bluuebunny/crossref_metadata_2025_split huggingface dataset:
Visual Navigation in Enclosed Waters
Authors: Mitchell J. B. 
Published: January 2010

Most shipmasters making a tortuous passage through a strait or among reefs and islands, after a long passage on one course in a vessel equipped only with magnetic compasses, are worried out of all proportion to the hazards of the manœuvre by reason of not knowing in all certainty what compass errors will pertain on widely different courses. Of course there is the Azimuth Record Book, but the last time similar courses were used could have been in the other hemisphere or under different conditions of trim, &c.Given time, weather conditions and other suitable opportunity a prudent master will have conducted a swing to ascertain the errors before approaching the stretch of dangerous water. This may not be possible and, again, he knows in his mind that azimuths taken under these circumstances, with little time to waste, do not always conform to the later findings.
Marine Casualties in the Pacific Islands and their Economic Consequences
Authors: Couper A. D. 
Published: January 2010

The economic development of archipelagic territories is intimately linked with shipping. In the archipelagoes of the Pacific small vessels connect many islands with one or two port towns. These towns are entrepôts for cargoes of consumer goods, petroleum and timber, and they are transhipment points for copra and fresh produce coming in from the island hinterlands. Towns, such as Suva, Lautoka, Apia, Nuku'alofa, also serve as local markets and educational, social and medical centres for the people of the outer islands.In Fiji there are about 90 inhabited islands outside Viti Levu. The villages and estates in the outer islands all focus in some way on the port of Suva. There are many economic and social problems in the islands and these are made more acute by high freight rates and the unreliability of some services. But most of the shipping operators would be hard put to reduce freight rates or to improve the quality of their ships and services. One reason for this is the burden of marine accidents.
The Costs of Terminal Area Delays
Authors: Attwooll V. W. 
Published: January 2010

Delays in the terminal area lead to increases in the operating cost of the aircraft involved. We assess these costs as one criterion of the effectiveness of the air traffic system in the terminal area, and to give a measure of the desirable expenditure on methods of reducing delay (e.g. improved radar, additional runways or even an extra airport). This note discusses methods of assessing the cost penalty of delays exclusively to the airline operator and gives examples for three types of aircraft, a short-range subsonic jet, a long-range subsonic jet and a supersonic transport.Terminal area delays occur essentially because aircraft apply for use of the runway, either for take-off or landing, in a random fashion and because the acceptance rate of the runway is limited by the need to maintain safe separation between aircraft on and in the vicinity of the runway. Such delays involve penalty to the aircraft operator in terms of extra time and fuel consumed and hence of extra operating cost.
Inertial Techniques for Marine Navigation
Authors: Bailhache H. N. 
Published: January 2010

The requirements of navigation entering or leaving harbour or in narrow waters are exacting, and a very accurate position is usually essential. For this reason it is believed that inertial techniques should be applied in the first instance only to ocean navigation as, although the system will give the ship's position continually, the accuracy will be of the order of one mile.The latitude and vertical references are absolute, but the longitude reference is relative to a known starting point. Besides position, an inertial system can also provide course, sidereal time and roll and pitch and, by comparison of successive positions, course and speed made good, and leeway. Furthermore the system could be used to feed position into an automatic plotting table, with a chart of suitable scale superimposed, so that the vessel's geographical location would be visible at a glance.
Some Considerations of Free-gyro Failure in Air Navigation
Authors: Green J. F. 
Published: January 2010

In polar regions great reliance has to be placed on the directional information provided by a free azimuth gyro. For sufficient reliability the use of three such gyros is advocated. An analysis is made of ‘the best two out of three’ principle—taking into account the fact that in practice no two gyro readings will be identical.It is demonstrated that for a given reliability attaching to an individual gyro, the reliability of a three-gyro system represents a vast improvement over a single instrument and that there is an optimum way of using the information presented. The advantages of middle signal selection are pointed out and the dangers associated with mean signal selection are explained. Attention is drawn to the extension of this principle to the problems of triple-signal selection in the automatic navigation system of the future.
The Role of the Computer in Automatic Navigation
Authors: Houghton P. A. , Lewis J. H. R. 
Published: January 2010

This paper discusses the operation of a simple computer which, when used in conjunction with a doppler sensor, will enable automatic navigation to be performed. It is primarily designed for the civil air operator. A series of rhumb lines may be flown and position relative to the desired track and destination will then be displayed. Directional command signals to the pilot and autopilot enable the track to be closely followed.A short technical description of the computer is given and the expected errors and methods of correction are evaluated. Procedures for turning corners, making diversions, regaining track and flying holding patterns are given, together with the limitations or inaccuracies of the navigational information under these conditions.
Recommended Routes for Ships in Congested Waters
Authors: Dickson A. F. 
Published: January 2010

The need for measures to guide shipping in congested waters to reduce collision risk has received a very considerable amount of attention over the past few years. The Safety of Life at Sea Conference in 1960 recognized the danger of collision in congested areas and required ship owners to formulate ways whereby some measure of control of traffic could be introduced with a view to reducing collision risks. Shell Tankers accept this responsibility and are, therefore, anxious to make some contribution towards the solution of the problem.Many valuable papers on the subject have been published in professional journals recently. Most of the authors have emphasized the difficulties in which Masters are placed when called to navigate their ships through heavy traffic in reduced visibility, and Calvert in his study of the collision-avoidance problem reached a first conclusion that whatever might be done to improve anti-collision manœuvring, there was an urgent need for regulation of traffic in areas of congestion.
Lasers and their Application to Navigation
Authors: King P. G. R. 
Published: January 2010

The navigator at the present time relies greatly on both optical devices and on radio systems utilizing electromagnetic waves ranging in wavelength from millimetres up to hundreds of metres. The laser extends the coherent properties of radio waves into the visible part of the spectrum. It is natural therefore to expect that this increased facility should lead to the possibility of devising systems based on the laser which might help to overcome problems that still exist in navigation.It is the purpose of this paper to describe the principles and performance of present-day lasers, to survey some of the techniques used in navigation in order to discover those in which the laser might conceivably play a useful part, and to comment on the laser's advantages and disadvantages in comparison with existing methods. Finally, a particular form of laser called the ‘ring laser’ is described and discussed in some detail. The ring laser is of great interest in that it provides a completely novel way of measuring direction relative to inertial space, and is therefore a possible competitor to the gyroscope for inertial navigation. The ring laser can also measure the velocity of a transparent medium moving relative to it, which could be of use in determining vehicle velocity.
Long-range Navigation Aids
Authors: Williams J. E. D. 
Published: January 2010

For a quarter of a century now we have struggled in a curiously impotent way with the problem of long-range navigation of civil aircraft and the associated problem of control of traffic in oceanic control areas. The deliberations of technical conferences of the International Air Transport Association alone during the past 15 years on the subject of Long-range Navigation of Civil Aircraft would fill a library.The development of navigation has always been retarded by difficulties with the analysis of the operational requirement. It is, for example, inconceivable that if the operational requirement for astronomical navigation had been properly explained to eighteenth-century astronomers, they would have waited for practising seamen to invent the position line almost by accident. As neither the authors of Long-range Navigation of Civil Aircraft (D. E. Hampton and J. R. Mills. This Journal 17, 183) nor any of the speakers recorded in the subsequent discussion are directly involved with the operation of aircraft some remarks on the assumed requirements may be helpful.
Reduction to the Prime Vertical Circle
Authors: Cotter Charles H. 
Published: January 2010

‘Surprise has sometimes been expressed by mathematicians who have been led by circumstances to look into the subject of nautical astronomy that no method is practised by sailors for reducing a longitude observation to the prime vertical in the same way that an observation for latitude is reduced to the meridian.’This quotation forms the opening paragraph of the first of three papers by Mr. H. B. Goodwin, R.N., written in 1904–6 relating to the problem of reduction to the prime vertical. The following description of Goodwin's work in this connection may not be without interest in view of the recent interesting paper by D. H. Sadler in which the author describes the investigations into the same problem made by G. F. Cunningham.The vast difference, to which Mr. Sadler refers, between proposing and translating into practice, a new navigational table, is exemplified in the case of Goodwin's P.V. Tables. All the intermediate steps between proposing and producing are described with utmost clarity in Goodwin's three papers.
Marketing a New Radar
Authors: Beattie J. H. 
Published: January 2010

Marketing a marine radar may not sound the most promising subject for a navigational paper. But in an age when almost anything is technically feasible, the direction of progress will be governed by many considerations which, if they are not themselves navigational, are nevertheless of great interest to those concerned with the subject. A new range of equipment for example must be related to the level of skill and training which actually prevails at sea; research and development costs must be seen in relation to the cost-effectiveness of the system; and finally purely operational factors such as traffic separation schemes may have to be taken into account. In this paper, originally presented in Paris to the French Institute of Navigation, some of these considerations are discussed in relation to the new Decca anti-collision radar.Just over 25 years ago, in the summer of 1944, a United Kingdom conference on radio for marine transport concluded that radar would be of great value to merchant ships. They asked the Royal Navy to draw up a specification for the average ship. Discussion with various shipping interests confirmed that there was in fact a requirement for a radar set ‘for navigation and pilotage as distinct from a collision warning set, which would, of course, be a much simpler and cheaper device’. The later 1946 Ministry of Transport Specification referred to the requirement ‘to provide warning of the proximity of other surface craft and obstructions which will enable collision to be avoided’. Now of course, after 25 years of hard experience, we know that the matter of avoiding collision at sea is not apparently so simple.
Inertial Navigation for the Merchant Marine
Authors: Videlo D. A. , Wright D. L. 
Published: January 2010

In this paper the history and development of inertial systems for the merchant marine is traced from the gyro-compass, familiar at sea since the beginning of the century, to complete inertia systems and integrated systems such as doppler/inertia.The paper was presented at the Marine Navigation Symposium held in Sandefjord, Norway, on 24–6 September 1969 and is reproduced with the permission of the organizers.The gyro-compass was first fitted on board a ship as long ago as 1908. Its function has been as the main reference by which the ship is steered and to which navigation by dead reckoning and direction finding is referred. The compass has been developed continuously to provide a more reliable, more accurate, and smaller instrument costing typically £1000 to £2000.
Distance Off by Vertical Sextant Angle
Authors: Crosbie J. W. 
Published: January 2010

Distance off by measuring the elevation of a mountain top above the horizon has been a popular means of finding position at sea ever since Captain Lecky published his famous tables. This popularity persists into the radar age because distance off can often be found from a vertical sextant angle long before a ship is within effective radar range of the coast. In view of this it is surprising that the standard textbooks on navigation give scant attention to this method and any seaman finding himself without Lecky's tables would find little guidance elsewhere.Wing Commander E. W. Anderson in The Principles of Navigation indicates that the whole angle subtended by a mountain at a ship can be found by adding half the estimated distance off in miles to the visible angle in minutes, having first corrected this angle for dip and refraction. This can be proved by simple geometry by showing that the angle subtended by the part of a mountain hidden to an observer at sea-level is equal to half the distance off.
Radar Plotting Errors
Authors: Topley H. 
Published: January 2010

Errors in the derived aspect, in course and speed of another vessel, or in the nearest approach, found by plotting radar ranges and bearings on a relative plot can arise in a number of ways, such as errors:(1) in the bearing as read from the PPI(2) in range as read from the PPI(3) in plotting the points on the plotting sheet(4) in estimating own vessel's course and distance run during the plotting interval(5) in timing the plotting interval(6) ‘blunders’.
The Physics of Collision at Sea
Authors: Morrel J. S. 
Published: January 2010

When two ships encounter one another at sea, there is a possibility that they will collide. Whether there is actual danger or not depends on the physical facts of their respective positions and motions. If danger does exist, the motions must be changed. The purposes of Dr. Morrel's paper are (1) to inquire what facts must be known, both to distinguish the cases of actual danger and to choose effective remedial action; (2) to determine when and how well these facts must be known; and (3) to consider how these facts may be obtained and how they may be best utilized.The paper attempts to construct an integrated treatment of the whole problem, in terms of the fundamentals that define its nature and shape its solution. The problem is large and complex. Consequently, a compact treatment of it must perforce omit most of the details; both of the evidence and analysis by which the principles are established and of the technology by which they may be exploited.Much of the treatment uses mathematics; but emphasis is placed on the implications rather than on procedures.The paper was presented at the meeting of the Ausschuss für Funkortung held at Kiel on 10, 11, 12 September 1960 and is printed with that body's kind permission.
Columbus the Navigator?
Authors: Taylor E. G. R. 
Published: January 2010

1. Journal de bord de Juan de la Cosa, second de Christophe Colomb. Presenté et commenté par Ignacio Olagué. Paris, 1957, 870 frs.2. The Journal of Christopher Columbus. Translated by Cecil Jane, revised and annotated by L. A. Vigneras with an appendix by R. A. Skelton. Anthony Blond and The Orion Press, London, 1960, 45s.Writing an Introduction to the Four Voyages of Columbus over thirty years ago, the late Cecil Jane remarked: ‘It might with justice be added that no event of such moment can ever occur again, unless, perhaps the tracts of space be bridged and communication established between the Earth and her sister planets.’ The fact that we are on the very eve of placing a man in the Moon should enable us to appreciate more justly the various ways in which, during the late fifteenth century, different people reacted to the daring proposal of Columbus to sail west to Asia.
The Cocked Hat
Authors: Cotter Charles H. 
Published: January 2010

As every schoolboy learns, a point has position but no size, and a line has length but no breadth. Nevertheless, to a navigator concerned with fixing his ship, points and lines are represented on his chart as fine pencil marks.The manner of representing the results of observations as pencil ‘points’ or ‘lines’, has undoubtedly led to the belief that a ship's position must be represented as lying at a point on a position line which is drawn on a chart. Nothing short of perfection in position lines is ever expected by most practical navigators, and two position lines crossing at a point are usually regarded by seamen as yielding a perfect position: and if three position lines meet at a point! … there is seldom even the slightest doubt in the mariner's mind about the reliability of such a fix. On the other hand, three position lines which do not meet at a point are usually regarded as being something not quite respectable.
Port and Terminal Navigation and Control
Authors: Brandenburg H. J. 
Published: January 2010

In this paper, which was presented at an Institute meeting held in London on 26 May 1971, Captain Brandenburg discusses the problems of port and terminal navigation control in the 1980s and takes up the questions whether such control will be needed and how much control will be appropriate.This paper is not concerned particularly with problems in Rotterdam, or indeed with any particular ports, but rather with an overall evaluation of probable port developments in the near future, say the 1980s, and with the steps which may be necessary to meet the problems that will arise. In speaking of port and terminal navigation one should distinguish between pilotage, which may be defined as conducting a ship in safety from one manœuvring area to the next, and manœuvre, which is the handling of a ship in confined areas with whatever aids are available. It is well known that the danger and difficulty of manœuvre varies greatly in different areas and this was the subject of an analysis by Captain Wepster, but I shall consider manœuvres common to all terminal areas:(i) picking up the pilot and lining up into the fairway channel,(ii) docking and undocking,(iii) lining up into the fairway channel again,(iv) dropping the pilot and heading up for destination.
Collisions Involving Very Large Ships
Authors: Watt J. 
Published: January 2010

Commander P. C. H. Clissold, in a contribution to Forum in the April 1971 issue of the Journal, makes a point concerning the collision-avoidance handling of very large single-screw ships. Commander Clissold writes:‘Because of their unwieldiness an avoiding action must be initiated while still at a considerable distance from the threat, if it is to have any effect. This distance is beyond that at which the eye of the navigator can accurately assess the risk of collision or the need to manœuvre. He must, therefore, depend upon instrumental information for making his decisions; in other words, in clear weather as in thick, he must use his radar and plot continuously if he is not to hazard his ship. If the argument is put forward that this will require two men on watch together and the state of manning does not permit this to be done, the answer is that a change in organization must be made to make it possible.’
‘The Sector Rule and the Collision Problem’
Authors: García-Frías J. 
Published: January 2010

Captain García-Frías has made the following comments on the discussion of his recent paper (this Journal, 18, 141) contributed by E. S. Calvert and S. H. Hollingdale.Captain García-Frías observes that while Calvert and Hollingdale recognize that this paper combines his earlier suggestion for a sector rule with a set of manœuvring rules, they have failed to recognize the fundamental distinction between the structural and operational aspects of an encounter; his proposed manœuvring rules deal with the operational aspect. These rules differ from the manœuvres they have themselves proposed in that they depend only on the bearing of the target as seen on the radar at a distance of 2 miles; they derive from his sector rule and do not require a quantitative estimate of the miss distance. His rules are only the same as their manœuvres for the case of a steady bearing since their manœuvres also require the sign of the miss distance.
The Three Stages of Radar Plotting
Authors: Topley H. 
Published: January 2010

Many discussions have taken place regarding the feasibility of plotting when using radar in reduced visibility and it soon becomes apparent that there is confusion in what each of us considers by the term ‘plotting’.These notes are to suggest definitions of the various stages of plotting and to consider the conditions under which each is necessary.Radar plotting can be divided into three stages:(a) Record plotting(b) Deductive plotting(c) Forecast plotting.
Radar at Sea
Authors: Wylie F. J. 
Published: January 2010

The twenty-first birthday of the Institute coincides very closely with that of commercial marine radar. Many merchant ships were fitted with naval radars between 1942 and 1945 but these bore little resemblance to the sets which would be needed for peaceful purposes.Even before the war had ended, the United Kingdom Conference on Radio for Marine Transport (U.K.R.M.T.) was set up under the auspices of the Radio Board of the War Cabinet, to discuss the peacetime applications of the war developments. This conference led to the establishment of an Application Committee (R.A.M.N.A.C.) which kept the administration, the user and the manufacturer in touch. Immediately after the war, the Admiralty was in collaboration with the Ministry of Transport (M.O.T.) and the shipowners to arrange the supply of surplus 3-cm (Type 268) radar to the merchant navy, pending the design and production of commercial sets. At the same time the Admiralty Signal and Radar Establishment (A.S.R.E., now A.S.W.E.) was drawing up a specification1 to meet the needs of navigation and anti-collision. A prototype to this specification was demonstrated to all concerned in 1946.