Within the University of Wales Institute of Science and Technology, a general study of navigation has led to a review of error distributions which has now reached the stage at which comment on a wide front would be particularly welcome. The work has been undertaken by Wing Commander E. W. Anderson who, with the generous permission of Smiths Industries Limited, is writing a thesis for the Department of Maritime Studies, and by D. M. Ellis, Lecturer in Statistics in the Department of Mathematics. In the first half of this paper, Anderson emphasizes the distinction between distributions involving one item or identical items and those involving a number of items which, though nominally the same, are in fact diverse. In the second half of the paper (from Section 8 on), Ellis shows how the apparent variation of results that arise in practice may be unified into a simple inclusive pattern.

The first step was to investigate the distributions that arise in practice. It was decided that the pages of this Journal would make ideal witnesses because they provide a broad sample and are impartial. From these pages every distribution was extracted which involved more than fifty observations and whose pattern was not markedly skew. The distributions were transferred to log-linear graph paper so that the horizontal error scale was linear and the probability of each error was plotted on the vertical logarithmic scale.

Perhaps the most surprising thing about sea waves is that they come in a vast range of shapes and sizes. The casual observer on a ship in waters not exposed to an ocean, for example the southern North Sea, may rightly think that the waves he can see have all been generated by the same wind blowing over some particular stretch of water for a fixed length of time. It then seems almost logical to deduce that all the waves ought to be of the same height, length and shape. Unfortunately this is not the case, the energy of sea waves is locked in wave components spread over a wide range of wave periods, each of which travels at a speed dictated by its period. Considering the very simple case of a sea with only wave components, when a crest of one component overtakes the other, a higher wave will ensue. As a result of this process, high waves come in groups; during the time in which the components gradually get into phase the wave height builds up giving a train of waves of increasing, which then decreases as the faster component travels away, until when they are out of phase the sea is temporarily fairly calm. This is the reason why it is commonly said that every seventh wave is the highest, although whether it is every fourth or every fourteenth depends on the relative speeds of the components.

In many critical areas today navigation is more concerned with maintaining the flow of traffic than with finding the way. In his Presidential Address, which was presented at the Annual General Meeting of the Institute in London on 14 October 1970, Mr. Stratton discusses some of the characteristics of sea and air traffic systems and how they interact with the costs and benefits to the community as a whole.

In my previous address I concentrated on the way in which new scientific principles have been applied to determining the basic quantities of position, course and speed as inputs to the navigation process and with some of the technological problems encountered. The science and technology of navigation, however, are but the means by which navigation fulfils an operational task which itself is directed at the safe and expeditious movement of passengers and goods or to some military ends. In this address I will concentrate on some of the current and future operational tasks for navigation on the sea and in the air in fulfilment of the commercial need to transport goods and passengers and of the personal use of the vehicle for transport and leisure.

In this paper, which was presented at an Institute meeting, held in Britannic House in London on 1 December 1970, the Chief Marine Superintendent of the BP Tanker Company examines the problems of operating large merchant vessels in the Arctic and describes the experience gained from the two voyages of S.S. Manhattan through the North-West Passage. The chair was taken by the President, Rear Admiral G. S. Ritchie, C.B., D.S.C, Hydrographer of the Navy.

During the past twenty-five years the aviation scene has progressed from one in which relatively small numbers of aircraft flew from point of origin to destination with the guidance afforded by very limited M/F range facilities and a great deal of individual navigational skill on the part of the operating crews. Air traffic control functioned only as a means of sorting out the order of take-off and landing. Moving forward to the present we see the already high density traffic serving the population centres of the world continuing to increase at a rate of around 10 per cent per annum. Both station referenced and self-contained navigational systems proliferate and control of traffic must be almost total if collision accidents are to be avoided. During the same time period aircraft speeds have increased threefold and necessitated a consequent improvement in the ability of the air traffic control service to react quickly and precisely to any conflict situations, either by detection in the strategic/planning case or resolution in the tactical frame by direct intervention before critical situations can develop.

It seems likely that the S.S. Andrea Doria of Genoa still lies on the shelf south of Nantucket Island's shoals, resting on her damaged starboard side with her port side only 23 fm. deep under position 40°29′.4 North, 69°50′.5 West; and that 2 miles to the north-west are to be found some-how fixed on the same bottom the two 700 ft bower chains, their windlass, and a large piece of the crushed bows, all detached from the M.S. Stockholm—but not her anchors. The U.S. Coast Guard Cutter Evergreen reported from the scene at the time the sinking of Doria as of 261409Z on the calm summer mid-morning of Thursday, 26 July 1956, New York civil time. A few minutes thereafter Stockholm, having after hours of effort finally cut her bower chains, left the empty scene at low speed and with escort bound for drydock in Brooklyn, her anchors firmly formed into the remains of her bows. Although full power was available and used, she had not been able to move from this unconventional but all too effective anchorage since about 11:09 by her bridge clock the night before when she had come from 18 kt. to a dead stop in something like 2 sec. of time. During the pleasantly warm and moonlit night, of the more than 2000 persons on the scene only a few, mainly those who had actually seen the event with their own eyes and lived on, knew that two ships had been in collision. No one in either ship had expected anything uncommon, at most a routine passing clear of another and unknown ship, until the last minute, and even then only two or three believed collision could, let alone had, come to pass.

Before turning attention to the problems of heavy weather sailing in yachts it is useful to attempt to define what a yachtsman considers to be a gale.

When I first took up ‘going foreign’ in my own boats cones were hoisted at signal stations when winds of Force 7 or above were anticipated. Thus it may be said that gales started at Force 7, but skippers of commercial craft such as Brixham trawlers (in which I occasionally sailed), barges and other coasters did their own forecasting and used their own judgment of what constituted a gale without bothering too much about the Beaufort notation. Amateurs followed suit in this matter and when wind or sea rose too high for their own particular yachts they would describe the conditions as a gale. It was not until the radio became a commonplace in yachts that a more scientific approach came to be made. Of recent years few yachtsmen will make even a cross-Channel passage without first receiving a weather forecast and the tendency is to rely entirely on forecasts. In passing, I would comment that the vagaries of the weather are such that some of the severest gales have occurred with only very short warning.

Marine traffic engineering is defined as the study of marine traffic and the application of such studies to improvements in navigation facilities and traffic regulation. The authors review recent Japanese work in this field.

Since the mountainous terrain of Japan hindered the development of road transport, goods have mainly been sent by ship, from the earliest times until the end of the last century. The rapid economic recovery of Japan after the Second World War owes much to the industrial belt along the coast which may be called the ‘Water Megalopolis’, with more than 70 million inhabitants. Shipping provides the greater part of both interzonal and international transport and consequently there is severe traffic congestion, accentuated by the presence of more than 200,000 fishing vessels.

M.V. Geestport of the Geestline left the island of Dominica on 1 February 1970. She arrived at Barry on 10 February 1970. Between these dates the ship underwent a considerable ordeal, seldom experiencing a wind-force less than 7, while all the time she was pitching heavily, thereby shipping great amounts of water owing to the heavy swell and rough seas. From the 2 February the barometer pressure dropped about 1 millibar per hour and then, from 04.00 G.M.T. on the 3rd until 12.00 G.M.T. on 5 February, a slow rise was observed, finally steadying at 1034.6 mb. From the latter date the pressure began to fall at a slow rate and on arrival at Barry the barometer reading was 1002.8 mb. During these ten difficult days the speed of the vessel was varied continuously between 120 r.p.m. (about 20 knots) and 50 r.p.m. depending on the circumstances.

In this paper, which was presented at the Quadripartite Meeting of the Institutes of Navigation in Rome, 11–14. May 1970, the author describes the precise acoustic navigation systems designed for use with submersible vehicles as distinct from typical cruising submarines. With recent technical advances in position finding a whole new range of underwater tasks for the submersible has been opened up.

The collision, in October 1970 in the English Channel, between the Liberian registered tankers Pacific Glory and Allegro may be thought to have brought an element of timeliness to the arguments advanced in this paper in favour of an international disciplinary court of justice and international standards for certificates of competency.

Dr. Buzek is both a Master Mariner and a Doctor at Law; Captain Wepster, the Institute's gold medallist for 1970, is with the Holland America Line.

In a speech before the seventh meeting of the Cultural Council of Europe, Dr. Mansholt expressed the opinion that in our highly industrialized western world, the time has arrived when environment is of equal importance with economy. On a world-wide scale we need general agreements on acceptable noise levels and pollution, with binding rules for industry, transport and agriculture as well as international control on the observance of these rules.

In a procedural Air Traffic Control environment, navigation standards are related to separation standards because of the way they both affect the collision risk. The Air Traffic Studies division of the Mathematics Department at R.A.E. has developed methods of estimating the collision risk procedural systems and these provide rational grounds for decisions on separation standards. In a radar-monitored system navigation accuracy and separation standards both affect the workload of the controller on the ground and it is necessary to study these effects to ensure that he is not overloaded. In addition the problems of estimating the collision risk will become more complicated. I shall very briefly describe the mathematical theory of collision risk for parallel tracks. A fuller description has been published in the Journal.

Digiplot is a marine radar aid for automatic anti-collision navigation which processes signals from conventional radar and presents computed information on a separate screen to give at-a-glance situation appreciation. The company's origin is touched on and conception and design are described as they evolved to meet operational requirements.

The majority of sophisticated radar equipments and devices available today have evolved from successive shipborne radar developments over a considerable period of years. With Digiplot it is otherwise. The Iotron Corporation was established in 1969 by a few men whose background had been information technology in the realms of fire control and navigational systems for submarines, aircraft, missiles and spacecraft, and reconnaissance systems using electronic and optical techniques; in all these systems digital electronics played a key role. The choice of the navigational functions of marine radar as the most appropriate subject for attention by the group was made after a general study of the commercial field, because of the revolution apparent in ships, their equipment and their operations.

Captain Dickens, an Elder Brother of Trinity House, here describes the history and function of the lighthouse authorities in catering for the needs of shipping around our coasts, and discusses the wide range of navigational aids now in use. The paper was presented at an Ordinary Meeting of the Institute held in London on 18 November 1970 with the President, Rear Admiral G. S. Ritchie, C.B., D.S.C., in the chair.

One of the first lights to be set up to aid mariners was the Pharos erected at the entrance to the port of Alexandria in 270 B.C. and said to have been visible at sea for 40 miles. With the development of maritime traffic, more and more lights have been established so that shipping can proceed in comparative safety around the various seaboards of the world. In the United Kingdom the early lights and beacons were either privately owned, attached to various monasteries or managed by the Trinity Houses, which were corporations of seafaring men.

This note complements the papers by White and Lloyd by commenting on some of the features of a preliminary statistical analysis of the N.A.T.C.S. data on track-keeping recently collected along Green I Airway near the Strumble VOR. All values quoted are illustrative only and have no firm validity at this time but they illustrate the numbers involved in determining acceptable separation standards for the lateral navigation case in a typical ‘continental’ environment.

The description by Captain Evans and Captain Burger of the damage sustained by the MV. Geestport suggests that at the time of the impact it was night and that therefore it was difficult for the officers to suit the ship speed to the waves. In general a decrease of ship speed in given sea conditions will have little effect upon pitch motion, but vertical motion, or heave, will be lessened, and because of changed phase relationships, the relative vertical motion between ship bow and wave will be markedly reduced. The choice of a prudent speed for a particular situation at present depends upon the judgment of individual Masters. Some are too cautious, and waste time at sea, while others are too daring, so that their ship suffers damage. It should be possible to select a speed which cuts the risk of damage to a relatively small one while the minimum possible time is lost. A particular Master might be able to judge his speed well, but how can such wisdom be transmitted to others?

This paper describes the application of an IBM 1800 computer installed in R.R.S. Discovery to the processing of oceanographical data, and in particular the navigational aspects of the system.

It is beyond the scope of this paper to discuss the development of computer applications in oceanographical research, for which a number of quite advanced systems have been projected or are already in operation. Factors affecting the choice of the computer system adopted for use by the National Institute of Oceanography may be listed as follows:

(i) Data logging, typically to punched tape, was becoming more complex with every cruise of the R.R.S. Discovery

In this paper, a version of which appeared in the October 1969 issue of the periodical Schip en Werf, Mr. Anneveld, who is the nautical adviser to a Dutch firm of marine solicitors, investigates the drift velocity and drift angle due to coriolis force on a vessel of a given size. He shows that these effects are not inconsiderable for large vessels operating in middle and high latitudes and may become of practical importance, particularly when berthing or navigating in the proximity of other vessels.

Captain A. Vreugdenhil first drew attention in 1955 to the effect of coriolis force on a moving vehicle and on ships in particular. Since then ships have increased greatly in size and as the coriolis force increases with the mass of the vehicle it may be useful to investigate the effect on the mammoth ships of today.

This paper is intended to show those areas in which improved avionics could, in the relatively near future, contribute to overcoming the limitations described by Reich and Dickie. Sir Robert Cockburn has pointed out that present-day avionics is ‘decision-limited’ rather than ‘technology-limited’. If the present paper is to do more than reiterate a melancholy list of avionics solutions which are still unsuccessfully seeking suitable problems, it is essential to consider the constraints under which the airspace planners must operate, and the contribution which good electronic design might make to breaking the decision-taking bottleneck.

This paper looks at the cost of navigation and endeavours to establish a relationship, of the type studied by Professor H. Benford, between manning and its associated cost in British shipping. Certain assumptions are made concerning the capital investment and operating costs for navigation equipment and from these the progressive savings are estimated for minimum manning and an unmanned bridge. Captain McKenzie is Managing Director of Marine and General Computer Consultancy (I.O.M.) Ltd.

After some considerable investigation into the costs of marine equipment and accommodation it has been found that there is the greatest difficulty in establishing a base cost on which to examine possible reductions. Equipment, salaries, accommodation and fringe benefits vary so much from company to company and ship to ship that any comparison is meaningless. Thus we must consider some hypothetical ‘standard ship’ and define fairly closely what equipment is already on board and the average salary for staff or crew members. It seems reasonable to look at a modern ship equipped with all the devices which an up-to-date shipowner considers necessary for her operation and—more important—her safety.