bluuebunny/crossref_metadata_2025_split huggingface dataset:
Safe Sub-Sea Operations
Authors: Grenfell E.W. 
Published: October 2008

For over 69 years since the advent of the USS HOLLAND on April the 11th, 1900, our American submarines have believed in the philosophy of safety, best portrayed by a short verse which I heard many years ago: I quote:Now I tell you, mate, we all temptFateWhen we dive beneath the seaFor a man is a fool to break theruleThat nature meant to be - - -Gardner Young
As a young man of 25, I joined our Submarine Force and quickly learned that to buck the laws of Mother Nature you had to maintain a constant "alert" when you operated in a medium you weren't designed to live in. You had to be "on watch" 24 hours a day if you wanted to operate safely under the sea. And so today as the growing number of new vehicles and their crews begin to challenge the deep sea more and more, the safety requirements and constant respect for Deep Sea operations must be adhered to at all times.
This became very apparent to me when as a consultant to General Motors Defense Research Laboratory in Santa Barbara, I noted that the early planning for the building of the Deep Ocean Work Boat (DOWB) included "safety" as a primary requirement - safety in the electrical design - safety in the life support system - safety in the ballasting system, etc. In other words safety seemed to be a prime factor. In this instance the normal attention to safety was probably enhanced due to the fact that the design characteristics were the responsibility of a former Naval Constructor who had the job of initial design planning for the USS DOLPHIN, the Navy's first Deep Submergence Submarine built and now operating out of Portsmouth, New Hampshire. That gentleman is Dr. Scott Daubin, now employed by Woods Hole Institute. Of equal influence in the operational planning was the current DOWB Project Manager, Captain Swede Momsen, USN (retired) whose responsibility covered all of the initial testing and operating schedule. Captain Momsen, son of a very prominent Submarine Admiral, and an active Submariner himself is a strong advocate of Safe Submarine Operations.
Last, but not least, the whole DOWB safety program was strongly supported by management who set up a "Safety Committee" to make certain that all in the program would be properly imbued with the "safetybrush."
Thus we see that with all this proper preliminary planning that the check-off lists for DOWE dives contain some 227 items from Pre-Dive status through to Post-Dive phase; of these 227 check-off items, about 20% are "safety" items.
To keep track of the DOWB on its dives, the Director of Operations, with a recorder at his elbow at all times, conducts and controls operations from the DSV tender and from a small boat which follows the movement of the DOWB acoustically. The Director talks, over the UQC, to the DOWB every 15 feet in depth for a communication check, every other one-half hour for an environmental check, and on every hour for a power parameter check.
Analysis of Peak Mooring Force Caused by Slow Vessel Drift Oscillation in Random Seas
Authors: Hsu F.H. , Blenkarn K.A. 
Published: October 2008

INTRODUCTION
Traditional naval architecture technology has not devoted extensive efforts to understanding of the requirements for mooring a vessel in the open ocean under storm conditions. Perhaps it can be said that conventional maritime practice would consider mooring under such circumstances an act of foolishness and therefore not deserving of serious technological effort. The demand on the offshore petroleum industry for mooring under trying conditions has, however, created the need for a clearer understanding of the physical phenomena involved. The offshore industry has experienced major difficulties in mooring under storm conditions and has suffered extensive financial loss. Over the years, attempts have been made to solve offshore mooring problems, utilizing a variety of vessels and mooring techniques. Results of experience and practice offer conflicting indications of the relative merits of various mooring systems. Various engineering and scientific studies have contributed toward an understanding of many factors influencing forces; however, it appears that previous studies have, for the most part, ignored a governing phenomenon. Specifically, there has been little attention devoted to the effects of slow vessel drift oscillation in random or irregular seas. It is this phenomenon which is the prime subject of the present paper.
Fig. 1 illustrates results obtained from model tests of a moored vessel in irregular waves. Shown in the figure, as a function of time, a-re the variations of wave height and period, the surge or drift position of the vessel and the tension in the primary mooring line. It will be noted that the surge motion of the vessel involves both a direct wave induced surge and a gradual slow drift taking place over a period of 1 minute or more in prototype time. The drift behavior shown in Fig. 1 is the phenomenon of critical importance. This type of drift motion is found in the motion records of moored ships in an actual ocean storm environment. Moreover, the basic behavior of slow oscillations is not unique to moored vessels. For instance, such behavior has been observed in tests involving vessels towed through irregular waves with a constant towing force. In such case, it has been observed that the vessel velocity exhibits slow oscillations with periods in the range of 1 to 2 minutes.
When an ocean wave is propagated toward a moored vessel, part of the wave is reflected, the remainder being transmitted on beyond the vessel. The conservation of wave momentum results in a net force applied to the vessel for each wave. For regular waves the consequence is a steady drift force resulting in a static shift of the position of the moored vessel. For irregular waves, on the other hand, a varying sequence of drift forces arises in correspondence to changes in wave height and period. Investigations leading to this paper show that the ensuing long period drift of the vessel can for many cases be the completely dominating influence in determining maximum mooring line tension.
On the Design of Offshore Supply Vessels
Authors: Mok Yingkei , Hill Ralph C. 
Published: October 2008

ABSTRACT
The offshore supply vessel came into being in 1954 to meet the demands of a rapidly growing offshore oil industry. The authors give a brief history of this development and present the arrangement and profile of atypical supply vessel as well as a complete table of characteristics on a number of vessels.
It is shown how the demand to carry large quantities of cargo on deck resulted in a somewhat unique hull form. Two particular areas of design are stressed, stability and powering. The question of stability is gone into in detail, including development of the current USCG stability criteria. The difficulty in estimating power requirements for the low speed length ratios associated with supply vessels is brought out. Data for estimating power requirements is presented.
The views expressed in this paper are those of the authors and do not necessarily represent the official view of the American Marine Corp. or the USCG.

INTRODUCTION
When the first offshore oil well was drilled in the Gulf of Mexico at the end of World War II, the need for delivery of supplies such as drill pipe casings; drilling mud; cement, etc., brought forward a new type vessel--- offshore supply vessel.
Among the first offshore supply vessels were the war surplus LCT's, primarily because they were readily available. They were adequate for the early offshore drilling sites close to shore. When new vessels were built, they were designed closely to the LCT's with the pilot house aft. Then in 1954, a new type of supply vessel came into being which was to set the pattern for the offshore supply vessels that were to come. These vessels had all of the crew quarters forward leaving a large deck area aft for carriage of deck cargo. Connection between the forward quarters and the engine room aft was through a passage under deck.
During the last 15 years, because of the rapid worldwide development of offshore oil fields, we have seen not only bigger, faster and more seaworthy supply vessels built, but have also witnessed the use of these vessels in many different roles. Offshore supply vessels have been used as seismographic exploration vessels, oceanographic research ships, tenders for deep diving submarines, telephone cable laying vessels, container ships, anchor handle vessels and seagoing tugs. This paper, however, will limit discussions only to the vessels that carry supplies.
It is the intention of this paper to provide designers and operators with a better understanding of the stability characteristics of offshore supply vessels, and to contribute some information concerning preliminary design structural design, and powering requirements, all of which have been lacking in this fast growing field.

ON THE PROPORTIONS AND ARRANGEMENT
The characteristics of 20 offshore supply vessels are given in Table 1. For quick reference, the average values of some of the particulars are plotted on Fig. 1.
Potential ties of Explo tlng Marine Algae
Authors: Claus George 
Published: October 2008

ABSTRACT
Marine algae have been utilized by man since prehistoric times as food, drugs or raw materials for chemicals; however, their more concentrated exploitation dates back only to the past 50 years or so. The discovery, isolation and purification of polysaccharides in the brown and red algae with characteristics favorable for different industrial applications created such a demand for these plants that worldwide shortage resulted, causing a keen competition among nations for the control of natural growing beds. Calculations are presented on the total potential world supply of harvestable algae and alternative solutions for satisfying the growing demands of the phycocolloid industries are discussed, including the current efforts to grow algae under controlled conditions for predictable harvests. The feasibility of such aquaculture ventures is evaluated and the pros and cons of creating algae factories are pointed out.

TEXT
Marine algae are lower plants restricted to the salt water environment. They range in size from the microscopic unicellular organisms to the largest plants on the earth. Certain groups of them reach considerable dimensions and are called kelps in general.
According to their pigmentation, one Distinguishes among green, brown and red algae. All three groups are quite distinct and were already recognized by the Romans. Different uses date back to early historic times, both as food and medicaments. The brown algae were found to accumulate large quantities of iodine in their bodies, and dried weeds were already used in ancient China for the treatment of goiter. Some green algae are still cooked especially by Oriental people - into soups or made into salads) while red algae are smoked and sold as a delicacy in many of the Nordic countries. These uses of algae, however, did not warrant their large-scale exploitation. Only the discovery in this century that both the brown and red algae contain substances which are relatively easy to extract and have characteristics useful in different applications, lead to the foundation of what might be termed seaweed industry.
Most of the marine algae have a highly slippery consistency, which is due to mucous substances which they manufacture in their cells and secrete toward the environment. These substances serve the protection of the plants and all have one common characteristic -- they are made up of long polymers of different sugars.
Since they will produce a colloidal system in water, they fall into the category of hydrocolloids and since. They are obtained from algae) the Greek name of which is Phykos, they are termed phycocolloids. In modern industry there are basically three such colloids which are Widely utilized: [1] algin, or alginic acid) and its different salts obtained exclusively from brown algae; [2] agar-agar, produced by certain red algae and [3] carrageen in, extracted from other red algae.
Alginates are widely utilized in different foods for the high viscosity solutions they produce where such requirement is present, as in creams, to which they impart a better whipping ability.
The Use Of Coated Fabrics In Containment Of Petroleum
Authors: Headrick Richard T. , Headrick Edward E. 
Published: October 2008

ABSTRACT
Some 30 years of experience in coated fabric fuel containment indicates similar permanency and sharply reduced fire hazard when compared with conventional metal containers. The use of "embankment liner tanks" with integral fabric floating roofs is common for water reservoirs and is now being examined for petroleum containment in refinery tank farm areas. Inflation of roofs with nitrogen atmosphere and available foam systems further reduces contamination and fire hazard. In the area of oil spills, coated fabric tents have been installed on the ocean bottom off Santa Barbara effectively collecting oil and gas seepage from the bottom and conducting the product to an adjacent platform or floating collector tank. Tent sizes range from 25 feet square to 115 feet square. Floating tanks may have any capacity, but one used successfully in the Santa Barbara channel is 10.000 gallons and is 22 feet square when empty. Another tent use is collecting fresh water from underwater springs in the ocean. This is planned for Ventura County, California. A collapsible oil containment boom has been developed for open ocean use which weighs under 2 1bs. per foot. Under development is a skimmer system to receive oil from the boom legs. Projected performance is to clean a 250 foot wide strip of sea at 3knots per hour in relatively heavy sea. The unusual boom design does not attenuate or deflect wave energy, has very little draft and freeboard and precisely contours wave surface contour & Materials used in ocean environment generally are based on nylon cloth coated with PVC or synthetic rubber, such as neoprene, Nitrile, Buna-N or Hypalon, compounded for resistance to petroleum, sea water and ozone and not sustaining combustion. This paper will emphasize the use of coated fabrics in oil spill control, substantiated by years of experience in using coated fabrics in difficult fuel containment problems, largely for the military.

INTRODUCTION
In 1939, the U. S. Army Air Corps approached Firestone with view toward developing rubber membranes to line calf hide tanks for aircraft fuel to reduce leakage. Firestone suggested substituting tire cord fabric instead of calf hide. Later, nylon cloth was substituted for tire cord to further reduce weight. Thus, modern aircraft tanks were born. Within two years, Firestone technology had tackled the complex problem of self-sealing tanks which were used with great success in World War II. The use of synthetic rubber coated fabrics for ground storage fuel containment has reached maturity after 25 years of very useful service largely for the military. The first ground systems were constructed for the Marine Corps as a "fuel system supply point" which was subsequently copied by the Army. Some of the original tanks are still in use. Literally thousands of tanks have been employed in the arctic for Dew Line since 1957 and more recently to support North Slope petroleum activities. Substantial capacity systems provide instant conversion of an "airbase of opportunity" into a sophisticated fueling depot.
Acoustic Valve Operating System
Authors: Haase W.H. 
Published: October 2008

ABSTRACT
As offshore pipeline systems expand into areas great distances from shore, and into deep waters, a method for locating and controlling isolated underwater valves is required.
The Bendix approach to fulfilling this requirement is the Acoustic Valve Operating System (AVOS). The system features coded interrogation, coded command, and five-year life. The coding, accomplished by using multiple frequencies, is designed to prevent unauthorized or accidental valve actuation.
A selected valve can be located from a three mile distance, and can be commanded to open or close from one-half mile. Range to the valve and actual status are automatically displayed and updated by a frequency coded reply to each interrogation.
In addition to performance requirements, the data presented includes design considerations, hardware items, and test data resulting from a Gulf installation.

INTRODUCTION
A need has developed for an easier way to operate isolated valves on offshore pipelines. While this requirement is primarily based on safety considerations and production convenience, it also bears upon pollution control.
The present method involves a diver's manual control of a valve. Although this method has been used for many years, it is slow and at times impossible due to weather and the diver's inability to locate the device. In fact, the time when you most want to operate a valve is usually during the worst possible weather, when diving may be impossible.
With these thoughts in mind, Bendix (working in conjunction with Tennessee Gas Pipeline Company) has developed an acoustic valve operating system (AVOS).
Several persons in the industry have stated that they have had valves down for years and never needed to operate them. This state of affairs, however, is true only of pipeline systems of the past, which offer little flexibility in today's market (these old systems use platforms with expensive risers as control points). In the future, we may see fewer structures used as control points. Pipeline systems will provide greater operating flexibility; flow will be stopped, reversed or split, and side systems cut in and out more quickly.
Most pipelines of today are located within reasonable diving depths and at medium distances offshore. As distance and depth increases, the need for a remote valve operating system becomes more apparent.

Design and Performance Requirements
The Acoustic Valve Operating System functions are as follows (see Figure 1):Provide a means for locating an isolated valve from at least three miles (equivalent sea state 3) acoustically.Report status of valve from three miles. The valve is either open or shut.Provide a means of commanding a desired valve to change status from the surface within approximately 1/2 mile range.The equipment in water at the valve is designed for a five-year, unattended life (including the battery pack).The surface equipment must be portable and usable from a typical crew boat, with no special installation requirements.
A Surface Tree Riser Tensioning System for FPSOs
Authors: Pollack J. , Poldervaart L. , Naciri M. 
Published: October 2008

Abstract
Today hard riser, dry tree systems not carried on a bottom founded structure are supported by either a TLP or Spar. Both of these systems directly or indirectly use buoyancy to achieve the riser tensioning. The use of buoyancy requires that the relative motions of the buoyancy and the risers be kept small. The TLP does this by tendon restraining the buoyancy, while the Spar does this by creating a somewhat quiescent water shaft in which buoys can effect a relatively uniform riser tension. The physics of an FPSO require that the tensioning system cope with draft changes and larger relative motions between riser and floater. A weight-based riser tensioning system has been developed and tested which is able to cope with both the large stroke and relative motions required to make hard risers practical for FPSO systems.

Introduction
Deep-water hydrocarbon production in depths above 500 m uses two generic modes of development. This involves either an FPSO with wet subsea trees and flexible risers, or motion restrained floaters like TLP or Spar with dry trees and hard risers. Dry tree systems are the preferred means for producing these reservoirs as it gives better well control, intervention and workover leading to optimum reservoir depletion. Unfortunately developments of fields in remote areas often require storage and thus FPSOs with wet trees make better economic sense. To overcome this dilemma, a riser tensioning system has been developed which enables dry tree production from a spread moored FPSO.
To realize a proper FPSO tensioning system, the system must be designed to cope with draft changes and with larger and faster motions between the FPSO and riser. To deal with this a tensioning system based on weight rather than buoyancy was developed. The weight lateral motion is controlled by placing it in the water, well below the FPSO from which they are suspended by tension members running over sheaves. This riser tensioning system named Tension Leg Deck (TLD) will be detailed. The basic physics of this tensioning system will be described along with corroborating model test results. The present day existence of hardware required to construct this tensioning system will also be discussed.

Deep Water Hard Riser Production
Systems that can support hard risers for dry production trees and surface BOP offer many benefits over those using wet trees and subsea BOP. The main benefits are those of surface control, access and the ability to perform low cost interventions and workover over the life of the field. The floating platforms required to support these hard risers in deep water are however more costly than floating platforms for wet subsea production and drilling. Examples of these lower cost platforms are weathervaning FPSOs which are being used to receive, process, store and offload crude from subsea or fixed surface facilities. More recently spread moored FPSOs are being used and considered for milder deep water areas like West Africa and Brazil.