The Royal Institute of Navigation, with its counterparts in France and Germany, played a fundamental role in the introduction of traffic separation at sea, a role that is freely acknowledged in Imco's publications on the subject. J. H. Beattie, who was a member of the successive international working groups whose reports led to the introduction of routing, first of all in the Dover Strait and later throughout North West Europe, recounts the history of routing at sea, whose origins lay perhaps in the Great Lakes. A condensed version of this paper was presented at an Ordinary Meeting of the Institute on 14 December 1977, followed by Captain Emden's paper which is printed at page 203 with the ensuing discussion. Captain Maybourn was in the chair.

It is now generally agreed that the principles of traffic separation, in formulation of which this Institute has played an important part, are proving themselves a success and now that Imco traffic separation schemes have acquired a legal status, specifically under Rule 10 of the International Regulations for Preventing Collisions at Sea (1972), it is appropriate to take stock of the situation and to look ahead.

As far as the Dover Strait is concerned it can be surely said that the number of ships contravening the Regulations continues to decrease and, more important, that the number of collisions has been reduced. Nevertheless apparent infringements continue to occur at the rate of nearly one. every hour and there have already been three collisions this year. In the Dover Strait we have a daily throughput of 300 ships and an average crossing population of about 200 passages each day. Nevertheless the average tonnage of all ships is only about 2000; it may well be a small ship which will precipitate a disaster, and it is mainly with the problems of the small ship that I am now concerned. The aim of this paper is to suggest possible steps which may be taken to improve the safety of navigation and by promoting discussion it may be possible to obtain a clearer view of the mariner's needs, what is practical in the way of meeting these needs, and what new ideas may have to be introduced if there should be a demand for further action. These include passive measures, which must be handled administratively and ashore, and active measures, which directly concern the master's navigation of his ship.

FOR traffic proceeding in random directions on a plane surface the frequency of collisions, if no avoiding action is taken, is approximately proportional to the square of the traffic density and directly proportional to the size and speed of the craft. Avoiding action is normally taken and the rate of collisions is therefore also governed by additional factors such as the visibility, the effectiveness of the collision-avoidance rules, the competence of personnel, the manoeuvrability of the craft and the efficiency of radar and other equipment.

In the post-war years there has been a considerable increase in the number of merchant ships. The number of vessels of ioo tons gross and upwards increased from less than 30,000 in 1948 to over 65,000 in 1976. When considering the population of ships at risk it is necessary to deduct special types of non-trading vessels and ships laid up. The number of trading ships in service has increased by approximately 100 per cent since 1950 (Fig. 1) and the greatest increase has been for large ships. The average length of trading ships has increased by approximately 40 per cent in the same period and there has also been an appreciable increase in the mean speed of ships.

Until its nationalization in 1956, the physical limitations of the Canal had greatly influenced world shipowners with regard to the sizes of ships built, particularly oil tankers. Following nationalization, in an era of cheap oil and transport costs, shipowners took the initiative and began to build large tankers. Mindful of the effect that such changes would have on the tonnage of oil transported through the Canal, the Suez Canal Authority began a programme of expansion in 1958 which was to be executed in two stages. The first stage was completed by February 1964 and consisted of widening and deepening the Canal so that ships with draughts of 38 ft could be accommodated, thus allowing vessels of 60,000 d.w.t. to transit fully loaded. The second stage of development was intended to deepen the Canal to accept vessels of draughts up to 40 ft, corresponding to ships of 70,000 d.w.t. This work was scheduled to be completed by the end of 1967, but the project was not finished due to the start of the Arab–Israeli war.

Captain Brett Hilder first published in 1973 his controversial theory that Torres used Endeavour Strait on his famous and perilous voyage through the intricate waters of the strait that now bears his name. This was the subject of his Macquarie University thesis of 1976, The voyage of Torres along the southern coast of New Guinea in 1606 and he has summarised his findings in a paper published in the September 1977 issue of this Journal. It now seems essential to question the validity of some of his assertions.

In 1966, in a note in the Forum entitled ‘Longitude without Time’, Francis Chichester described a method of determining longitude, or time (G.M.T.), from observations of the altitude of the Moon; and this gave rise to considerable interest. Recently a number of papers, of varying standards, have been published on the same subject; some, ignoring fundamental principles, have described techniques that are erroneous or misleading. Those principles, which have been well known for centuries, are here restated. In general, techniques of observation, calculation and plotting are not given; they are matters for the choice of the individual.

Concorde has now been operating on routes both east and west of Europe for over a year and has become an accepted part of the international air transport scene. This paper examines these operations in the light of experience, with emphasis on navigation and operational planning. Of special interest is the way in which the triple inertial navigation system on the aircraft has been used to ensure accurate and reliable track keeping on complex routes. Concorde routes are constrained as much by political as by operational considerations and long term planning was necessary to obtain route profiles which gave the shortest distances and optimum acceleration/deceleration points.

A recently completed preliminary long-term study of air traffic control systems in Europe1 suggests that traffic density is likely at least to double before the end of the century. The study also concludes that, apart from the problem of airport capacity, which was not considered, the existing ATC systems in Europe will not be able to cope with such an increase in traffic. There is therefore a need to consider methods of increasing the capacity of the European ATC system or providing a new system and, in view of the time required to effect significant changes to such systems, the task is becoming urgent.

Assumingthere is to be no deterioration insafety, theprime requirements for any proposed changes are economy and flexibility. Apart from its obvious intrinsic value, economy is necessary because there is an increasing trend towards recovering the total cost of ATC from the user. Higher charges are therefore likely to stultify the growth in air transport and an underlying assumption is that this would be undesirable. Flexibility is required because traffic forecasts so far into the future are likely to be in error and the system design must allow for this because there is likely to be some economic penalty if the forecast proves to be either too high or too low.

Collision avoidance radars formed the subject of an Institute meeting held in London in October 1975 (this Journal, 29, 232). The subject has been given a sharper edge by President Carter's message to the U.S. Congress on 18 March 1977 which proposed, amongst other regulations, that all oil tankers over 20,000 dead weight tons which call at American ports, should carry ‘back-up radar systems including collision avoidance equipment’. The issues are highly contentious and the Institute has published a great deal on either side as the debate has grown. The papers which follow describe a research project carried out at the Department of Maritime Studies at Liverpool Polytechnic for Shell International Marine. They were presented at an Institute meeting held at Shell Centre on 17 November 1977 with Captain Ralph Maybourn in the Chair.

J. A. Butt, Head of the Communications and Navigation Department at Shell International Marine, first looks at the investigation from the shipowner's point of view. Captain K. D. Jones, an Extra Master, and Director of Research in Maritime Studies at Liverpool Polytechnic, then discusses the scope of the project and describes the range of experience undertaken. C. G. Rowsell, seconded from Shell Tankers U.K. Fleet to the Operational Services Department, Shell International Marine, finally, gives a detailed account of the investigation and its results. The discussion was opened by Captain A. Wepster, Director, Navigation Research Centre, Netherlands Maritime Institute, and Captain F. J. Wylie, provides a written commentary.

This note on the distribution pattern of some Omega observations is based on a study of the phase differences observed at the Faculty of Fisheries at Hokkaido University (41° 48·4′N., 140° 43·3′E.). The A—D pair was investigated continuously, at half-hourly intervals, from i February 1974 to 31 January 1976, the A—C and C—D pairs from 1 January 1975 t o 31 December 197J and the A—H and D—H pairs from 1 January 1976 to 31 December 1976.

The number of ships in the world's fleet increases each year, and at an increasing rate. In 1975, 2530 new steam and motor ships went to sea, compared with 1006 in 1965 and 134 in 1955. The tonnage increase is even more startling. Lloyd's Register of Shipping quotes the 1975 total world tonnage of vessels of 100 gross tons and upwards as 342,162,000 tons, an increase of about 10 per cent over the previous year and double the figure recorded in 1966. These larger ships are less manoeuvrable and more difficult to stop. They are also restricted in where they can go in safety and thus constitute a considerable collision and stranding hazard. The growth is most apparent in tankers, ore carriers and OBOs (oil, bulk or ore carriers). The French Shell tanker Batilus (550,000 tons) quoted as having a 72 ft draught is operating close to home and recently discharged 170,000 tons of crude oil at le Havre before continuing her passage to Rotterdam. In January 1977 the Chairman of Globtik Tankers ordered three nuclear powered oil tankers for delivery in 1985, 1986 and 1987. Their size is quoted as 600,000 tons, and their speed as well over 20 knots. The Globtik Tokyo is already at sea—469,470 tons deadweight, 1243 feet long, 203 feet beam and 92 ft draught! She sails under the British flag, and trades between Japan and the Persian Gulf. The U.K. has now nine ships of over 140,000 tons gross (275,000 tons deadweight) out of a world total of 59 and the world total of ships over 100,000 tons gross was 479 at the last count.

Ample information is available on the growth-process of the International Regulations for Preventing Collisions at Sea 1972. However, after having been set to words little has been published in the Netherlands to assist the ‘men on the bridge’ in the practical use of these Rules of the Road. In the Netherlands—as elsewhere—seafarers have attended courses which dealt with the use and interpretation ol the revised Rules. Little is known of deliberations and consultations between national and international Institutions and consequently it must be feared that mariners have not been uniformly advised.

AN interesting account of the deliberations leading to the international acceptance of the new buoyage system (Iala Buoyage System ‘A’), the first phase of which came into effect last year and which was described by the Hydrographer of the Navy in the January 1977 issue of this Journal, formed the subject of one of the papers presented at the International Hydrographic Conference in Monaco in April. The author, Captain J. E. Bury, who is a senior Elder Brother of Trinity House, has for some years been Chairman of the Iala sub-committee which formulated the new system.