bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Improvement of Navigation lights and Signals
Authors: Hayman Bernard 
Published: January 2010

Douglas Lindsay's article in the Journal (20, 249) raises numerous interesting points and I agree with much of what he says, but he has orientated himself so strongly towards the problem of the big ship that he has recommended a change that would bring complete confusion at the smaller end of the scale.The most useful points Mr. Lindsay raises are the need for increased ranges for ships' navigation lights, coupled with the dangers of extraneous lights. Both these points apply in their own way to small vessels. However, I disagree with Mr. Lindsay's article where he refers to the meaning of a single white light. He starts his argument by saying:
Signals for Vessels in Sight of One Another
Authors: Rodger D. A. 
Published: January 2010

I Have been following the articles on this subject in the Journal 1 with some interest and hope that the personal views of one comparatively junior officer may be of some interest.It is implicit in all these articles that, except in the close-quarter situation which the Rules are surely designed to prevent, the sound signals are unsatisfactory. What is not stated in so many words is that, international conferences notwithstanding, Rule 28 (a) is more observed in the breach than otherwise. I cannot of course be sure, but I suspect that this has been so since electric navigation lights superseded oil in general use, thus increasing the recognition range and allowing avoiding action to be taken at greater distances. There is also the natural human, if not legally commendable, desire to let sleeping captains lie.
‘Underkeel Clearance’
Authors: Ewing J. A. 
Published: January 2010

I would like to comment on the change in underkeel clearance due to the motion of a ship in a seaway (A. F. Dickson, thisJournal, 20, 363).Captain Dickson, in his conclusions, states that known techniques do not allow underkeel clearance to be calculated when ship motion is present. In fact there are a number of reliable ways of calculating the motions of a ship in waves (for example References (1) and (2), which treat the case of pitch and heave) which may help in this problem. These methods usually assume the ship is in deep water and is heading directly into the waves which are further assumed to be long-crested; but I believe it may also be possible to make reliable calculations for shallow-water effects and for waves which are, in reality, short-crested.
‘Radar and the Rule of the Road’
Authors: Burger W. , Corbet A. G. 
Published: January 2010

We would like to reply to some of the comments and all the criticisms made on our suggested amendments and additions to the existing (1960) Regulations for Preventing Collisions at Sea, which have appeared in this Journal(20, 103, 340).to Captain G. Swallow, R.N.Upon reflection we agree to some extent with the comment on our suggested re-wording of section 16 (b). However, for the very reasons he has pointed out, with reference to certain court cases, we feel that the mariner must be made absolutely certain about his position in law with regard to this section. This section, as it stands, can be very misleading in that it gives the mariner in charge of a power-driven vessel the impression that he need not always stop his engines if he hears a fog signal forward of his beam from another vessel, which has not been sighted. Yet in all the court rulings that we have seen, concerning the interpretation of this section, there is not one case where a mariner has been excused from failing to stop his engines on the grounds of the ‘apparent’ escape clauses, i.e. because of ascertainment of position and/or practicability.
The Nature of the Information to be Displayed at Sea
Authors: Le Page L. S. 
Published: January 2010

The view is taken in this paper that an automatic navigation system should be capable of weighing up data and issuing instructions, in the same manner as a human navigator. Conventional information tends to offer static rather than dynamic data.It is suggested that there are several stages of development towards completely automatic navigation: (i) a dynamic interpretation of the existing navigational situation, (ii) the automatic prediction of future situations, (iii) automatic navigational advice, (iv) automatic control of a ship under the supervision of a navigator. Such control would not take care of all situations but would be particularly suited to some; a list of the information likely to be required for presentation is given.For entirely automatic navigation to be feasible, the whole of the process of transport at sea may have to be reviewed. It is suggested that the trend should be towards presenting error, rate of change and forecast data.
Inertial Methods in Hybrid Navigation Systems
Authors: Adams D. E. 
Published: January 2010

Some general features of inertial and hybrid inertial systems are examined in relation to the navigational problem in its two essential aspects:(i) The present situation.(ii) The action required.As the fundamental D.R. system, inertial navigation has the virtue of independence but suffers from time-dependent errors. The engineering complexity and delicacy of adjustment of purely inertial navigation systems of long-period accuracy detract from its general application where other aids are available. On the other hand, increasingly stringent demands on flight-path computation and control justify an examination of the benefits to be derived from exploitation of the particular short-period merits of an inertial element used in conjunction with other aids.Principles of mixing are discussed in relation to quantity and quality of information inputs. Examples are then given of fallacies which may arise from the omission of essential information or from ignoring cross-coupling, and of the impracticability of mixed systems which assume too much of the quality of the input information.After summarizing the main features of inertial, radio/radar and astro aids, examples are given of practical and useful mixed systems which do not require the highest precision of inertial components. For example, auto-astro and inertia/doppler/ground fix contain the necessary and sufficient ingredients for combining long-period accuracy with short-term memory, speed of response in manoeuvre and instantaneous outputs such as are required for precise control and for flight path monitoring.Summarizing, it may be said that the value of true and hybrid inertial systems in the military context is evident. For more general application we may hope to see a gradual evolution of small, accurate and reliable central reference systems which will permit the employment of inertial methods suitable for mixing, especially with doppler in an accurate D.R. system. The outputs will be suitable not only for flight-path monitoring, but as providing information of a quality very well suited for integration into the control system and so into any overall system of flight automation.
North Sea Nemedri Routes—A Collision Problem
Authors: Beattie J. H. 
Published: January 2010

In the discussion which followed the Institute's proposal on routing, Captain Oudet proposed that the collision problem should be investigated in other areas where the risk was known to be high. This paper discusses the origin of NEMEDRI routes and the collision problem on specific NEMEDRI routes in the North Sea.The origin of NEMEDRI (Northern European and Mediterranean Routing Instructions) routes is a matter of history and necessity, some understanding of which is necessary in any analysis of present problems, NEMEDRI routes are those swept routes through declared danger areas due to mining in World War II in North European waters, the Mediterranean and Black Sea. These routes take their name from the NEMEDRI publication issued to mariners giving the relevant hydrographic information for these particular areas. The swept routes and declared danger areas in many other areas, such as the remote Kerguelen Islands, Tonga or off Korea, have no such special publication and are notified in Notices to Mariners. The present navigational significance of the NEMEDRI routes is that they carry a very substantial amount of the world seaborne trade.
An Alternative to Full Inertial Systems
Authors: Stevenson J. D. , Wright D. L. 
Published: January 2010

It is not the purpose of this paper to enter too deeply into the controversy between heading reference systems (combined with a velocity sensor) and full inertial systems. Rather it is intended to indicate what may be achieved at the present time, and in the next few years, using a heading reference system combined with a velocity sensor such as doppler radar. In conclusion the performance, weight, size, cost and reliability of such systems will be compared with similar figures for a full inertial system in the hope of stimulating thought and discussion as to what is the correct choice of system as well as to what the user may be able to afford.In the early part of the last decade the most widely used heading reference was the gyro-magnetic compass—a flux-valve being used to give good long-term heading accuracy whilst short-term variations are smoothed out by the integrating action of a' directional gyroscope. The directional gyroscope was in fact slaved to the magnetic reference. Accuracies of 1°·0 (r.m.s.) are typically achieved by such a system, although higher accuracies are sometimes claimed under certain specified conditions.
ILS and Landing in Zero Visibility
Authors: Lebleu M. 
Published: January 2010

Only ten years ago it would have been premature to imagine that ILS was likely to provide the basic means for completed landing in zero visibility. The system, designed in 1939, had then received only technological improvements, and no feature seemed to lend itself to any notable development. A frequency of 110 Mc/s is much too low to obtain a narrow beam; all the rival systems now being developed experimentally use frequencies 10 to 100 times higher. Nor is the measurement of difference in rate of modulation the most accurate operation possible with electrical magnitudes; pulse-systems or phase-comparison systems are better adapted.In view of the number of installations in use on the ground and in the air it was, however, practically impossible to envisage any other guidance system to replace ILS; for modifications would have to be ‘compatible’, i.e. not involve a change in airborne receivers.
The Use of Apparent Consistency in Errors of Latitude in the Identification of 16th and 17th Century Pacific Island Discoveries
Authors: Jack-Hinton Colin 
Published: January 2010

In several studies of the Spanish and Dutch voyages in the Pacific in the sixteenth and seventeenth centuries it has been suggested that an apparent consistency in errors of latitude determined by the navigator in question can be used as evidence in the identification of island discoveries, and can be regarded as confirming the identification of one or the rejection of another possibility. I am extremely doubtful about the validity of using such apparent consistency of error, even as secondary evidence combined with other indications, and have no doubts about its invalidity as primary evidence.Andrew Sharp, for instance, when considering the identification of the Los Bajos de la Candelaria of Mendaña's voyage of 1568 in his The Discovery of the Pacific Islands, remarks that whilst both Ontong Java and Roncador Reef in the Northern Solomons are possible identifications: ‘The steady southerly error in Gallego's latitudes … points to Ontong Java’.
Astrofix and Rectofix Tables
Authors: Sadler D. H. 
Published: January 2010

(1) Through the above contribution by Captain Charles H. Cotter, my attention has been drawn to the fact that the essential principle of the ‘Rectofix Tables’ is not only quite old but has been incorporated in a set of published tables —the Position Line Star Tables (for fixing ship's position by reduction to meridian and prime vertical without logarithmic calculation) by H. B. Goodwin, R.N., J. D. Potter, London, 1906.Understandably, there are considerable differences in methodology and presentation, but all the essential concepts underlying the method are incorporated in Goodwin's tables; the main improvement introduced by Dr. Cunningham (who was, of course, quite unaware of these tables) is the inclusion of tabulations for the azimuth (Journal 17, 17).Although none of the colleagues to whom I showed my short article called my attention to the existence of Goodwin's tables, I must accept sole responsibility for not having made a more thorough search of the published literature on the subject. This omission does, however, serve to underline the general note in that article on the difficulty of assigning priority for particular methods.
Manned Spaced Flight Navigation Techniques
Authors: Wicker F. D. P. 
Published: January 2010

I have read with great interest the article entitled ‘Manned Space Flight Navigation Techniques’ by Major R. C. Henry in the October issue of the Journal.It would appear that much of the imagined difficulty in interplanetary navigation is due to the fact that until now man has really been concerned with fixing his position and controlling his path on a spherical surface, the third-dimensional problem in air navigation has been one of altitude—i.e. definition of the surface concerned. Now, for the first time, we are involved in what at first sight appears to be a truly three-dimensional problem, and its solution appears difficult, partly because we are to be removed from our familiar graticule of earthly meridians and parallels.If the problem be divided into two parts, an obvious solution presents itself. At sea, a ship must be on the surface of the water, and is mainly concerned with its position and course on that surface. An aircraft determines its surface of reference by barometric pressure (which by tradition is termed Pressure Altitude and expressed as a linear measure), and again is then concerned with a twodimensional problem on that surface.
Navigation for Apollo Lunar Landings
Authors: Mayer John P. , Osburn Richard K. 
Published: January 2010

Whatever else may be said about man's first landing on the Moon, it was surely the most spectacular navigational achievement of all time.In the following paper Dr. Mayer, Chief of the Mission Planning and Analysis Division at the Manned Space Flight Center, Houston, and Mr Osburn give a general outline of the operational use of the space navigation systems which contributed to the success of the first manned lunar exploration mission. The ground and onboard navigation systems, their interfaces with the Apollo guidance system, and their uses in various phases of lunar landing are reviewed. The navigation procedures are then discussed, with particular emphasis on the Apollo 11 mission, the first manned Moon landing. Post-flight analyses and actual mission results from Apollo 11 are examined to give an accurate assessment of the overall performance of the navigation system.The paper was presented by Dr. Mayer at a joint meeting of the Institute and the Royal Astronomical Society held in London at the Royal Geographical Society on 1 October 1969 with Professor Sir Bernard Lovell, F.R.S., in the Chair.A list of the terms and abbreviations used in the paper is given on page 148.The Apollo navigation problem may be divided into two general areas. The position and velocity of the vehicle must be determined at some specified time, present or immediate past. (This will be referred to as orbit determination.) This information must then be utilized to determine the future course of the spacecraft. (This is referred to as trajectory prediction.) Ground orbit determination may be performed in either a low-speed or a high-speed mode. Low-speed computations require 5 to 10 minutes for processing, while high-speed solutions are available virtually instantaneously. The ground system utilizes both types of processors. Low-speed solutions are used for trajectory prediction and, in a few cases, for processing astronaut observations. The high-speed processor is used to monitor manœuvres such as the descent to the lunar surface and for special situations where near real-time orbit solutions are necessary. The spacecraft system uses only a high-speed processor, modified slightly to facilitate manual use by the astronaut in some cases.
The Use of a Weather Radar as a Terrain Warning System
Authors: Cox V. J. 
Published: January 2010

Although it has been technologically possible for some years to give warning of ground collision hazards, the specialized radars for this purpose have been limited to military aircraft. Because of complex cost and installation problems, radar of this type have not been installed in civil aircraft.This paper discusses possible developments in civil weather radar to enable it to give a warning of ground collision hazards. The paper was presented at an Ordinary Meeting of the Institute held in London on 19 November 1969 with the President in the Chair.For the purpose of this paper, ground collision is defined as an error of navigation or height management, which results in a zero ground clearance. The error can, of course, be human or instrumental but the assumption is made that the aircraft was basically capable of avoiding the hazard. There has been a tendency to associate ground collisions, particularly hill and mountain collisions, with the older piston-engined aircraft. Its importance in terms of airlines operating modern jet aircraft is not always well appreciated. It is true that the normal operating altitude of jet aircraft almost eliminates ground collision hazards in the cruise phase, but in general they suffer from a longer response time and a higher approach speed, which makes them more vulnerable in the let-down and approach phase. Since in any event the let-down and approach phase accounted for about two-thirds of the accidents with piston-engined aircraft, ground collision hazards remain a serious problem with pure jet aircraft.
Temperature Trial Forecasting for S.S.T. Cruise Levels
Authors: Wehry W. 
Published: January 2010

S.S.T. flight operations are likely to commence early in 1970 and meteorological briefing for all flight levels must therefore be established, especially for temperature, wind and clear-air turbulence. This paper, which was presented to the S.S.T. Working Group, outlines the accuracy of temperature prediction over 24-hour periods and suggests forecast rules. Finally the resultant requirements are stated.Several conceptions of possible and desirable temperature forecasting accuracy have been expressed in relation to S.S.T. performance by different panels. For example, the Fausst WP 529 (Franco-Anglo-U.S.-S.S.T. Working Paper 529), revised 3 March 1967, recommends a maximum standard error of 3°C for temperature forecasts at the S.S.T. level, which means the accuracy of temperature forecasting must be within a range of ± 3°C in 68 per cent of all cases. After other recommendations, such as the I.C.A.O. S.S.T. panel, July/August 1968, the subsonic requirements may be adopted for the S.S.T. too; these recommendations allow a standard error of 1°·8C, i.e. the accuracy of temperature forecasts must be within a range of 1°·8C in 68 per cent, or 3°C in 90 per cent, of all cases.
Integrated Navigation by Least Square Adjustment
Authors: Ramsayer Karl 
Published: January 2010

For the integration of different navigational aids of an aircraft by a general purpose computer the following way is proposed: The basic navigational system is a doppler or inertial dead reckoning system (D.R.S.). The other navigational aids serve for control measurements, with the help of which the error of the D.R.-position and the most important systematic error sources of the D.R.S. are determined by least square adjustment during flight. These error quantities are then used for a corresponding correction of the D.R.S. The supplementary navigational aids are consequently used both for the correction of the D.R. position and for the calibration of the D.R.S. The method is described for the example of the integration of a doppler D.R.S. with Tacan.From the great number of different navigational aids, which are today available or in development, we can draw the conclusion that none of these navigational systems can satisfy all requirements. Therefore, for many years it has been the custom to combine several navigational aids, and thus the human navigator has the task of evaluating the different navigational information. This evaluation is, however, often disturbed by unfavourable conditions. In a high-speed aircraft for example the navigator is overburdened by a lack of time and space, errors in the navigational sensors, &c. This necessarily means that the evaluation of the data is reduced to a minimum, and that a great deal of the available information is lost.
Rhumb-line Sailing with a Computer
Authors: Turner R. J. 
Published: January 2010

Continued discussions on techniques of rhumb-line sailing might well be considered irrelevant in today's climate of navigational technology. However, there is apparently one group of navigators who have a need for rhumb-line sailing by computation as opposed to direct measurement from a chart: this group comprises the navigators of merchant ships.It may well be argued that traditional methods are adequate and that, although imprecise, the resulting errors are swamped by the errors of the data used. This argument is satisfactory for established navigators but, with the great improvements that have taken place in nautical education, does not hold for the teaching of newcomers.
The Torrey Canyon Commission of Inquiry
Authors: Oudet L. 
Published: January 2010

In a book entitled The Black Tide, Richard Petrow presents a panoramic view of the events concerning the loss of the Torrey Canyon on the Seven Stones on 18 March 1967. The massive spillage of oil made it into a world disaster which called for a complete revision of many of the principles on which maritime transport is based. For seamen, however, the really important part comes before the spillage, when the ship stranded in apparently ideal navigational conditions. The Liberian Commission of Inquiry threw little light on the subject and criticism of the master does little to satisfy those with a professional knowledge of the sea. Here Commandant Oudet, relying heavily on the facts disclosed in Petrow's book, examines the circumstances of the disaster and comes out with strong criticisms of the Commission of Inquiry. If the subject is not exclusively navigational, it must be of great concern to all navigators.Mr. Petrow's book contains what professionals need, even though the author recognizes that many questions must still remain unanswered. He has had access to the record of the Commission's investigations, but not to the report of the observer whose presence at the inquiry was secured by the British Government in spite of the owners' protests. While Mr. Petrow was able to spend four days interviewing Captain Rugiati, six months after the accident, he was unable to pursue his investigation by speaking with eye-witnesses, either those whose evidence was received by the Commission or those whom they failed to question.