The total loss statistics for 1979, published in the Casualty Returns of Lloyd's Register of Shipping, provide further evidence of the increasing disparity between the safety records of vessels operating under different flags. Statistics of total losses are likely to be almost completely accurate, especially for ships of over 1000 tons gross, and can be used as the most reliable indication of trends in serious marine casualties. This review of recent total losses will be restricted to trading ships of over 1000 g.r.t.

The purpose of this paper is to look at the nature of the advances being made in inertial navigation and in navigation displays. In avionics as a whole the advance from one generation of equipment to another can take different forms; sometimes, notably in flight control and instrumentation, the potential of new technologies is exploited almost immediately to provide more advanced operational facilities and systems become more complex. Alternatively, as in the application of solid state electronics to produce equipment for general aviation, the technology is exploited to reduce weight, volume and costs. Inertial navigation exhibits both trends but to a comparatively small degree; the basic system requirement is simple to define and has changed very little, one of the reasons being the particularly demanding nature of the technology and the very long development time scales involved.

Captain Scott went to the pole over the Ross Barrier, up the Beardmore Glacier (Fig. 1) which is about 100 miles long, and then on to the south pole, coming out by the same route. The great Norwegian explorer Amundsen went in from the other side over the shelf, up one of the glaciers and on to the pole. Admiral Byrd flew in and out again in 1929. Apart from these expeditions very little has been done in Antarctica and nearly all of it, apart from the fringe, is untouched.

When we started surveying Megalithic sites in Britain we used a cloth tape, but after some years it was realized that it was necessary to be more precise and now we use a steel tape for the important sites. Similarly with astronomy; at first we considered it sufficiently accurate to work to ¼° but now we know that it is advisable to work always to within a minute of arc. This is because we have found out that the erectors of the stones sometimes used distant foresights, either artificial or natural, and by using these they could get an accuracy of better than a minute. The method of observing was for the operator to watch the edge of the celestial body grazing a foresight or running down the edge of a hill. He moved sideways until he got exact coincidence and then marked the position. This first came to our attention when we measured up the site at Ballochroy on the west side of Kintyre.

The first point to note about the North Atlantic air traffic system is the diurnal pattern of flow. This is strongly tidal, with westbound flow predominant during daylight hours and eastbound flow overnight. There is some traffic which flows against the main stream, particularly during the day, but the strong tendency for one-way traffic results from the difference in local times on opposite sides of the ocean, together with the transit times of flight at current speeds. This means that the general pattern will probably persist, unless and until aircraft speeds change radically.

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.

Anthropologists tell us that over 500000000 years ago the seas swarmed with some type of marine life and that during the Devonian period of 350 0000 000 years ago we could find the first species of monk fish that is now in high demand on the fish market place and sought after in strange hostile waters by European fishermen. The sharks were introduced to the planet at about this time and until this day have had the reputation of being the ocean's most voracious predators.

Reference to a chart of the Thames Estuary will show that the dominant feature of the submarine morphology is the series of elongated banks, of which the Barrow, Sunk and Long Sand are the most important. Between these banks, and with the same north-east to south-west trend, are the navigable channels of the Swin, Barrow and Black Deep (Fig. 1).

The alignment of the channels suggests that they originated as a result of tidal-stream scour of a fairly uniform sheet of fine silt and sand. In each tidal period, streams enter the estuary from the north and flow on the flood in a south-westerly direction parallel to the Essex coast. After about six hours they slacken, turn and flow out of the estuary in the reverse direction. This continuous flood and ebb stream action, with a maximum velocity varying from 2·3 to 2·9 knots depending on whether the tide is neap or spring, has apparently scoured out channels to depths which exceed 10 fathoms in places. If the channels largely arose in this way, the banks represent the modified remnants of the initial surface. These banks are constantly being extended seaward as more riverine silt is emptied into the estuary by the Thames, Medway and the rivers of Essex. The distal end of Long Sand alone has grown almost ½ mile in the past 100 years (see Figs. 1 and 4).

A continuing study of ship's bridge design and ship control conducted by the Defence Research Board of Canada has recognized that the conventional method of issuing and executing verbal orders contains inherent delay and is a possible source of error in ship control. As a partial solution to this problem, it was proposed that ‘the officer originating decisions to change the course and speed should implement these decisions himself through the direct control of helm and engines on the bridge’ (p. 21). It was further proposed that the direct controls be located on a console positioned at the front of the bridge on the centre-line of the ship.

The conventional location and arrangement of the bridge restricts visibility, however, in areas close to the ship, and this limited visibility from the bridge often causes manœuvring difficulties. In some instances, distances as great as 800 ft. ahead of the bow and 50 ft. abeam are ‘blind areas’. In most cases, areas aft on the centre-line cannot be seen at all. In an attempt to alleviate these problems, bridges have been extended to the sides of ships, or bridge wings provided so that much of the ship's side can be seen by the conning officer. With direct control from the centre-line and the use of a television system, bridge wings could possibly be eliminated, while still providing better close-in vision.

The proposal by A. J. Wright (this Journal, vol. 34, no. 1, p. 142) that banded contour charts should be introduced, appears attractive at first sight. It appears to provide immediately recognizable indication of safe areas for the navigation of those ships whose draught is within certain limits. However, I feel that the system as proposed suffers from some major weaknesses

Allowance for height of tide. Tidal ranges of several metres are by no means uncommon. Failure to make proper allowance for this could result in a wrong assessment by the user of where navigationally safe water lies. Such tidal ranges frequently occur in areas of high-density traffic. Here, the pressures on the mariner are such that the temptation to ‘eye-ball the navigation’ is greatest – yet it is in such areas that positional accuracy based on sound chartwork procedures is vital.

Until 1950 the largest ships of the merchant fleet and the major warships had the same draught, about 12 m. Hydrographic offices concentrated their efforts on those areas likely to contain hazards to such vessels, that is to say the areas extending from the shallow waters to the 20 m contour line. The maximum draught of warships has been stable whereas the draught of merchant vessels increased considerably up to 30 m in recent years. A VLCC may risk grounding after having crossed the 30 m line or even the 40 m line. Nowadays, the part of the continental shelf which is best known is the part in which the largest vessels are unable to operate.

The paper by Captain Cotter on Edward Johnson and the early history of ship's magnetism published in the September Journal sets the scene for the birth, in 1842, of the Compass Department of the Admiralty. Commander Fanning, a former Deputy Director of the Admiralty Compass Observatory, as it later became, here relates its subsequent history. The paper was presented to an Ordinary Meeting of the Institute held in London on 19 December 1979 with Dr J. F. Kemp in the Chair.

This paper traces the fortunes and development of a small department, one of the oldest Admiralty technical departments, from its early struggles with the magnetic compass, through many vicissitudes, economies, defence cuts, wars, intrigues, take-overs and even human frailties. We shall see how technical advances have led to ever more demanding requirements and I hope to show how, by meeting each new challenge, there has emerged the lively, forward-looking organization that today is still responsible for ‘everything that matters’ in navigation equipment, as it was at its inception in 1842.

This paper formed the 1988 Anderson Memorial Lecture, and was presented to the Boscombe Down Branch on 17 March.

Wing Commander Anderson, in addition to his many distinctions connected with our Institute (a Founder Member, President, Gold Medallist, Honorary Member and frequent office holder) was above all an indefatigable worker for the science and artistry of navigation, which he regarded as a basic activity of all mankind. In 1939 he was headmaster of a school and by 1945 had become one of the most outstanding operational navigators in the Royal Air Force. In that year he was chosen as navigator of the research aircraft, Aries I, for those epic flights over the North geographic and magnetic poles, investigating compass performance in high latitudes.

The least spherical distance between two points on the surface of a sphere is that along the minor arc of the great circle on which the two points lie. It is an easy matter to demonstrate this using a cord stretched between two points on a small globe; noting that the circle whose plane coincides with that of the cord contains the centre of the sphere and that it is, therefore, a great circle. It is a little more difficult to prove the fact analytically. The practice of sailing along the shortest route on an ocean passage—sometimes known as ‘orthodromic’ as opposed to rhumbline or ‘loxodromic’ sailing—would require the course to be continually changed (except, of course, in cases in which the rhumb-line and great circle arc coincide). This would clearly be impossible; the term ‘approximate great circle sailing’ is sometimes used to describe the techniques of following a great circle route as closely as practicable.

There is an urgent need, both at international and national level, for more operational research into marine traffic and the associated collision casualties. At the present time marine traffic research is in its infancy and official analysis of collision is on a national basis with few attempts to correlate the two together and on an international basis. Without this basic information and research on the traffic and accident pattern, it will not be possible to plan effectively to reduce the high cost of collision casualties to ships' operators and to make the necessary improvements in safety over the next decade. This decade will see increasing carriage of dangerous cargoes in bulk, a continual large increase in the number of pleasure boats and the current trend of increasing numbers of merchant ships, fishing and other work-boats will probably continue. Due to this large increase and the trend to mammoth ships, the effective amount of sea space is being rapidly reduced and traffic control is inevitable in some areas.

In the next decade there will be an increasing demand for more accurate self-contained navigation systems due to more stringent air traffic control requirements, particularly with the introduction of the supersonic transport. Although inertial systems have been fairly widely used in military aircraft and missiles, the only self-contained systems in service in civil aircraft are dead reckoning systems based on measuring the aircraft's velocity and heading and drift angle. A big improvement has been effected in the measurement of velocity and drift angle by the introduction of doppler radar. The accuracy achievable with doppler is not matched by the accuracy of existing heading reference systems and the overall accuracy is, at present, inadequate for future requirements.

An inertial navigation system is a possible alternative but its cost will be two to three times that of a doppler heading reference system.

It does indeed give me great pleasure to have been honoured by the request to give this lecture. And it is with a little trepidation that I have chosen my subject, the very title of which could frighten off many people, and I am very glad to see that your Institute consists of people made of sterner stuff. On the other hand, I did feel that the subject in question met the nature of this lecture. It was generally cultural and it relates to navigation. And so let me start on this subject which has a reputation for being difficult. And let me assure you that Einstein's work on relativity is not at all difficult. It is very simple. But it rests on the extremely difficult, abstract theories that we owe to Galileo and to Newton.

An application of the model to manoeuvre ships based on the range to domain over range rate (RDRR) concept is described. A simulation of a training simulator has been set up on which the target ships manoeuvre by the RDRR model in response to mariner controlled ships. Results of experiments show that the RDRR model manoeuvres targets realistically. The applications are reduced instructor work load and increased simulator reality. The method has the potential for development to manoeuvre ships at sea.

B. A. Colley is now with Plessey Marine, R. G. Curtis is with the Department of Trade and Industry and C. T. Stockel is at Plymouth Polytechnic.

As a result of the loss of the French passenger liner Antilles after grounding on an uncharted rock in the Grenadine Islands in the West Indies, on 8 January 1971, the owners of the ship filed a petition for limitation of or exoneration from liability in the United States District Court for the Southern District of New York. A number of claimants against the owners, chiefly passengers in the ship at the time of loss, entered the limitation proceedings and moved the New York Court to transfer the case to the District of Puerto Rico. After the case had been so transferred, several claimants filed direct action suits against the owners and their insurers; these suits were stayed pending the outcome of the limitation proceedings.