The principal aim of this paper is to explore some of the wider social and economic implications of reductions in the real costs of sea transport as a result of the changes in maritime technology since about 1960. In this wider approach we have to consider shipping not as a series of mechanical links meeting with land transport at port interfaces, but as a system which has in recent years undergone processes of transformation, technically and organizationally, which have been of such fundamental significance as to affect several aspects of the spatial organization of society.

Major transport advances have had a considerable impact on society at various times in the past – the industrial revolution in Britain has equally well been described as the transport revolution; but it is always difficult at the time to discern the significance of the social and economic impact of such changes – even now there is some controversy as to whether the too early allocation of resources to railroads in America inhibited nineteenth century rates of economic growth in that country. But what have been common to all transport revolutions are the ways in which they have acted to converge time and space through increased speed of transit and reduced costs of overcoming distance. This in turn has affected perceptions of the value of places, the accessibility of resources and markets, and has influenced decisions relating to the location of mining, agricultural, and industrial activities.

There can be little doubt that the concept of using wind power for ships has a great deal to commend it and equally little doubt that the extensive use of the natural power available from wind, sea and sun in order to conserve fossil fuel resources must be urgently considered. If we leave aside sea and sun, although both are potential sources of some proportion of propulsion, and concentrate on wind power the immediate and largest problem is one of the time available. We may all believe in the principle but the problem is one of arriving at an industry with the appropriate technical ability in any short time. We know that it is possible, as witness the hovercraft industry, and this was achieved by grafting the new technology to the stem of the existing aircraft industry. It might equally have been attached to shipbuilding or boatbuilding or even the car industry. I think in fact that the right decision was made and that hovercraft have benefited from their attachment to the industry with the greatest life in it.

This paper, by the Deputy Operations Manager of the Marine Department of Hunting Surveys Limited, was presented on 15 November 1979 at a meeting of the Solent Branch of the Institute held at the College of Nautical Studies, Warsash. It deals with the operation of semi-submersible laybarges based on experience in the northern North Sea from 1975 to 1979. It covers, from the survey contractor's point of view, the different phases of operation from the time the oil company selects the route until the line is laid and surveyed on the seabed. Some aspects of the work described would not normally be associated with surveying or navigation but have been carried out by survey teams in laybarges.

Certain measures now before IMCO require all vessels of particular classes to carry automatic radar plotting devices with a specified level of performance. Tankers over 10 000 tons trading to the United States will be required to carry such equipment from 1982 and the IMCO requirements will apply progressively to different categories of vessel over 10 000 tons from 1984–89.

The Technical Committee met in open session in London on 16 January 1980 to discuss the implication of these measures and some of the contributions to the discussion are printed below.

In this paper, which was presented at an Ordinary Meeting of the Institute in London on 23 May 1979 with S. Ratcliffe in the Chair, Dr R. L. Ford outlines proposals for an airborne traffic-situation display. By providing pilots with a visual synopsis of ATC strategy in the terminal area and a collision warning facility, the display would enable them to play a more constructive role in maintaining safety and efficiency in aircraft operations.

The two papers which follow (Jones and Ratcliffe) were presented in the course of a seminar sponsored jointly by the Institute with the Nautical Institute and held at the City of London Polytechnic on 13 December 1979. The purpose was to examine the usefulness of transponders for marine purposes. Seven papers were presented and these may be obtained at £7.50 (£5 for Members) from the Nautical Institute.

The term transponder is usually interpreted by practising mariners as the simple inband swept frequency device, called Racon, with which those mariners are most familiar. It is this concept which largely colours the mariner's views on the topic, and is perhaps the reason for the obvious reluctance to accept expanding use of transponders which is apparent in the marine industry. Their personal recollected experiences of the clutter caused by Racon and the possible problems that could result from proliferation of such beacons give justifiable cause for this hesitancy.

It is usually accepted that the visual estimation of miss distances at sea is difficult and that it is advisable to employ plotting methods with visual observations (or radar echoes) to assess the positions and movements of neighbouring vessels. Nevertheless, direct visual assessment is likely to remain a useful adjunct to more sophisticated methods, at least under conditions of good visibility, particularly as the use of radar does not absolve the mariner from keeping a good look-out at all times. It seemed, therefore, useful to examine some of the factors involved in the visual estimation of miss distance, in the hope that such an analysis might suggest ways in which the direct assessment of close-quarters situations could be improved.

The steering and sailing rules are changing with the development of available sources of information. This latest development is of special interest, as radar navigation has prompted a return to the principles of the ‘Larboard Helm Rule’ -if the compass bearing of an approaching vessel does not appreciably change, each of the vessels involved shall alter course so as to place herself to the right of the line of compass bearing o t the approaching vessel’.

This rule offered simple sailing instructions: each party to an encounter was required to take action. There was no stand-on vessel and no right of way. Our modern steering and sailing rules are based on the right of way of the vessel on the starboard side and this gives rise to difficulties unknown in the days of the larboard helm rule:

(i) There are two vessels on collision course, one large and slow-acting, the other small and manoeuvreable; the smaller vessel can easily take avoiding action. As, however, she is approaching from starboard she is the stand-on vessel. The large vessel, though restricted in her ability to manoeuvre is thus obliged to take avoiding action.

(ii) The officer on the bridge of the stand-on vessel recognizes risk of collision. The navigator on the bridge of the burdened vessel is distracted from his duty of keeping a proper look-out. Our existing rules require avoiding action on the part of the vessel that has not recognized the risk of collision.

Air transport is characterized by a rapid and fairly steady growth in the size, numbers and speed of the vehicles. The systems for navigation and control of this traffic have evolved with the changing problem, and heavy demands have been, and are being, made on electronic technology. At the same time, heavy emphasis is laid on the need for evolutionary changes; old and new systems must be compatible. The present investment, world-wide, in civil air transport is about £100000M. World-wide compatibility is essential between air and ground electronic subsystems, and such systems and operating procedures are, eventually, the subject of international agreements. It follows that any system changes must be heavily influenced by past history, and for that reason it is proposed to discuss airborne secondary radar transponders on a historical basis.

In this paper we shall seek to discover what information we need in order to navigate and how this information is obtained. To do this we first define what we are talking about and then, by a logical process, determine the components involved and the ways they can be measured. Efforts to discover whether another science has been approached in this basic way have failed. All that can be said with certainty is that the path is fraught with difficulties.

The word navigation has nautical origins but the scope of the discipline is far wider today. Nevertheless, a modern definition must stem naturally from marine operations. There would seem to be four factors:

(a) A ship at sea is not navigating when she is docked. There has to be motion.

(b) Rocking to and fro is not enough. The motion has to be from one place to another.

(c) Drifting helplessly before the wind is not being navigated. The motion has to be under control.

(d) The word ‘control’ has a negative and restricting connotation whereas travel has positive aims. Hence the control has to be exercised to a purpose. Steering aimlessly, however complete the control, is not navigating.

A definition of navigation should therefore include four features, motion, place, control and purpose. A possible wording might be:

‘Navigation is purposeful control of motion from place to place’.

The shipping industry is faced with unilateral legislation proposed by the United States of America covering navigational equipment and, in the interests of harmonization, IMCO is compiling performance specifications and carriage requirements for navigational equipment including collision avoidance systems; the establishment of type approval procedures can be anticipated. The shipowner has reservations, in respect of the need for adequate training in the use of advanced systems and the risk of navigators placing reliance on such devices as collision avoidance systems when their constant availability cannot be guaranteed.

The object of this paper is to describe, in principle, a method of reducing astronomical sights, of plotting the resulting position lines and of calculating a position from two or more sights. The method, which is thought to be new, requires neither a calculator nor extensive tables and appears to possess some advantages over more conventional methods. After a general description, and illustrations of two variations, the method is analysed in sufficient detail to indicate that its practical realization, to meet any specific requirement, is a straightforward matter of detailed design.

No attempt is here made to translate the principles of the method into a form for practical use. The paper is mainly addressed to those interested in the theory of astronomical navigation; the description, together with the analysis and the illustrations, is available for use as a basis for a practical method of sight reduction – should anyone consider that there is a requirement! The treatment is intended to be rigorous, though much elementary mathematical detail has been omitted; in a practical application some care may be required near the singularities.

A recent oceanographic cruise of the Spanish research vessel, B. O. Cornide de Saavedra, provided a suitable platform from which to survey ship traffic through the strait of Gibraltar covering several days. This was long enough for a representative sample to be taken, 472 ships. It was observed that only 65 per cent of the ships passing through the strait observed the traffic lanes. The current structure of the Alboran Sea may offer economic advantage to a different traffic convention. The present mean traffic is 5·8 ships per hour which represents a density greater than that of the Strait of Dover. This suggests that traffic regulation, in the interests of preventing loss of life and oil spills, may be necessary in the near future, particularly when the Suez Canal has been opened to larger tankers.

A few years ago a series of papers by Frank Coffman Bell was published in this Journal suggesting how collision avoidance manoeuvres could be analysed using projective geometry. However it is probably true that most non-mathematicians have little experience of any type of geometry other than the Euclidean metric geometry which is taught in schools. Euclid's approach was to elaborate a science of the measurement of physical space and for this purpose he deduced a number of geometrical theorems starting from the intuitional ideas of point, line, distance and length. To Euclid and his followers the notion of distance was completely obvious and basic and underlay everything in geometrical science, hence the terminology that is given to this work ‘metric geometry’. Another concept of geometry was however put forward by a group of geometers of whom Pappus is one of the best known. His work shows that he was interested in theorems concerned not with distance but with such things as concurrence of lines and collinearity of points. This type of theorem may be thought of as the projective type. If for example it is assumed that any two lines in a plane meet in a point, then two parallel lines must also meet in a point which may be termed a point at infinity. In projective geometry no distinction is then made between ordinary points and points at infinity.

The aerospace industry has demonstrated very effectively the accuracy and reliability of both manned and unmanned vehicles on extensive and sophisticated missions. There is little doubt that the next two or three decades will see the rapid introduction of further automated and computerized techniques into ship operations and there is a great deal that the shipping industry can learn from civil aviation – in particular, traffic regulation, automated navigation, accident investigation, and training techniques. Three accidents which illustrate some of the problems associated with the operation of merchant ships are cited, and comparisons made with the operational procedures used in aviation.

The motor vessel Blythe Star of 321 grt sailed at 1830 on 12 October 1973 from Hobart, Tasmania, bound for King Island with a cargo of bagged superphosphate. At 0800 on 13 October she heeled over to starboard and sank. The weather was fine, with light winds, slight seas, and very low swell. All of the ten persons aboard abandoned ship in an inflatable life-raft. One died at sea and two others died after reaching shore in southern Tasmania. The remainder, after landing on 21 October, made their way to a logging contractor and safety on October 24. The accident resulted in the biggest search and rescue operation ever conducted in Australia.

Sailing Directions nowadays implies ‘Pilots’, with which all mariners are familiar. However, the term in a broader sense embraces a wide range of printed and descriptive material of help to the seaman. In this paper, which was presented at a meeting of the Solent Branch of the Institute in December 1979, Dr Cotter traces the origins of the publications – pilot books, light lists, tide tables, and indeed charts – which are now available to the navigator. The paper has been abridged.

Men sailed the seas and made extended voyages, without benefit of instruments now considered vitally necessary, thousands of years before the invention of chart and compass, the pre-eminent instruments of navigation. To the question: ‘How did an ancient sea-trader shape his course in the confident expectation of reaching his destination safely?’ there is no complete answer. But we can be fairly certain that early seafarers learnt the techniques of their craft through observation and experience supplemented by verbal instruction and advice from their more-experienced contemporaries.

Shiphandling training simulators have come into use since 1967. Several such simulators, with differing technical characteristics and training goals, are now in use around the world. They are commonly used to familiarize already competent masters with new vessels, restricted water areas, or some form of standard bridge procedures. Acceptance of these simulators by highly experienced master trainees has been predominantly favourable. Ship radar simulators have been in use for a somewhat longer time. They are typically used for training entry level officers as well as experienced masters.

The aviation and nuclear reactor industries, with a greater experience of simulator technology and its training value, use simulators for both training and licensing. The military (e.g. Navy) and other government agencies (e.g. National Aeronautics and Space Administration) have extensively used simulators for training and qualification. It has been suggested (Schumacker, Madsen and Nicastro, 1972; IMCO Standards of Training and Watchkeeping Convention of 1978, Resolution 17) that simulators could be used for proficiency demonstration on the part of mariners. The US Port and Tanker Safety Act of 1978 requires standards for licence qualifications by use of simulators.

The United States Coast Guard and Maritime Administration have funded research into the role, technology, and effectiveness of ship-handling simulators. Depending partly on conclusions from this research, the Coast Guard will consider partial credit toward licences for successful completion of approved simulator training. The Maritime Administration may assist maritime training academies to design and procure simulator-based training systems.

As sea traffic grows, so too does the problem of the acoustic pollution of fishing grounds. This paper describes the measurement and analysis of ship-produced underwater sounds and their effect on the behaviour of certain fishes. It would seem that their influence on marine organisms is a growing problem and should not be ignored by navigators, for the sounds produced by large or high-speed vessels, or even fishing boats, can frighten fish shoals or cause them to change their migration routes.

After a series of tests to measure and analyse the underwater sound, the output of submerged loud-speakers, either at sea or in an aquarium, was adjusted to ensure that the sound intensity near the fish was at the required level and the fish behaviour was carefully observed. For these experiments a hydrophone was connected to a pre-amplifier. A signal amplified by the pre-amplifier is attenuated before being sent to the main amplifier, the sound level being read directly on an indicator using the sound analysing character ‘C’. A tape recorder registers the sound signal in a flat response from 20 to 50 Hz to within 3 dB. A tracing recorder was also sometimes used and the two methods gave almost the same results.

In 1873 Marcq St Hilaire introduced the concept of the intercept method of constructing a position line, with the use of an assumed position chosen to facilitate calculation or tabulation. This same basic principle is here used to facilitate direct calculation without the use of logarithms or calculator; a simple table of a natural trigonometrical function is required and, preferably, some aid to multiplication. Apparently the method has not been proposed before, and it is ironic that it should be considered when the availability of calculators has essentially removed any requirement for it! It is put forward mainly for theoretical interest, but there may be a place for it for emergency use when (for some reason) neither conventional tables nor a calculator is available.

Most lists of the seven wonders of the world include the Colossus of Rhodes. This bronze figure of Apollo, which the sculptor Chares took several years to construct, stood near a harbour on the island of Rhodes in the Eastern Mediterranean. It is reported that ships in full sail could pass between its legs whilst navigation lights were kept burning in its eyes. Whilst such descriptions are coloured by romance and myth, there is little doubt that early lighthouses were substantially tall towers supporting an open wood or coal fire. Such lights existed in Britain until as late as 1819, when Flathom light in the Bristol Channel was replaced by more modern equipment.

In time the open-flame coal brazier gave way to tallow candles. In 1696 Winstanley introduced a chandelier with tallow candles into the lantern of his famous Eddystone Tower. In 1759 Smeeton's Tower, which now stands on the Hoe at Plymouth, incorporated two superimposed iron rings that contained twenty-four candles.

By and large it was the improvements in optical systems that governed the development and introduction of oil and then, at a later date, electric illuminants.

The first attempt to intensify a lighthouse beam was in 1727 by the French at Cordouan. Mariners had complained that they could not see the light at more than 2 miles. In an attempt to improve on this, a cone of wood was covered with tin plate and suspended above the open fire.