The United States Maritime Administration recently published the results of a study, undertaken by the Norden Division of the United Aircraft Corporation, on automation and the operation of merchant ships. Mr. Clayton, the author of this important report, described the findings of this investigation, in so far as they affect navigation, to an Institute Meeting held in London on 16 November 1962. The paper, which is presented here, was written in association with Mr. Kurz of the U.S. Maritime Administration. It describes navigation systems for partially and fully automated vessels, and discusses the basic system requirements, accuracy and reliability criteria. A command philosophy for automated ships is developed, and finally a marine course computer, which is the first component of a partially automated navigating system already manufactured, is described. This is the first of several equipments being manufactured under contract to the Maritime Administration.

In early 1959 United Aircraft Corporation, led by its Norden Division as systems manager, undertook a company-sponsored study of the technical feasibility of operating merchant ships automatically. The results of this study were circulated throughout the industry. In April 1960 the Maritime Administration awarded a contract to Norden to study the economic and technical feasibility of automating merchant ships. The principal objective of the study was to develop a consistent series of planned, orderly, and reasonable steps towards completely automatic ship operation. The technical feasibility and economic advantage for each significant advance would be thoroughly established and then presented in a form suitable for selective application according to the particular requirements of individual ship operators.

The Council's report, our increasing membership, the eminence and wide range of activity of the new Fellows and the growing status and rising circulation of the Journal show that the Institute is making very good progress. I felt, nevertheless, as former Presidents have, that I should attempt some kind of reckoning and try to make some useful suggestions. I soon found that I could not improve on what Sir Robert Watson Watt said when he addressed us in 1950 and 1951, what he said seems all the more appropriate now. When he spoke, this country had the world's largest shipping and shipbuilding industries and a lead in the design and manufacture of the most advanced types of civil aircraft. He was concerned that we should do all we could to maintain and increase such dearly bought greatness. We could no longer afford, he said, to concentrate almost exclusive attention on the big 10 to 20 per cent factors which govern overall efficiency in such industries, and must give a greater share than before to the small 1 to 5 per cent factors. These, he pointed out, were mainly advances in the arts and sciences on which navigation depends for its full usefulness, and on which navigators depend more or less consciously in making their decisions. They generally advance with the help of new methods and practices which, though at first too novel or too elaborate for ordinary use, become commonplace before long.

Navigation by the use of inertial information is now an accepted technique for military aircraft and for missiles. In civil aircraft the application of inertial techniques are, as yet, limited to defining the vertical and providing a memory of azimuth direction; that is, as aids to flight rather than a primary or even sole navigational aid. Although the principles applied—the inertial properties of matter and the laws of gravitation—are the same, the accuracy of the inertial sensors differs by some three orders of magnitude, and the cost by some two orders, between these two extremes.

Mr. A. Stratton of the Royal Aircraft Establishment first of all presents in perspective the range of application of inertial techniques that are available for civil use and suggests how the information obtained by inertial means can be related to that from other airborne sources. He shows that even if the expense of an accurate inertial platform of ‘navigational’ quality should not be justified, considerable advantage over existing sources obtains in terms of accurate attitude reference, and instantaneous velocity and acceleration, by the use of a lower-grade platform in conjunction with other navigation aids.

In 1960 Hanssen and James described to the Institute a system developed and used by the United States Hydrographic Office for selecting the optimum track for transoceanic crossings by applying long-range predictions of winds, waves and currents to a knowledge of how the routed vessel reacts to these variables. The paper (Journal, 13, 253) described how, over a period of two years, an average reduction in travel time of 14 hours was achieved over 1000 optimum routes.

In the present papers, presented at an Institute meeting held in London on 19 April, Captain Wepster of the Holland-America Line first of all goes into the benefits which effective ship routing offers the ship operator and then describes the results of the experimental routing programme undertaken by his Company in association with the Royal Netherlands Meteorological Institute. Mr. Verploegh of that Institute then discusses the programme from the forecaster's point of view.

The navigational aspects of the requirements for a medium altitude satellite communication system are discussed. Twelve satellites have to be injected into a circular equatorial orbit with very great precision. It is not practicable to navigate the launching vehicle accurately enough to obtain the correct orbit at first injection and the satellite itself has to be controlled and adjusted until finally it is correctly positioned with the right period.

The navigation of the third-stage rocket is discussed as this effects the limits of adjustment required for the satellite. Some error in period is necessary at injection in order to position the satellite correctly in orbit, in a reasonable time. A suitable tolerance on the period at injection is 3 minutes in 8 hours. This must be reduced, by fine adjustment of the satellite speed, to less than 30 milliseconds. Methods of measuring the orbital period to this accuracy are discussed.

When the 12 satellites are finally in orbit and equally spaced around the orbit they should remain for up to 5 years with the pattern substantially undisturbed.

This paper was presented at an Ordinary Meeting of the Institute held in London on 18 January.

The basis of navigation is the finding of present position and velocity so that the necessary action can be taken to guide the craft or vehicle to its destination.

The earlier experiments in the weather routing of ships, which in the middle fifties were carried out in the United States of America, have shown that in some instances the combined use of wave-condition charts and extended weather forecasts enabled a ship to follow a more direct route across the ocean without encountering the hazard of a severe storm and a great loss of time, which the shipmaster would have tried to avoid by taking a more southern and generally much longer route.

The objects of this paper are to present in perspective the range of application of inertial techniques that are available for civil use and to suggest how the information that can be obtained by this means relates to that from other airborne sources.

The Transit navigation satellite system, scheduled to become operational in the near future, has been publicized sufficiently for its main features to be rather well known. The excellent article by Dr. R. B. Kershner and Dr. R. R. Newton in the April 1962 issue of this Journal provides a particularly thorough description of the system. In the same issue, Dr. H. C. Freiesleben gives a clear summary of the principal alternative solutions to the navigation satellite problem.

Lucretius, in the century before Christ, was by no means the first wise man to ponder and seek to explain the apparent mystery in this biblical citation, and he is but one of a great company of ancients whose recorded sayings are a delight to all who love the sea. We shall come back to Lucretius.

The theory of the problem of collision at sea has been formulated by many authors and the results of the theory have been used, notably by Morell, Hollingdale and Calvert, to establish practical manoeuvring rules to avoid collision. Any treatment which attempts to take into account the uncertainties in the information available to the navigator is bound to be technically difficult. It is arguable that a theory in which no account has been paid to the possibility of equipment errors is incomplete.

Inertial navigation systems have become of great importance in the navigation of military aircraft and in recent years there has been a growing interest in their application to civil transports. A special problem arises with this class of equipment in that the axes require to be set before navigating and a particular difficulty arises with the azimuth. This involves penalties in special pre-flight routines or in extra cost and complexity of equipment which are of concern to the airline operator who is attempting to assess the usefulness of inertial techniques. The purpose of.this paper is to discuss the general principles on which azimuth alignment schemes can be based with reference to the likely penalties involved.

The paper is primarily concerned with systems where aircraft accelerations are measured by accelerometers mounted on a gyro stabilized platform and then integrated to obtain velocity. The velocity may be either used directly in a navigation computer or mixed first with velocity from another source, such as doppler radar, as described in Ref. 1. However, all dead reckoning systems require a knowledge of heading and in cases where a better accuracy is required than can be obtained by reference to the Earth's magnetic field, a low-drift gyroscope can be used as an azimuth memory. Some of the alignment schemes discussed would be applicable to these heading references as well as to stable platforms with accelerometers. With most inertial systems, alignment to the Earth's magnetic field would be made before fine alignment commenced.

In the next decade there will be an increasing demand for more accurate self-contained navigation systems due to more stringent air traffic control requirements, particularly with the introduction of the supersonic transport. Although inertial systems have been fairly widely used in military aircraft and missiles, the only self-contained systems in service in civil aircraft are dead reckoning systems based on measuring the aircraft's velocity and heading and drift angle. A big improvement has been effected in the measurement of velocity and drift angle by the introduction of doppler radar. The accuracy achievable with doppler is not matched by the accuracy of existing heading reference systems and the overall accuracy is, at present, inadequate for future requirements.

An inertial navigation system is a possible alternative but its cost will be two to three times that of a doppler heading reference system.

In the discussion on the theory and practice of collision avoidance, two areas have been particularly liable to dispute, namely the rules for direction of manoeuvre and for responsibility for manoeuvre. Where two craft meet, some propose a rule of manoeuvre direction fixed by relative bearing, others a flexible rule designed to increase initial miss distance. Some think both craft should manoeuvre (dual responsibility), others only one (single responsibility).

A meeting of the Technical Committee was held on 9 January in London, at a session which was open to Members of the Institute and to various other people by invitation. From the Chair Wing Commander E. W. Anderson explained that the object of this kind of meeting was to enable the Institute to consider more or less informally matters which were in dispute and to give all Members an opportunity of attending these discussions. The subject under consideration had been discussed, sometimes with vehemence, at meetings, in private correspondence, and in The Journal but agreement among the contestants seemed no nearer. An exchange of views at a technical session might be fruitful. In this account of the discussion, written contributions not presented at the meeting have been included.

Rule 25 of the Collision Regulations lays down that, when it is safe and practicable, ships in narrow channels shall keep to the starboard side. The idea behind routing is to extend this type of organization to areas where, because of the concentration of traffic, the problem begins to resemble that of narrow channels. In the open sea a busy route presents no great problem. But where shipping lanes converge the collision problem often becomes serious. This is to a large extent a modern problem which has arisen not only with the increase in maritime traffic, but also with the ability of ships to navigate where they will. Further, the average speed of ships, in all conditions, has greatly increased.

This paper is concerned with the effect on airline operation of the introduction of inertial equipment, from the engineering viewpoint. It is difficult to avoid entirely all operational considerations but the main object here is to stress the economic and engineering aspects arising from the use of this equipment.