If you are among those who take machinery propelled ships down to the sea you must know that according to International Rules of the Nautical Road, you have got to have, for use as audible signals, a bell, a fog horn and a whistle or siren.
International Rules of the Nautical Road, or Regulations for Preventing the Collision of Vessels at Sea, were adopted following the 1889 International Marine Conference in Washington D. C. and have never been revised. This conference was attended by delegates from twenty-six countries representing most of the principal maritime nations of the world. The regulations were formulated by some of the world’s leading maritime men, and they were so wisely and comprehensively written that their observance after sixty years still is effective in preventing collisions at sea.
Since 1889 many changes have been recorded in shipping and navigation that would indicate need for revision of the International Rules. In size, ships of today dwarf those of the nineties; and new types of vessels, new means of propulsion, tripled speeds and radically new navigation aids, radio, radar and sonar, all have contributed to present a maritime picture contrasted strongly to that of 60 years ago.
It is not surprising then that proposed revisions of the International Rules have been listed at practically all marine conferences since 1889, including the recent London Conference of 1948. However, it appears notable that emphasis in most of the recent proposals for revisions was not so much on the changed conditions of sea transportation but rather on the conflict between the International Rules and the Inland Waterways and Pilot Rules, which are promulgated by and for individual nations.
This article is not intended to explore exhaustively the problems of revising the Rules but rather to discuss the audible signal equipment required by the Rules.
A part of Article 15 of the International Rules requires the sounding of whistle signals by steam vessels (now interpreted as any vessels propelled by machinery), on the whistle or siren. Article 15 states also that: “a steam vessel shall be provided with an efficient whistle or siren, sounded by steam or by some other substitute for steam, so placed that the sound may not be intercepted by any obstruction, and with an efficient fog horn, to be sounded by mechanical means, and also with an efficient bell.”
So you have got to have a bell, except that if you are sailing a Turkish ship, you may use a drum. This exception reflects the Moslem religious attitude toward the use of bells.
It appears that the first recorded shipboard use of a bell was on the British ship Grace Dieu about 1500 a.d. It is recorded also that in the days of the ^ hour sand glass it was the duty of the ship’s boy to turn the glass when the last sands had trickled through and as evidence that he had performed his duty, to strike the bell on the quarter deck. It may be assumed that from this practice Quartermasters got the idea for using the bell to mark the passage of the watch and to call the next watch, and thus developed the present practice of striking the time on the ship’s bell.
In addition to the popularly known practice of striking the time, the ship’s bell also is used as a fire signal, and, in the only International Rules requirement, as a signal when the ship is at anchor in fog.
The composition of bell metal bronze has remained practically unchanged for over 400 years at about- one part tin and four parts copper. Early in World War II the Japs overran Malaya and the Netherlands East Indies, principal sources of the world’s tin supply, and left the United States with only her stock pile and about 20,000 tons per year from South America. With copper in short supply also, ships’ bells came under the scrutiny of Bureau of Ships conservation engineers, and became the subject of a recommendation that: “in view of the principal use of bells as inboard signals, and the very effective interior communication system available on Naval ships, bells be eliminated from ships’ equipment, at least for the duration.” It was a good try but the answer was a terse, “Maritime Law requires bells—find alternate non-critical materials.”
Navy specifications for ships’ bells require, in addition to composition limits, certain dimensions and a certain pitch in the bell tone. For power boats 26 to 65 feet in length, a 9¾ inch diameter bell, weighing 20 pounds, and pitched to the key of “A” flat, with a frequency of 415 vibrations per second, plus or minus 8, is required. The audibility in decibels is not specified. As tonnage displacement or length of vessels increases, the weight and size of the bell increases, and the pitch is lowered. Formerly the letters “USN,” and, on the larger sizes, the ship’s name and the date were cast on the face of the bell.
Under this system it is possible to identify approximately the size of the ship by its bell toll. Therefore if you are on a sizeable craft and hear a high pitched “ding” in the fog, there is no cause for worry unless perhaps you are concerned for the life and property of the other fellow. If, however, you hear a deep, bass “dong,” you must choose between whistling one toot and turning to starboard, sounding two toots and changing to port, giving three toots and reversing engines, or sounding your siren to close watertight doors for a smash.
It was not easy to find a non-critical alternate material with low damping properties, for the four-century-old bell metal. Tonal quality, the rich over-tones and under-tones of music, were sacrificed; pitch also was discounted, and the emphasis was centered on audibility. The bell must make a noise. The material finally chosen was a high test white cast iron, sometimes called semi-steel, in which the carbon was in combined form rather than in the form of graphite.
So the Navy used cast iron bells until copper alloys again were available. They were not very musical and a number of them cracked, but the Liberty Bell was made of bell metal, and it cracked. It can be said for the cast iron bells, however, that they did make a noise if and when they were struck. In that connection it is noted that on board some ships, when the writer asked about the bell, it took some inquiry to find out where it was stowed.
International Rules require an efficient fog horn, to be sounded by mechanical means when the ship is under way in fog, with the signal varying depending on whether the ship is under way with way on or without way on. Naval ships carry such equipment but seldom use it since the whistle is a more convenient signal.
Either a whistle or siren is required by International Rules. Naval ships are presently equipped with both but use the siren only as an inboard collision alarm and all clear, for closing and opening watertight doors. The siren’s days on Naval Ships may be limited however, as will be noted later.
Probably no other piece of shipboard equipment has caused skippers, engineers and ships’ cooks more embarrassment and concern than the whistle. The ship’s cook is involved because according to Naval tradition, he is responsible for keeping the whistle polished. There is really very little malfunctioning of the whistle, but the exceptional case is always so noticeable. Whistle cases are of brass and sometimes crack; condensate drains may clog up; condensate may freeze in cold weather; and on rare occasions salt water corrosion may interfere.
Since they are more frequently used, audibility has greater significance in whistles than in bells. They are also more complicated in construction and operation and the specification, inspection and procurement is more involved, with considerable testing required. This testing has always been most objectionable to Naval laboratories and to the populace for miles around, but the situation is improved now with the use of sound chambers in which audibility may be determined by decibel readings at short range.
As in the case of bells, the pitch of whistles also lowers as the ship’s length or tonnage displacement increases. However specifications for whistles, unlike bell specifications, depend on the required size of the cylinder to approximate the desired pitch. These sizes go up to 24 inches in diameter which is the size whistle used on ships such as the Queen Mary. Another similarity with bells is that whistles also crack.
On one occasion, according to an unauthenticated report to the writer, a battleship, about to get under way, found her whistle cracked, with the only substitute, available before sailing time, a small high pitched whistle intended for a much smaller vessel. A new whistle was requisitioned for delivery at the next port of call, and a disgusted crew installed the smaller whistle on the big ship. Upon arrival at the next port, disappointing news awaited—no delivery yet on the whistle. Came the night before sailing with still no whistle, and came also a small yard tug in to tie up close by and to toot a whistle fathoms deep. Next morning the battleship got underway with her crew in high spirits, but with a whistle that had grown mysteriously hoarse during the night.
In the latter part of 1948, two proposals were made to the Chief of Naval Operations. The first suggested the elimination of sirens, air or steam, from Naval Vessels; and the second involved discontinuing steam whistles and using only air whistles. In April of 1949, the Chief of Naval Operations directed that in new construction surface vessels, an electronic signal, synthesizing the siren signal, should be installed in lieu of steam or air sirens for collision alarm and all clear signals. Consideration of the second proposal has been postponed for reasons hereinafter described.
Events leading to the proposal to standardize on air whistles in the Navy had their origin in the late 20’s after Diesel power was adopted on U. S. submarines and air whistles were used because there was no steam. The problem arose again at the beginning of World War II as the Diesel powered Navy auxiliary program got under way. There again air whistles were used after the possibility of supplying auxiliary steam from donkey boilers was explored and abandoned.
Air whistle signals are not lacking in audibility, but they make no visible plume, and mariners have always been accustomed to seeing the plume from steam whistles, and from it they have identified vessel signalling, and have gotten a few seconds advance notice of a maneuver. It is true that International Rules permit a suitable substitute for steam operation, under which air whistles qualify; however, in some maritime court cases, the lack of a visible whistle plume has been cited as contributing to the collision. All these factors are reflected in the hesitancy to substitute air whistles on ships where steam is available for the toot, and in the attempts of many marine activities to develop substitutes for the steam plume.
In 1927 the U. S. Navy installed a chemical plume apparatus on the air whistle of the submarine S-1, but after the black smudgy powder had clogged the whistle valve and corroded the container, the equipment and the deck, the equipment was removed. Many Diesel powered vessels have used steam from donkey or waste heat boilers to synchronize with the air whistle and produce a plume. Some Maritime Commission Diesel vessels had low pressure boilers installed and used two whistles, air at sea and steam in harbors.
The latest development in a visible signal is more comprehensive than just replacing the original steam whistle with a chemical or auxiliary steam plume. It is based on the concept that the steam whistle was only effective in daylight and could not- be seen at night. The new proposal would provide a light amber light, synchronized with the air whistle. Such light are presently used in the New York area both on tugs and steamships, and on Diesel driven vessels on Puget Sound. They are approved by the U. S. Coast Guard; being mandatory on Western rivers (flowing into the Gulf of Mexico); optional on the Great Lakes, and not prohibited anywhere. The Coast Guard has prepared a procurement specification for light amber whistle lights.
Light amber for whistle lights was chosen to avoid confusion with other signal lights, and appears logical since dark amber at a distance tends to look red, blue sometimes appears green, and on and off white, while having greater visibility, is sometimes confused with steady white, which at a distance often twinkles and appears be on and off. There is sometimes a mistaken assumption that amber light is more visible in fog, and the automobile fog lenses are given as a basis. These automobile fog lights are not visible at a greater distance, because any colored lens filters out some light and reduces its intensity; however, the auto fog lights do eliminate some of the white light which the fog particles reflect back into the driver’s eyes, and this permits the driver to see farther ahead of his car.
It is conceived that amber lights would have limited visibility at a distance in daylight, but these navigational signals are most frequently used at short range. They would not satisfy the nostalgic longings for the steam plume of yesteryear, but they would notify that an air whistle was being blown and would identify the tooter, both in daytime and at night. The amber light synchronized with the air whistle was listed at the 1948 London Maritime Conference as a proposed revision of the International Rules.
There we have the case of the audible signals required by the 60 year old, unrevised, International Rules of the Nautical Road; and here in closing we have three observations.
First, it is suggested that every law, regulation, rule or organizational set-up should be susceptible to reasonable modification for adaptation to the conditions of a changing world; and that the organizational set-up for the promulgation of the International Rules of the Nautical Road did and does lack such provision.
As a second observation attention is invited to the International Civil Airways Organization (ICAO) which promulgates the international rules for the airways. It meets annually at its Montreal, Canada headquarters to review and rewrite international airways rules. Members, who have voting power, are supplied with the agenda in advance of annual meetings so that they may receive prior instruction from the nation they represent. In the United States an ICAO panel is formed of representatives from the Air Force, Navy, Civil Aeronautics Authority, Civil Aeronautics Board, and the Department of State, Post Office and Treasury (Coast Guard and Budget Bureau). One U. S. vote is cast in accordance with previous agreement of the panel. The rules adopted seem to serve more as international standards than laws, and nations may be granted exceptions when for financial or other reasons they cannot conform. ICAO is a specialized agency of the United Nations. It has 53 member nations.
The final observation invites attention to the Intergovernmental Maritime Consultative Organization (IMCO), set up under the United Nations in 1947. The constitution was drafted by the United Nations Maritime Conference, in Geneva in March of 1948, and provided for certain consultative and advisory functions, and for participation in technical matters of maritime safety and efficiency. The International Conference on Safety of Life at Sea and in the Air, held in London in April of 1948, assigned to IMCO duties in connection with their enforcement.
According to its constitution IMCO becomes effective upon ratification by 21 nations, 7 of which have a total tonnage of not less than one million gross tons of shipping. At the time of this writing only the United Kingdom, Netherlands and Canada have ratified. Apparently other nations are waiting on the United States, since our shipping would be necessary to obtain the required million tons in seven member nations. It is understood that in June of 1948, the President of the United States recommended ratification of IMCO to the Senate. No action has yet been taken