bluuebunny/crossref_metadata_2025 huggingface dataset:
Automatic Altitude Reporting
Authors: Glover B. W. , Haddock W.
Published: January 2010

This paper describes an experimental system of representing the reading on an altimeter in the form of a digital code, and controlling the standard I.C.A.O. secondary surveillance radar transponder to give a corresponding pulse pattern.

Different code arrangements are examined and their capacity noted. A possible use of the system in collision avoidance is suggested for use outside areas of close air traffic control. This use would require little additional equipment.
An Automatic Dead Reckoning Computer
Authors: Ramsayer K.
Published: January 2010

Dr. Ramsayer's paper, presented at the tripartite meeting on automatic navigation held in Paris last April, describes a dead-reckoning computer on which position is presented instantaneously on a map.

The so called Automatische Koppelkarte has been developed by the Institute of Air Navigation of the Technical University of Stuttgart, and is a new type of dead reckoning computer differing from the usual navigation computers in that position is immediately indicated on a map; there are many possibilities for combining the device with other navigational aids.

Fig. 1 shows a schematic diagram of the computer. It consists of the computer, the map display and the course and track indicator. The station selector and the coordinate transformer shown in Fig. 1 are additional units, only used when monitoring by tacan is desired, as will be described. The computer is fed by a gyro-magnetic compass and a true airspeed transmitter. The wind is set at the map display, and ‘grivation’ at the course and track indicator. From these data both the flight path and the track are computed. The flight path is resolved in two rectangular components and is displayed by a light pointer on a map of conformal conical projection. The standard parallels of the map are selected in such a way that the distortion in length is practically negligible for the area of interest.
Heading Definition in Commercial Aircraft
Authors: Green J. F. , Glenny A. P.
Published: January 2010

In this paper, methods of defining heading are enumerated and the limitations of magnetic and gyroscopic devices are analysed in detail. Particular attention is paid to the development of the rotated race principle which is likely to be responsible for a large improvement in the basic azimuth gyro. The gyro-magnetic combination is scrutinized and the errors inherent in this compass system are classified. The possibility and consequent effect of diminishing certain categories of error are presented. The current position is summarized and an attempt is made to suggest possible future trends. The authors are, respectively, with Smiths Aircraft Instruments and the Sperry Gyroscope Company.
Amending the Collision Regulations
Authors: Clissold Peter , Fendig N. L. , Taylor W. B. R.
Published: January 2010

The International Regulations for Preventing Collisions at Sea are of the first importance to the navigator; as Marsden puts it, they are ‘the paramount Rules of Navigation’ and it follows that any trouble taken to perfect them is well worth while. They must be comprehensive and clear, simple enough for the sailor yet precise enough for the lawyer. Considering this, the wonder is perhaps that they are as good as they are. Since they are to be discussed at the International Safety of Life at Sea and Load Line Convention this year, the subject of their revision is a topical one and worth the attention of every mariner.

The story of the Regulations is not without interest. They did not, of course, spring fully fledged into being and they are little more than one hundred years old—a very small fraction of the time that man has been navigating the seas.
The Arrangement of Navigational Equipment in Modern Cargo Vessels
Authors: Wepster A.
Published: January 2010

The main reason for improving the navigation of merchant ships today is economic, determined by factors such as the price of long-shoring and the penalties for late (or early) arrival in port. In this paper, which was presented at an Institute meeting on 13 April 1962, the Assistant Marine Superintendent of the Holland–America Line examines critically the standards of equipment and operation in modern cargo vessels and suggests a whole range of improvements based on experience within his own Company.
II—The Value of Simulator Training
Authors: Jones E. O.
Published: January 2010

Even as recently as 1954, although informed opinion ashore was otherwise, at sea, and here one can only broadly generalize, the principles of plotting were neither universally accepted nor practised, and it may be that this was due largely to the fact that there still remained disagreement as to the practicability of plotting. Indeed, even now, there must be a limit on the number of targets that can conveniently be manually plotted.

The Safety of Life at Sea Convention, 1960 amended the Collision Regulations to take cognizance of radar, and to give guidance on the use of radar in fog. The Admiralty Court has indicated that if a vessel is fitted with radar she is obliged to use it and, even more important, that there is an obligation upon the observer to use the radar properly. The phrase ‘using the radar properly’ has in Case Law been judged to necessitate some form of plotting, and it is of passing interest to note that the vast majority of collisions involving vessels fitted with radar can be attributed to immoderate speed, or a failure to appreciate the information provided by the PPI.
The Use of VLF Transmissions for Navigation
Authors: Powell Claud
Published: January 2010

The use of VLF radio transmissions as the basis of a navigation system has been under consideration for many years, and has been the subject of extensive theoretical work and field trials. Although a system of this kind has yet to reach operational status, the subject is of considerable interest in relation to marine and to air navigation. This paper indicates the main features that might be expected to characterize a practical VLF navigational aid, and outlines some of the work that has been carried out in this field. Brief reference is made to the question, so far largely unresolved, of the operational scope for VLF systems.
Photographic Radar at Sea
Authors: Sims D. W.
Published: January 2010

The first shipboard installation of the Kelvin & Hughes rapid processing photographic radar system has now completed 500 hours service aboard the P. & O. liner Canberra and the navigational and technical staff in the ship have had a reasonable opportunity to evaluate the equipment from all practical aspects. The advantages of this type of display are, in summary:

(1) A full size plotting screen (in this case 24-in. diameter) is available for direct plotting.

(2) All operations may be carried out in broad daylight without the necessity of having to accustom the eyes to a dimmed PPI.

(3) There is no radar hypnosis. Information is presented as a solid, steady picture at the end of each cycle.

(4) A permanent record of the radar information is immediately available for playback at any later date.

(5) Several officers may view the screen at the one time and discuss the plot while it continues uninterrupted. This is a very favourable point in a large vessel of high speed where three or more senior officers may wish to know at all times exactly what is happening on the radar plot.

(6) By using a processing/exposure cycle of seven seconds or more, a build-up of picture strength, true track of vessels, &c. is possible.
Philosophy, Rules and the Collision Problem
Authors: Morrel J. S.
Published: January 2010

Captain Wylie begins his paper by evoking a philosophic vision: a planet full of colliding ships, all staffed by mathematicians. He concludes by rejecting, on behalf of mariners, the help of the mathematicians. The maritime record also evokes a vision: the colliding ships are somewhat fewer, but the main difference is that every one is staffed by persons other than mathematicians. The latter vision rather implies a need for help from somewhere.
Ocean Routing Charts
Authors: Dickson A. F.
Published: January 2010

Passenger and cargo liners sailing on regular routes follow tracks for a given voyage, taking account of the various seasonal conditions which may apply, and masters of these ships, with many years experience in a particular trade, can decide without great difficulty the most advantageous track for their ship when planning a voyage for a given time of year.

In the transport of oil, on the other hand, it is not common to employ ships on regular voyages, and the great majority of tankers are employed in world-wide trading, so that although a particular oil company may have a number of ships constantly voyaging on a particular route, a high degree of flexibility is maintained and ships are regularly changed from one route to another. This means that the tanker master is called upon to consider the requirements for optimum routing of his ship on any ocean voyage. Further, he is often given his orders with fairly short notice and, in some cases, he may have his destination changed either at the last moment or during the voyage, leaving him little time to consider the many factors which have to be taken into account when planning the best route for the voyage to be undertaken.
Interpreting Astro-position Lines at Sea
Authors: Richey M. W.
Published: January 2010

‘The mark of a good navigator is not so much his ability to obtain accurate information as his ability to evaluate and interpret correctly the information available to him.’ So writes Captain Alton B. Moody, U.S.N.R. in the course of an interesting correspondence in the February number of the U.S. Naval Institute Proceedings. In the August 1961 number (page 132) Captain Robert Lee Rhoads, Jr., a shipmaster, suggests that the ‘cartwheel’ set of astro-sights, where four position-lines intersect each other at angles of about 45°, is inferior to the square where the position-lines intersect at approximately 90°, which gives a more reliable fix. One of Captain Rhoads's illustrations shows a case of a 4-minute systematic error in a ‘cartwheel’ fix giving a position 6 miles in error, where the same error would have had no effect on the position interpolated from four sights taken at 90° to each other.
Astro Ranges in Arctica
Authors: Collins Oliver C.
Published: January 2010

This paper discusses celestial navigation within the Arctic Circle by the use of great-circle position lines. Application of this method in this area is indicated by:

(1) The freedom from need to correct for atmospheric refraction.

(2) The lack of dependence on either D.R. or assumed position.

(3) The simplicity of drawing the great-circle position line.

(4) The freedom from need for making instrumental scale readings and corrections thereto, other than in respect to the time of the observation.

The adequacy of available stars is examined.
The Value of Moon Sights
Authors: Burton S. M.
Published: January 2010

Timed sextant observations of the Moon when it is suitably limbed are obviously as easy to take as those of any other body, and the results obtained are no less accurate or reliable. It is therefore surprising that only about 5 per cent of Merchant Navy navigators appear to take sights of the Moon, and that about 75 per cent of the defaulters seriously believe the Moon to be of small value for navigation, other than for compass checks.
The Selection of Navigation Systems for Military Aircraft
Authors: Bower D.
Published: January 2010

In December 1949 Adams and Uttley presented to a joint meeting of the Institute and the Royal Aeronautical Society a paper surveying the field of navigation systems for air use, in which they set out in some detail the principles, possibilities and limitations of the various aids which the scientist has to offer toward the solution of the navigation problem. In their conclusions they rightly pointed out that all these devices fall short of the ideal to a greater or lesser extent, so that the potential user is faced with the task of choosing from a bewildering and diverse array of imperfect systems those which are most likely to fulfil his needs.
A Radar Survey of the Ice Barrier
Authors: Higgins R. G.
Published: January 2010

The 600-ton Norwegian sealer Norsel, commanded by Captain Guttorm Jakobsen, made the last of her annual relief trips to Queen Maud Land when she went south last December to bring home the Norwegian-British-Swedish Antarctic Expedition from Maudheim. During this trip the writer was attached to the expedition as naval observer. The ship remained at Maudheim for three weeks while an aerial survey was being carried out by the Swedish air unit which she had brought with her; during this time advantage was taken of fine weather and favourable ice conditions to make two survey trips along the barrier, one to the eastward and the other to westward from Norsel Bay where the ship was harboured.
Meteorology and Navigation
Authors: Satow P. G.
Published: January 2010

Although meteorology probably has a greater influence on marine and air navigation than any other individual science, many users are not fully aware of the problems of present-day forecasting, nor do they make full use of the services available. This paper is intended to give some idea of the value of observers' reports, the importance of communications, and the problems of present-day forecasting. In particular, attention is drawn to the rapid increase in upper air soundings and the interdependence of surface and upper air observations in predicting the elements for all marine and aeronautical services. Arising from the application of upper air data to surface forecasting, the paper emphasizes the value of applying comprehensive analyses and of marine forecasts prepared by weather centrals ashore; in areas where facilities are not available to the marine user, however, knowledge and experience of single-observer forecasting are still needed.
H.M.S. Challenger's Investigations in the Pacific Ocean
Authors: Ritchie G. S.
Published: January 2010

H.M.S. Challenger is one of Her Majesty's surveying vessels. She is a ship of 1140 tons and carries a complement of 96 officers and men. Built in 1931, she is named after her illustrious predecessor in which the wellknown world oceanographic cruise was made in the years 1872–6. This expedition brought back a great wealth of chemical and physical data, and a huge collection of plants and animals from the oceans. These were checked and analysed and eventually, under the guidance of Sir John Murray, who had been a scientist on board, the results were published in fifty folio volumes known as the Challenger Reports. These reports still form, the starting point for the study of the oceans and marine life.
The Origin of Ocean Currents
Authors: Crease J.
Published: January 2010

Although the approximate position and strength of the main ocean currents have been known for upwards of two hundred years, it is only in the last few decades that oceanographers have attempted to explain them on the basis of sound physical theory. For many years the progress of oceanography was hampered by the lack of sufficient experimental data; today much new information is being gathered throughout the world, enabling existing theories to be examined critically and providing a basis for new work. It appears from the latest investigations that ocean currents are subject to quite large ‘synoptic’ changes superimposed on the general ‘climatic’ pattern in a similar manner to the movement of air masses in the atmosphere, but on a much reduced scale. This and other developments of theory during the century will be discussed in this paper.
A Survey of Requirements for Port Radar
Authors: Le Page L. S.
Published: January 2010

In 1947 it was felt by the Ministry of Transport that although the radar to be installed by the Mersey Docks and Harbour Board at Liverpool would demonstrate the suitability of this type of equipment in meeting the requirements of the larger ports, it was probably beyond the resources of many small ports and indeed was too elaborate for their needs. It was therefore decided that the Ministry's Operational Research Group should survey representative small ports in the United Kingdom in order to estimate the advantages that could be expected if shore radar were to be fitted and to discover what limitations there were likely to be in such fittings. As a sequel to this inquiry, it was proposed to select one port as the site for a trial, to be sponsored by the Ministry, in which a simple radar installation would be employed. The vital importance of having direct radio communication between ship and radar station was fully recognized from the start, and it was assumed throughout the investigation that this facility would be ancillary to the radar, the pilots probably carrying portable transmitter-receivers.
Air Traffic Control and the Jet Aeroplane
Authors: Fraser D. O.
Published: January 2010

The fact that the de Havilland Comet cruises at nearly double the flying speed and nearly double the flight altitude of comparable piston-engined airliners is a measure of the great leap forward in air transport which the introduction of gas-turbine engines has brought about. It also illustrates an inherent feature of jet aircraft, for only at high speed and high altitude do turbo-jet engines, and to a less critical extent turbo-prop engines, operate at their maximum efficiency, expressed in distance flown per gallon of fuel consumed. With reduction of altitude and speed, however, the fuel consumption does not fall off proportionately and efficiency decreases rapidly. For example, even when taxying on the ground the Comet's fuel consumption is about 70 per cent of that at cruising altitude, and when flying at sea level the still-air distance flown on a given quantity of fuel is less than half of that at cruising altitude. In other words you get the best out of a jet aircraft when you are going somewhere fast, and when the length of the flight is sufficient for the aircraft to climb to its optimum cruising altitude and remain there for a considerable proportion of the flight time.
Instrument Approach and Landing Charts
Authors: Freer T.
Published: January 2010

The purpose of an instrument let-down is to bring an aircraft past all hills and obstructions to a particular position at low height. If the pilot follows the correct procedure, the aircraft will obviously clear the hills and obstructions. But owing to various interruptions and distractions, difficulties of reception or the need to give partial attention to other duties, he is often unable to follow the procedure exactly; he will then want to know whether departure from the procedure requires immediate rectification, or whether he is at liberty to return gradually to the correct path. A badly working radio aid, or some other difficulty, may make it necessary to abandon a partly completed approach; he will then want to know the best way to extricate his aircraft from a possibly dangerous situation. Furthermore, the pilot often has to improvise an ‘intermediate procedure’, to connect between his arrival over the aerodrome and the beginning of the let-down. For these reasons he needs to know the positions of the hills and obstructions in relation to the let-down; and the only way to present this information to him quickly and unambiguously is by making hills and obstructions the principal features of let-down charts. The local knowledge possessed by pilots of scheduled services does not lessen the need for an effective presentation of this feature on the charts, as it is precisely when landing at unfamiliar aerodromes that the charts will be most used.
Multi-star Sextants
Authors: Fox W. A. W.
Published: January 2010

Amongst the schemes for simplifying the processes of astronomical position fixing the family of multi-star sextants contains some interesting material. By the simultaneous observation of two or more stars through an optical system coupled to a gravity reference, it is possible to determine the observer's position directly in latitude and longitude, with little or no computation.

The number of instruments on these lines which have been designed is very large and it would not be possible to describe them in detail in the course of a short paper. A few remarks about their principles may, however, be of interest since they are, in general, sound in theory and fall short of practical requirements only because, when used on an unstable platform such as a ship or aircraft, they make too heavy a demand on the skill of the observer.
Radar Chart-matching Devices
Authors: Dickson J. Home
Published: January 2010

The usual method of using radar for navigation at sea is to transfer the information from the PPI to the chart. In many instances, however, the pilot will con the ship directly from the PPI, using his local knowledge, which is equivalent to using a chart impressed on his mind. In such cases it is necessary to identify immediately and unambiguously the PPI paints, which often bear little resemblance to the shape on the chart of the feature which is producing the echo.
Hariot's Instructions for Ralegh's Voyage to Guiana, 1595
Authors: Taylor E. G. R.
Published: January 2010

The year 1952 is the fourth centenary of the birth of Sir Walter Ralegh. So far from being the great romantic of tradition Sir Walter was a hard-headed practical man, and the first Englishman to engage a scientific and technical expert to advise him on his colonizing enterprises. He brought the brilliant young mathematician Thomas Hariot, some eight years his junior, direct from Oxford to Durham House, his mansion in the Strand, where, setting his instruments up on the leads, Hariot laboured for years at improving observational technique and revising the Ephemerides. Meanwhile he gave instruction in navigation to the officers of Ralegh's ships, himself obtaining practical experience on the voyage to Virginia in 1585, when he was able to observe the seaman's difficulties and the errors to which he was prone. He had already by 1584 written a new Instruction Manual which he entitled Arcticon, but this is unfortunately lost. We have, nevertheless, an epitome of its contents, for Ralegh asked for a ‘refresher course’ on the eve of his departure for Guiana, which was to take place in February 1595, and Hariot's teaching notes in his own (very crabbed) handwriting, besides fair copies of the tables he drew up, are now at the British Museum.
The Evolution of the English Nautical Chart
Authors: Robinson A. H. W.
Published: January 2010

In a previous contribution Professor E. G. R. Taylor has reviewed the development of the sea chart up to 1600, the year in which Edward Wright published his celebrated chart of the world on Mercator's projection. Wright's chart represents one of many minor incursions on the part of English cartographers into the field of nautical cartography, which at that time and for the next hundred years was dominated by the flourishing Dutch school of hydrography. It was not until the latter began to decline towards the end of the seventeenth century that the English cartographer really came into his own and began to produce charts to assist the navigator. Thus the evolution of the English nautical chart to its present state of development covers a relatively short span when measured against the whole background of maritime enterprise and endeavour.

The development over the past two hundred and fifty years has been sporadic rather than continuous, being characterized by sudden advances followed by long intervals of consolidation. Factors such as the needs of national defence, the invention of navigational instruments and advances in hydrographic surveying technique, have at various times acted as stimulants to chart evolution. Throughout the period under review responsibility for supplying the navigator with accurate charts has gradually passed from the many private publishing firms to a specially created national department.
The Accuracy of Bubble Sextant Observations
Authors: Hagger A. J.
Published: January 2010

The Editor welcomes this opportunity of publishing an account of the valuable and fundamental work done by the Navigation Section of the Aeroplane and Armament Experimental Establishment at Boscombe Down. Some of the results have previously appeared in reports with limited circulation, but no full account has yet been published.

The Navigation Section of Aeroplane & Armament Experimental Establishment (A. & A.E.E.) had, at the outbreak of war in 1939, only recently been established, and was in the charge of Squadron Leader (later Air Commodore) D. J. Waghorn, who was followed by Wing Commander W. S. Jenkins. Both of these officers were keenly interested in methods of astronomical navigation, and in development work. Professor H. H. Plaskett, F.R.S., Savilian Professor of Astronomy at Oxford, was attached to the section, and brought to it an invaluable experience in observational theory and techniques.

The work of the section in the earlier part of the war mirrors exactly the state of knowledge in astronomical methods in navigation at that time. A bubble sextant, the Mk. VIII, had been in use for some time, although knowledge of astronomical methods was limited to comparatively few highly trained members of aircrew. The potentialities of astro-navigation were appreciated, however, and the Mk. IX sextant was being developed.
Exploration of the Deep Sea
Authors: Deacon G. E. R.
Published: January 2010

Few aspects of geography are more satisfying than to follow the progress of geographical discovery across the oceans from the documents that remain to us, and the careful work of many scholars allows us to find some of the excitement of the early voyages without much effort to ourselves. But geographical exploration was only the first phase, and during the past 300 years much effort has been spent in finding out something about the oceans themselves: as early as 1698 Halley sailed as far as S. 52° on a purely scientific voyage, returning with useful information about magnetic variation and the trade winds. The promoters of the scientific voyage of H.M.S. Challenger argued that the vast oceans lie scientifically unexplored, and we say much the same today; but much has been done and in its way it provides a story as interesting as that of geographical discovery.
A Racon Beacon for Reception by Civil Marine Radars
Authors: Randall-Cook C.
Published: January 2010

In about 1946 work was begun both in the United States and in the United Kingdom on the development of radar beacons which could be used to make certain required points more conspicuous and to increase their detection range.

Two basic types of beacon were considered: ramarks, which are intended to give bearing information only and which appear on the PPI as a bright radial line passing through the position of the ramark, and racons, which give range as well as bearing information. The range information is given by die beacon transmitting one or more short pulses, the first of which appears on the PPI at the correct range and bearing of the beacon.
The Accuracy of Astronomical Observations at Sea
Authors: Harding G. A.
Published: January 2010

It was with some surprise that I read Commander Sharpey-Schafer's ‘Some Notes on Astronomical Observations at Sea’ (this Journal, Vol. VI, p. 362), especially his conclusions regarding the fixing accuracy obtainable with marine sextant observations.
I can makeno claim to be an experienced navigator myself, but, as a member of the staff of H.M. Nautical Almanac Office, I was privileged, in 1949, to spend three months as an observer on board H.M.S. Dalrymple, a newly-commissioned surveying ship, under the command of Captain (now Vice-Admiral Sir) A. Day.
Radar and the Compass Bearing
Authors: Wylie F. J.
Published: January 2010

To quote the Collision Regulations—‘Risk of collision can, when circumstances permit, be ascertained by carefully watching the compass bearing of an approaching vessel.’ Most seamen are so familiar with this injunction and with the practice it describes that any particular significance in the wording probably escapes them. It is, however, important in considering the operational use of radar to note that the compass bearing and no other kind is specified and to appreciate that this is so because the relative bearing will only give quite comparable assurance when own ship maintains a perfectly steady course during the approach.
Aerial Magnetic Survey
Authors: Roberts G. E.
Published: January 2010

In his Presidential Address to the Institute this year the Astronomer Royal, Sir Harold Spencer Jones, stresses the importance of an early resumption of the general survey of the Earth's magnetic field and developments in airborne magnetometers in the United States have suggested the possibility of using aircraft for this purpose. The techniques which are available for aerial survey will be discussed in this paper and an attempt will be made to evaluate the relative merits of conducting world wide magnetic surveys by sea and by air.
Loxodromic Distances on the Terrestrial Spheroid
Authors: Williams J. E. D.
Published: January 2010

This paper is concerned primarily with an investigation of the loxodromic distance between two points on the spheroid. This is derived by a modification of the meridional parts method in terms of the track angle and the difference of latitude reduced by a correction which is a function of the latitudes concerned.

Since the method is unsuitable when the track angle is near to 90°, the known formula for the mid-latitude correction is examined and an alternative method suggested for use in this case.

The results obtained are compared in a practical example with those found by the usual methods, and finally means are proposed by which the refinement described above can be incorporated into current plotting practice on aeronautical Mercator charts.
Siting the Radar Scanner
Authors: Wylie F. J.
Published: January 2010

Probably the most important single factor governing the value which can be obtained from a given radar equipment in a ship is the presence or absence of blind or shadow sectors. This is entirely dependent, on the siting of the scanner. There is no arc of bearing on which the careful seaman does not keep a visual lookout, constant or periodic, when his ship is at sea. As radar is capable of providing him with a means of detection on all bearings, which will often be more effective than his eyes, it would be surprising if he were not prepared to go to some lengths to avoid obstructions to its ‘view’.
A Voyage from Blackwall to Southampton in 1582
Authors: Taylor E. G. R.
Published: January 2010

English sailors came more than half a century late into the world of transatlantic voyages and new discoveries. Nor should this surprise us when we remember the exasperating delays they had to expect when getting out of our long river estuaries into the narrow seas, and out of the narrow seas into the Atlantic Ocean. Once there they still had to encounter prevailing head-winds, where a Columbus had only to launch himself on the steady trade winds to discover America.
Blunders in Computation and Proof-reading
Authors: Sadler D.H.
Published: January 2010

Captain Majendie would restrict the use of the word blunders to those aberrations of human behaviour which cannot be attributed to any avoidable cause. For my purpose this definition is unduly narrow and I use the concept in a slightly wider sense, namely: ‘errors, or aberrations, without apparent cause’. An understanding of the underlying causes of blunders is essential to their proper study, and to the reduction of blunder rates. Assuming that these causes are factors of human behaviour, there should be some connection between the occurrence and causes of blunders in different fields of human activity. In the hope that this may be so, I summarize the conclusions drawn from investigating blunders over a period of 25 years with a staff of 20–30 engaged on numerical computation and proof-reading.
Abnormal Errors and Aircraft Separation over the North Atlantic
Authors: Durst C. S.
Published: January 2010

In a recent paper I endeavoured to give a statistical solution of the problem of the separation of aircraft tracks with safety. In it I assumed that the distribution of errors of navigation made by the aircraft was a normal gaussian one; but I added a proviso that the effects of blunders might modify the result. From enquiries of various navigators as to the frequency with which they considered they were likely to make blunders I gathered that with a good navigator an undetected blunder might occur on 1 per cent of occasions and further it seemed reasonable to assume that a blunder might be defined as an error greater than three times the standard error of normal navigation. These assumptions are of course quite arbitrary but they seemed to be suitable to give examples of the effect on track separation; this was done in an unpublished paper. In these examples it was supposed that aircraft flying in the same direction were using two parallel tracks distant L apart and on each track aircraft were flying at fixed intervals but quite independently of the aircraft on the other track.
The Chance of Obtaïning Large Errors
Authors: Parker J. B.
Published: January 2010

The problem considered in this note is that of determining an upper limit for the chance that an error will not exceed some given quantity. Where the pattern (orfrequency distribution) of the errors is either known or assumed, the solution to the problem is merely a matter of calculation. This note starts by making the minimum assumptions about the pattern of errors, and then examines the effect of gradually increasing the restrictive assumptions.
A Modern View of Astronomical Navigation
Authors: Sadler D. H.
Published: January 2010

In the course of the development of the practice of astronomical navigation, a straightforward approach to the subject could never be adopted mainly because time (that is, Greenwich Mean Time) either could not be obtained or could not be relied upon to adequate precision. Methods of observation and techniques of reduction were introduced to give the best results from the equipment then available; and these traditional methods, which have continued long after the need for them has vanished, have tended to obscure and to complicate the fundamental simplicity and generality of astronomical navigation.
Instrumental and Automatic Control for Approach and Landing
Authors: Fearnside K.
Published: January 2010

The flight instrument systems used in large modern transport aircraft represent a considerable development from the standard instrument panel in use at the beginning of this decade. Radio and navigational information is coordinated in a single display and flight direction is provided by means of a separate instrument in which it is normally composited with attitude information. The system contains sufficient redundant information to provide positive warning of a malfunction, and is normally used in conjunction with an automatic pilot which is capable of carrying out the approach accurately and reliably, monitoring control being exercised by the pilot by means of the flight system. Synthetic damping and automatic throttle control of airspeed may also be provided.

Statistics based on autopilots in current airline service suggest that an acceptable standard of safety for scheduled automatic landing is not attainable by single-channel autopilots. Adequate safety during the automatic landing manoeuvre can, however, be attained by a multiplex autopilot now under development. Provided that the necessary ground aids are installed, it appears feasible to introduce scheduled automatic landing by 1970.
The McIntosh Parallel Ruler
Authors: Hilder Brett
Published: January 2010

A new type of parallel ruler on rollers, devised and patented by Mr. Ian A. McIntosh of Sydney, deserves the attention of marine navigators. The new ruler is apparently similar to the brass-roller type used in the Navy, but it has the great advantage of omni-directional mobility. It also has much easier manœuvrability than the parallel rules used in the Merchant Service, known as Captain Field's or the ‘walk-about’ type.
The Brest—Canaries Race
Authors: Bini Mario
Published: January 2010

In the Brest to Las Palmas de Gran Canaria race held last August by the Sail Training Association I was skipper and navigator of the 7-ton yawl Artica II of the Italian Navy (which incidentally obtained the best corrected time of all three classes). From the navigational point of view the race offered no particular difficulty because although long—1400 miles—we were on a reach most of the time, a condition that makes the navigator's job much easier. It might in any case be interesting to those who are keen on ocean racing, to hear about some of the dodges (certainly not new to them) used on board Artica II:

(a) A gnomon pin (about two inches long) had been welded in the centre of the compass rose: when the Sun was low and the boat sufficiently steady the shadow of this needle enabled us to have very good compass checks.
The Beaufort Scale
Authors: Delmar-Morgan E. L.
Published: January 2010

I was particularly interested in Commander C. E. N. Frankcom's note on the Beaufort wind scale at the end of the article by the Hydrographer of the Navy on Admiral Sir Francis Beaufort (this Journal, 11, 266).

Commander Frankcom states that from time to time attempts have been made to abandon the Beaufort scale and adopt some other form of scale but that efforts to do this have failed. Efforts to improve on or change the form of the Beaufort scale are, in my opinion, likely to continue to fail for the very good reason that the existing scale is almost flawless mathematically.
The Construction of Hyperbolic Lattices
Authors: Sadler D. H.
Published: January 2010

A common feature of all systems of hyperbolic navigation (such as Gee, Loran and Decca) is the necessity of interpreting the instrumental readings of lattice coordinates and of transforming them into position—either directly into latitude and longitude or relative to neighbouring geographical features. Several methods are in use: elaborate tables giving latitude and longitude in terms of the lattice coordinates are published for use with Loran; chartlets, on a special projection, are available for certain routes on the Decca system; but the most generally useful form of interpretation, combining both presentations, is the latticed chart. This paper is concerned solely with the construction of such charts. Although formulae and examples are given, details of the computing techniques are deliberately omitted; it is hoped to issue a fuller account with the tables that have been prepared for the use of this method.
Simplified Flight Planning
Authors: Hamer W. G.
Published: January 2010

The basic procedures used by most airlines to compile their flight plans are very similar, and are by no means as simple as they could be. When a choice of routes exists it is the normal practice to compile a series of flight plans from which the one giving the most advantageous route in the prevailing weather conditions is selected. In the absence of a direct approach to the problem of selecting the best route, the method of comparing different flight plans is improved by increasing the number of plans; it is therefore desirable that a method of speeding up the process of compilation should be evolved so that a greater number of plans can be prepared. Also the increased aircraft speeds which are to be expected in the future, and the requirement to reduce fuel loads, especially fuel reserves, to a minimum call for some rapid method of modifying the flight plan on receipt of in-flight forecasts and observations.
Applications of Oceanographical Research to Navigation
Authors: Deacon G. E. R.
Published: January 2010

Oceanography is concerned with the applications of all sciences to the study of the sea, and navigation, in its widest sense, with the application of any science and systematic knowledge to the purpose of maintaining safe and efficient communications across the oceans. They have something in common, but oceanographical work, whatever its future promise, is primarily academic, and navigation the application of well-tried conclusions. It would be wrong to suggest that basic studies of sea conditions are followed by systematic attempts to use them to improve navigation. Progress is sporadic, depending on individual enthusiasms and commercial enterprise as well as the efforts of government departments and professional associations. There is no sharp division between the basic work and its applications, or, after allowing for some extremes, between the scientist and the authority on navigation.
Plotting a Position Line Without Reference to an Azimuth
Authors: Castle Geoffrey L.
Published: January 2010

The following method of drawing a position line from a celestial observation is suggested as a possible means of simplifying a small portion of the navigator's work. It avoids the use of azimuths, thereby simplifying chart work.

The method is based on a geometrical construction whereby the position line is determined from intercepts relating to two separate adjacent Assumed Positions; this construction may prove simpler than the present orthodox method, particularly as it does not involve the measurement of angles.
Legal Aspects of Radar and Collision—II
Authors: Wylie F. J.
Published: January 2010

This article may be regarded as a continuation of the previous article in this Journal (18, 203) and it has the same basis and purpose. It deals first with an unusual case of collision, while overtaking in the presence of a second threat, and secondly with an Appeal case.

The lessons of the Nassau–Brott collision relate to the duties of the overtaking and overtaken vessels, poor look-out, and too short a range-scale.

The Crystal Jewel–British Aviator case relates to excesssive speed, failure to stop, failure to avoid close quarters and the cumulative turn.

The Nassau–Brott case was an extremely interesting one in which one ship, Brott, was being overtaken in open waters by another, Nassau, and, at the same time, having a third ship, Haminella, coming down from ahead. The latter presented the more immediate threat.
An Ocean Platform and Submarine Cable System for the North Atlantic
Authors: Wood K. A.
Published: January 2010

The paper proposes highly stable moored ocean platforms and a transatlantic submarine telephone cable to provide a reliable v.h.f. communication service and other A.T.C. facilities to civil aircraft on the main air routes across the North Atlantic. The main features of the platform and cable system are discussed and some idea of the time scale and costs is given.

The planning of facilities needed to enable future operations over the North Atlantic to accommodate reduced separation standards and to satisfy the specialized requirements associated with operating S.S.T. aircraft has emphasized the present unsatisfactory standard of communication services in the area.
Factors Affecting Navigation of the S.S.T.
Authors: B.O.A.C
Published: January 2010

This note provides some qualitative impressions of the need for precise navigation in the S.S.T. operation having due regard to performance and noise. It highlights the increased signific
ance of the vertical plane, but quantitative conclusions as to horizontal ability cannot be made in the absence of knowledge of traffic amounts. It suggests that any tactical ‘chasing’ of noise reduction through performance variations not planned before flight is impracticable.

In common with other aircraft types, the S.S.T. has three distinct phases of flight apart from take-off and landing: climb to cruise altitude, cruise and descent. The S.S.T. climb is characterized by an acceleration phase dividing the subsonic portion of flight from the supersonic. Similarly, the descent profile includes a deceleration phase which restores flight to the subsonic region. Contained in these three phases of flight unique to the S.S.T.—acceleration, supersonic flight and deceleration—are some of the special factors affecting aircraft navigation.
The Role of Satellites in Aircraft Navigation
Authors: Moody Alton ‘B’
Published: January 2010

A Joint Navigation Satellite Committee has been formed to determine the potential for a common satellite system to meet the needs of various agencies. As a potential aid to air traffic, satellites would appear to be most effectively used in cooperation with ground stations at which measurement and computation would be made. Possible user benefits include more effective communications, more reliable and possibly less expensive airborne navigation equipment, reduced diversions and delays, obstacle avoidance capability, more effective emergency warnings, and reduction of communication traffic. For the provider States benefits may include more reliable communications, reduction in number of control centres, improved data collection and distribution capability, reduction in number of facilities, and improved search and rescue capability. A systematic approach to long-range goals is indicated.
The Dawn of Modern Navigation
Authors: Taylor E. G. R.
Published: January 2010

How did Francis Drake navigate his ship when in 1577 he embarked upon his famous voyage round the world ? Strictly speaking he did not navigate her, for the task was delegated to subordinate officers. The Pelican (or Golden Hind as she was later renamed) carried, as was customary, a master and a pilot whose duty it was to make the necessary observations and lay the ship upon her course. But these had signed on for a supposed voyage to Alexandria to load currants, and Drake knew well enough that no English pilot could then compare with a pilot of Spain or Portugal, whether in training, experience or equipment: for these nations, as pioneers of the Great Discoveries, had also taken the lead in the development of nautical science and in the formal schooling of seamen. That explains why Captain Francis furnished himself with the latest chart from Lisbon, and why, when he reached African waters, he kidnapped a Portuguese pilo to sail him into the Pacific, only to maroon the unfortunate man in Central America when he had served his turn and a Spaniard was indicated for the next stage of the voyage. Hitherto no English ship had left the Atlantic, and apart from a few men trained in the Muscovy Company's service the average English sailor laughed at the idea of navigating with charts and instruments. He had his compass, he knew his landmarks, and once he was in soundings he could cast the lead and feel his way into harbour blindfold. To see a man ‘shooting the Sun’ (as it was already termed) with a cross-staff was an occasion for mockery. ‘Have you strook it?’ he would cry, ‘Have you strook it?’ And as for charts, he wanted none of your sheepskins, he could make his voyage as well upon a board! It was upon a prepared sheepskin that the mediaeval charts were drawn and painted, the neck to the left, while the ‘board’ was the traverse-board marked with the thirty-two rhumbs. These were pierced with holes at regular intervals, into which pegs were inserted at each turn of the sand-glass, thus recording the time sailed on any particular point of the compass.
The Place of Astronomy in Navigation
Authors: Sadler D. H.
Published: January 2010

Of the 293 papers published in the Journal, eighty-two, or 28 per cent, have been concerned with astronomical navigation. This, however, gives a false impression of its present-day importance. There was a time when conventional astronomical navigation provided the only means of determining position, in the absence of recognizable landmarks; and it still provides the only fundamental method independent of man-controlled devices. But there has been no change in principle since accurate time became available through the combination of radio time-signals and chronometers. The papers have dealt with techniques only. The large number is evidence of the abiding interest in astronomical navigation; but it also indicates the realization that, while the principles of astronomical navigation are unchanged, the conditions of its application have undergone radical change. Techniques have had to be improved under the pressure of necessity, so that the practice of astronomical navigation is now simpler than it has ever been.