The recent developments at the Gironde-estuary have aroused great interest and, particularly in ports where radar installations covering the approaches are in operation today, the question arises whether the adoption of some such scheme would be feasible and advantageous.

Considerable experience with shore—based radar assistance had been gained over the years, but so far information only has been supplied and never advice. It was reasoned that only the men on the spot—master and pilot on the bridge—can decide what is to be done; advice from the shore, given without proper knowledge of what goes on on board, has been looked upon as dangerous.

The problems posed by the ever increasing size of tankers are not those of ‘bigness’ alone, or even at all. Southampton has been accustomed to the world's largest ships since the turn of the century; such as instanced by the Aquitania of 43,000 tons gross of pre-1914, the Majestic, 53,000, Normandie, 73,000 and Queen Mary of 83,000 between the wars, and since, the Queen Elizabeth, 85,000 and more recently France, the longest ship in the world, at 1043 ft. All these ships, however, are quadruple screwed, and for that matter there is not a cargo or passenger ship of more than 14,000 tons gross coming to the port which is not at least twin-screw. It had always been supposed that there was a limit to the size of ship which could be safely manœuvred with a single screw in confined spaces. The advent of the single-screw mammoth tanker, turbine engined, has put a new angle on this problem, but pilots generally are not at all sure that this is in the best interests of safety.

Much attention has been given in the past to the need for aligning navigational systems in the horizontal and the vertical planes. The alignment problem has, in the main, been that of aligning inertial navigators or gyro platforms, but the problem also affects all navigation and attack equipment.

In the past insufficient consideration has been given to the alignment of navigational sub-systems (including missile guidance systems) to the aircraft on which they are carried. The Experimental Navigation Division of the Aeroplane and Armament Experimental Establishment is investigating current methods of aligning equipments to aircraft with a view to improving them and recommending a future policy for the overall alignment of navigation and weapon systems, for service and civil aircraft.

There are two approaches to the study of errors in astronomical observations at sea. One is to collect as much information as one can from practising navigators; the other, described here, is to carry out controlled experiments with the object of breaking down the various causes of error, a virtually impossible task if the first approach is adopted. In both cases a large mass of data must be carefully studied and analysed, and this is particularly important where one aims to resolve the errors into separate components (those due to dip uncertainties, horizon, body, degree of twilight, and sea state).

In this paper, which was presented in a fuller version at an Ordinary Meeting of the Institute held in London on 20 December 1963, Mr. Kurz of the United States Maritime Administration and Mr. Bentkowsky and Captain Quinn, both of the Sperry-Piedmont Company, describe a control console for ships which was developed by the Sperry-Piedmont Company under contract from the Maritime Administration. The console, which has its sea trials early this year, comprises five sub-consoles which cater for navigation aids, communications-radar, steering, position plot, and ship condition. The paper enumerates the advantages that might be expected from such an arrangement.

The word ‘statistics’ implies populations. The practical navigator uses the methods of statistics to reduce errors. However, he is concerned not with a number of craft but with one particular craft. He may therefore use statistical terms in a somewhat inexact fashion. For example, the navigator generally assumes that the distribution of errors is Guassian because he has no way of telling what it really is. In navigating a craft, the blunder rate tends to add large skirts to the Guassian distribution. In equipments, these skirts may be suppressed by limits in manufacturing tolerances.

This paper, which was presented at an Ordinary Meeting of the Institute held in London on 15 November 1963, sets out to comment on certain aspects of the long-range navigation of civil aircraft. It concentrates on three areas where there seems to be room for improvement: reliability (a failure rate of 1 : 10 is suggested); the integration of navigation information into a single system and display; standardization of navigation facilities so that all aircraft can use the same basic system.

It is concluded that a reliable system is required down to ground level, an indication of reliability should be presented to the pilot, that high reliabilities can be obtained by comparison of ground-based and self-contained aids, that a navigation computer is necessary to reduce the information to a presentable form, and that the use of very low frequencies seems to be the most promising way of developing an aid along these lines.

Terminal area A.T.C. must provide each aircraft with access to a network of different facilities. If these each treat their customers on a “first-come first-served” basis, congestion arises which could be avoided by more comprehensive planning. In a large busy terminal area it is at present necessary to decentralize the control process to avoid overloading the human controllers and it is then hard to avoid using “firstcome first-served”. This undesirable trend can be reversed if we hand over part of the decision-making process to an electronic computer.

This paper will be presented for discussion at the Eastbourne tripartite conference, 12–14 May.

This paper, which will be presented for discussion at the Eastbourne tripartite conference, 12–14 May, examines the efforts made in recent years to improve marine radar in three respects, namely greater expressiveness of the display, simplification of measurement and computation, and increased reliability. Particular developments in each of these directions are discussed, their effectiveness and shortcomings mentioned and the conclusion reached that there is still a long way to go.

Major Richard C. Henry's paper (Journal, 16, 449) is timely. These comments are restricted to mid-course navigation and are intended to expand and clarify some parts of this excellent paper.

Major Henry divides space navigation into two parts, orbit and trajectory navigation: the first about one body, and the second, about two bodies. For example, Echo Satellite is in orbit about the Earth, while if its path were to include an orbit about the Moon as well as about the Earth, its path would be called trajectory. If we consider the path of a lunar capsule as determined by lunar perturbations of a body in orbit about the Earth, astronomers should be able to compute its trajectory, or path, or ephemeris, or orbit, and supply the information to the space navigator in the form of a Space Almanac. The guild of space navigators would use this shelf item, along with an accurate timepiece, and a marine type sextant, as the basic equipment for accomplishing mid-course navigation.

It may be unexpected to some to find that among all the unsolved problems in the history of the magnetic compass there is a shortage of information on the form and arrangement of binnacles during the eighteenth and first part of the nineteenth centuries. The cupboard type of binnacle designed to take one or two steering compasses, according to the size of the ship, is pretty well documented for it is described in most of the books on navigation published in the French and English languages from the middle of the seventeenth century. There are also drawings in some books and there is a watercolour in the National Maritime Museum which shows the steering binnacle on the deck of His Majesty's Ship Deal Castle about 1775. This is however the only deck scene of the period known to me which does show a binnacle and very few binnacles appear in contemporary ship models.

When the Offshore Powerboat Race was first held in 1961, navigators made the painful discovery that conventional methods of coastal pilotage were useless in a comparatively light, high-performance powerboat being driven to its limit.

Taking part in the race is like driving a Mini-Cooper over a frozen ploughed field in intermittent fog from London to York, the same distance as the course from Cowes to Torquay. Chart-work is out of the question. It is physically impossible to lay off a bearing or read a course. Furthermore, the figures and symbols are too small to be read, and, as often as not, the chart gets blown overboard. Radio bearings are unobtainable over the engine interference. A hand-bearing compass cannot be held steadily enough. Parallel rulers, dividers, pencils and the navigator's notebook end up in the bilges.

‘Collision Avoidance by Discussion’ (see this Journal, p. 159) has been part of the radar controversy since it began. If it is assumed, as I think it must be, that no solution is acceptable which does not apply to multilateral situations, the complications inherent in such a proposal become apparent. A bilateral agreement, for example, on alterations of course will be based on the situation as seen at a given moment; this may change drastically within minutes as other ships' bilateral or monolateral decisions are put into effect. These may necessitate changes in intention and further confabulation, possibly now with others than the ship originally contacted, and so on.

In a recent contribution to Forum by Commandant L. Oudet (Journal, 17, 88) the problem of the rational form that marine radar displays should take has been raised. The old argument of ‘ship's head upwards’ or ‘north upwards’ may be resolved by a combination of the best of both systems without compromise to either school of thought.

Before starting on how this may be achieved a short digression on terminology should not be out of place. The advantages in the use of a ‘north upwards’ display, i.e. true bearings, lack of smear, accurate plotting and the ability to add ‘true motion’ do not stem fundamentally from the fact that north is at the top but because the picture is ‘compass stabilized’. The ‘north up’ condition is purely a matter of convenience. The ‘north upwards’ display would be better termed ‘compass stabilized north upwards’.

If the day is not far off when communication satellites will lessen a navigator's dependence on conventional astronomical aids it is surely overdue for the deletion of obsolescent and superfluous items from the M.O.T. syllabus for candidates.

Of the three ‘standard’ formulae for finding a position line from an altitude of a celestial body (ex observer's meridian) only one, Marcq St. Hilaire, is in general use at sea today. The other two, Longitude by Chronometer and Latitude by Ex-meridian, depend for survival on the patronage of the Ministry of Transport and the Nautical Schools.

The use of the Greenaway grid (curved) lines has enabled us to measure grid directions correctly on a Lambert chart (in middle latitudes). However, due to the fact that some charts are printed with only straight grid lines (such as the NAT 3071), a transport rate correction was devised which is supposed to combine both the correction for Earth rotation and the correction required because of the straight grid lines.

Whilst the idea is an interesting one, a basic mistake is introduced which leads to serious errors in grid direction measurement.