farklı haberleşme cihazları ile donatılmasını öngören GMDSS sisteminin ardından tehlikeli okyanuslarda gemi seyri daha güvenli hale gelmiştir, fakat üreticilerinin tasarım hataları ve operatör kaynaklı hatalar nedeni ile sistem halen çözülemeyen birçok sorun yaşandığı bildirilmektedir (Tzannatos, 2004). Gemi elektronik haberleşme sistemlerindeki yanlış alarmların miktarının belirlenmesinden sonra elde edilen sonuçlar çerçevesinde mevcut sistemin daha iyi çalışmasını sağlayacak önerilerin ortaya konulması bu çalışmanın amacını oluşturmaktadır. GMDSS sisteminin en önemli sorunlarından biri olan yanlış alarmların dünya genelinde Arama Kurtarma birimlerini gereksiz meşgul ettiği ve büyük maddi zararlara neden olduğu bilinmektedir. Bu çalışmada ülkelerin arama kurtarma faaliyetlerinden sorumlu birimlerinden tehlike alarmı verileri talep edilmiştir. Arama kurtarma birimlerinin paylaştıkları veriler kullanılan INMARSAT, COSPAS-SARSAT ve DSC (Digital Selective Calling-Sayısal Seçmeli Çağrı) haberleşme yöntemlerine göre sınıflandırılarak veri tabloları oluşturulmuştur. Dünya genelinde alınan yanlış alarm sayısında yıllara oranla azalma eğilimi gözlemlenmiştir. Farklı GMDSS haberleşme yöntemleri kullanılarak gönderilen alarmların % 88,8 ile 97,5 aralığında yanlış alarm olduğu göze çarpmıştır. Elde edilen sonuçlar çerçevesinde SOLAS'a tabi gemilerde halen kullanılmakta olan GMDSS haberleşme sisteminin güncellenme ihtiyacı olduğu anlaşılmıştır.

Communication at sea has become one of the most important elements of maritime transport due to potential hazards of marine environment and important role of time element in trade. It had been seen that as first communication devices on ships are the radio telegrams that have been used from on the beginning of the twentieth century. The tragic consequences of the Titanic accident that took place on 15 April 1912, it had been for the first time caused the authorities to draw their attention to the limited communication facilities of the vessels and its consequences. The London Conference was held on 5 July 1912 because of this Accident. The radio watchkeeping hour on ships has been arranged and the 500 kHz determined as priority ship communication frequency at the London Conference. In a meeting held by The International Maritime Organization (IMO)in 1979 had been decided to establish a The Global Maritime Distress and Safety System (GMDSS) has search and rescue (SAR) infrastructure to increase safety at sea. The requirement of GMDSS It has become mandatory for ships subject to Convention on the Safety of Life at the Sea (SOLAS) by adding to the Chapter IV of the SOLAS. After the GMDSS System which has different communication device requirements for the ships according to the sea areas they navigate, navigating ships in dangerous oceans has become safer but it is reported that there are also many problems in which the system cannot be solved yet by the manufacturers design errors and operator borne errors (Tzannatos, 2004). It is the purpose of this work to establish proposals to make the existing system work better within the framework of the results after determining the amount of false alarms in ship electronic communication systems. It is known that one of the most important issues of the GMDSS system is that false alarms have unnecessarily occupied the Search and Rescue units around the world and caused huge financial Damage. In this study, demanded distress calls datas were from the units responsible for the search and rescue activities of the countries. Data tables were created by classifying the data shared by search and rescue units according to INMARSAT, COSPAS-SARSAT and DSC (Digital Selective Calling) communication methods used. The number of false alarms worldwide has been trending down compared to the years. The alarms send by using different GMDSS communication methods are the false alarms in the 88,8 to 97,5 percent range. it is understood that The results obtained from study confirm that the GMDSS communication system currently in use on ships subject to SOLAS needs to be updatedGMDSS devices, including satellite communications devices, were added to Chapter 4 of the Convention for the Safety of Life at Sea and became compulsory for ships subject to SOLAS at the end of the 7-year transition period following 1 February 1992 (IMO, 1992). With the GMDSS system, it was thought that a rapid and effective communication between the ship in distress and the search and rescue teams would be provided in possible dangerous situations at sea. Today, vessels need communication systems for pilotage and towage services even before leaving the port. GMDSS system devices are used to make contact with other vessels in crossing situation from the beginning of the navigation, to report the information requested from vessel traffic operators through specified vessel traffic service areas, to get weather forecasts, and to provide commercial and routine communication of ship’s crew. After GMDSS came into force, qualifications and training of radio operators were rearranged. According to the new arrangement, the fact that deck officers and captains were given an opportunity to become a General Radio Operator obviated the need for vessels to have another radio operator (Regulation on Radio Operator Qualifications and Examination, 2004). GMDSS communication devices are designed to transmit distress alarms from the sea to the land with at least two different and independent communication devices. The functional requirements of the devices have been specified in Rule 4 of SOLAS Chapter 4. Marine navigation has become safer in the dangerous oceans following the GMDSS system, which requires ships to be equipped with different communication devices according to sea areas where they are navigating, but it is reported that the system has many insoluble issues due to design flaws and operator-induced errors (Tzannatos, 2004). A false alarm is an event in which an alarm system works for any reason other than its intended purpose and in which one of the communication devices activates the function of sending a danger message for any reason. Design flaws of device-operator interface caused by GMDSS system device manufacturers lead to false alarms at an unacceptable rate (Tzannatos, 2004). Another factor that negatively affects the operation of the GMDSS system is that vessels have different communication techniques for different sea areas (Tzannatos, 2002). In the study, we contacted the stations in different regions responsible for search and rescue operations within the framework of the International Convention on Maritime Search and Rescue (SAR) by email and asked for statistics on received distress alarms in the past years and data showing which GMDSS communication method was used to receive these alarms. The data obtained from the search and rescue units of Germany, the USA, and Brazil were classified according to the communication methods Inmarsat, COSPAS-SARSAT and DSC and standardized data tables were created. The aim of this study is to propose suggestions to make the existing system work better in the framework of the results obtained after determining the amount of false alarms in ship electronic communication systems. It is known that false alarms, one of the biggest problems of the GMDSS system, unnecessarily occupy the Search and Rescue units and cause serious economic damage around the world. Tzannatos, in his study conducted on false alarms in GMDSS communication techniques in 2004, used the data on false alarms of Greek Search and Rescue units. At the end of his study, Tzannatos found that at least 98% of the alarms received by using the COSPAS-SARSAT technique, 87% of the alarms received by the DSC technique, and 88% of the alarms received by the Inmarsat technique were false alarms. False alarms are known to cause Search and Rescue units to spend unnecessary overtime and money on the land (Sudol, 2011). Due to the fact that false alarms prevent the Search and Rescue units from working effectively, helping casualties may be delayed in case of real danger. Digital selective calling devices have the function of automatic distress relay routing. This function causes a false alarm to be received several times by the receiver of a ship thousands of miles away. This situation affects the safe of navigation negatively by distracting attention of deck officers in charge of watchkeeping on the bridge in the traffic-intensive areas. According to the data of Bremen Search and Rescue Service in Germany, it is seen that the devices that use the COSPAS-SARSAT technique in this area cause the most false alarms. When all the calls received by the Search and Rescue Unit in Germany were examined, it was seen that 96,3% of all distress calls received via Inmarsat, 97% of calls received via Cospas-SARSAT and 93,3% of those received via DSC were false alarms. It is understood that the number of false alarms received in all communication techniques tended to decrease in the period between 2000 and 2012 and that 95,55% of all alarms received by Search and Rescue units were false alarms. When all the calls received by the Search and Rescue Unit in Brazil between 2006 and 2011 were examined, it was seen that 96.6% of all distress calls received via Inmarsat, 97.5% of calls received via CospasSARSAT and 93.5% of those received via DSC were false alarms. It was observed that the number of false alarms received in all communicationtechniques tended to decrease in the period between 2006 and 2011 and that 95.9% of all alarms received by Search and Rescue units were false alarms. When all the calls received by the Search and Rescue Unit in the USA between 2003 and 2010 were examined, it was seen that 92% of all distress calls received via Inmarsat and 88,8% of calls received via DSC were false alarms. While the number of false alarms tended to decrease in Inmarsat communication technique in the period between 2003 and 2010, it was observed that the number of false alarms sent via DSC technique tended to increase after 2007. It is also understood that at least 90,4% of the alarms reaching the search and rescue units were false alarms.