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^aval Reserve Force Destroyers: The Second Team? 95 % Commander William G. Carson, U. S. Navy
^eeping the Seas Clean: An International Concern 97
BV Asst. Professor Charles L. Cochran, U. S. Naval Academy
^hree-Point Anchoring In the Deep Ocean 100 % Commander Earl D. Bronson, U. S. Navy (Retired)
N;
the
reserve force.
to
joining units? A day-to-day working n°wledge of these and many other Such matters is required. And there is n° school which teaches these subjects.
Courage? What if you were required 0 etnbark 80 or so reservists at 1600 0fl Sunday, integrate them with your sPatse nucleus crew, and get under way
reservists? About reserve underway
^aval Reserve Force destroyers:
^he Second learn?
% Commander ravy. Commanding Officer, USS lb°maston (LSD-28)
^ Having served on board two Naval eserve Force destroyers, I have witnessed the stigma that is associated with SUch duty. The disrepute—totally unwarranted in my view—manifests itself ^ rnany ways, including references at aPpy hour to being on the "second ^am.” and in the "Why me?” attitude rhose who receive orders to ships of
p ^ tour of duty in the Naval Reserve 0rce represents a challenge that is all t0° °ften not appreciated by one’s fellow naval officers. To run a Naval Reserve , ”*P 'well requires a wealth of specialized n°wledge, more courage than one W'ould imagine, versatility, and as much Patience as most people use in a lifetime. Specialized knowledge? What does e average line officer know about the by 6 reserve enlistment program? “out the limitations of the Uniform °de of Military Justice when applied for a major fleet exercise at 0800 on Monday? Wouldn’t you be worried that your one boiler on the line was partially manned by unproven reservists, or that the maneuvering board recommendation from CIC might have been generated by a reservist? Such examples are extreme, but they do happen, and they do require courage.
Versatility? Cross training is necessary for survival. There are three general quarters bills; the one to be used depends upon whether there are reservists embarked and what kind of reservists they are. Watch bills, abandon ship bills, and the like are often generated overnight out of necessity.
Patience? Consider taking to sea 100 reserve seaman recruits who have never before been on board a ship. Then consider that the nucleus crew must be motivated to conduct meaningful training for these reservists in spite of standing one watch in two and doing normal ship’s work. Or, consider the patience required of a division officer dealing with a man who believes the chain of command starts with his Congressman. Or, consider the frustration of an executive officer who calls absentee crewmen and asks them to come to drill because they are required to steam the ship.
By now some of the challenges of Naval Reserve Force duty should have become apparent. Let’s examine more closely this often misunderstood program. It was created in 1958. Over the years, the force has evolved into five squadrons of FRAM I destroyers. Two- thirds of each ship’s crew consists of regulars (the nucleus crew), and the remaining one-third is made up of reservists (the selected reserve crew). The ships have home ports in cities such as Brooklyn and Tampa because the selected reserve crews come from these coastal areas.
The peacetime mission of these destroyers is two-fold. First, they must integrate their selected reserve crews and nucleus crews and train the integrated crews for war. Second, they must provide seagoing training in large quantity for other reservists. The first missiontraining of the integrated crews—must be accomplished in one weekend each month plus one two-week period a year. On the designated weekend of each month, the reserve crews report to the ships, and usually all ships in the same general area get under way on Saturday morning for exercises together. They conduct gunnery, antisubmarine, or other drills, according to the services available and return to port Sunday afternoon. But a significant portion of the training of the integrated crews is accomplished during the annual two-week active-duty-for-training (AcDuTra) in which several ships cruise together in order to conduct a vigorous schedule of drills and exercises, especially exercises which could not be completed during the year’s weekend drill periods.
Training of the integrated crews is readily acknowledged by all concerned to be the most important peacetime mission. Since the selected reserve crews are embarked only about 10% of the time, however, the ships often spend more time on their secondary mission of training other reservists. There are two types of two-week AcDuTra cruises in addition to the one for the selected reserve crew. The first, often called a "kiddie cruise,” provides reserve recruits with their initial shipboard indoctrination. Most of the time is usually spent dockside, with only enough time at sea to allow for underway watch qualifications. The second type of cruise is for reserve petty officers. It is primarily underway, usually includes several ships, and provides more advanced training including, occasionally, participation in a fleet exercise.
As in other ships, manning of Naval Reserve Force destroyers considerably affects their capability to fulfill their missions. A ship with a fully manned integrated crew should have the same capability as any other destroyer of the same class. With only the nucleus crew on board, the capability should be somewhat reduced, and the endurance considerably reduced because of crew fatigue. With the nucleus crew plus AcDuTra reservists, the capability should be somewhere in between. At present, however, capabilities are usually lower because of current manning problems. Just as in the rest of the Navy, the Naval Reserve Force ships’ nucleus crews are below wartime strength. But,
since the nucleus crew is only two-thirds to start with, undermanning has an especially serious effect, both on operations and maintenance. The selected reserve crews are also affected by the same manning problems as the regu- lars—recruiting and retention.
One of the most unusual and challenging leadership problems in the Navy is motivating the selected reserve cretv and the nucleus crew of a Naval Reserve Force destroyer to function as truly one crew. The problem has two elements^ making the part-time reserve cresv members feel that they are really a parf of the crew and are responsible for then ship, and continual indoctrination o( ‘ the nucleus crew to restrain them from thinking of the reservists as second-class sailors. There are enough sources friction between regular and reserve
sailors to make the concept of an integrated crew ineffective if the problem is left untended even for a short while. The extent to which this problem is solved on board a particular ship depends largely upon the attitude of the commanding officer—whether he himself can accept the fact that reserve sailors are a part of his crew, and that he is responsible for them as much as he is responsible for the regular sailors.
As is the case for all challenging jobs, there are rewards commensurate with ffie hard work. After every cruise, Naval Reserve Force sailors have the satisfaction of seeing the increase in ability and confidence of reservists leaving after
Just two weeks on board. I’ve had no other job in the Navy where the results °f hard work were so readily apparent *n such a short time. Another satisfaction is serving with outstanding reservists. Although there are large numbers of reservists who are only marginally motivated, there is also a hard core °f dedicated and patriotic reservists whose motives are love of the Navy and service to the country. Among this latter group one finds the selected reserve crew senior petty officer who hasn’t ntissed a drill since the program started, and who often spends evenings working aboard ship. One also finds the reserve officer who takes a two-week cruise without pay, and the commanding officer of a reserve unit who consistently sacrifices time with his family to spend extra time on his Naval Reserve duties.
The next time you see a Naval Reserve Force destroyer fueling alongside
using only one station, conducting a firing exercise with only half the battery manned, or trying to make a rendezvous with speed limited by one-boiler operation, don’t think ill of the ship. Instead, recognize that the ship, despite personnel shortages and a mixed crew composed of reserves and regulars, is there and getting the job done.
Keeping the Seas Clean: An International Concern
Assoc, Professor Charles L. Cochran, department of Political Science, U. S. f'laval Academy
A 1970 United Nations study of national legislation and international agreements concerning pollution shows concern up to that time to be limited almost exclusively to oil pollution. The documents that do refer to other forms °f pollution refer vaguely to "marine Pollution by substances other than oil.” There is general agreement that a coastal nation may regulate sewage disposal—according to the standards she sets—by all ships within that coastal nation’s territorial sea. Attempts to provide international standards for pollution control in territorial seas have been consistently beaten back as being incom
patible with the sovereign jurisdiction of the coastal nation over her own territory-limited only by the right of innocent passage.
The Conference of the Law of the Sea convened by the United Nations General Assembly has as its goal the achievement of a comprehensive agreement on the law of the sea. In order to facilitate its work, the conference’s preparatory committee was divided into three subcommittees. The first two subcommittees are territorial in nature. The task set for Subcommittee III on Pollution and Scientific Research is functional rather than territorial, although its work has frequently coincided with that of Subcommittee II which deals with coastal nation jurisdiction.
With Subcommittee III a "Working Group on Marine Pollution” was established in the summer 1972 session of the Seabed Committee. However, no specific proposals were formally submitted until March 1973, which means that much of the work preparatory to the 1974 session in Caracas, Venezuela, was insufficient on several important issues.
During the spring and summer sessions of 1973, 13 different draft proposals on marine pollution were submitted. The proposals vary widely in
tone. A Kenyan draft on an exclusive economic zone concept is quite vague as to the precise obligations of nations to prevent pollution, but it leaves the interpretation and enforcement of the provisions to the coastal nation in the economic zone beyond her territorial sea. This territorial sea would extend to a distance of 200 miles.
Draft articles submitted by Canada suggested that global and/or regional standards on pollution by vessels should be established but left the maximum limits adjacent to the territorial sea for enforcement open. The Canadian draft would allow nations facing grave and imminent danger from pollution or from threat of pollution which may reasonably be expected to result in major consequences to take such measures "as may be necessary to prevent, mitigate or eliminate such danger.”
The Canadian draft specifically exempts naval vessels:
This Convention shall not apply to those vessels and aircraft entitled to sovereign immunity under international law. However, States shall ensure by the adoption of appropriate measures that such vessels and aircraft owned or operated by them act in a manner consistent with the object and purpose of this Convention.
Interestingly enough, the draft articles for a convention on general principles for the preservation of the marine environment put forward by the U.S.S.R. contains an almost identical qualification.
The rules and standards adopted by States for the prevention of pollution of the marine environment should not infringe upon the immunity of vessels and aircraft which enjoy such immunity under international law.
Of course, neither Canada nor the Soviet Union is suggesting that naval vessels are above the law, but only that the coastal nation cannot initiate enforcement measures directly against the war vessel concerned. Rather, a protest would be made to the government whose flag the warship flies. The government involved would then be liable for damage caused by the warship.
A universal territorial sea of 12 miles would transform more than 100 international straits into territorial waters.
Few of these straits have any major geopolitical significance.
The United States has indicated it will accept a 12-mile limit for a territorial sea if the right of free passage is retained through the straits that will become part of the territorial sea of various nations. The Soviet Union, whose military access to the sea would be more adversely affected by any transit restrictions, is insisting on free transit through only those straits that link open seas. Many European, Asian, and North African states argue that "free passage” would prejudice coastal nation interests in preventing pollution. They insist that they have no interest in interfering with commercial traffic if it takes place with reasonable pollution control devices on the ships. At a minimum they can insist that sewage not be dumped during passage through these straits by foreign ships. This would require the ships to use holding tanks for sewage. Other states are simply not in a position to argue against this concession.
One of the Soviet draft articles on straits used for international navigation provides that vessels transiting between one part of the high seas and another part of the high seas shall enjoy the same freedom of navigation for the purpose of such transit as they possess on the high seas. But the draft contains two qualifications:
Ships in transit through the straits shall take precautionary measures to avoid causing pollution of the waters and coasts of the straits, or any other kind of damage to the coastal States of the straits; Liability for any damage which may be caused to the coastal States of the straits as a result of the transit of ships shall rest with the flag-State of the ship which has caused the damage or with juridical persons under its jurisdiction or acting on its behalf; . . .
Archipelagic nations in Asia have made almost identical arguments concerning the right of foreign ships to innocent passage through their waters. Passage is innocent so long as it is not prejudicial to the peace, security, and good order of the archipelagic nation. The potential threat to the good order of the nation can occur when a vessel polluting the sea causes damage to the ecosystem. There is a natural temptation to reject such arguments on the grounds that this would be the first step in the eventual recognition of the extravagant claims to territorial seas made by archipelagic nations.
An international law of the sea does not depend solely on the Law of the Sea Conference which is scheduled to reconvene next month in Geneva. Other organizations such as the Intergovernmental Maritime Consultative Organization (IMCO) can and have produced treaties for signature and ratification. In the fall of 1973, IMCO completed a major new treaty aimed at controlling pollution from ships. The treaty on the Prevention of Pollution from Ships has five annexes, each dealing with a particular problem: oil, noxious liquid substances, pollution by harmful substances carried to sea in packaged forms, pollution by garbage, and pollution by sewage from ships. The treaty and its annexes are rather narrow in scope and regulatory in character. Since it is so specific, it is easier to revise -than a law of general principles.
The IMCO treaty provides that all new ships under the organization’s administration must be provided with holding tanks to collect and store sewage, with minimum specifications depending on the tonnage and the number of personnel normally on board. The ships must have equipment and fittings of a standardized type to comply with the requirements of the treaty. Periodic surveys are provided for in the treaty.
The discharge of sewage into the sea is prohibited except under certain specified conditions. Discharging sewage is permitted if it is pulverized and disinfected using a system approved by the administration and at a distance of more than four nautical miles from the nearest land. If it has not been pulverized and disinfected, it may not be discharged closer than 12 nautical miles from land. Sewage from holding tanks must be discharged at a moderate rate rather than instantaneously, and the ship must be making at least four knots during the process.
The point is that regulations now exist beyond the territorial sea which specify the conditions under which sewage may be discharged. The prospect is that the regulations will grow more rather than less severe. Of course, war-
ships are not under IMCO jurisdiction. However, if warships do not comply, it ls expected that they would become an easier target for recriminations by certain groups and countries.
In November 1973, IMCO concluded a protocol on Intervention on the High Seas in Cases of Marine Pollution by Substances Other Than Oil. The Conference noted that IMCO had intensified its work on all aspects of pollution by substances other than oil. The parties tQ rhe protocol agreed that:
Parties to the present Protocol may take such measures on the high seas as may be necessary to prevent, mitigate or eliminate grave and imminent danger to their coastline or related interests from pollution or threat of pollution by substances other than oil following upon a maritime casualty or acts related to such a casualty, which may reasonably be expected to result in major harmful consequences.
fbe intervening party has the burden °f proof at the time of the intervention t0 show that there is a grave and immi- ner>t danger to the resources of the sea before taking action. The action may 'Uclude removal and destruction of the ship. Once again, this intervention could not take place against warships, but it shows the direction of the restrictions.
An acceptable compromise on the Suestion of sewage disposal and pollution problems on board ships must take 'nto account certain political facts of life. One such fact is the process of creeping nationalization of the ocean and the claims raised in opposition to this process by major maritime powers in order t0 preserve freedom of the seas against encroaching national territoriality. Negotiations at the Law of the Sea Conference have centered on the attempts to reconcile the thrust to preserve and consolidate the principle of freedom of the seas in its traditional application and the 'feive to extend various forms of national jurisdiction farther into the open Seas. The task of the negotiations then looks fairly straightforward: strike a seties of trade-offs between competing claims of national prerogatives and the claims of freedom of the seas. This was, *n fact, the general mode of the negotiations at Caracas. If the present array of forces is maintained, it is likely that the eventual outcome of the negotiations
will be a bargain which trades greatly increased national jurisdiction over the adjacent ocean to a distance of 200 miles for freedom of movement (within acceptable limits) for all nations in the entire ocean.
The 1958 conventions acknowledged the coastal nations’ rights to establish sanitary regulations throughout their territorial seas. The convention will likely achieve a concession on a 12-mile uniform width to the territorial sea if there is a reciprocal agreement that adequately guarantees freedom of movement through a number, if not all, international straits that would be enclosed by the extension of the territorial sea. Most countries now have national legislation prohibiting the dumping of ships’ sewage within the territorial sea. This would extend the prohibition to a uniform 12 miles.
The bargain on a 12-mile territorial sea has an additional element, and that is that coastal nations would receive (or have recognized) claims to jurisdiction for economic purposes, to a distance of approximately 200 miles. The area between 12 and 200 miles would be known as the patrimonial sea. The primary motive for coastal nations aspiring to such a right has been justified by Mexico and an increasing number of other nations as being nothing less than the close interrelationship between land and sea in the environment. Others see the need for the establishment of a buffer zone to protect against pollution.
Since the claim is also made that coastal nations’ rights should also include the exclusive right to exploit and profit from the living and non-living resources of the area, the right to regulate and control activities for all purposes including environmental protection, subject only to the reserved freedom of navigation and overflight. Many see this as a threat to "free navigation” because the environmental protection right would include the regulation of pollution from vessels. This could hamper traffic if each state had a different set of standards. Some fear that this could be used as a subterfuge to restrict the flow of traffic.
Coastal nations maintain that their right to the partrimonial sea is meaningless if they cannot protect the environment in that area which includes vessel
pollution. There is little doubt, however, that the environmental regulation of vessels navigating within the patrimonial sea, regardless of the destination, will not be left exclusively to the coastal nation. The IMCO treaty is an indication that uniform standards will be applied in terms of holding tanks and the prohibition of dumping within territorial seas. The IMCO agreement lays down certain restrictions on dumping beyond the territorial sea. These will likely be revised in the future, providing for more stringent controls on dumping.
It is highly unlikely that the law of the sea treaty will confer a blanket authority on the coastal nation to pass national legislation concerning pollution in her economic zone. On the other hand, a coastal nation can and increasingly will insist that any ship transiting her patrimonial sea en route to one of the coastal nation’s ports must abide by her rules and regulations concerning sewage pollution by vessels. This would suggest that new ship construction should include holding tanks adequate to store sewage accumulated for several hundred miles. This would allow for ' traffic parallel to the coastline in excess of the width of the patrimonial sea. It seems unlikely at this juncture that the coastal nation will be given the authority to prevent traffic which passes through her patrimonial sea even though it is not destined for her own ports. The Law of the Sea Conference will probably provide for broader standards of pollution or establish liability for vessels causing environmental damage by pollution.
Finally, if a treaty is successfully concluded, it will deal separately with the problem of fixing the authority to enforce environmental protection regulations. There is a greater sentiment now to give coastal nations the right to enforce regulations enacted by an international authority than there has been in the past. In any event, there is little likelihood that a treaty could be agreed upon that would authorize an international agency to enforce the applicable conventions. A report on ocean environment sponsored by the American Society of International Law held that the United States’ proposal was the most far-reaching in that it would empower the coastal nation to take en-
forcement measures against "all vessels of a given flag following an international determination that the nation of registry has failed to take enforcement measures itself.”
The law of the sea treaty may well also enunciate a general principle of national responsibility and liability for injury to the marine environment of other nations. From most of the discussion on pollution at the conferences thus far, one gets the feeling that oil spillage is the main concern rather than sewage pollution. Regulation of sewage pollution in some form to the 200-mile limit is increasingly likely. Beyond that limit, minimal regulations laid down by IMCO apply to commercial vessels. The Law of the Sea Conference beyond the 200-mile limit will do no more than lay down the general responsibility of nations to insure that activities within their control do not cause damage to the environment.
Three-Point Anchoring In the Deep Ocean
By Commander Earl D. Bronson, U. S. Navy (Retired), former Marine Coordinator, Marine Physical Laboratory of the Scripps Institution of Oceanography, San Diego
FLoating Instrument Platform #1, (FLIP) a 355-foot-long, spar-shaped, two- attitude research vessel, was developed by the Marine Physical Laboratory (mpl) under Office of Naval Research sponsorship and has been operating since 1963.
Having no propulsion power, FLIP is towed to station in the horizontal attitude, then "flipped” to the vertical working position (Figure 1) by controlled flooding of the large ballast tanks which comprise much of her long slender hull. Her working draft is 300 feet.
As operational experience was gained, it became apparent that some types of research could be conducted more efficiently by restricting the drift of the platform. Among these were ambient noise measurements and long range sonar phenomena. In fact, any program which called for precise ranges and/or a static bottom profile would be enhanced by anchoring.
In March 1970, FLIP was successfully moored from one point in 3,000 fathoms of water. In November of that same year, a three-point test moor in 700 fathoms was conducted in a semisheltered location. The actual deep mooring, three points in 2,250 fathoms (13,500 feet), was put down under MPL supervision from the MV Pacific Apollo, an offshore supply ship, on 2 April 1971. During both of the scientific operations, Mr. William Whitney was the scientist-in-charge on FLIP. The writer was in charge of the anchorings.
All of these anchorings were made using sacrificial bottom tackle attached
to a simple shear pin assembly, thence to neutral buoyancy line, and finally to a positive buoyancy section of line nearest the surface. The single-point moor used a surface buoy, with FLIP making up to the buoy. The multiple-leg moors were modified to exclude this buoy, having the buoyant sections of line directly connected to FLIP with a constant recording load cell between. The singlepoint moor was not intended to be continuously under tension; the others were deliberately pretensioned to reduce surface excursion of FLIP during research activities.
The 2,250-fathom moor required very few modifications to the system used in the 700-fathom test. However, it was necessary to find a ship capable of towing FLIP and at the same time stowing the 19,200 feet of line required for each leg, plus the 30 tons of scrap chain and three Danforth anchors used as bottom tackle. The offshore supply ship with her huge clear deck space aft proved ideal for this service. A diesel-powered towing winch was installed, and there still was plenty of space for the spools of line and bottom tackle, including room to work them during the plant and recovery.
Material Data: The line used in these moorings is procured in 6,000-foot lengths for handling convenience, and so that it can be used again in various depths. Multifilament polypropylene (MFP) has a specific gravity of 0.91, while that of power braid (nylon over a polypropylene core) is 1.04. The former is l1/ inches in diameter, and the latter is iyi6 inches. Both have an average breaking strength of 45,000 pounds. Both are elastic, with about 20% stretch before the breaking point is reached.
Because this line, even with standard thimbles and shackles, maintains a slight positive buoyancy, all of its potential is available for the mooring stresses, rather than partial self-support as is the case with wire or line of negative buoyancy. Any catenary which may occur will be up, precluding the possibility of a "nest” on the bottom.
Bottom tackle, if in one piece, would be hard to handle. Scrap chain was selected because it was available and could be "walked” out in steps. A 750-pound Danforth anchor was added to keep the chain from dragging along the bottom. Total weight of the bottom tackle was
19,0 pounds in air and about 85% of this in water.
A plastic marker buoy was attached to each leg with 800 feet of 1-inch MFP at the 1,200-foot connection ahead of the first 6,000-foot length. The shear pin system was decided upon after considering acoustic releases (expensive and delicate), magnesium bolts (unreliable and affording no latitude in release time) and various weak links (shackles and pear rings which are unreliable). A primary release of 18,000 pounds was desired so that the pin would be sheared without overloading the line. This also allowed a differential of only 2,000 pounds between the bottom tackle weight and shearing tension (yi6-inch round stock was just right).
Operational Narrative: On 29 March 1971 flip departed San Diego under tow bV the Pacific Apollo for a position west °f Guadalupe Island. The depth was m°re than 2,000 fathoms, and our first °bjective was a three-point moor.
Very rough weather was encountered, causing an extra day in transit and some problems with chain storage. Arriving 0ri station at 0500, 2 April with Sea State about 4, FLIP was disconnected to start transition to the vertical position "■'bile we on the tug began walking out tbe bottom tackle for leg No. 1. At 9800, a 1,200-foot section of MFP line was passed to flip for connection to its keel-shackled wire pendant. The tug then got underway, upwind, paying out kne. When the 1,200-foot section was °ut, the tug was stopped while a marker buoy on 800 feet of 1-inch MFP and the 9,000-foot section of 1 '/2-inch MFP were attached. The tug then moved off, still upwind, while marker buoy line and anchor line were concurrently payed °ut. The marker buoy went over the °pen fantail when its scope was run, and rbe ship continued. When the MFP spool etnptied, the ship was held into the ^ind while a 6,000-foot length of 1%6- inch power braid was connected. This procedure was then repeated for the other spool of power braid. By 0900, the tug was directly upwind from FLIP with 19,200 feet of 45,000-pound breaking strength line on or near the surface. The bottom tackle was shackled into the bitter end of the line with the shear pin assembly between, and suspended straight down from a pelican hook. A strain of about 8,000 pounds was put on the anchor line (tug underway slowly and anchor line stopped off to avoid undue stress on the shear pins) to remove surface catenary from the entire line. Finally at about 0930, the tug was stopped, the stopper removed, and leg No. 1 was tripped.
The load cell recorder indicated a drop time of 33 minutes for this leg. Maximum tension was 13,500 pounds, which was identical to that recorded for leg No. 1 in the test moor. Drop time in the 700-fathom test moor was five and a half minutes, a velocity of about 12 feet per second. The time required for the anchor to bottom in 2,250 fathoms indicates a drop velocity of only 6.8 feet per second. It seems sensible that the additional drag imposed by the much greater length of line was responsible for the slower descent.
Legs No. 2 and No. 3 were then planted on courses 120° from the No.
1 leg heading, using the same sequence. It was necessary to impose strains to
13,0 pounds on these lines to reduce surface catenary prior to release. Leg No.
2 bottomed in exactly the same time as No. 1. Leg No. 3 provided some anxious moments when 39 minutes elapsed before bottoming. Although the area had been previously surveyed by echo sounders, we began to wonder if we had discovered an "inverted” sea mount. It seems in retrospect that leg No. 3 and flip, working against tension on legs No. 1 and No. 2, were probably drawn
toward them during the drop, causing the anchor to traverse a much longer arc before hitting bottom. All three lines appeared to settle out with similar angles to the surface, indicating little difference in water depth.
With flip in position, less than three miles from the exact target, transponders were put down from the Apollo, and the surface position was pinpointed. Average excursion (Figure 2) during the five weeks on station was in the order of 250 yards, considerably better than the one-fourth mile specified by the scientist-in-charge.
It had been found in the test moor that the natural drag of the anchor line during the free fall of the bottom tackle was sufficient to cause all three legs to end up under tension with no posttensioning required. The same conditions obtained in the deep mooring (Figure 3), with tensions running between 2,000 and 9,000 pounds during the period in which the moor was in use. Provision had been made to apply additional tension by shortening legs No. 2 and No. 3 should surface excursion prove unacceptable after the system had settled out; this was not necessary since the excursions were well within the desired limits.
Recovery: On 8 May, after remaining in the moor some five weeks (position reports became monotonous), the Apollo was recalled to the scene for recovery. This evolution, essentially the same as the test moor recovery, was accomplished in about ten hours.
Leg No. 3, having the least tension, was taken in first. FLIP gathered in some slack by hauling in and stopping off. The loose end then was passed to the tug, which got underway from flip. The line was shackled to the towing wire and enough power applied to shear the shear pins. Line was then spooled back on the shipping reels, which had been strengthened, fitted with a pneumatic powered spooling device, and mounted on suitable stands welded to the tug’s deck. Legs No. 1 and No. 2 were then recovered in the same manner. Some
60,0 feet of line was taken up by 12 spools on the open sea, using only a standard rotary pneumatic tool for power. Air was supplied by a portable compressor. A portable gas engine driven capstan was used for taking the
line from the sea, so that respooling could be done with minimum tension.
Wind and Current Data: Tensions on the three legs were constantly affected by exterior forces: wind and/or current, figure 2, compiled from transponder- furnished data, indicates several rather large surface excursions. These excur- slons, when compared to wind and current data, indicate that the elements exerted a combined influence in the same direction at the same time. The exceptionally large excursion which occurred on 15 April was caused by a 0.3 knot current on the entire sub-surface length of flip (300 feet) plus a 20-knot Wlnd from the same general direction. Tension on legs No. 1 and No. 2 increased from a rather normal aggregate
7,0 pounds to over 15,000. This was rhe only time that the current meter did n°t indicate directional variations over FLIP’S length. Although wind from the prevailing direction exceeded 20 knots Lnxny times, current influence appears to have been predominant when in conflict with wind forces. Current during the er>tire stay on station ranged from 0.15 knots to 0.3 with layer variations.
Comments:
^ As in the test moor, the marker buoy lines became entangled with the anchor line during pickup. It would be helpful to disconnect marker buoys by small boat and attach a weight to their lines t0 keep them under some tension and clear of the 1,200-foot section of anchor line.
^ Although there have been many au- rhenticated reports of sharks and fish attacking the enticing white line, there has been no bite evidence in connection with flip. Line is respooled and inspected prior to each service.
^ When time and funds permit, it is Proposed to construct large storage sP°ols with integral braking and respooling devices, so that all the line required for each leg may be connected and spooled in one piece. This would allow each leg to be payed out under constant tension without the necessity °f stopping to connect, with the attendant disadvantage of gaining catenary ^hile dead in the water.
Communications between the tug (irnplantment vessel) and FLIP are ex- rremely important. Loss of contact during irnplantment could result in overloading the line while pulling out catenary. Primary and secondary frequencies were manned during pickup and release periods.
► The 1%: 1 scope of line to depth seems to be as steep as practicable. I would prefer 2:1 so that operators would have more leverage in post-tensioning (more holding power).
► I believe that by engineering this system to meet the situation, any vessel can be moored in any depth and held to reasonable surface excursion. Further, a combination of this moor and dynamic positioning utilizing leg tensions to activate the dynamic system could produce vernier results.
► The three-point-deep-moor has become standard procedure for many operations of both FLIP and the MPL’s Ocean Research Buoy (ORB). In many cases mooring negates the need to keep a ship in the vicinity during operations, a welcome saving in ship costs.
There have been only four improvements of any magnitude, to the system since flip’s initial three-point moor in 1971.
► Because of the rather delicate balance between bottom tackle weight and the tension required for shearing out, a new shear-pin assembly has been developed. This is a combination of magnesium bolts and thd original 7/16-inch shear pin. Six magnesium bolts sized to erode in a few hours are used to increase the holding strength of 37,000 pounds during the drop, negating the possibility of premature shearing.
► In order to reduce the deck space required to fake out the chain used for bottom tackle and the drudgery required in walking it out for irnplantment, large metal chain lockers (one for each leg) are now used for chain storage on board the towing-support vessel. Chain and anchor are stowed so that after the mooring line is attached and surface catenary reduced, a pelican hook is released and the entire bottom array is allowed to run free. This also greatly reduces the time required for implant- ment.
► The use of MFP (more expensive and of larger size than power braid) has been deemed unnecessary as little if any actual advantage is derived from its lesser specific gravity. In the interest of standardization, only power braid purchased in 6,000-foot lengths is required. Size has been increased to 1% inches, breaking strength 55,000 pounds.
► Finally, and most significantly, a capability of utilizing the mooring legs as instrument positioning devices has been developed and successfully employed. A trolley device, having nylon rollers and instrument attachments, is run down the taut mooring line to a predetermined depth and stopped off. This device may be used on each leg so that a horizontal array can be streamed to depths of about 5,000 feet (to the first shackle). It can go deeper, if the first and second lengths are spliced instead of shackled together. This innovation is of great value to scientists in the area of long-range acoustics, as well as internal wave studies, current phenomena, and in thermocline reactions.
It is interesting to note that FLIP has made 12 multiple-leg anchorings in depths from 700 to 3,000 fathoms. All of the original spools are still in use as is much of the original line.
The ORB moors on practically every operation. She has moored 74 times: 24 one-point; eight 2-point and 42 from three points. As a rule, ORB does not operate in great depths but some have been in 1,500 fathoms. ORB’s system is somewhat modified in that there is enough deck space to carry its own line and bottom tackle and enough capstan power so that bottom tackle is usually recovered and used again. Line is minutely inspected during recovery in all cases and any marginal areas are cut out and ends spliced. Line splices are capable of about 85% of original strength. Chafing is the primary enemy of synthetics and must be avoided at all times.
There have been two legs lost during all of these operations—one during an attempt to shear out with an underpowered tug (attributed to chafing at the shackle) and the other to premature shearing during the drop (replaced by spare bottom tackle with no loss of line or time on station).
Practically all scientists scheduling FLIP or ORB now desire some sort of moor. Ship costs have mounted relative to other expenses, and operating independently has become increasingly desirable for this reason alone.