SIGNALLING AT SEA.
The wonderful improvements which have been effected in modes of communication during the latter part of the present century have resulted in bridging over space, and bringing the dwellers on this planet into closer and more constant intercommunion. Submarine cables, telegraphs, and telephones have each contributed their aid towards the realisation of Puck’s idea of putting ‘a girdle round the earth;’ and, as might have been expected, the inventive faculty has been directed, in some measure at least, towards enabling those ‘who go down to the sea in ships’ to communicate with each other on the ocean highways with such facility as might be found practicable under the ever-varying conditions which obtain at sea.
At no very remote date, the appliances at the command of a shipmaster who might desire to convey a request to a passing vessel consisted mainly of a pair of strong lungs and a speaking-trumpet. A variation was occasionally attempted by the introduction of a plank and a lump of chalk. The writer remembers having seen an English brig in the South Atlantic, during a strong gale, attempting to convey to a stately frigate an intimation that the brig’s chronometer was broken, and that, in consequence, her worthy captain was at sea, in more senses than one. The brig, which had been running before the wind, braced up on the port tack, and ran as close under the frigate’s stern as was deemed prudent under the circumstances. The captain, clinging to the weather main rigging with one hand, and using the other as a speaking-trumpet, yelled forth a sentence or two which met the fate of most utterances under similar conditions. ‘I’—‘of’—and ‘the’ were faithfully re-echoed from the hollow of the frigate’s mainsail, but the vital words of the message were borne away on the wings of the gale. A similar attempt failed; and finally it occurred to the skipper to write with chalk upon a tarpaulin hatch-cover the words, ‘Chronometer smashed, bound Table Bay.’ The tarpaulin with the foregoing legend was exhibited over the side for a few brief seconds, till a fiercer blast than usual whirled it high in air, and then bore it away to leeward. Fortunately, the purport of the writing had been understood on board the frigate, and no time was lost in displaying a black board with the latitude, longitude, and magnetic course for Table Bay inscribed thereon. Now, if the brig had been provided with the International Code of Signals, the trouble and delay involved in the attempts to communicate by hailing or by written signs, would have been obviated; and whilst holding on her course, the hoisting of a few flags would have completed the entire business in less than five minutes. The Code was certainly in existence at the date referred to, but its use was neither general nor compulsory.
The peculiar requirements of the service upon which ships of war are engaged, and the practice of cruising together in fleets or squadrons, necessitate the establishment of a system of signalling which shall be both rapid and effective. Such a system has been in operation in the Royal Navy for many years. Numerous modifications have been made latterly in the Admiralty signal books; those changes being rendered necessary by the altered conditions of naval warfare and the scientific precision which is desirable in the movements of a fleet of warships. An admiral in command of a fleet has now at his disposal such an effective equipment and complete organisation as would enable him to manœuvre his ships in presence of the enemy with almost mathematical exactitude. The ‘signal staff’ on board the ship which carries the flag of the commander-in-chief consists of about twenty persons, officers and men, whose duty it is to convey the admiral’s orders to the captains under his command by the varied systems of signalling prescribed for use in Her Majesty’s ships. The ‘staff’ is divided into ‘three watches;’ and by day and night, in harbour and at sea, a vigilant ‘lookout’ is kept, not only on board the flagship, but on every vessel in the fleet. Each ship on being commissioned is provided with a General Signal Book, Vocabulary Signal Book, and a semaphore. For use at night, a flashing lamp, and recently, an electrical apparatus, are supplied. By an ingenious arrangement, any of the signals contained in the books may be made during thick weather by the steam whistle or the fog-horn.
Before putting to sea, a ‘fleet number’ is assigned to each ship, the admiral’s ship being No. 1, the remaining numbers being distributed according to the seniority of the respective captains. If the commander-in-chief wishes his squadron to sail in one line, he makes the signal, ‘Single column in line ahead,’ by means of three ‘numeral’ flags. This signal, like every other evolutionary signal, is kept flying at the mast-head until the signal officer reports, ‘All answered, sir.’ The fact that the admiral’s signal is seen and understood is signified, in the case of tactical orders, by each ship repeating the flags. When the proper moment arrives for executing the movement, the flagship’s signal is swiftly hauled down, the helms are put ‘hard over,’ the ships swing round in the admiral’s wake, and the evolution is complete.
Communication between the vessels of the fleet is effected at night by means of the flashing light worked on the short and long flash principle, invented by Captain Colomb, R.N. There are few sights more suggestive of the advance in modes of communication and the development of the inventive faculty than that of the admiral ‘talking’ to his captains by means of the flashing lamp in the darkness of the night and far out on the trackless ocean. It may be necessary during the night to alter the course of the squadron. If the course indicated at sunset be due north, and it be required to alter the direction to west, all lights on board the flagship, except the flashing light, are carefully obscured, and the brilliant rays of a solitary lamp leap through the darkness conveying the order, ‘Alter course to west.’
The instructions contained in the General Signal Book are varied and comprehensive. Upwards of a thousand separate signals, adapted to every probable change of condition and circumstance in times of peace and in the exigences of battle, are concisely set forth, every tactical order being elucidated by diagrams showing the direction to be taken and the position to be assumed by each ship. The Vocabulary Signal Book, as its name indicates, is a sort of dictionary, but possessing also the character of a lexicon, as not only words in alphabetical order, but phrases under their proper heading, are methodically arranged in its pages. For example, under the heading of ‘Admiral,’ which word is represented in ‘flag language’ by A.H.V., will be found, ‘Admiral desires,’ ‘Admiral intends,’ and the cheerful announcement, ‘Admiral requests the pleasure of your company to dinner.’
It will be seen from the foregoing observations that the signal system adopted in the Royal Navy approaches as near to perfection as is possible under the circumstances; and therefore, when the occasion arose for a revision of the mercantile signal code, the Committee appointed by the Board of Trade for that purpose had recourse to the Admiralty Codes as a basis for the International Code of Signals, which is now used by most of the maritime countries of the world. This Code is the universal means of communication between the ships and signal stations of all nations. Translations of it have been made by France, Germany, Italy, Austria, Denmark, Holland, Spain, Portugal, Sweden, and Norway. The captain of a British vessel being desirous of conveying a message to an Italian ship, for example, may do so by simply hoisting the flags indicating the letters which are found opposite the words that express his meaning in the Code; and, similarly, vessels of any nationality may communicate with the utmost facility, although the parties so signalling may be totally unacquainted with any language but their own. For signalling purposes, eighteen flags and a copy of the Code are required. The combinations which are possible with that number of flags amount to the extraordinary number of seventy-eight thousand six hundred and forty-two, using two, three, and four flags at one hoist. The Code is divided into four parts: (1) Brief signals; (2) vocabulary; (3) distant and boat signals; (4) an appendix containing the distinguishing letters of every vessel to which a Code signal has been allotted. ‘Urgent signals’ are made by means of two flags only, and in the following manner: J.D., You are standing into danger; N.S., I have sprung a leak; H.M., Man overboard; P.C., Want assistance; mutiny. The square shape of the uppermost flag, and the number of flags used, indicate the urgent character of the message, and its specific meaning is ascertained by reference to the book. Latitude and longitude, geographical and time signals, are made by three flags. A vocabulary message is transmitted by using four flags, thus: D.R.Q.L., If you do not carry sail, we shall part company.
The vocabulary section of the Code is frequently used for messages which do not strictly refer to matters maritime. The valedictory ‘Farewell’ or the cheerful ‘Welcome’ may be transmitted with quite as much ease as the purely nautical ‘Square your mainyard.’ Even in departments of human activity so far removed from marine affairs as art or politics, the Signal Code may find some application. During the summer cruise of the British fleet in the Mediterranean in 1869, and whilst the ships were steaming through the Straits of Messina, a steamer flying the Turkish flag was sighted steering towards the harbour. The Code ‘pennant’ hoisted under her ensign indicated a desire to communicate; and on the signal being answered from the flagship of the commander-in-chief, the Turkish vessel made the following communication: D.G.N.H. = Irish; C.P.B.R. = Church; C.S.L.P. = dislocated; D.J.K.P. = Her Majesty’s government; D.M.G.T. = surplus. This being rendered into the vernacular, was understood to mean that the Irish Church Disestablishment Act had been passed by a large majority. The captain of the steamer, who was an Englishman in all probability, was laudably anxious to communicate a piece of information which could not fail to be full of interest to the people of the English squadron. His use of the verb ‘dislocated’ was forced upon him by the absence of the word ‘disestablished’ from the Code; and a similar reason necessitated the substitution of ‘surplus’ for ‘majority.’ Having regard to the circumstances, it will probably be admitted that the courteous captain’s arrangement, if not strictly syntactical, was certainly apposite.
Strenuous efforts have been made by the Lords Commissioners of the Admiralty, the Board of Trade, and the Committee of Lloyd’s Registry to instruct the officers of the mercantile marine in the use of the International Code. The Admiralty has ordered that all men belonging to the Royal Naval Reserve shall receive instruction in its use; and all candidates for officers’ certificates of competency are required by the Board of Trade to pass a satisfactory examination in signalling. Notwithstanding these regulations, there is good reason for believing that many officers in the merchant service are not so well acquainted with the working of the Code as they ought to be. Blunders are frequently committed, either in selecting the wrong signal or confusing the flags, which lead to serious inconvenience, not to say danger. A very superficial acquaintance with the Signal Book led the captain of an English steamer to neglect the ‘vocabulary’ part of the Code, and have recourse to the singular expedient of using the flags as a medium for spelling his communication. As read on board the New York liner to which the signal was directed, it took the cabalistic form of ‘MCHDRGDWNTW.’ As no flags denoting the vowels are contained in the Code, the difficulties of spelling were obviously increased; and it was only by the ingenuity of a passenger on board the liner that a translation was effected in the shape of, ‘Machinery deranged; want tow.’ On another occasion, the master of a timber-laden ship bound from Quebec to Liverpool had been prevented by foggy weather from taking solar observations for the purpose of verifying his position, and having sighted a steamer bound to the westward, he hoisted the prescribed signal, asking the steamer to indicate the latitude and longitude at the time of meeting. Either through carelessness in manipulating the flags or from an imperfect acquaintance with the Code, a position was signalled which located the ship in the immediate vicinity of Mont Blanc!
Upwards of thirty signal stations have been established at various points on the coasts of the British Isles, where messages may be transmitted from passing vessels by means of the International Code; and there are twenty stations in various parts of the world, as widely apart as Aden, Ascension, Malta, St Helena, the Cape of Good Hope, and Skagen in Denmark, where communication may be effected by the same means. Many of these stations have direct telegraphic connection with London, so that shipowners may be kept acquainted with the movements of their vessels, and may also transmit instructions for the guidance of their captains. It is matter for wonder and regret, notwithstanding the existence of a carefully elaborated system of signals and a world-wide network of shore stations, that the use of the Signal Code is not in any sense compulsory on the part of shipowners. Considering the innumerable advantages which a speedy means of communication must afford to all concerned, it is with surprise that one learns, from a note prefixed to the official Maritime Directory for the past year, that ‘cases have been reported in which officers at the signal stations have hoisted the International Code Signals warning ships of danger, and the ships have been afterwards lost, from the inability of the masters to read the signals.’ This is a state of affairs which ought not to be permitted to continue in the interests of the men whose lives are at stake. Another and still more serious defect in a system which is admirable in many respects, is the total absence from the Code of any method of signalling at night. As we have seen, Her Majesty’s ships are provided with appliances for this purpose which are skilfully adapted to the end in view; but merchant vessels are absolutely without the power of communicating after darkness sets in. It is true that by private arrangement with the shore stations on several parts of the coast, the steamers belonging to the great Companies may by the use of certain lights indicate their names and the Company to which they belong; but this cannot, save in the most elementary sense, be regarded as a satisfactory method of communication. It is probable that the night signals in use in the Royal Navy are too complicated in character to permit of their being learned and worked efficiently without much more study and practice than can reasonably be expected from the master of a merchant vessel. Still, it ought to be within the power of science to suggest some plan for enabling a vessel to signal to ship or shore during the hours when the perils of the sea are rendered more terrible by darkness.
In these days, when our ocean highways and harbours are crowded with shipping, a collision between two of our large iron or steel vessels, which might happen at any time, would send one of them to the bottom in a few minutes. Two vessels, each going at a speed of twenty miles an hour, and sighting one another at two miles off, with this joint speed of forty miles an hour, would meet in about three minutes. Hence the importance of a ready and efficient method of signalling.
By the present system, red and green lights are placed on each side of the vessel, a green light on the starboard side, and a red light on the port side, with a board shutting off each light from the opposite side. An officer seeing a coloured light at a distance of two miles has no indication what course the vessel is steering. Hence the importance of the apparatus invented by The Right Hon. J. H. A. Macdonald, Q.C., M.P., Edinburgh, an Associate of the Society of Telegraph Engineers and Electricians, which he calls the Electric Holophote Course-indicator, for the prevention of collisions at sea.
By means of a powerful electric light, the approach of another vessel is indicated, and information is given at the same time as to what course she is on and what course she intends to hold to. The light is also useful for illuminating the water immediately before the ship, and is also valuable when passing down a river, through shoals, or close to a lee shore. The instrument consists of a strong reflector, with an arc light placed in the middle of it, which is affected by every movement of the helm. As long as the helm is amidships, the handle cannot be moved at all, but is held firm by two pegs. But if the helm is moved from amidships, an electric circuit is formed, which actuates an electro-magnet, and thereby removes one of the pegs. When the helm is ported, the reflector is set free by the removal of one of the pegs, so that by working the handle, the light can be swept from amidships over the starboard bow, and brought back again. If the helm be starboarded, the reflector is freed from the other peg, so that the light can be swept from amidships over the port bow and back again. But as this is a mere side-to-side movement, means are provided for giving more intelligible information, such as a driver gives when waving his hand to indicate his course, by a shutter connected with the reflector in such a way that when the beam has completed its side-movement, the shutter rises up and obscures the light, and does not drop again until the reflector has been turned back to its middle position. The shutter then falls down; and the light being again exposed, the process of sweeping round to starboard, screening, and bringing back to amidships, can be repeated as long as the helm remains at port. When the helm is starboarded, the light can be swept round to port in the same way. The light is immovable when the helm is amidships, and can be swept only over the starboard bow when the helm is ported, and only over the port bow when the helm is starboarded. In order to guard against the risk of the reflector being carelessly worked by not completing its sweep either way, the instrument is provided with two tell-tale bells, which will enable the officer on the bridge to check the working of the reflector.
In foggy weather, when the light would be ineffective, two steam whistles can be shunted into action by the reflector handle, one giving off a succession of short shrill notes, the other a succession of deep long notes, according as the helm is to starboard or port. This invention has been awarded a medal at three Exhibitions, including the Inventories; while Admiral Bedford Pim, one of the nautical jurors, has styled it an ‘excellent course indicator.’