Proceeding of The 5 th Annual Basic Science International Conference Received, , Accepted, , Published online, . Probability of Ship Collision Using Minimum Distance to Collision (MDTC); A Case Study of Surabaya West Access Channel (SWAC) Benedicta Dian Alfanda 1* , A.A.B. Dinariyana 1 , Ketut Buda Artana 2 * Master Student of Department of Marine Engineering, Faculty of Marine Technology, ITS-Surabaya, Indonesia 1,2 Lecturer of Department of Marine Engineering, Faculty of Marine Technology, ITS-Surabaya, Arief Rahman Hakim Street, Surabaya, Indonesia 60111 * Corresponding authors: [benedicta13@mhs.na.its.ac.id] Abstract – By 2013, it was recorded that the density of ship traffic in the Madura Strait reached 43.000 ship calls. This number is considered exceeding the existing capacity of Madura Strait which is only 27.000 ships per year (Kabar Bisnis, 2014). With the plan of port development around the area, the existence and future oil and gas platform installation, subsea gas pipeline and cables around the shipping channel, it is estimated that the density of Madura Strait is even more congested. It is important, therefore, to assess the probability of maritime accidents due to the high potential hazard in the area, and one of which is the ship collision. The existing shipping line condition in Madura Strait is limited (narrow) and not proportionate to the number of ships passing, and this could lead to ship collision. The loss caused by ship collision can be in many ways, such as loss of life, loss of environmental impact caused when oil spills, physical damage and economic loss as a result of the damage to the cargo. This research utilizes the Minimum Distance method to Collision (MDTC) to get an estimate value of the probability of ships collision (Montewka, 2011) and found the probabilities of ship collision as follows: in the inner channel at 19,000 to 30,000 spots in head-on collision 2,138 accidents/year and the lowest probabilities of ship collision is overtaking in the outer channel 0.086 at 13,000-19,000 spots accidents/year. While the Traffic Based Model (Kristiansen, 2005) found that the highest probability of ship collision in the inner channel at 19,000-30,000 spots in head-on 1,151 accidents / year and the lowest probabilities of ship collision is overtaking in the outer channel at 38,000-43,000 spots 0.130 accidents/year. Keywords — : probability, minimum distance to collision, ship collision, Surabaya West Access Channel (SWAC), traffic based model. 1. INTRODUCTION Surabaya West Access Channel (SWAC) is the entrance to the Tanjung Perak Port and some surrounding port. The SWAC recent condition is width 100 meters with a depth -9 m LWS, supported with only one lane trajectory and 8.5 meters maximum ships draft. A lot ship accident reported in the Madura Strait, especially around the Surabaya West Access Channel (SWAC). Fig.1 represent in detail the ship accident in SWAC. Fig. 1. Number of Ship Accidents in SWAC Limited width and depth of Shipping lanes conditions is one of the high potential causes of accidents .The restrictions on the allowable draft of ships into the Madura Strait due to the shallow waters, also result in delays in the rate of the economy in eastern Indonesia. To solve the problems above, the following plan to revitalize in shipping lanes: