Mr. Chairman and Members.
Gentlemen:—I have the honor of calling your attention this evening to a subject, the importance of which, I feel sure, we will all agree to recognize. It is the avoidance of collisions on the sea at night, and in this connection the employment of double side-lights, so that the course of an approaching vessel may be the more readily and the more accurately determined.
I.
A new Cunarder, the Umbria, has steamed at the rate of twenty and a quarter knots on the measured mile. She is five hundred feet long, and has a displacement of something near ten thousand tons. Here is a condition of affairs on the sea for which we must prepare ourselves, and the first question to be asked is, are the rules of the road as they stand on our statute books applicable to such large steamers, making such great speeds and having such great turning circles, and are the official instructions to pilots in some cases proper ones?
I have here a diagram (Plate 1), where I have laid down to scale the conditions liable to govern two steamers, each moving at the rate of twenty knots, where one would have to maneuver to keep out of the way of the other.
We notice, first, that O is the vessel, under the law, which must give way and avoid a collision with either A or B, since O has them on his Starboard side. A and B are each half a mile from O. Let us for the present consider B out of the way altogether, and see what O must do to avoid A.
The distance OX is half a mile, which O covers in 1 m. 30 s. O's helm begins to act in 15 s. at 0' , and she turns through 4 points in 45 s. (making allowance always for loss of speed in turning), when she will be either at O" or 0\. She turns through 8 points in 1 m. 20 s., when she will be either at O" or O1. She has advanced when here 1600 feet, and has transferred 1200 feet.
We see that A is in the octant lying between a bearing of 4 points on O's bow and his beam, and we will consider her as standing along the line A V.
Now O can stand on at full speed; slow, and go astern of A; stop, and let A pass her; turn to starboard or turn to port.
First, then, if we suppose she stands on to X at full speed, she will pass ahead of A in 1 m. 12 s. at Y, 733 feet, A being then at A'.
If O slowed to ten knots, she would be at Z in 1 m. 37 s., when A would be at Y, where she would have passed ahead of O 726 feet.
If O stopped, and Professor Osborne Reynolds is correct in saying that she would come to a state of rest in six or seven times her length, independent, or nearly so, of the power developed by her screw when backing, the ship would be somewhere between B' and Y, dead in the water; time required being between two and three minutes. The chances are that A will have by this time passed safely ahead, but it might happen that O, not being under control, might, from a false appreciation of As speed and course, arrive at Y just in time to have A ram her.
Now suppose that O, instead of controlling her speed to clear A, used her helm. In the instructions given to pilots, under the present statute, by the Board of Supervising Inspectors of steam vessels, we find that when O must maneuver, the two vessels being situated as in the diagram, she must put her helm to port, and pass astern of the other vessel, while A must continue on, or ''port her helm" if necessary. This last instruction is clearly opposed to the International Regulations, which, although not law, distinctly state that where one vessel is to maneuver, the other vessel must keep her course.
Now would it be proper to port in this case? I think not. If O did she would be at O1 in 1 m. 12 s., when A is at A, and they would have approached one another within 385 feet. Rather close quarters, so close that a slight misjudgment of A’s speed on the part of O might make her do the very thing she was trying her best to avoid, ram A, since it will be observed that (9's course cuts the line along which A is standing at O3.
As we know, there is one thing more that O can do, she can starboard her helm and turn to port. Suppose that she does so through 4 points to O'. This will take her 45 seconds. If now from here she stood on, at full speed, along the line O" V, she would pass ahead of A at V (A then being at A") in 2 m. 10 s. at a distance of 1000 feet. Of course O, after she gets to O", can elect with safety to slow or stop, or use her helm to pass astern after A has arrived sufficiently on her bow.
I take it that maneuver is best which brings about the best results. That is, the vessels being on safety points, or those positions where the danger of collision is passed, the conditions governing that movement which makes the separation of these points the greatest distance, and which makes the ships' courses the more nearly parallel throughout the maneuver, is the best. Therefore I should conclude from the diagram that the best thing for O to do is to starboard; and for this reason I term the octant in which A is located the octant of starboard helm.
Let us now take into account the case of B and O. We see that B lies in the octant XON, or on a bearing between ahead and four points on the starboard bow of O. B is steering a course B C, and O must maneuver to avoid her, as in the case of A. If O and B stood on they would collide at B, if we considered that their speeds were equal. If O slowed or stopped, the same thing might happen, the distance separating them being so short. If O star-boarded her helm and turned to port she would be at a safety point O" in 45 seconds, when B was at B', separated 440 feet, and O's keel line at right angles to B's. But if O ported her helm, her turning circle lying inside of that of B's course, would be at all times clear of B; and although in passing they would come within 325 feet of one another, still their courses would be nearly parallel. The danger of collision can, of course, be lessened by (9's slowing. Turning to starboard for O is unquestionably the proper course for her to take, and so we can call the angle XON the octant of port helm.
II.
It was not until the autumn of 1864 that the carrying of side-lights of the present system by vessels became compulsory. Almost from the time that steamers made their appearance at sea, a red light and a green light were carried, but this was without force of law. The only recognized light for vessels at sea was the bowsprit cap-light—a white light—and before this, prudence had dictated a lantern carried forward to show over the ship's side when necessary.
Admiral Ammen suggested in i860 a light to be carried by sailing vessels on the bowsprit cap. It consists of a lantern divided into three parts. The starboard side green, showing from two points abaft the beam to two points on the bow, or through eight points, the port side showing red through the same arc. That portion of the lantern from two points on the starboard bow to two points on the port bow showed white. Here is what may be said to be the beginning of the system of double side-lights, since there was a danger octant shown. That is, there was a sector of two points on each side of the fore and aft vertical plane shown by the white light.
Undoubtedly as soon as commerce on the sea began, or armed flotillas for war or rapine traversed the waters, the necessity for some means of indicating a vessel's position became apparent, therefore at night a flame of some kind was exhibited. The museums furnish us with many forms of the cressets or fire baskets which were carried by the galleys of the middle ages, and later on we come across the elaborate lanterns which adorned the poops of the flagships of the Genoese and Venetian admirals and those of the superior officers of the fleet—works of beauty which might have come from the forge of Quentin Matsys, or from the ateliers of any of the Italian masters of this craft. This state of lighting, white lights forward and lanterns of different colors on the poops, continued until very recently. In the days of the sailing ship an approaching vessel was warned off by a lantern swung over the side. When steamers came in, it became necessary, from the increase of speed and from not having the wind as a factor of normal reference for courses, to show more nearly, by some signal, how a vessel was standing, hence the colored side-lights; so that now-a-days we can tell within ten points how a vessel is steering. But higher speeds exact a more intimate knowledge of the course of the other vessel, and for this reason the suggestions of practical men to gain this knowledge have all pointed one way, the employment of more lanterns. I will not discuss in this paper the means and methods which should be used to insure a good, bright, steady and reliable illumination of the side lanterns, but I shall confine myself to showing you the principal systems designed to accomplish the end I have spoken of. I am aware that in order to do this, bad elements as well as good are brought into the question, but I am of the opinion that the advantages of using more lanterns greatly preponderate.
It may be stated concisely that the disadvantages are greater cost and a greater number of lights to be kept burning, consequently a greater likelihood, in case one of the lights is obscured, that collisions will happen through a wrong appreciation of the vessel's course. The advantage is that we know how the other vessel is steering within less than ten points, and therefore we can proceed at higher speed, while the danger of collision is thus lessened.
Since there are people who are color blind, and since a white light can be seen a longer distance than can one which is colored, there has often been a move made to substitute groups or arrangements of white lamps, and to do away with colored screens. Unfortunately there is much to interfere with this scheme. There is, however, one arrangement which in a way takes in this element, and is the very best, but which, it is to be regretted, is not applicable to sea-going vessels. We mean the range light, but we will pass by its consideration at present and will discuss it further on.
The white light is the illuminant by which the human eye sees at night; therefore should side-lights be merely some new arrangement in, or repetition of this color, it might happen that circumstances could combine to produce the wrong impression, so that a collision would be courted. Take for instance the suggestion that three white lights, one above the other, should show the starboard side, and that two white lights disposed in the same way should indicate the port side. An accidental putting out or shutting out of one of the starboard lights, something very likely to occur, might give the impression that the port side of the ship was visible to you. Again, a deck lantern improperly exposed above the port light would lead you to suppose that you saw the vessel's starboard side.
In my opinion, this possibility would more than offset any error liable to arise from color-blindness. If the side-light—either a red one or a green one—was extinguished, although a collision might occur from the fact that the ship approaching was not seen, still there could be no misleading as in the case of white side-lights.
From what has now been said I think that we are confined to colors, and I am of the opinion that the solar spectrum does not furnish any others more distinctive than those now used.
III.
Methods have been devised to show how the helm is put, by means of signal lights being displayed to the other ship. In one system for steamers a whistle is also automatically blown to show the condition of the helm. In another system the way the helm is put is shown by a second side-light, perhaps of a different color, surmounting the regular side-light. These ideas as regards lights are all fundamentally vicious, all equally bad. Imagine the confusion likely to arise by a green light appearing in company with a red one, or a red light surmounting a green one.
Should it become necessary to apprise an approaching vessel of the state of your helm, nothing is better than the blasts of the steam whistle as now laid down, and which in my opinion should be incorporated in the international rules of the road.
Since the year 1871 all steam vessels whose cruising is confined to sounds, bays, estuaries and rivers of the United States, have, in addition to the ordinary lights carried by vessels at sea, displayed a white light on a pole at the stern, to show above the white light at the bow. This range-light, as it is called, shows unobstructedly around the horizon. The lights now carried are, as we know, two colored side-lights, green to starboard and red to port, showing from ahead to two points abaft the beam on each side, through ten points, and which are invisible half a point on the other bow. As we know, this is the outfit for sailing vessels, and for steamers we add the masthead white light, showing through twenty points from ahead through ten points on each side. When we add the white range-light aft, which shows all around the horizon, we have a vessel ideally lighted. I can think of no better way, since every change of direction is immediately shown. But unfortunately its use is not applicable to the open sea. The drawback being that it cannot be seen when sail is set; again, smoke and the large tops in men-of-war, now larger than ever, since mechanical gun fire from aloft is necessary, interfere with its efficiency; but the principal reason is, that the rolling of the ship destroys the range, and so we reluctantly leave it to look at some of the substitutes furnished us to gain this end. This is generally brought about by the employment of more than one light of the same color, or of different colors, on the same side of the vessel, which arrangement is generally known by the name of Double Side-Lights. But there are some systems which have this object in view, and at which we intend to give a passing glance, where the side-lights as now fitted are disposed in some regular figure, any change in which shows a change of course for the ship.
There is one, for instance, where the side-lights and mast-head light are arranged in an equilateral triangle in a plane parallel with the midship section. The advantage of this system is that the course of the vessel is indicated nearer than ten points, by the practiced eye marking the angle made by a line passing through the mast-head light and one of the side-lights and the horizon. The disadvantage is that the mast-head light would generally have to be carried too low, or else the side-lights would have to be carried on outriggers, and therefore the plan is hardly feasible.
Another method is to have the mast-head light carried so far aft of the side-lights that when the ship presents a beam view, a line passing through the mast-head light and one of the side-lights makes an angle of 45° with the horizon, and when the eye of the observer is four points on the bow the mast-head light is right over the side-light. The plan, if it were practicable, would be fairly good, but generally vessels are so sparred and rigged that it cannot be done.
Admiral Ammen suggests that steamers carry the ordinary sidelights, and his light for a mast-head light. This would be in many wars an improvement, and I regret that I cannot show it on my model, with which I hope to demonstrate to you practically this evening the value of the systems I am now bringing to your notice. If there is any drawback to this method it will be found, I fancy, in the sails, smoke and top-hamper obscuring it and making the colored shades non-effective.
IV.
One of the first to present a system of double side-lights was Captain von Littrow, Here is a diagram which shows his method (Plate II, Fig. 1). It will be noticed first, that neither of his lights shows abaft the beam. There is a light of the proper color on each side, showing from ahead to abeam, and in addition to these sidelights there are other side-lights of the same color, showing, through an arc of four points, from four points on the bow to abeam. These second lights are placed as far aft as possible. All these side-lights are in the same horizontal plane. It will be easily seen that the ship's course with this system of lighting is more closely known. If one light is seen, the ship is heading within four points of a course which is the opposite of your bearing from her. If two lights are seen, the ship is heading between four points and eight points of the direction you are bearing from her.
Now the disadvantage of this arrangement of lights is that the lights being separated as far as possible and being on the same horizontal plane, the conditions in a long steamer would be such that she might be mistaken for a steamer and a sailing vessel astern of her.
As regards distances between lights, we see here (Plate II, Figs. 2 and 3) a plan almost the opposite of the foregoing, the two lights being arranged in the same light-box only 4 feet 6 inches apart, and on the same horizontal plane. This system is the invention of Mr. George Tracy Parry, of Philadelphia. A Naval Board reported last April that they had had practical workings with it on the Delaware River, and had found that the lights were too near together. This we can easily see is the case, and since they are both in the same horizontal plane they blend at even short distances. Again, although the most dangerous sector, the two-point sector, is shown by one light (and I would call your attention to the fact that this is a good point), supposing that each light could be seen for itself if we were within the illuminated arcs; still, outside of this the ship's course is not known within eight points, since the after light shows through this many points.
Let us next look at the system proposed by Senor Giralt—a Naval Instructor in the Spanish Navy (Plate II, Fig. 4). Although his idea is something rather different from double-side-lights, still, in the arc extending from two points forward the beam to two points abaft the beam, two lights, a red and a white, or a green and a white, are seen, and the vessel's course may be said to be indicated within four or six points. This method of lighting was intended to furnish additional safeguards to navigation, and was contrived to show one ship, overtaking another, the presence of the leading ship. In other words, a vessel's lights were to be seen from every point of the compass. These are really good points for a system of lighting to possess, but the accidental showing of a white light—a deck lantern for instance—abaft the red might lead another vessel to suppose that safe courses were being steered when in fact a collision was imminent. This alone would do away with all possible good of such side-lights as these. Vessels stopped, with the likelihood of being rammed in the stern by an approaching steamer, would do well to have a light waved over the stern, but I do not think that there would be any use to habitually illuminate ships in this way.
The system of Captain Manzanos of the Spanish Navy next claims our attention (Plate III, Figs. 3 and 4). Here is a second light in range, which shows through six points, between one point on the bow and one point forward of the beam. This light is elevated any height above the after one, which has the common arc (ten points) of illumination. Now it will be noticed that one light will be seen by an observer located on a bearing half a point forward the beam of the ship (which will then be crossing the other's bows, and each will be safe from the other); and that the same conditions of only seeing one light will take place when the observer is located half a point on the bow of this vessel, when each will probably be in imminent danger of collision. Again, two lights being seen, the distance between them being arbitrary, where this was small, as in a short ship, it might have the appearance of a larger ship steering a course heading more nearly for you. This might or might not add to the danger of a collision, but it would certainly add to one's perplexity.
I think all the advantages of double side-lights appear in the system which I submitted to the Bureau of Navigation of the Navy Department in 1883. Here it is! (Plate III, Figs, 1 and 2). We have the ordinary side-lights forward, and twenty metres directly abaft them and at two metres elevation, a side-light on each side, of the usual color to show from ahead to four points on the bow. The distance between the lights, and the height of the after-light above the forward-light, are invariable for every vessel. It will be observed that two lights will be visible when the vessel is steering for you within four points; also, that the range is preserved throughout and is properly made, the after-light being the higher, and not as in the system of Captain Manzanos, where the contrary is the case. Then again, the lights being always the same distance apart, both in the vertical and horizontal measurements, and that distance being sufficiently great to prevent blending, and small enough to make the system applicable to small steamers, the eye will become accustomed to the angles subtended by the two lights for the different courses steered by the ship, so that I fancy the direction in which the vessel is standing, whose two lights are seen, can be determined within one point. I am also of the opinion that all the bad qualities inherent in the other systems are overcome in this. If we turn to this diagram (Plate IV), I think we will discover the advantages of this method. You will remember that at an early stage of this paper we called the octant which corresponds to A the octant of starboard helm, and the octant which corresponds to B the octant of port helm. Now, the positions in this diagram are precisely the same as regards bearing as those which occur in Plate I, and O, which is steering a course OX, must maneuver to avoid collision. First, let us consider A. If two lights are seen, A must be steering for you, as we have said, within four points, or somewhere in this darker shade between DA and CA. Her general course will be along the line AA', and the distance she must make to collide with you is so great that you could certainly go ahead of her without danger, or at most you would have to ease the slightest off to starboard, supposing, of course, that the speeds of both vessels are considered as equal. Now if only one light is seen, then A is steering somewhere between four and ten points of your bearing, in this lighter shade, or between DA and EA, in the general direction AA"; or your courses, in other words, are converging, and therefore the danger of collision is probable on the other side of X on the line OX. So I call this octant YOP the danger octant for one light, or, to lay down a rule: When you make one red light in the octant between four points on your starboard bow and a bearing abeam, use your starboard helm to avoid collision, turning completely round and going under the vessel's stern if necessary.
Now let us consider B. Here if she shows two lights to O she will be steering somewhere in the sector GFB on the general course BB'". As we have before said, O should port immediately, and slow, stop or back, or a collision will occur about B'", If only one light is seen by O, then B is steering somewhere in the sector GBH on the general course BB", and will certainly clear O, especially if O slows. A collision, therefore, is most likely to occur when two lights are visible, and so I call the octant XO Y the danger octant for two lights; and since it is also the octant of port helm, the rule of the road may be stated thus: If you make two red lights to starboard, between ahead and four points on the bow, put the helm hard to port immediately, and if the lights look near, slow or stop and back.
I do think though that it would be better if B in this case was also made to maneuver—to port her helm and turn through 4 points. It would not complicate matters, as the rule would read: Vessels making two lights between ahead and four points on the bow of the other color than what they show, must put their helms hard-a-port and turn through enough points to shut in one light, slowing if necessary.
It might be urged in opposition to what I have said that the duty would be so divided that in case of collision the blame could not be attached to either; but we know that under all circumstances the other vessel did the wrong thing, and there would be as much of a chance for a court to decide under the rule I have laid down as there is now.
I wish now to say a word upon a subject which formed the basis of a communication I had the honor to send the Department.
The fact cannot be ignored that as a nation we are not sea-faring. In the old days, before the newer portions of our country were accessible, the spirit of adventure sought the sea as the theatre of his exploits. In case of war now—and it will be a naval war—we will not have the same hearty emulation as existed in 1812 between the hardy fishermen of Massachusetts Bay and the Gulf of Maine, the dexterous pilots of the Delaware, said to be the best sailors in the world, and the daring men of the Chesapeake, but we will find ourselves almost without trained men of the sea. True, we can find plenty who follow the various sea-trades, the stoker, the fireman, the boatman, and the man aloft; but the skilful steersman, the trained lookout, are wanting, and so I conceive that we must lose no time in gathering together and educating material which will be needed at the very outbreak of hostilities.
In my opinion this condition is best met by recognizing that there is, beside the seaman gunner, a co-ordinate outgrowth for the Naval apprentice, the intelligent Helmsman, who is developed through the Signalman, I will not weary you with the requirements of the different grades into which he is put, how he is paid when there, and under what circumstances he goes from grade to grade, according to his attainments in the line of study I have laid down, or how he must be neither short-sighted nor color-blind; but I will say that the course goes systematically, from holding a deck lantern properly to understanding all sorts of signals, including those made by electricity. Now while the Signalman is in this school, he is being developed coordinately all the time, and he becomes in turn the messenger, the quarter lookout, the lee helmsman, the leadsman, the bow lookout, the weather helmsman, the Coxswain and the Quartermaster. These conditions being fulfilled, our navy could be expanded at pleasure, since vessels could be commissioned and go immediately to sea with men whose training brings the handling of the vessel to the highest standard, and diminishes to a minimum the chances of collision.
Before closing this lecture and showing you how the systems we have been discussing look upon the model I have here with me, I would say that since such a bad state of affairs exists as regards rules of the road and the lighting of ships, which together with colorblind and short-sighted people add needlessly to the dangers of navigation, would it not be well for us as a nation to call upon maritime powers to join us in a Congress to which these things will be referred? I feel certain the necessity exists, and the sooner we get about it the better. In conclusion, I can only urge upon the members of this Institute and others who are here this evening, to use all their influence in this direction, and in conclusion, to permit me to thank them for their kind attention.