bluuebunny/crossref_metadata_2025_split huggingface dataset:
‘Studies of Interaction at Sea’
Authors: Corlett E. C. B. 
Published: November 2009

I note with interest Dr Barrass' comment in the January issue of the Forum (33, 139). He deals with three subjects: (i) the ultimate trim of tankers in shallow water; (ii) the question of increasing rpm in interaction situation; and (iii) the final turning diameter in shallow water.Dr Barrass' curves (p. 140, Fig. 1) are useful approximations to squat and to ship characteristics but cannot be treated as definitive.Fig. 2 is a particular interpretation of practice and not necessarily universally accepted, particularly in respect of the LCB position. In some recent VLCC work benefits have been obtained by moving the LCB aft in association with a buttock-flow stern. Furthermore, the dependence of block coefficient upon Froude number is not realistic, especially in the finer vessels; it is the prismatic coefficient that is dependent upon Froude number. It cannot be taken, therefore, that absolute curves for these factors exist as inferred from Fig. 2.Turning to Fig. 1, the curves showing sinkage in confined channels are for the blockage ratio bracketing 0·1–0·3. This is a large range of blockage and as a result the curves can significantly underestimate and overestimate sinkage, depending upon where in this bracket a particular example falls. Similarly, the solid curves show sinkage in open water conditions over depth/draft ratios 1·1 – 1·2. This is quite a large range and a unique curve cannot represent these two values.
Changing the Admiralty Chart
Authors: Haslam D. W. 
Published: November 2009

Presented at a meeting of the Solent Branch of the Institute held, by courtesy of the Director, at the College of Nautical Studies, Warsash, on 21 September 1978.Put your trust in God and the Admiralty Chart! Every one of nearly four million charts issued each year by the Hydrographic Department is as up to date as possible on the day on which it leaves our premises; nevertheless we are increasingly conscious that far too many of the charts are no longer adequate for the uses to which they are now being put.
The Effect of Neglecting the Shape of the Earth on the Accuracy of Sight Reduction
Authors: Bennett G. G. 
Published: November 2009

In text books on astro navigation, the fact that the Earth is not spherical in shape is seldom discussed and therefore one presumes it does not have a significant effect on the accuracy of sight reduction, and yet it is quite remarkable that it is not uncommon to find discussions of the phenomenon of augmentation (a correction to the altitude or semi-diameter of the Moon that amounts to about 0·25 at an altitude of 60°) in these books. It will be shown that discrepancies of the same order of magnitude as augmentation may be present in the calculated altitude of the Moon because of neglecting to take into account the shape of the Earth.In the following (1) rigourous expressions for correcting the observed altitude and geocentric declination of a body close to the Earth are derived, (2) simple expressions which are sufficiently exact for the purpose of sight reduction for the Moon are given, and (3) an example, using different methods of reduction, is shown in detail to illustrate the theory.
Position Fixing Requirements for the Merchant Ship
Authors: Ligthart V. H. M. , Wepster A. 
Published: November 2009

The subject of this paper is the merchant marine user requirements for position fixing systems (a merchant marine with approximately 40000 ships operating). These requirements are varied and can be summarized as follows:(i) accuracy(ii) availability (possible fix frequency)(iii) reliability(iv) coverage(v) user skill and workload(vi) presentation of information(vii) ambiguity(viii) environmental constraints(ix) operational constraints(x) system control(xi) system user costs.These eleven requirement elements should together serve the two basic purposes of merchant marine navigation: (a) provide a service adequate for safety and (b) enhance economic performance/benefit.
Error Distribution in Navigation
Authors: Anderson O. D. 
Published: November 2009

In an earlier paper the present writer drew attention to the distinction between mixed and aggregated distributions. Incidentally, two minor mis-statements in that paper should be corrected. The first sentence in the last paragraph of section 2 (page 72) should read ‘As σ2/σ1 (=k say) tends to either zero or infinity, X/σ increases indefinitely; whilst for k nearer unity, X/σ is smaller’. Also the last line of the Appendix should not terminate with ‘X/σ = 3·724’ but with ‘X/σ→∞’.Mixed distributions arise when for example an error occurs either from one distribution with probability p, or from another with probability 1–p, as in a set of position line errors due sometimes to one and sometimes to the other of a pair of observers of differing precision. An aggregate distribution occurs when the error consists of, say, two sub-errors, one from each of the two distributions; as when Captain Flint marks the chart and Long John subsequently reads it.
The Inter-Governmental Maritime Consultative Organization
Authors: Srivastava C. P. 
Published: November 2009

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.
Nautical Astronomy: Past, Present and Future
Authors: Cotter H. 
Published: November 2009

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.
New Prospects—The Structure of Sea Lanes
Authors: Richardson R. B. 
Published: November 2009

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.
Polish Cartography in the Sixteenth and Seventeenth Centuries
Authors: Wereszczyński Jan 
Published: November 2009

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.
The Mystery of Captain Lane's Compass
Authors: May W. E. 
Published: November 2009

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.
Simple Sextant Calibration
Authors: Kerst D. W. 
Published: November 2009

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.
Reporting Near Misses at Sea
Authors: Nicolson D. 
Published: November 2009

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.
Saving Money by Cutting Corners
Authors: Proctor J. D. 
Published: November 2009

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).
Matthew Flinders and Ship Magnetism
Authors: Mörzer Bruyns W. F. J. 
Published: November 2009

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.
Integrated Navigation Systems for Aircraft
Authors: Stokes R. F. , Smith S. G. 
Published: November 2009

Work on integrated navigation for aircraft started at RAF Farnborough at least as early as the mid 1950s. At that time the Inertial Navigator (IN) for a guided bomb was being developed and the navigation of the aircraft to the target used a combination of the weapon IN, Doppler radar and position fixing. An output of the navigation process was a calibration of the weapon IN. The operational concept was interesting in that after weapon release the aircraft had to return home using Doppler and compass.Development of this system included flight trials in raf and a & aee aircraft using the Decca Navigator chains in Southern England for position reference. The same method was used in the development of the FSP 100 IN intended for the TSR 2 which took place in 1960/63. On these trials an early airborne digital computer on board the trials aircraft enabled Decca, Doppler and the IN information to be recorded and processed in-flight in a form suitable for post-flight analysis using a ground digital computer. This technique formed the basis for producing the reference navigation system which has been used for all our subsequent trials. The production of a position, velocity and attitude reference system for trials of inertial and other navigation systems has formed a major objective for RAE work on integrated navigation since that time.
New Display Systems for the Next Generation of Civil Aircraft
Authors: Bernard Maurice 
Published: November 2009

The history of aeronautics has been marked by a number of revolutionary breakthroughs influencing both designers and users. A major example is the advent of jet aircraft. In flight deck instrumentation the technical revolution has followed a steadier course, enabling a gradual evolution from the rudimentary instruments used on yesterday's aircraft to the sophisticated instruments used today.In this respect, the information displayed has evolved both in quantity and quality. This has gradually led to new flight deck designs such as that used in the Airbus A 300. The impression of a gradual evolution in instrument technology is due to the fact that information is often displayed in the same manner as before, i.e. using dial indicators. Today, a new revolution is taking place in commercial aircraft flight decks: the use of digital systems displaying processed data on cathode ray tube (CRT) displays.Preliminary Studies. The use of CRT in flight deck instrumentation has been under study for a number of years. Many aircraft are already fitted with CRT for specific applications such as weather radar information and computer-processed data (on display units linked with computers).The present CRT breakthrough is tending to compete with or replace conventional instruments. This tendency started in 1968–70, giving rise to a number of preliminary studies, with military aviation quickly taking the lead. Studies were also carried out in commercial aviation, for example those of the Boeing SST programme which, as is commonly known, was later cancelled.
Collision Threat Parameters for a new Radar Display and Plot Technique
Authors: Lenart Andrzej S. 
Published: November 2009

The paper, an edited and shortened version of the original, discusses a new approach to the display of collision threat parameter areas, obtained as a result of theoretical considerations. It can be applied to radar-computer anti-collision systems as well as manual radar plots.With the development of digital techniques, and electronic digital computers in particular, radar-computer anti-collision systems are now aboard ships. Digital processing of signals and data in such systems can be divided into three stages as follows:(a) Primary processing, which includes an analysis of radar signals within one rotation of the radar antenna. A result of this processing would be the position coordinates of detected objects. For relatively simple algorithms and high speed of analysis, special devices are usually employed.(b) A secondary processing, which includes a correlation of the information obtained in the primary processing stage; the objects' position coordinates in consecutive antenna rotations; and an estimate of position, motion and approach parameters. For secondary processing devices general-purpose mini- and microcomputers are usually applied.(c) A graphical display of the calculation.
Collision Avoidance from the Shore
Authors: Degré Thomas , Lefèvre Xavier 
Published: November 2009

French maritime surveillance centres have been operating for several years. Experience gained over this period, and the French government's desire to take all steps to limit the possibility of catastrophic pollution, has led the French lighthouse and navigation service, in cooperation with the transport research institute, to implement an updated programme for maritime surveillance centres to allow them to carry out their existing tasks more efficiently and increase the scale of their activities. For this reason, a new system is being tried out at Gris-Nez Centre. It comprises a computer, which receives radar data from the radar tracking computer and effects partial automatization of the operator's tasks. In the future, it is hoped to use this new computer to help the operation centre detect the most dangerous encounter situations between vessels.Obviously the centre is not intended to replace the officer of the watch, who will retain full responsibility, but it can assist by putting him in touch with vessels which he could encounter. A typical case where the centre might help is that of a vessel whose radar is out of service, or a vessel hindered by her deep draught and limited manoeuvrability.The participation of such centres in preventing collisions is a new factor in maritime operations and can only be introduced when all preliminary investigations have been carried out.
Quantitative Measurements of Navigational Safety
Authors: Goodwin E. M. , Lamb W. G. P. , Kemp J. F. 
Published: November 2009

In recent years it is probably true to say that the main pressures for inprovements in navigational safety have come from public and hence political sources. The pressure has usually taken the form of proposals for increased regulation of marine traffic. Often there is a defensive reaction from the professional mariner on the grounds that there is no real evidence that the proposals will produce a significant improvement in safety. Shipowners are also worried because of potential increased costs and curtailment of operating freedom.It is therefore important that more information is made available so that both the safety aspects and economic aspects of additional regulation may be assessed. This paper is an account of a study into the development of danger criteria for marine traffic flows. This study was the key part of a larger one which was funded by the Department of Industry through its Ship and Marine Technology Requirements Board, now superseded by the Marine Technology Committee.Collision rates on their own are usually not suitable for measuring safety risk, as collisions in a specific area are normally a very rare event. It is also not advisable to use data collected over several years as the traffic is likely to change, e.g. size of ship. Another approach might be the reporting of near misses, but there are considerable problems if navigators are asked to do this especially as there might be subjective judgments on whether to report an incident or not.