In coastal countries like Vietnam, sea transportation has always contributed greatly to the development of the national economy. The development of sea transportation depends on many factors. Among these factors marine traffic safety in ports and adjacent waterways is one which directly influences this development.
The launch of the Vessel Traffic Service (VTS) has contributed significantly to improving safety in waterways such as harbor waters, fairways and straits which have high traffic density. After six months of official operation, the Vung Tau VTS Center in Vietnam has helped to reduce the number of accidents in the VTS area by 60%, compared to the same period in the previous year, 2012.
However, the rate of accidents related to traffic in the Vung Tau VTS area is still high, about 70% of total accidents. It is because of the “dis-order” traffic in the waterway.
Navigation assistance and traffic organization are two of the main functions of a VTS system. So that improving the effectiveness of the Vung Tau VTS Center in these two functions is one of the feasible and effective solutions to solve this problem.
After studying the work of VTS officers (VTSO), it was found that the key factor in deciding the performance of a VTSO is his/her ability to assess the risk of vessels. In fact, at all VTS centers this process totally depends on the assessment of the VTSO. These assessment results greatly depend on human factors such as working experience, working conditions, human error, etc. An effective solution for this problem is the application of a quantitative risk assessment model to evaluate the risk of a vessel’s traffic safety.
For this reason this dissertation researches and develops the Real Time Supporting System (RTSS) for VTS officers. It is able to help VTSOs determine the collision risk of vessels quantitatively and alert vessels which have un-acceptable risk of collision. In addition, the RTSS is also able to alert vessels which have the possibility of going aground or being off-route or over-speed.
This RTSS was designed for application in the Vung Tau VTS Center to improve marine traffic safety in the three main fairways in the Vung Tau Waterway. It will contribute to the economic development of the Important Triangular Economic Zone in the southern part of Vietnam (Ho Chi Minh City, Dong Nai Province, and Ba Ria-Vung Tau Province).
For the purpose of this research a survey of traffic in the Vung Tau Waterway was conducted. Traffic environment factors were studied and statistical data of marine traffic and marine accidents in the waterway were collected. To find the assessment model most appropriate for the Vung Tau Waterway, this data was then analyzed, evaluated, and compared using various methods such as evaluation based on experts’ surveys or based on assessment models, comparison evaluation results with statistical data, etc. Results showed that the PARK model (Potential Assessment of Risk model, developed in Korea) is the most appropriate model for the Vung Tau Waterway.
This RTSS was developed based on this model. Its functions and user interface were designed according to survey responses of VTSOs in the Vung Tau VTS Center.
After development this RTSS has gone into trial operation at the Vung Tau VTS Center where it obtainned data about traffic through the AIS (Automatic Identification System) receiver device. Then the feedback of VTS officers was collected and analyzed for further study on improving the RTSS.
The findings of the dissertation are summarized as follows:
1.The affects of marine environment factors such as winds, currents, tides, waves, fog, rain, width and depth of waterway on marine traffic safety were analyzed. It was found that they have a small negative affect on traffic safety in the Vung Tau Waterway
2.Through traffic survey and quantitative assessment by the IWRAP model, it was found that the “dis-order” movement of traffic in this area by ocean vessels, barges, tug boats, fishing boats, etc. is the main factor which affects traffic safety in this waterway. This problem can be looked into by many ways. However, an effective and feasible solution is improving the effectiveness of the Vung Tau VTS Center
3.The effectiveness of the Vung Tau VTS Center is still restricted because of lack of sea and working experience of VTS officers. So a supporting system to support VTS officers for improving their competency and the Vung Tau VTS Center’s efficiency needs to be established. The supporting system should be able to help VTS officers to assess collision risks of vessels quantitatively in real time. It must be built based on an assessment model that takes into account the risk of human factors
4.Through analysis it was found that some models other than the ES model and the PARK model use statistical measures or the opinions of experts, but they do not take into account the risks of human factors. So these models cannot be used to assess collision risks of vessels in real time. By qualitative analysis and assessment of VTS officers about the ES model and the PARK model, it was shown that the PARK model is the most appropriate model for evaluating risks of collision in the Vung Tau Waterway in real time
5.The Real Time Supporting System (RTSS) for VTS officers was developed. It is able to evaluate collision risks of vessels based on the PARK model in real time and alert vessels that run a risk of collision. In addition, it can alert officers about vessels’ going aground, being off-route and over-speed vessels. The RTSS was put in trial operation in the Vung Tau VTS Center. Most VTS officers have given the same feedback, i.e., that it is a useful tool and should be improved to become an indispensable part of the VTS system
From these results this dissertation recommends to the Maritime Administration of Ho Chi Minh City, which manages the Vung Tau VTS Center, to give permission for connecting the RTSS with the VTS system to enable complete traffic data gathering for implementing the subsequent trial operation steps. In this way the RTSS will continue to be assessed, modified, and then put into official operation.