Collisions at sea continue to be in the news, many of them, as usual, inexplicable, navigationally as well as radar-wise (a curious phrase in this context). Little is said about radar in the Press because, no doubt, being complicated and technical to the layman, it is not newsworthy like oil pollution or wreck marking. Were the philosophy of its use more generally understood, the equipment might be better matched to the potential value of radar as an aid to collision avoidance.

The following discussion took place at an open session of the Technical Committee held at the Royal Aeronautical Society in London on 19 January 1972 with Mr. H. E. Smith in the Chair.

The Chairman: Relative navigation has a wide connotation, but for the purpose of our discussion it may be applied firstly to aircraft management in the positive or passive sense, arising from an air-to-air navigational interrogation capability, and secondly to the means whereby this capability may be realized.

Many may consider it presumptuous of the guinea-pig to voice an opinion on the experiment to which he is to be subjected. I hope this is not so, because I view the shipowner not as the guinea-pig but as the prospective customer for any advances which are made in marine traffic engineering technology. The shipowners of the world are undoubtedly going to pay directly or indirectly for any traffic regulation schemes which are set up. It is certainly not part of my theme that the customer is always right—he may not know what he wants until he has been subjected to a promotional advertising campaign and he may be excessively gullible in swallowing such propaganda—but there is possibly value in the customer saying what he thinks he wants and airing doubts he may have before he is subjected to these pressures. I therefore welcome the opportunity to give a shipowner's view on traffic regulation.

For a number of years ship's equipment has included automatic steering, off-course alarms, speed and distance logs, &c., all of which make use of separate electronic or electro-mechanical devices. The digital computer has meanwhile come into use for a large number of control systems, mainly ashore, and has improved in reliability and cost. The question therefore arises whether ships could be operated more efficiently and safely by making use of the rapid and accurate calculations which the digital computer can perform. Data loggers may produce such a profusion of information that it becomes an embarrassment and we may not see the wood for the trees. The ability of the digital computer (or processor) to edit and analyse information, as well as to store it, makes it a logical step in developing optimum performance.

At present all ports operate some form of traffic regulation within their limits. Harbour masters and port authorities may limit the passage of vessels either out of, or into, the port and special light or shape signals indicate to a vessel that such control is in operation. Dock and lock masters decide the priority of vessels through the entrance to closed systems. In channels outside the closed systems pilots and regular port users have developed standard patterns of behaviour for their mutual safety and convenience. Evidently this regulation is acceptable and as its development has been spontaneous it must have been considered necessary.

Enunciating the doctrine of the freedom of the high seas, Queen Elizabeth said ‘… the use of the sea is common to all, neither may any title to the ocean belong to any people or private man…’. It might have been more appropriately phrased if she had said—the sea is a free-forall, because until comparatively recently the common interpretation of the freedom of the sea has been the right for all to sail as and how they please, unhindered and unrestricted except for some internationally agreed rules for preventing collision and the demands of prudent seamanship to avoid stranding. Indeed masters and owners alike considered it their unquestioned right to use the waters of their choice and, in close quarter situations, it was often the man with the strongest nerves who won the day.

In a recent article I spoke of the situation now reached in the circulation of traffic at sea as ‘a second spring’. Indeed, after a gloomy winter marked by a sequence of disasters in the Dover Strait it was some comfort to regard them as seed sown in a soil from which new life would not be slow in coming forth. This promise of spring was clear for example in the bold propositions adopted by Imco: ‘To prohibit traffic in the opposite direction on one-way routes’ and ‘to establish a Dover Strait fund’.

In this paper, which was presented at an Institute meeting held in London on 26 May 1971, Captain Brandenburg discusses the problems of port and terminal navigation control in the 1980s and takes up the questions whether such control will be needed and how much control will be appropriate.

This paper is not concerned particularly with problems in Rotterdam, or indeed with any particular ports, but rather with an overall evaluation of probable port developments in the near future, say the 1980s, and with the steps which may be necessary to meet the problems that will arise. In speaking of port and terminal navigation one should distinguish between pilotage, which may be defined as conducting a ship in safety from one manœuvring area to the next, and manœuvre, which is the handling of a ship in confined areas with whatever aids are available. It is well known that the danger and difficulty of manœuvre varies greatly in different areas and this was the subject of an analysis by Captain Wepster, but I shall consider manœuvres common to all terminal areas:

(i) picking up the pilot and lining up into the fairway channel,

(ii) docking and undocking,

(iii) lining up into the fairway channel again,

(iv) dropping the pilot and heading up for destination.

This is a survey of a subject for which there are few positive conclusions on the reasons for existing controls and control practices. The position of the operator of a vehicle or craft, the preferred side for the control or conning position and the ‘rules-of-the-road’ for land and water transport and also air transport seemed to have evolved through innate and conditioned human preferences such as ‘handedness’, through customs and traditions and, possibly to a lesser extent, by arbitrary rule making. In general, man is outwardly laterally symmetrical but has a dominant side and a preferred-hand. Within the majority of ethnic groups right-hand preferring people make up 90 per cent of a population. However, despite innate preferences about which there is inconclusive evidence and the influences of a ‘right-handed’ world imposed upon the maturing child, man can acquire through learning and training a sufficient degree of ambidexterity to operate effectively the controls of complex man/machine interfaces. As long as tools, vehicles and all other artifacts remained essentially simple to use or operate they could be controlled, governed or steered by either hand or by one hand—usually the preferred—or by both hands. However, the preferred hand with any of these combinations would ‘lead’ and would provide precision or ‘fine’ control. The introduction of writing and similar tasks requiring coordination of mind, hand and eye has always reinforced the ‘right-handed’ world. For convenience this survey is divided into three major evolutionary paths: sword, steering oar and left-hand circuit.

In this age of explosive expansion in nearly every aspect of human endeavour our ability to make accurate forecasts is becoming increasingly important. We cannot wait until we run out of oil to find a new source of energy. We cannot wait until we can't stand living on the earth to slow down the rate of pollution. We cannot wait until there is no room left to stand on dry land before we do something about birth rate. We must predict what is likely to happen as a result of trends and then find ways either to change the trends or protect ourselves from the consequences.

One might well begin with the conclusion: ‘It is quite obvious that computer systems are rapidly being accepted on Norwegian ships’ although shipping opinion is still divided into two camps, the believers and the agnostics. The believers foresee a single large computer or several smaller systems covering most functions on board, the doubters think that computers are a passing fancy. There has certainly been too much talk about computers as if they were an end in themselves—the computer is an aid; in Noratom-Norcontrol we look on it as a component which enables us to solve certain system problems we were unable to tackle before, or to solve them better.

The committee which looked into the scientific and technological aspects of the Torrey Canyon disaster in 1967 recommended that an assessment should be made of the probable future frequency of large-scale oil pollution along the United Kingdom coastline so that the scale of effort necessary to meet such threats could be determined. The Defence Operational Analysis Establishment of the Ministry of Defence, which has considerable experience in the collection and analysis of large amounts of data, was considered best suited to undertake such an assignment.

This paper was presented at a joint meeting of the Institute and the R.A.F. Specialist Navigation & G.D. Aero-Systems Course Association in London on 21 April 1971, with Group Captain D. F. H. Grocott, C.B.E., A.F.C., in the Chair. At the meeting the paper was illustrated with many slides which greatly facilitated understanding of some passages. Only a proportion can be reproduced here.

Obviously there are many occasions when the navigator would like to retain a full visual capability at night; this is certainly so in the military context where it may be essential that aircraft operations shall be fully effective under night conditions. It is similarly a truism that the acuity of the human eye, that is the ability to resolve fine detail in the image, decreases as night falls and the illumination level is reduced. Because of this there have been many research programmes over the years to develop sensors to extend the capability of the human eye, and one of the most important developments has been the use of low light television (LLTV) systems as an aid to night vision.

Radar was fitted to merchant ships after the last war in the belief that, amongst other things, it would help to reduce collision casualties. However, by the early 1950s people were talking about ‘radar assisted collisions’ and today, in spite of improved radar equipment and training facilities, we read all too often of collisions between radar equipped ships. The question remains why such collisions occur; in part the answer lies in the fact that modern merchant ships have limited manpower so that the officer of the watch is often the only man on the bridge for long periods, and plotting ships' tracks from radar information is a time consuming business. The result is that, although radar provides the information required to avoid a collision, it is not in a form readily assimilated by the operator and incorrect interpretations can occur. The obvious solution is automatic extraction and processing of the radar information so that it can be presented to the operator in a form which will enable him to assess the situation rapidly. This would eliminate the tedious process of plotting, but retain the information normally obtained from a plot.

The year 1971 marked the first centenary of the publication of a paper on navigation which appeared in the Proceedings of the Royal Society of London in which the author, Sir William Thomson (later Lord Kelvin) described a new method of determining an astronomical position line. The method was impracticable and was not, therefore, adopted by practical seamen. Nevertheless, its design is ingenious and interesting, and an investigation of its principles adds lustre to the genius of its inventor—reputedly one of the most eminent philosophers of the nineteenth century. Although the method failed in the eyes of the mariners for whom it was intended, Thomson sparked off an interest in short-method tables which has persisted even to the present day.

In this paper a study is made of that area of marine traffic engineering which is concerned with collision avoidance, and within that area the sub-section in which human factors are involved.

Collision avoidance at sea is mainly achieved by adherence to the rules for preventing collisions, by routing schemes for separating traffic in high density areas and, within certain port limits, by local rules and advisory services, or occasionally by direct control of ship movements. To these well defined factors may be added the mariner's accumulated experience and instinct for self-preservation which gives rise to such nebulous, but not negligible, entities as the ‘seaman's eye’ and the ‘navigator's sixth sense’.

In this paper which was presented at an Institute meeting in London on 17 November 1971, Mr. O'Hagan describes a system for advising cooperating ships in a Surveillance Area. The system includes accurate position sensing through on-board equipment, high frequency telephonic communication, a general survey of all shipping and other hazards in the area based on primary radar, analysis of the data by computer, and the employment of an experienced Master Mariner ashore to assess the situation and offer advice to the cooperating vessels.

The discussion was opened by R. H. Farrands, Vice-President of the European Maritime Pilots' Association. The Chair was taken by the President of the Institute, Rear-Admiral G. S. Ritchie, C.B., D.S.C.

After reading the first two reports on the surveys of marine traffic in the Dover Strait conducted by the National Physical Laboratory, it was decided to investigate the possibility of applying the results to two points raised in recent issues of the Journal.

The first question studied was one suggested by Beattie, in his article on the first of the above traffic surveys. It was noted that there was quite a variation in the number of ships per hour passing through a given area. This could have been caused by a systematic tendency for ships to come through in clusters or could be a perfectly random variation. If the variation was completely random then the frequency distribution of ships per hour should follow a standard statistical distribution known as the Poisson distribution. For each of six separate distributions obtained from the results of the surveys on 26 February to 1 March 1971 and 27 April to 29 April 1971, the appropriate theoretical Poisson distribution was fitted and tests made to assess how close the theoretical and observed distributions were. The results of the calculations are summarized below in the table.