510 



KNO\A/^LEDGE 



[ApniL 11, 1882. 



COLLISIONS AT SEA. 



IJV TIIK KdITOR. 



IT hon liM'n no unusual circumstance for two ships in 

 opiMi liayliplit, and in culm, clear weather, to be 

 brought into collision through what landsmen might regard 

 ot tirht siglit as absurd bluiidering, thougli seamen know 

 that the indications wliich should liave guided the 

 maniruvres of either ship have been quite naturally mis- 

 understood. In point of fact, the risks of collision at sea 

 may be divided at present into two broad classes — the 

 avoidable risks, ond those which are unavoidable. Of the 

 latter class of collisions it would be useless to speak ; but 

 of the former there is much to be said, and for their 

 prevention much might well bo done. 



The lirst and most striking circimistance in the history 

 of all such collisions as might in reality have been avoided, 

 is the uttt-r alisencc of any proper means of communication. 

 Flog signalling is, of course, very often a ready and con- 

 venient method ; but under certain conditions, of not 

 unfrequent occurrence, it fails either wholly or in part. 

 The wind may be insufficient to display the small signal 

 flags, or may be so light and variable tliat they are not 

 quickly or readily discerned. Again, the wind may blow 

 in sucii a direction that the flags, though well displayed to 

 viewers in other directions, are invisible to those for whom 

 they are intended. Then anyone who examines the flags 

 used in signalling will note that, although when the whole 

 of each flag is squarely shown, one cannot possibly be 

 mistaken for another, this is by no means the case when 

 the flags are exhiVuted at some distance, in light winds, and 

 under varying atmospheric conditions. 



I have before me as I write pictures of a set of signals 

 devised by Mr. A. Stewart Harrison, in which these 

 objections are entirely ob\-iated. In the first place, all the 

 signals are of the same kind, and formed in a similar 

 manner. In each signal there are two vertical rows of 

 bright discs on a black ground, which may be set facing in 

 any direction. (The discs at night can be illuminated either 

 by reflected or transmitted light, as may be most convenient. ) 

 Each row may show any number of discs from to .5, and 

 as the eye can in a moment tell whether one, two, three, 

 four, or five balls are exhibited in each row, any combina- 

 tion is at once recognised, and can be immediately replaced 

 by the next, and the next, and so on, till the necessary 

 message has been spelled out Nothing could possibly 

 be simpler or less likely to be misunderstood than 

 this method of signalling. The discs could be dis- 

 cerned witli the naked eye at a considerable distance in 

 ordinary weather ; and could be read ofl' at two or three 

 miles distance, in clear weather, with a telescope. The 

 actual distance at which two discs of given dimensions 

 could be separately discerned with a telescope is known 

 already to astronomers from the experiments which have 

 been made by Dawes, 0. Struve, and others on artificial 

 double stars ; and it can readily be sliown that with such 

 dimensions as !Mr. Harrison proposes for the discs, the 

 range of distance obove mentioned would be well within 

 the powers of this method of signalling. It is not too 

 much to fay that if this method were adopted, a large pro- 

 portion of the collisions which now occur would be rendered 

 impossible, or possible only through utter negligence on 

 the part of all concerned in directing the coui-se of the 

 two ships. 



It is singular, liowever, that even those whose safety 

 depends on tlie use of such methods seem unready to adopt 

 any improvement in signalling at sea. After a method 

 has been shown by experience to be quite inadequate, 

 reliance continues to be placed upon it as though it liad 



never failed. As an instance in point, consider the 8hip.s 

 lights now in use. I rememlH-r, fourteen years or so ago, 

 writing on article for the Daily Nfva on u lamentable 

 collision which had then recently occurred in consequence 

 of the want of any means of recognising, in good time, a 

 change in the course of ono or other of two approaching 

 ships. Nothing could, in o scientific sense, Ik; less suited 

 to the requirements of the ca.se than the actual arrange- 

 ment of a shi|)'s lights. That a light on the port 

 side should be of one colour, and a light on the 

 starboard side of another, is well so far as it goes. But 

 it does not tell another ship much. The approaching ship 

 might cliange her course considerably, and yet show the 

 same two colours, not greatly clianged in apparent position. 

 If only two lights are to be shown, these might be much 

 more effectively placed than as at present. Suppose, for 

 instance, a red light were carried in some well-chosen 

 position amidships, and a green light near the bows, and at 

 a lower level, both being so placed that they could Vje seen 

 well from either the port or starboard side, or in front 

 Then an observer on an approaching ship would know on 

 what course a ship carrying these lights was steering. If 

 the green light were seen to the right, he would know- 

 that he was on her starboard beam ; if to the left, that 

 he was on her port beam. If the red light were directly 

 above the green, he would know that she was bearing 

 full upon him. If she changed her course, the two 

 lights would be brought either nearer together or further 

 apart. At present there is absolutely no indication of 

 another ship's position (on a dark night when only her 

 lights can be seen), unless she is steering on such a course 

 that no precautions are required to avoid her. That is to 

 say, if a ship, still at a moderate distance, is sailing in a 

 course which will not bring her at all near another, an 

 observer on this other ship will know what that course is, 

 for he will see either a red light only or a green light 

 only, according as her course is (in non-nautical terms) 

 from right to left or from left to right. But if she 

 is bearing nearly towards his ship, he will see both 

 her lights, and nearly in the same relative position, 

 whether her course would carry her past his ship 

 (if it were at rest) on one side or on the other 

 side. He has no means of knowing, therefore, to which 

 side he should direct his course. There are the rules 

 of the road at sea, of course, and if these were always, 

 or could always be, strictly followed, the present arrange- 

 ment of a ship's lights would serve well enough. But it is 

 only necessary to read the reports of cases in our Admiralty 

 Courts to learn that instances frequently occur where the 

 rules of the road cannot be — or, at any rate, are not — 

 followed. Even in broad daylight, and in clear weather, 

 collisions have occurred when the vessels have been cog- 

 nisant of each other's actual course and changes of course 

 for a distance of two miles before collision actually 

 took place, the oliserved manwuvres having lieen simply 

 misinterpreted. How largely must the risk of collision 

 be increased at night, in hazy weather, or under con- 

 ditions otherwise unfavourable? Yet nearly all that is 

 wanting to prevent sxich collisions absolutelj', and all that 

 is wanting to render them infrequent, is an arrangement 

 by which not only the course, and any cliange of course, 

 of each of two approaching ships may be quickly made 

 known to the other, but also (as in ]\Ir. Stewart Harrison's 

 ingenious arrangement) by whidi each ship may quickly 

 convey directions or warnings to the othei\ It is the in- 

 terest of all who travel by sea, and the duty of all who 

 care for the safety of our seamen, to urge that the simple 

 measures required for preventing avoidable collisions should 

 as soon as possible be carried out. 



