This address by the Secretary-General of Imco was given at a meeting of the Institute in London on 10 March 1976, with a Vice-President, Mrs. Mary Pera, in the Chair.

IT gives me great pleasure to be here today and I should like to thank you most warmly for your kind invitation to speak on the work of the Inter-Governmental Maritime Consultative Organization, or IMCO as it is commonly called. Naturally I do not need much encouragement to talk about Imco but I consider this to be a rather special occasion, because of the long and close association between the Royal Institute of Navigation and Imco. I shall advert again and more fully to this association later.

As you know, Imco is a specialized agency of the United Nations charged with important responsibilities in the maritime field. It was established by the Convention on the Inter-Governmental Maritime Consultative Organization, adopted by the United Nations Maritime Conference held in Geneva in 1948. Imco began life in January 1959 and its Headquarters have been in London from that time.

Time is so much a part of everyday experience that no thought is normally given to the meaning of the word. The scientific measurement of a quantity such as time, however, requires the definition of a gauge as a standard of measurement that is reasonably invariant to human experience and the creation of a measurement language capable of independent empirical reproduction so that one laboratory can share experience with another using only a written language to do so.

Time as a means of scientific measurement for navigation requires a further extension of this experience to independent reproduction on a moving craft.

Chart, compass and log are the three fundamental instruments of navigation. It was not until mediaeval times, coinciding with the early development of these instruments, that navigation became scientific; and certain it is that without them the opening up of the oceans for exploration, as a preliminary to maritime trade, would have been delayed.

The defects of ‘dead reckoning’ navigation, the process by which a vessel's position may be pricked on a chart from compass and log observations, were of little consequence to medieval navigators whose activities were confined to the Mediterranean Sea and the coastal waters of Atlantic Europe. But following the advent of the Golden Age of Discoveries initiated by the Portuguese in the fifteenth century, when western Europeans first struck out to cross the Atlantic, the pressing need for a reliable method of checking DR positions led to the rise of nautical astronomy. The practice of this art which is secondary to the primary navigational aim of finding the way embraces the traditional methods of mathematical astronomy for ascertaining latitude and longitude. A nautical astronomer requires skill, mathematical and scientific expertise and certain indispensable equipment. A chart for pricking position as a preliminary to setting or rectifying a course, mathematical and astronomical tables to facilitate computations and instruments for measuring respectively altitudes and times; these are the main tools of nautical astronomy.

Two hundred years ago a signal book was issued to a Captain Cornthwaith Ornmary of H.M.S. Tartar. The date was 13 June 1776 and the signal book contained the earliest reference which the author has been able to find to a positive rule of the road at sea. The signal book was the work of Admiral Lord Richard Howe, who in 1776 was commanding a fleet off the coast of north-east America in support of his brother G eneral William Howe. Brother William was enjoying considerable success in 1776 but his contribution to history did not survive his encounters with George Washington in 1777 and 1778. Brother Richard meanwhile, perhaps fortunate in not meeting the counterpart of George Washington at sea, went on to add further illustrious chapters to an already distinguished career. His modest rule of the road has not only survived almost unaltered to the present day but it has also formed the basis for our entire system of rules for preventing collisions between ships.

There has been considerable progress within the last three years in the evolution of various traffic procedures in coastal and waterway areas. Society at last seems to be awakening to the need for some order and conformity as a means of protecting the marine environment. And sea people have accepted that communications—like steam—have altered the face of the Earth. Learned societies and professional institutions have each played their part on the new frontiers of sea affairs and we have between us not been backward in promoting our ideas as to what the new order could be. We begin to acknowledge that we belong to our times.

We have used the bones of Torrey Canyon and her more recent successors in the Dover, Magellan and Malacca Straits to climb out of an age of obstinate rejection into one of enlightened self-help. Modern life does not tarry with yesterday, and the headlines of past accidents are not necessarily the right titles for future remedies. But they are very useful pointers along the way. Perhaps at last we have understood the nature of the traffic question and can now begin to seek the answers with a broader base of consensus.

This account of the practical steps taken by British Airways to provide the Concorde with a reliable navigation capability which meets the needs of supersonic flight on commercial routes covers: the features of supersonic flight which lead to new navigation requirements, the social and political constraints on supersonic flight, and the need for the crew both to be well informed of the progress of the flight and prepared for the possibility of return to subsonic flight. These factors have led to special techniques for route planning, flight planning, documentation (including charts), and accuracy of navigation.

All these techniques are based on a navigation system constructed from standard components, but meeting the aircraft's needs for accuracy and automation.

Circumstances of collision. Over a fourteen-year period more than 80 per cent of all collisions in the Dover Strait occurred in reduced visibility. The majority of the ships concerned were carrying radar, so a possible inference is that the information available from this source is less effective than direct vision in successfully resolving close-quarters situations. The introduction of the Imco recommended routing scheme, the support measures mounted from the two sides of the Channel and sustained improvements in navigation have together led to a significant reduction in the number of collisions in poor visibility. However the risks, though reduced, remain higher than in good visibility.

The circumstances leading to collision are very rarely known reliably or in any detail, but such facts as are known can be helpful if treated with caution. Reference 1 gives details of manoeuvres preceding 47 collisions, nearly all in fog, where helm orders were noted in crew reports (Table 1). About three-quarters of these collisions (and of collisions as a whole) occurred when ships were on opposing courses, as defined by their ports of call.

Air Traffic Control is part of the process by which aircraft ‘go about their ways’ and thus can fairly be regarded as a branch of navigation. Because of the existence of centralised control organizations, and because much of the total flight time is spent in the vicinity of system ‘hubs’, air traffic interacts with itself in very complex ways. For this reason the traffic as a whole behaves in a manner that could not easily be predicted from an inspection of the system elements. Thus there can be said to be a ‘system’ problem, where by a system is meant, not the specific hardware but the abstract elements which determine the essential overall performance. These abstractions would, for example, be common to a computer simulation of an ATC system and to its real-life counterpart. The present paper will attempt to discuss, at this ‘system’ level of abstraction, the problems facing air traffic control and the principles on which the system design should be based.

Dr. Jan Wereszczynski, a member of this Institute, describes the little known Polish contribution to the mapping of eastern Europe at a time when interest in maps of the known world had been stimulated by the rediscovery and publication of Ptolemy's great work on Geography, written in the second century AD and forgotten during the Middle Ages.

The history of the cartographical development of the Baltic and Black Sea coasts reveals a significant contribution from Polish cartographers in the sixteenth and seventeenth centuries. The ‘father of Polish cartography’, and one of the most famous scientists of his day, was Bernard Wapowski (1450–1535) who published two maps of Sarmatia. One covers the northern part of the Balkan peninsula, a large part of the Grand Duchy of Lithuania, the Crimean Khanate and part of the Grand Duchy of Moscow. The other covers the country north of a line from Toruri to Novgorod. It should be emphasized that Wapowski's geographical coordinates are of outstanding accuracy, most of them, especially the latitudes, being based on his own astronomical observations.

Following a general discussion on the effect of sea states on vessels at a meeting of the Technical Committee, held in London on 7 January 1976, those taking part were invited to submit written contributions, a selection of which is printed below.

P. H. Tanner (Glasgow University): It is a matter of experience for most small craft users that the steepest seas encountered in open waters are those that originate from the bow wave systems of passing ships. It is a matter of observation that these bow waves are of great persistence.

On 29 October 1969, taking the chair at a Duke of Edinburgh Lecture, the great educator Lord Butler commented, ‘…in my view, it would do a great deal of good if navigation could be considered an educational subject’. Indeed, we know that by 1700 the discipline was being taught in ordinary schools in this country, and it is perhaps worth repeating Isaac Newton's remarks on the Christ's Hospital syllabus: ‘he that is able to argue nimbly and judiciously about figure, force and motion is never at rest until he gets over every rub’.

The inclusion of navigation in the curricula of schools during the 17th century was for financial rather than for educative reasons. In those days, the master of a ship was responsible for its navigation and invariably had a stake in the marine enterprise. Thus he might make a small fortune in a single voyage. By 1800, the introduction of the limited liability shipping company and the growth of marine insurance were beginning to relegate the captain to the status of a hired servant paid the minimum wage. Navigation rapidly disappeared from ordinary schools and was taught only in the specialized nautical establishments. Nevertheless, it is worth noting that today, the mariner, the submariner, the pilot and the astronaut have restored to the subject its original lustre and the yachting explosion has given the discipline a wide appeal.

Most professional navigators would agree that navigation could play a useful role in general education. How are teachers to be convinced of this and how are they to be persuaded that its introduction is desirable ? If navigation is to be introduced as an academic subject into the school curriculum we must endeavour to remove the mystique with which it is often surrounded and dispel the suggestion that it is an art rather than a science. The notion that successful sailormen must have a seafaring background has been proved wrong time and again; let us also dispense with the misconception that good navigators are born with a gift similar to that of a homing pigeon. Man has a natural instinct to explore and find his way; the purpose of navigation in education should be to exploit and develop this natural instinct to the full.

Charles Henry Lane was born at Hereford about the year 17J4 and at the age of 17 joined the Buckingham, 70 guns, Captain John Symons. In this ship he went to India, spending about four years in her, the first two as able seaman and the second two as midshipman. Returning home he joined the Enterprize, 28, Captain Sir Thomas Rich, spending about two years in her in the Mediterranean. Of these the first three months were as able seaman and the rest as midshipman.

In July 1777 he successfully passed his examination for lieutenant and in September received his commission to the Royal Oak, 74, initially as 5th lieutenant but rising to 3rd before, in April 1778, he was appointed 1st lieutenant of the Surprize, 28, Captains Robert Linzee and later Samuel Reeve. In that ship he served just over three years, each year making a voyage to Newfoundland and back from about June to November. While in those waters on the third voyage he was transferred to the Portland, 50, Captain James Luttrell. Then in September 1782 Vice-Admiral John Campbell promoted him to Commander and placed him in command of the sloop St Johns, which had been purchased locally. Exactly a year later the St Johns was paid off and Commander Lane returned home and was placed on half-pay.

When the scale readings of a sextant are suspected of error, or if an assurance of scale accuracy is needed, optical equipment for establishing angles is rarely available. Comparison with another sextant is possible, but if the arc between two stars were measured by bringing them into coincidence this could be compared with the calculated angular distance. To calculate the distance from a spherical triangle, knowing the stars' declinations and right ascensions, would be laborious and the refraction corrections would be difficult to apply—as they were in the old lunar distance methods. It is far simpler, in the northern hemisphere, to take Polaris as one of the two stars. If the other is within an hour of its meridian passage, so that the measured arc is approximately vertical, the usual corrections for refraction are sufficient. Also the calculated angular distance will then be simply 90° – δ, where δ is the declination of the star selected. This calculated distance is therefore subject to two corrections:

(i) refraction corrections for both stars,

(ii) a correction for Polaris not being exactly at the pole.

Not surprisingly much of the work that has been done on collision at sea has involved the study of collisions which have actually occurred. There must however be a wealth of untapped data relating to ‘near misses’ judging by the hair-raising stories often told by ships' officers. These accounts, sometimes of ships passing one another so closely in fog that human sounds have been heard, are doubtless subject to embellishment but are, nevertheless, the stuff that nightmares are made of.

An interesting point which (perhaps predictably) features in many such stories is that the navigator presents himself as a victim of circumstances rather than one who has suffered the effects of a wrong decision. Curiously the ‘other ship’ sometimes shares this diplomatic immunity. Discounting ‘acts of God’ then, is there room for a category of encounter in which blame is minimized or even ruled out? In the discussion following a recent paper Captain F. J. Wylie states that between 1948 and 1966 most of the collisions he had studied which had come to court had, according to the Judge, been due to personal error (generally related to the Rules or misinterpretation of radar information). This no doubt reflects the situation in a true light provided one accepts that it may occasionally be necessary to distinguish between ‘personal error’ and blame. The two might not go together, for example, when the error is due to overloading of the human system or under-exposure to congested waters—a view which appears to be gaining support in some quarters.

This note assesses the savings in (time- and fuel-dependent) direct operating costs that are possible if every turning point on an airway is passed on the inside. Figure 1 shows a route with turning points at A, B and C. If a pilot follows the standard procedure of flying along AB until he is sure that he has passed B, his total track distance is (c + d + a + b).

To simplify the mathematics let us assume that he turns instead through half the required angle at a distance d before he reaches B and completes the turn after passing B abeam (and very close). His track distance will be (c + e + f). The difference in distance δ, representing the saving, is therefore (d + a + b) – (e + f).

Readers of Captain Cotter's paper under this title in the April 1976 issue of the Journal may be interested in some evidence that Dutch seamen in the seventeenth century were aware of this phenomenon of ship magnetism.

Abraham de Graaf in De seven Boecken van de Groote Zeevaert, published at Amsterdam in 1658, warns ships' officers taking bearings with the compass-that metal objects in their clothing can seriously deflect the compass, and mentions iron buttons and buckles. This was an important contemporary work on navigation and de Graaf was an examiner of officers of the Dutch East Indies Company from 1679 to 1714.