THE TOWBOAT Esso Pennsylvania shown underway shortly after her completion last year. Part of the fast growing inland-waterways fleet, the vessel, when pushing an eight-barge integrated tow, transports 17,000 to 180,000 barrel oil cargoes between Baton Rouge and Pittsburgh.

Captain A. H. McComb, Jr., USCG

Chief, International Maritime Safety Coordinating Staff, Member

Commander W. F. Rea III, USCG

Chief, Merchant Vessel Inspection Division, Member

Captain William R. Sayer, USCG

Executive Secretary and Member

FRONT COVER

Jack and the Bean Stalk-the St. Johns Light Station radiobeacon tower appears to reach through the clouds, although in actuality the Mayport, Fla., installation is only 110 feet above terrain.

BACK COVER

The sad safety history of Stanislaus Peck, by G. Seal

DEPOSITED BY THE

UNITED STATES OF AMERICA

FIXED

9. ARTIFICIAL ISLANDS AND STRUCTURES ON THE OUTER CONTINENTAL SHELF.

10. RULES OF THE ROAD.

11. TRANSPORTATION AS "BULK" OR AS "PACKAGES" OF FLAMMABLE OR COMBUSTIBLE LIQUIDS AND COMPRESSED GASES.

The Merchant Marine Council accepted most of the proposed changes to the regulations, with certain changes from the agenda which reflect actions taken with respect to comments received. Items 3 and 9 were accepted without change. Because of the number of comments received or questions raised with respect to certain proposals in the other items, the Merchant Marine Council mended final actions be deferred to permit further study of such proposals and comments. The changes in the regulations will be published in the Federal Register as soon as possible.

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The proposals regarding small passenger vessels in item 1 were accepted in substance. Minor changes in proposals for those vessels over 65 feet in length and under 100 gross tons were accepted. The principal changes were: (1) Continued requirement for rescue boats unless Officer in Charge, Marine Inspection, determines such boat is unnecessary in specific situations; and (2) continued requirement for power fire pump to be fitted with a pressure gage and to be capable of maintaining a capacity of not less than 50 gallons per minute at a pressure of not less than 60 pounds per square inch at the pump outlet.

The proposals regarding uninspected vessels (motorboats) in item 2 were accepted; however, final action with respect to the specification for the backfire flame arrester for carburetors was deferred until all the comments could be reviewed and problems resolved.

The proposals regarding bulk shipments of ethylene oxide and liquefied inflammable gases in item 4 (tank vessels), and the special construction, arrangement, and provisions for certain dangerous cargoes in bulk on

1963, AT WASHINGTON, D.C.

barges in item 5, were commented on extensively. Therefore, final actions on these proposals were deferred until all the comments could be studied and indicated problem areas satisfactorily resolved. The proposal regarding ring life buoys for unmanned inspected barges was intended to clarify the existing requirements and many comments received objected to requiring ring life buoys on barges. Final action was deferred pending a further review of existing requirements, the proposal and comments received and establishment of a uniform position with respect to the various types of unmanned barges now in use. The other proposals in items 4 and 5 were accepted with minor changes based on comments received.

The proposals regarding marine and electrical engineering in items 6 and 7 were accepted with minor changes based on comments received.

As announced at the public hearing, the final actions with respect to the proposals regarding "poisonous articles-radioactive materials" in item 8 were deferred so that the requirements of the Interstate Commerce Commission and the Coast Guard will be in agreement when published. It was noted that the ICC notice of proposed rulemaking on this subject will be published in the near future. The Atomic Energy Commission also requested postponement of final action until the proposed ICC regulations on radioactive materials can be reviewed and identical comments made concerning identical proposals. The text of all comments received by the Coast Guard will be made available to the ICC.

The other proposals in item 8 were accepted with minor changes based on comments received. With respect to castor beans and castor pomace, these materials will have to be regulated; however, final action was temporarily deferred until certain questions raised could be resolved and the feasibility of alternate suggestions determined.

A number of comments pointed out serious objections to the proposals concerning lights for moored barges in item 10. Therefore, the final actions on these proposals will be taken in a piecemeal manner as the questions raised are satisfactorily resolved. The Western Rivers Rules of the Road will be revised first to permit barges on the Mississippi River above Cairo, Ill., and rivers above that point which are tributary thereto to use the proposed rule changes.

The proposals regarding regattas and marine parades in item 10 were

accepted with minor changes. A number of comments objected to the proposals permitting States to regulate any regattas. This is presently permitted and several States now perform this work. This practice will be continued.

A number of comments were received concerning the transportation of inflammable or combustible liquids and compressed gases, and the proposals regarding these commodities in item 11. Certain comments raised questions concerning requirements applicable if these commodities are carried on board cargo vessels or barges in portable containers or tank trucks approved by the ICC and considered to be in quantities coming within the interpretation of a "bulk" shipment and therefore subject to the tanker act (46 U.S.C. 391a). Final actions on these proposals were postponed until the comments and views can be resolved and the corollary problems raised concerning inspection certificate limitations or endorsements can be reviewed by a special committee.

THE MERCHANT MARINE COUNCIL

Numerous Federal laws pertaining to maritime safety prescribe that the Commandant, U.S. Coast Guard, shall promulgate regulations to implement those laws. Included are those laws which govern the construction, inspection, manning, equipment, and operation of certain commercial vessels; the equipment, operation, and numbering of certain other craft; the rules of the nautical road; also the safety requirements relative to offshore drilling platforms, rigs, and associated vessels.

To advise and assist the Commandant in meeting these responsibilities a "Merchant Marine Council" was first established in 1942.

The Merchant Marine Council is a deliberative body to advise the Commandant as to policy in connection with matters affecting maritime safety. It has no operating authority. The Council makes recommendations to the Commandant on proposed legislation, rules, and regulations governing the construction, navigation, inspection, equipment, manning and operating of certain privately owned vessels; the rules of the nautical road; and the safety requirements applicable to offshore drilling rigs, platforms, and associated vessels. The Council provides a forum where maritime safety problems may be considered informally.

bility was done solely by relying on radiobeacons, supplemented by soundings, the importance of this aid to navigation can be better understood. As mariners became familiar with this means of navigation, the demand for radiobeacons increased. The first radiobeacons operated continuously on their assigned frequencies. The reassignment of a frequency depended only on geographic separation to prevent interference. Unfortunately, only a limited number of frequencies had been set aside for the operation of marine radiobeacons. This meant that if the number of radiobeacon installations was to con

tinue to increase without harmful interference resulting, a means of separating radiobeacons in addition to frequency and distance had to be devised.

Accordingly in 1929 a plan was developed whereby three radiobeacons used the same frequency on a timesharing arrangement such that each radiobeacon would transmit for 1 minute, remain silent for 2, then transmit for 1 minute, etc. Each beacon transmitted its signal in rotation in accordance with its assigned sequence. This procedure was repeated around the clock in reduced visibility, but during clear weather

this rotation took place only during two 10-minute intervals 20 minutes apart.

One of the difficulties of this method of operation was that during clear weather when a vessel wanted a radiobeacon fix, it seemed to invariably be at the time when the desired beacons were silent. Another difficulty was that during poor visibility more beacons were in operation than there were in clear weather. This increase in the number of beacons operating resulted in overcrowding of available frequencies with the possibility of interference and hence inaccurate bearings.

A revision of the radiobeacon system to be completed this month on the Atlantic and gulf coasts, and next month on the Pacific coast, is designed to correct these undesirable aspects of the system and to improve the radiobeacon service provided the mariner.

Briefly, the revision is the time sharing of a frequency by six radiobeacons instead of three; the elimination of the 20-minute period of silence in clear weather; the adjustment of service ranges; the addition of a 10-second dash in the characteristic identifier and the superimposing of the characteristic on a continuous

carrier. The following paragraphs describe these changes in greater detail.

With the operating schedule of 1 minute on and 5 minutes off, twice as many beacons can be grouped on a single frequency. This more efficient use of available frequencies allows wider separation of adjacent frequency groups. This wider separation reduces the probability of interference. Where feasible, adjacent radiobeacons have been assigned to the same frequency and operate on consecutive minutes. This method of operation was not practicable in all cases because

varying service ranges of the radiobeacons and the characteristics of the coastline.

Radiobeacon ranges have been reviewed primarily for the purpose of reducing the range of those beacons which extended far beyond the range actually required for safe navigation. A radiobeacon is basically a short- to medium-range (of 50 to 100 miles) aid. Radiobeacon bearings taken beyond this range have positional inaccuracies of greater than 5 miles. At ranges of about 120 miles the positional error is likely to exceed 7 miles. It will be noticed that even though the range of many radiobeacons is 50 miles or less, there are still a number of beacons operating at a range of 100 miles or greater. The real marine navigational requirement for these long ranges is questionable. They have been allowed to continue to operate at these ranges for two reasons: (a) Some of these fulfill air navigational requirements and are integrated into the FAA system of beacons, thus necessitating longer ranges; (b) are specific marine requirements; and (c) they provide some "comfort" to a navigator homing on the beacon. These long ranges will be maintained as long as possible; however, the ever-increasing need for more beacons will result in a periodic review of these beacon ranges and possibly a gradual reduction in their ranges.

The following will illustrate the problem faced by the radiobeacon system planner. Two beacons with a service range of 20 miles are able to operate the same minute on the same frequency without harmful interference, if the distance between them is 244 miles. Two 150-mile beacons would have to be 655 miles apart, and two 350-mile beacons would require a distance of 1,125 miles between them. It can be seen that if the necessary number of radiobeacons are to be accommodated within the frequency band 285 to 325 kc/s, service ranges must be kept to the absolute minimum required to meet the needs of the mariner.

In order to make the use of radiobeacons as simple as possible, the characteristics assigned to radiobeacon stations in this country have been limited to a brief and simple combination of dots and dashes. They are thus identified on the same principle as our lights along the coast. Now, a 10-second dash is being added to the characteristic of beacons to permit the navigator to refine his bearing. In addition, the identifying signal of all beacons has been super

imposed on a continuous carrier, when they are transmitting, to facilitate their use by navigators using automatic direction finders.

The entire transmission for most time-sharing stations is a repetition of the assigned signal for 50 seconds followed by a 10-second dash. There is a minor variation to this in the case of distance-finding stations. These stations transmit their assigned signal for 48 seconds, followed by 2 seconds of silence and then a 10second dash.

Distance-finding stations are equipped so that a mariner, within the range of the fog signal and having a radio receiver, can determine his distance from the station. The 10second radio dash and the long blast of the fog signal may be used for this purpose. The 10-second radio dash and the long (5-second) blast of the fog signal commence at the same instant. Since the radio signals arrive practically instantaneously (speed 186,000 miles/second), the later arrival of the sound signal (speed approximately 1,100 feet/ second) gives an indication of the distance traversed by the latter, thereby indicating the vessel's distance from the station. The elapsed time for the distance computation is obtained by starting a stopwatch the instant the 10-second radio dash is heard (it is preceded by 2 seconds of silence), and stopping it when the long blast of the fog signal is heard (it is preceded by a 1-second blast). Dividing the elapsed time by 5.5 gives the distance in nautical miles with an error that should not exceed +10 percent. As this method depends on hearing a sound-in-air signal, it is subject to the same uncertainties that affect fog signals. Cautionary notes concerning both radiobeacons and fog signals are printed in the Coast Guard's List of Lights and Other Marine Aids.

It would be convenient to the navigator to have all radiobeacons send continuously without any silences, thus making these aids to navigation always available as are lighthouses and buoys. The revised system is a compromise; it allows for the maximum beacon on air time and yet keeps interference at a minimum. Some beacons are, however, operated continuously. These beacons quired to meet specific marine or aeronautical needs and are located in areas where the number of beacons is not so great as to preclude this method of operation.

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In addition to time sharing (sequenced) and continuously operating It can be seen that radiobeacons are

shown on the accompanying chartlets. It can be seen that radio beacons are located at all important entrances and at outstanding intermediate points along the coasts. Marker beacons are radiobeacons of low power for local use only and are located on sites where, for various reasons, the installation of a sequenced beacon would not be practical. The characteristic of marker beacons is a series of 2-second dashes for 132 seconds, silent 12 seconds, repeated continually. Station identification is achieved by noting the assigned frequency on the chartlet and on the receiver dial.

The changes being made to the radiobeacon system will be made to approximately one-half of the radiobeacons on the Atlantic and gulf coasts on June 4, 1963, with the remaining beacons on these coasts being changed on June 11, 1963. Weekly Notice to Mariners No. 7 dated February 16, 1963, listed the changes to be made with the effective dates and contained a chartlet. This chartlet shows the system as it will be operating on June 12, 1963, except that the Canadian radiobeacons at Partridge Island, Lurcher Shoal L/V and Seal Island will operate on 308 kc/s, sequence II, V, and VI, respectively. The revised system is also shown on the June issue, Pilot Chart No. 1400 of the North Atlantic Ocean.

The changes to those beacons located on the Pacific coast will be made on July 9 and July 16, 1963. Weekly Notice to Mariners No. 18 dated May 4, 1963, contained the information concerning the Pacific changes and Weekly Notice to Mariners No. 20 contains a chartlet depicting the changes. The revised system will also be shown on the July issue, Pilot Chart No. 1401 of the North Pacific Ocean.

Since radiobeacons in the same general area are operating on the same frequency around the clock, timesharing beacons cannot operate at any time other than their assigned minute without causing interference. these Therefore, beacons cannot transmit continuously for directionfinder calibration. Special calibration stations are located along each coast. These stations transmit on a frequency in the marine band, and on 480 kc/s, to allow for the calibration of direction finders. For complete details on these stations, consult the appropriate volume of the List of Lights and Other Marine Aids.

For information on accuracy of bearings, plotting, and other matters, the navigator should consult the current issue of H.O. Publication No. 117, "Radio Navigational Aids."