This paper presents some preliminary conclusions about navigation requirements for supersonic aircraft, in particular those which relate to management of the aircraft along its vertical flight path.

The conclusions are based on an evaluation of some 200 computer-simulated flights of the mach 2 Concorde. The simulation contained models of real-world atmospheres for polar, temperate and tropical latitudes taken from actual upper-air observations and integrated over selected great circle routes used in the study.

The computer programme was designed to permit three kinds of flight schedule: operation according to the manufacturer's recommended mach-altitude profile, operation with respect to a set of arbitrary A.T.C. profiles, and operation along an optimum-energy profile. The results permit us to suggest objectively, performance capabilities, airspace requirements, and limiting conditions which are essential factors in specifying the vertical requirements.

Presidential Addresses over the years have covered a variety of subjects, mainly scientific and generally devoted to navigation. Being neither a scientist nor, strictly speaking, a navigator, I have chosen the work of the Institute as the subject of my Address. Today, the Institute celebrates its twenty-first anniversary and we can suitably reflect on its growth and achievements. We are immensely proud of the fact that Your Royal Highness consented, as long ago as 1952, to become our Patron. We are always honoured and delighted that you have been able to attend so many of our Annual General Meetings and to take the Chair. You inspire us, Sir, to keep in full view the objects of the Institute, which were laid down in 1947 and which are:

‘To unite in one scientific society those interested in navigation’ and ‘To advance the science and practice of navigation and its associated sciences’.

The question of the reverse stopping ability of a ship is well known but is yet a fresh problem. Until about twenty years ago the distance required to stop a.ship from a service sea speed ahead by using her engines full astern with helm midships was comparable to her advance while stopping with helm hard-over. However, at present this head reach of a 100,000- d.w. supertanker may range from 10 L to 15 L while her advance with maximum helm angle might only be from 5 L to 7 L. At first sight this appears to be a surprising phenomenon, but it is little wonder since the mass of the ship and hence the inertia increases with the cube of her length, while the total resistance of her underwater hull only with the square of her length.

The question of stopping very large supertankers is one of some significance both from the viewpoint of preparing to pick up a pilot, anchoring, berthing, or similar everyday operations and of avoiding collision or grounding in an emergency.

FOR some 15 years past, Dr. J. C. Beaglehole has been editing the Journals of Captain Cook for the Hakluyt Society. These embrace the three great Pacific voyages, and it is a happy circumstance that the two volumes covering the third voyage, and which complete a series of four massive volumes, have been published by the Cambridge University Press in 1967 in good time for the 200th anniversary, on 26 August this year, of the sailing from Plymouth of Cook in the Endeavour on his first great voyage to the Pacific.

Having loosed the topsails as a signal for sailing and hoisted a Jack at the fore topmast to inform Mr. Banks to come on board on 25 August 1768, Cook sailed in Endeavour next day. The undramatic entry in his journal began—‘At 2 p.m. got under sail and put to sea having on board 94 persons including Officers, Seamen, Gentlemen and their Servants, near 18 months provisions, 10 Carriage guns, 12 Swivels with good store of Ammunition and stores of all kinds’.

Now, with these four volumes, the Hakluyt Society, for the first time, has made available to us the daily entries set down by Cook from that first day of sailing in 1768, throughout the three voyages, until his final entry on 17 January 1779.

Professor Tani's paper (p. 119) describes recent work on the problem of calculating head reach for mammoth ships of one kind and another. Handling these vessels in confined waters and bringing them alongside the berth also poses particular problems to pilots. This paper illustrates some of these problems, which of course differ to some extent for each port, by describing the pilotage procedures used in one of the new Japanese ports built to accommodate very large vessels.

1. The inland sea and large vessels. The Inland Sea has a coast line of about 4272 kilometres and covers an area of 18,000 square kilometres, equal to that of Lake Ontario. The distance from east to west is about 260 miles and the broadest part from north to south is about 30 miles wide. Navigable channels or waterways for large vessels run in all directions.

In this paper M. Villiers, Ingénieur en Chef de la navigation aerienne, and M. de Barbeyrac, of the Société d'Etudes des Systèmes d'Automation, discuss the application of a satellite monitoring system to A.T.C. procedures.

The paper first discusses control of lateral separation under the headings of present navigation accuracy over the North Atlantic and by a satellite monitoring system. It goes on to discuss control of longitudinal separation with and without monitoring, and finally discusses intervention procedures and aids.

The writers conclude that it is possible with a mathematical model to establish a general relationship between the performance of aircraft navigation systems and a monitoring system on the one hand, and the lateral and longitudinal separation of aircraft and the mode of A.T.C. action on the other. From this relationship the number of A.T.C. interventions can be computed and it appears that the reduction of separations resulting from a satellite monitoring system will fit such a system to the forecast air traffic beyond 1975. In addition, the requirement for voice communication, specific to A.T.C., would be extremely limited. The paper was presented to the S.S.T. Working Group, sponsored jointly by the French, German and British Institutes of Navigation.

In ‘A Modern View of Lunar Distances’ (Journal, 19, 131) H.M. Nautical Almanac Office has already covered most of the technical aspects of the method of lunar distances which the Almanac made practicable; in ‘The Foundation and Early Development of the Nautical Almanac’ (Journal, 18, 391), Dr. E. G. Forbes has given a scholarly, fully documented, account of the early history of the Almanac; and Mr. Sadler himself has written many articles on various aspects of the bicentenary. This general account, which necessarily must duplicate parts of these articles, is directed as far as practicable to those aspects that are likely to be of greatest interest to members of the Institute not technically concerned with astronomical navigation. The paper was presented, in an abridged version, at the Annual General Meeting on 25 October 1967.

The economic development of archipelagic territories is intimately linked with shipping. In the archipelagoes of the Pacific small vessels connect many islands with one or two port towns. These towns are entrepôts for cargoes of consumer goods, petroleum and timber, and they are transhipment points for copra and fresh produce coming in from the island hinterlands. Towns, such as Suva, Lautoka, Apia, Nuku'alofa, also serve as local markets and educational, social and medical centres for the people of the outer islands.

In Fiji there are about 90 inhabited islands outside Viti Levu. The villages and estates in the outer islands all focus in some way on the port of Suva. There are many economic and social problems in the islands and these are made more acute by high freight rates and the unreliability of some services. But most of the shipping operators would be hard put to reduce freight rates or to improve the quality of their ships and services. One reason for this is the burden of marine accidents.

CAPTAIN JAMES COOK is deservedly esteemed as a great seaman, and he must be acclaimed also in the more particular role of a great navigator. For although he made no specific contribution to the art of navigation as such, he advanced it by sheer force of character. It was, indeed, a task for the mathematicians and astronomers, not for the sailors, to lay down new principles and new observations or calculations by which a ship's position could be found and her course directed when at sea. And it was for the mathematical and optical instrument-makers to design and perfect the instruments by which such observations could be made. But, in the last resort, everything depended upon the ships' captains, the masters and the pilots. They alone could decide whether some novel principle should be mastered, some new instrument actually used. ‘We have piped unto you and ye have not danced’ is a cry which echoes through the ages. For the sailor was not alone in turning a deaf ear to the advice of public men, scientists and his own professional instructors. He was hostile to change, he preferred some old rule of thumb. And this is to be expected from all such men as learn the actual practice of their trade or craft by working beside an experienced master who in turn is passing on the traditions of an earlier generation.

In this paper, which was presented to the Institute at an Ordinary Meeting in London on Wednesday, 14 February, the Managing Director and Chief Operator of Hoverlloyd describes his company's experiences in operating hovercraft across the Channel and its hopes with regard to the 250-passenger SR.N4. The characteristics of hovercraft and their implications for navigation are described.

Cross-Channel operations in SR.N6 hovercraft. In 1965 the Swedish Lloyd and Swedish American shipping groups placed an order for two SR.N4 hovercraft for introduction to the cross-channel route in 1968 and 1969. As a prelude to this service, an order was placed for two SR.N6 machines with which the parent companies intended to operate a pilot service between Ramsgate and Calais during the summer months of 1966 and 1967. These craft were delivered in the spring of 1966 and have now completed two years' activity, not only in the cross-channel field but in all spheres of commercial hovercraft activity.

The problem of collision-avoidance at sea by means of radar is constantly under discussion in maritime circles within the U.S.S.R. This paper, and that of Captain Bukhanovski (Journal, 20, 247,), describe one direction of research that has been actively pursued in the Soviet Union.

The device described was developed by the Central Scientific Research Institute for Water Transport for the Ministry of Merchant Marine and sea trials were carried out in the Black Sea during the summer of 1962. The present paper describes the principles of the device and the performance during trials. It has been prepared for publication in the Journal in collaboration with Captain G. Shoomayko.

Articles on the prototype have appeared in Morskoi Flot (no. 122, 1959, no. 2, 1964), Die Seewarte (Hamburg, October 1961) and Navigation (Paris, July 1962).

For a considerable time fishing vessels, merchant ships, long-range forecasters and oceanographers have needed up-to-date sea ice information. This paper describes how the heterogeneous mass of ice information combined with the very thorough climatic analysis now available has been used to produce for the first time an up-to-date picture of the entire distribution of ice in the Polar Basin and areas adjacent to the Atlantic Ocean.

For over a century a function of the Marine Division of the Meteorological Office has been the recording of Arctic and Antarctic sea ice, particularly since the Titanic disaster. However, the comprehensive hemispherical ice maps produced internationally have been several years in arrears. Ice information supplied to ships was therefore usually based on average conditions which suffice for planning well ahead or on long-range weather forecasts where it is necessary to follow ice development closely. It was decided in 1959 to organize a synoptic ice map with up-to-date ice and sea temperature information. Ice being more conservative than the weather, a map produced every ten days has proved to be sufficient.

The advantages of a standardized avoidance manoeuvre as distinct from a late collision avoidance manoeuvre are discussed with reference to passenger comfort. The general use of plan type displays suggests the possibility of having a standard manoeuvre based upon turning one aircraft on to a new heading.

An analysis of this manœuvre was undertaken in order to obtain data as to the closest permissible approach between pairs of aircraft on various collision courses. Results show that the permissible closure is smallest if the faster of the two aircraft is manœuvred, and that little is gained by changing the heading by more than 30°. The results of this type of analysis can assist also in the programming of the computer in a future automated A.T.C. system.

Some forty years ago, in the early days of automatic steering, autopilots were looked upon as a mere addition to the gyro-compass equipment. It was a black box, which was said to be able to reduce fuel consumption. It was also a gadget that amused passengers. The original introduction of the autopilot was based on these two aspects and its application was consequently confined to a small number of large passenger vessels.

Yet the name autopilot clearly indicates the possibility of automating an important element of the ship's routine, the steering. However, at this stage shipping in general was not ready for this aspect. The cost of labour on board played a less important part then than it does today. It took another twenty years before it became clear that it was precisely the labour-saving capacity of the auto- or gyro-pilot which would play such an important role in the rationalization of the ship's manpower requirements.

Temperature frequencies near the flight level of S.S.T. aircraft are here treated with regard to the areas Western Europe–North America–North Pacific. The used values are taken from charts of the 50-mb level (ca. 20 km.). They are divided into three groups: (1) Temperatures higher than standard temperature, i.e. higher than - 56° C (Figs. 1, 2) showing very clearly the big North Pacific warm area, (2) values higher than -46° C (standard temperature plus 10° C) (Figs. 3, 4), mostly expressing the polar warming in summer, and (3) temperatures lower than -65° C (Fig. 5), only occurring in winter and concentrated in the European sector of the Arctic. These effects are described along some flight routes.

In this paper, M. Blaise, Chairman of a committee of the International Association of Lighthouse Authorities, and the General Secretary of the Association, M. Pétry, comment on certain changes impending in the notation of luminous intensity and the range of marine lights. They conclude that the changes will be of benefit to navigators at sea and engineers.

In November 1925 the International Hydrographic Review published a report under the title ‘Observations of Visibility Lighthouses’. Since then notable progress has been made towards a standardization of methods. Relatively recently (1966), the International Association of Lighthouse Authorities (I.A.L.A.) published a recommendation for the notation of the luminous intensity and range of lights.

On 30 March 1966, Captain A. Wepster, of the Holland-America Line, presented a paper to the Institution on collisions in Western European rivers. Through its publication in the Journal it had considerable impact on opinion abroad and in particular in the Netherlands where it became popularly known in nautical circles as the Wepster Report.

The Netherlands Pilots’ Association invited its nautical committee for the areas most concerned to investigate the findings of Wepster's paper and it is their report which is presented here.

The Wepster Report is a general discussion of the dangers and problems of navigation on the five main navigable rivers of Western Europe. It attempts a critical investigation into the causes of the decline of safety on these rivers and a good deal of attention is paid to the working methods of pilots and of the various institutions charged with organizing river traffic. Captain Wepster concludes his lecture with the remark: ‘… it is now to be hoped that others will throw some light upon it from another angle.’

This paper describes a series of data handling systems, termed MARIDAS, which would cater for various maritime problems and situations. Eleven specifications have been prepared, of which three, those for hydrographic work, harbour and pilotage, and merchant ships, are reproduced as Annexes here. A version of the paper has appeared in naval publications with restricted circulation.

In the past decade various navies have introduced electronic data processing to ease the strain on ship captains and their officers in order to increase their efficiency. The need is urgent as the quantity of information now available from the many sensors has grown so remarkably, and the speeds of aircraft and targets have increased to such an extent, that human reaction and ability is fully extended. However, the thought processes in all the operations which have to be performed have remained the same. These processes are largely related to the solution of trigonometrical or triangulation problems: Spherical, for astronomical or satellite navigation; Plane, using distances and angles for geographical or relative position problems and speeds and angles for relative velocity problems, avoidance of collision and intercept.

By having a better understanding of the criteria needed for Category I operations we not only aim for an improvement in safety in Category I operations but we can move off from a more rational basis into Category II. In any case the dividing line between Category I and Category II, that is 200-ft. decision height and 800 m. RVR is not very well chosen as far as the RVR quantity is concerned and in the U.K. we generally refer to Category II as meaning a lowering of the decision height as airlines have been using lower RVR minima than 800 m. for a number of years. With the final part of the approach still having to be made visually, the main instrument approach criteria with which we are concerned are the weather minima—the critical height or decision height and the RVR or Met. visibility.