bluuebunny/crossref_metadata_2025_split huggingface dataset:
Marine Traffic Behaviour in Restricted Waters
Authors: Coldwell T. G. 
Published: November 2009

This paper, which was presented at an Ordinary Meeting of the Institute held in London on 26 January 1983, outlines the development and analysis of the ship domain in restricted waters and illustrates some of its uses in a buoyed channel.The analysis of marine casualties raises the question of how casualties occur, and may indicate the circumstances most likely to lead to a casualty. In addition, information may be gained as a basis for estimating the risk of a casualty and for assessing the effectiveness of proposals for improving the safety and efficiency of navigation in the area.The use of casualty statistics as a measure of marine risk has distinct limitations. In most areas a casualty is a reasonably rare occurrence, so that any systematic analysis of casualties will normally have to take place over a period of a few years; and, if improvements are made, a further period of time is necessary to measure their effectiveness.
Defining the Close-Quarters Situation at Sea
Authors: Hilgert Helmut 
Published: November 2009

The International Regulations for Preventing Collisions at Sea contain several important terms which are open to different interpretations such as ‘safe speed’, ‘close-quarters situation’ and ‘risk of collision’. It is not possible to give exact definitions of these terms as some of the factors involved are difficult to quantify but there is little doubt that mariners would welcome some official guidance on their application.The following paper by Dr Hilgert proposes a method of defining ‘close-quarters situation’ in terms of the principal factors which apply. The method is of particular interest because it is actually used by the maritime administration of one government and has been submitted to the International Maritime Organization for consideration. The IMO Sub-Committee on Safety of Navigation has taken note of the suggested approach and has invited comments.It is suggested in the paper that a simplified version of close-quarters situation could be determined in terms of the quantifiable parameters of speed, manoeuvrability and angle of approach. The method could be used to establish minimum values of a close-quarters situation but other factors would have to be taken into account such as the close presence of navigational hazards or other vessels, radar performance including the effect of errors and the desirability of keeping out of audible range of the fog signals of an approaching vessel.Despite some obvious limitations the method serves to indicate the least values which should be used and the paper contributes to a better understanding of this aspect of the avoidance of collision at sea.
Nautical Chart Standardization
Authors: Newson D. W. 
Published: November 2009

This paper deals with the work of the International Hydrographic Organisation (IHO) during the last ten years towards the standardization of nautical charts. The work began with the devising of a regional scheme of medium- and large-scale sheets of the north-east Atlantic area, to be co-produced by member nations as contributions to an International (INT) set of charts. It subsequently became clear that, as well as the scheme, a detailed set of specifications would be necessary to secure uniformity of choice of symbols and abbreviations throughout the International series, and also in the various national chart series of which it would form a part.The history of nautical chart standardization has recently been traced by Ritchie – gradual at first after the beginning of the International Hydrographic Bureau in 1921, and later speeding up when the International Hydrographic Conference of 1967 established a study which led to two series of INT charts on very small scales. After this the process gathered further speed with the successful establishment of the two bodies with whose work this paper is primarily concerned: the North Sea International Chart Commission (NSICC) in 1972 and the Chart Specifications (later Standardization) Committee (CSC) in 1977. The ten-nation NSICC, in drawing up the network of INT sheet-lines for its area, established the principles on which such schemes would be extended worldwide and also did extensive groundwork for the Chart Specifications of the IHO. These were completed for worldwide application by the seventeen-nation CSC.
Ship-based Weather Routing Using Dynamical Meteorology
Authors: Motte R. 
Published: November 2009

Many vessels trading on North Atlantic routes are equipped with weather facsimile receiving devices of various types. Ship-masters engaged on regular voyages in this area are thus able to conduct their own passage planning using the information readily available from these intruments. The capital cost in relation to other ship operation costs is negligible; in US dollars (1983) it is likely to be of the order:There would be no problem in planning a vessel's route across an ocean if it were possible to forecast with total accuracy the actual sea state existing for the duration of a voyage. Such an ideal circumstance does not yet exist and a method must thus be used which incorporates flexibility to modify a voyage plan as actual weather varies from the prognosis. This means that a subjective approach to storm avoidance may, on occasions, be preferable to the stringent demands of a least-time track. The obsession of routing agencies with the latter method may be one reason why weather routing has not achieved the success it perhaps deserves.A ship may be damaged or delayed by the action of sea waves on her hull or structure. Hull form and ship dimensions are usually selected on the basis of calm-water performance, rather than for sustained sea-speed.
In a Flat Spin
Authors: Williams J. E. D. 
Published: November 2009

An announcement of Wing Commander Anderson's recent death appears on another page. Mr William's spirited criticism of Anderson's ‘Rotations in Navigation’, and by implication his more recent note on Coriolis (May 1983 issue), was of course written before the sad news was known. It is published here without modification (and in spite of the author's offer to withdraw it) as would undoubtedly have been Wing Commander Anderson's wish.At the end of the last war Wing Commander E. W. Anderson was one of the most distinguished practising navigators in the Royal Air Force. ‘Andy’, as he is known to so many, has since become navigation's leading exegete through his work in this Institute, his articles, lectures and books. ‘Rotations in Navigation’, however, has got him in a flat spin. The reason why has wider implications worth examining.Andy starts by suggesting that the difficulty of explaining Coriolis ‘may be due to the intellectual danger of trusting mathematics without making sure that the right circumstances surround the formulae which emerge’. This observation illustrates how well one can write English without saying what one means. Circumstances, right or wrong, cannot surround a formula although the statement a formula makes may be irrelevant to our circumstances. It is precisely because pure mathematics is the language, as Russell put it, ‘in which we do not know what we are talking about or care whether what we say about it is true’, that applied mathematics is the language in which we are obliged to say what we mean or be seen to use the language wrongly.
‘What Course Should You Steer?’
Authors: Muir Langley R. 
Published: November 2009

Van de Ree has provided a solution to what must be a fairly common problem in navigation. The problem may be stated as follows.A ship on a rhumb-line course encounters head-winds and heavy seas requiring her to reduce speed. If she alters course, but does not change the rate of fuel consumption, her speed will be given by (a + b sin A), where A is the course change, a is the speed into the head sea and a + b is the speed in a beam sea. How far should the navigator alter course so that, after a given time, the ship will be nearer the destination than on any other course and, in addition, the labouring of the vessel will be reduced?Van de Ree's trial-and-error solution assumed the destination to be initially 63 miles away, a = 12, b = 5, and the optimization period 1 hour. His solution was to alter course by 20(± 2·5)°. It is possible to obtain a general algebraic solution to this problem, but it requires differentiating complicated trigonometric functions and solving a complicated trigonometric equation, and so the algebraic solution is not practically useful. It is also possible to solve the problem graphically. This solution is by far the simplest one and would be recommended in place of either Van de Ree's laborious numerical solution, or the equally difficult algebraic solution.However, one could question whether the chosen tactic is the appropriate one.
Statistics of Ship Collisions
Authors: Cockcroft A. N. 
Published: November 2009

FOR traffic proceeding in random directions on a plane surface the frequency of collisions, if no avoiding action is taken, is approximately proportional to the square of the traffic density and directly proportional to the size and speed of the craft. Avoiding action is normally taken and the rate of collisions is therefore also governed by additional factors such as the visibility, the effectiveness of the collision-avoidance rules, the competence of personnel, the manoeuvrability of the craft and the efficiency of radar and other equipment.In the post-war years there has been a considerable increase in the number of merchant ships. The number of vessels of ioo tons gross and upwards increased from less than 30,000 in 1948 to over 65,000 in 1976. When considering the population of ships at risk it is necessary to deduct special types of non-trading vessels and ships laid up. The number of trading ships in service has increased by approximately 100 per cent since 1950 (Fig. 1) and the greatest increase has been for large ships. The average length of trading ships has increased by approximately 40 per cent in the same period and there has also been an appreciable increase in the mean speed of ships.
New Studies in Collision Avoidance Radars
Authors: Butt J. A. , Jones K. D. , Rowsell C. G. 
Published: November 2009

Collision avoidance radars formed the subject of an Institute meeting held in London in October 1975 (this Journal, 29, 232). The subject has been given a sharper edge by President Carter's message to the U.S. Congress on 18 March 1977 which proposed, amongst other regulations, that all oil tankers over 20,000 dead weight tons which call at American ports, should carry ‘back-up radar systems including collision avoidance equipment’. The issues are highly contentious and the Institute has published a great deal on either side as the debate has grown. The papers which follow describe a research project carried out at the Department of Maritime Studies at Liverpool Polytechnic for Shell International Marine. They were presented at an Institute meeting held at Shell Centre on 17 November 1977 with Captain Ralph Maybourn in the Chair.J. A. Butt, Head of the Communications and Navigation Department at Shell International Marine, first looks at the investigation from the shipowner's point of view. Captain K. D. Jones, an Extra Master, and Director of Research in Maritime Studies at Liverpool Polytechnic, then discusses the scope of the project and describes the range of experience undertaken. C. G. Rowsell, seconded from Shell Tankers U.K. Fleet to the Operational Services Department, Shell International Marine, finally, gives a detailed account of the investigation and its results. The discussion was opened by Captain A. Wepster, Director, Navigation Research Centre, Netherlands Maritime Institute, and Captain F. J. Wylie, provides a written commentary.
Collision Avoidance as Observed by Shore Based Radar
Authors: Barratt M. J. 
Published: November 2009

Of all forms of transport, ships are unique when it comes to avoiding one another. Compared with both land vehicles and aircraft they have remarkable freedom of action, so that collisions are avoided less by external regulation than by mariners exercising their individual skill. A framework for their actions is provided by the collision regulations which have evolved over hundreds of years, a process which seems unlikely to reach an end in the near future. Since it is reasonable that any changes should be informed by events, information on what mariners actually do to avoid one another can only contribute to the safety of ships at sea.This paper is concerned with obtaining information on collision avoidance from radar records. It describes the data extraction and the selection of encounters between vessels, and presents some sample statistical results. Finally, probable applications of the information are discussed.
Further Analyses of Position Errors in Navigation
Authors: Hsu D. A. 
Published: November 2009

In a recent paper the author reported a distribution theory which rationalizes some fairly well established phenomena in navigational errors. Adequacy of the implied model and other existing models was investigated in the light of empirical evidence. A summary of the findings has been available in a previous issue of this Journal.This paper provides further insights into several theoretical models, establishes formal procedures for the estimation of parameters crucial to the evaluation and design of navigational systems and investigates the potentials of a broader system of distribution models. In addition, some simplified results aiming at practical use for navigators and air traffic control authorities are provided. A real-world application of the suggested methods and theoretical results is also demonstrated.
An Automated Conflict-alert Function for an Air Traffic Control System
Authors: Bertolazzi P. , Lucertini M. 
Published: November 2009

The major purpose of an air traffic control system is to ensure the separation of two or more aircraft flying in the same airspace, with an efficiency that can be expressed in terms of capacity and cost. As air traffic grows in numbers it becomes necessary to reduce the workload of the controllers by relieving them of many monitoring tasks, and eventually some decision-making tasks, through computerized automation. In this context many developments tend to build up an efficient conflict-alert subsystem.The problem of conflict-alert in the air needs strategic tools, to make collision unlikely or even impossible, and tactical tools to detect impending collisions. The latter detect potentially hazardous aircraft encounters and alert the controller in time to warn the pilots (if necessary) and should obviously provide this capability with a minimal number of false alarms and no increase in workload.
Modern Doppler Navigation Systems
Authors: Gray T. , Thorne T. G. 
Published: November 2009

This paper, which was presented at an Ordinary Meeting of the Institute in London on 21 November 1979, with S. Ratcliffe in the Chair, traces the evolution of airborne doppler navigation systems over the past two decades and discusses the treatment of errors introduced when flying over water. Both authors are with Decca Radar Ltd.The object of this paper is to describe briefly the major developments which have taken place in doppler navigation systems during the past 15 years or so, to indicate the current state of the art and to examine in some detail the behaviour of doppler systems when flying over water. The year 1960 is taken as a starting point since by that time commercial doppler systems were established. A typical general purpose system of that generation (Fig. 1) consisted of the following units:1. An antenna, probably mechanically stabilized.2. A transmitter/receiver using either pulse or FMCW modulation.3. A tracking system.4. An analog computer.5. A display of ground-speed and drift-angle.6. A display of present position.
The Cost-Effectiveness of Inertial Navigation for Civil Aircraft
Authors: Edwards A. A. 
Published: November 2009

Inertial navigation has been in airline use for some five years and a substantial amount of experience has been built up. The system seems to have fulfilled the expectations of operators. In this paper, which was read at a meeting of the Institute in London on 8 January 1974 with the President in the Chair, Mr. Edwards of British Airways discusses its accuracy and the cost of ownership.In 1969 a paper was presented to this Institute by F. J. Sullings of the then B.O.A.C. which described some of the engineering aspects of INS and predicted in some detail the costs of operating such equipment for a fleet of twelve B747 aircraft. It is the purpose of this paper to refer back to those early predictions and to make comparison with what has actually been realized. Sullings also referred to the anticipated navigational accuracy of the equipment and this paper will demonstrate that the anticipated accuracies have consistently been exceeded since the first use of the equipment by B.O.A.C. in May 1970. Finally, since the equipment has now been in use for five years, it is considered appropriate to review some developments in which airlines are taking an active interest.
Future Trends in Flight Control Systems
Authors: Hunt G. H. 
Published: November 2009

This paper was presented at a joint meeting of the Institute with the Institution of Electronic and Radio Engineers in London on 15 January 1975. The theme of the meeting at which six papers were discussed (a selection of which will be published in the Journal) was Advances in Airborne Equipment for Navigation and Freight Control.Modern data processors because of their increasing power and flexibility are increasingly used for a variety of functions in modern aircraft, both civil and military. It might seem that a flight control system could be designed of the form shown in Fig. 1, with a powerful central processor taking in signals from all the relevant sensors, gyros, pressure sensors, radar, &c., and operating the control surfaces so as to drive the aircraft along any desired course. But such a system would be quite inadequate in two vitally important aspects: there is no facility for inputs from the aircrew and no account has been taken of failure cases. These and other factors drive the control system designer inexorably towards a total system structure very similar to the type currently used in operational aircraft. There are of course a wide variety of such systems, but most of them are characterized by a number of common features.
Alone to Antarctica in Ice Bird
Authors: Lewis David 
Published: November 2009

In 1974 Dr. David Lewis was awarded the Institute's Gold Medal for his work on indigenous navigation methods in the Pacific, and his many remarkable feats of practical navigation. The following account is of perhaps the most remarkable of his voyages which was an attempt to circumnavigate the Antarctic Continent on his own. The first part of the voyage, which culminated in January 1973, was mentioned in the formal citation for the award; the second part, which is every bit as remarkable, finished in Capetown in March 1974.No one had ever sailed single-handed through the Southern Ocean to any part of the Antarctic continent, not even by way of Drake Passage from Tierra del Fuego, which involves a crossing of only about 400 miles of open sea. Since the sole practicable Antarctic landfall for a small vessel is the Antarctic Peninsula (formerly Graham Land) below Cape Horn, Australia, some 6000 miles to the west, was a far from ideal starting point. However, this was where I was working so that there was no alternative but to make Sydney the point of departure.
A Statistical Study of Ship Domains
Authors: Goodwin Elisabeth M. 
Published: November 2009

A ship domain may be thought of as the sea around his ship which the navigator would like to keep free, with respect to other ships and fixed objects. In this paper, which was read at an Institute meeting in London on 12 February 1975 with Captain R. Mayboum in the Chair, Mrs. Goodwin describes studies to determine the dimensions of a domain based on radar simulator performance and traffic surveys in the North Sea. She also suggests applications of this domain concept to marine traffic engineering problems and to traffic control schemes.In recent years there has been an increasing interest in the sea for it is to the world a means of communication, a source of food and a source of minerals.
The Arithmetic of Navigation Position Errors
Authors: Parker J. B. 
Published: November 2009

In a notable series of articles, Hsu advances theoretical models which are used to graduate 7582 observations of aircraft lateral deviations. The goodness of fit of these models, as judged by the χ2 test, is satisfactory. Hsu's main theoretical model is the Double Double Exponential distribution (DDE), a three parameter model whose probability density function is given byOther model types are also considered, such as the family of exponential power distributions whose probability density is cited by Hsu insection 9. This leads to a four-parameter model, and the fit is (not surprisingly) better even than that of the DDE.
Crossing the Dover Strait Separation Scheme
Authors: Irving I. D. 
Published: November 2009

In this paper Captain I. D. Irving, master of a cross-channel ferry, discusses some of the problems which arise from the operation of the 1972 Collision Regulations within the Dover Strait Traffic Separation Scheme. The paper is a revised version of one presented at the Fourth International Symposium on Vessel Traffic Services.The Dover Strait and its approaches form one of the world's busiest waterways. Perhaps inevitably therefore it has been the scene of a large proportion of the world's collisions and strandings, and for this very reason became the site of the first offshore Traffic Separation Scheme. At first the scheme was only voluntary, but with the introduction ten years later of the 1972 International Regulations for Preventing Collisions at Sea, compliance with the IMCO-approved scheme became mandatory for all vessels.
On Error Distributions in Navigation
Authors: Anderson O. D. 
Published: November 2009

In this note I wish to enter however belatedly into the discussion of error distributions in navigation (cf. Anderson and Anderson and Ellis). Not being a navigator my arguments will be purely statistical, but I hope that they will throw some light on the problem, which seems to be an important one.Hampton and Mills have commented that large errors occur more frequently than is predicted by gaussian behaviour; and Anderson remarks that in practice the ‘skirts’ of the empirical distribution are commonly hitched high over the estimated gaussian tails. The conclusion drawn is that navigational errors follow a distribution closer to the two-sided negative exponential than to the normal though, instead of peaking to a sharp point at the centre, the empirical distributions seem to have rounded heads.
Education and the Sea
Authors: Fifield L. W. J. 
Published: November 2009

Professor M'Pherson's paper on ‘Education and the Sea’ does somewhat less than justice to the non-university sector of the British educational system; his Appendix A lists only two university undergraduate courses in nautical—maritime studies, whereas six such courses are offered by polytechnics and the first of these was approved ten years ago.More recent developments have included a B.Sc. in Fishery Science; a number of degree courses in Environmental Studies and Geography, which contain substantial elements of meteorology, oceanography, cartography and marine surveying; and post-graduate courses in Shipping Management and in Hydro-graphic Surveying. These courses gain awards of a first degree or the diploma of the Council for National Academic Awards—a body which deserves much credit for encouraging experimentation in many ‘new’ areas of study.