Sailing Problems Within and Near Traffic Separation Schemes

Abstract

Traffic separation schemes have been established all over the world with the aim of reducing the danger of collision. Field observations have shown that despite the adoption by IMO and the laying down of the schemes on nautical charts a good many vessels do not comply with the steering and sailing rules applicable at traffic separation schemes. This paper attempts to review the apparent difficulties met. Some suggestions for improving of the situation are made.1. I N T R O D U C T I O N . The separation of traffic into two streams moving in opposite directions has been introduced with the aim of reducing the incidence of collisions. Such a measure results in a decrease of the rate of encounters and an almost total elimination of head-on or fine crossing meetings which are considered dangerous especially in restricted visibility. Investigations have confirmed the effectiveness of the measure in achieving the purpose provided that the steps taken are reasonable from a practical point of view.Today, traffic separation schemes are established in busy areas in many parts of the world. Despite the fact that most of these routing schemes have been adopted by IMO and details of them are depicted on nautical charts, a good number of vessels seem to have difficulties in complying with the respective rules. The purpose of this paper is, first, to show where problems affecting the safe and smooth flow of traffic arise and secondly, to indicate how these problems could be cleared away. The findings are based on long-term observations of shipping movements within and near the traffic separation schemes in the Bight of Heligoland. It is believed, however, that very similar problems exist within or near any established traffic separation scheme, so that the questions discussed here may well be of general interest.2. SPECIFICATION OF THE PROBLEM. Traffic separation schemes are intended to give order to an existing traffic situation at the price of the freedom of ship movements. Therefore, such schemes should be introduced only if they are indispensable for the maintenance or the improvement of safety. The successful working of a traffic separation scheme depends, first, on the layout of the scheme and, secondly, on the acceptance of the scheme by the users. We shall, however, not investigate the quality of any traffic separation scheme in the present paper. Nor shall we discuss whether or not in certain areas it is justified to restrict the freedom of ship movement. The concern about a possible propagation of schemes is well recognized but will remain undiscussed. We will assume at the moment that the competent authorities have made appropriate investigations before implementation of the schemes, that they have proved 398

Supporting Situation Awareness on the Bridge: Testing Route Exchange in a Practical e-Navigation Study

“…However, onboard the St-Germain the intention was not at all to cross the traffic separation scheme diagonally in front of Artadi, but instead to turn port and follow outside the boarder of the NE going traffic lane until the traffic cleared and she could make the crossing at a right angle (according to rule 10c). In the subsequent collision two persons were killed (Kwik, 1984; Office of the Commissioner for Marine Affairs, 1979). …”