bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Reel Pipelay Ship Under Construction - Applications Up To 16 Inch Diameteh Pipe 3000 Feet Of Water
Authors: Friman Kenneth  R. , Uyeda S.T. , Bidstrup Herman  R. 
Published: October 2008

ABSTRACT
There is an increasing need in the offshore petroleum industry to lay pipelines in deep and rough water, in multiple pipeline bundles, and in remote areas. The industry's first dynamically positioned Reel Pipelay Ship, the APACHE, now under construction, is one approach to these problems.
The paper presents a discussion of the design parameters, special features and details of the ship. Also presented are applications such as pipelines in very deep water where normal anchoring is not practical, pipelaying with limited offshore work time, pipelines in remote areas, subsea completions, bundled pipelines, and removal and reuse of pipelines. The paper includes a typical operating example.
The reel ship will have a capacity to carry up to 2,000 short tons of pipe on its permanent large reel and additional pipe on portable reels. This tonnage is equivalent, for example, to approximately six miles of 16-inch pipe, or 20 miles of a inch pipe. The ship will have the capability to lay pipe up to two miles per hour. The pipeline equipment is designed to allow the pipe to leave the ship at departure angles up to 60 degrees from the horizontal. This allows pipelaying in very deep water. The ship will have a 12.5 knot cruising speed and an operating range of 5,000 miles.
The reel ship, patterned after the reel barge presently operated by Santa Fe Engineering & Construction Co., significantly extends the range of the Reel Method of laying offshore pipelines.

INTRODUCTION
The first reel pipelay ship is presently under construction by Todd Shipyards Corp. in Galveston, Texas. The vessel will be owned and operated by subsidiaries of Santa Fe International Corp. It is scheduled to start work in January 1979.
The vessel, named Apache, (Figure 1) will be the first self-propelled vessel ever built for laying pipe from a reel. It will use a vertical reel, a concept first introduced by Santa Fe at the 1975 Offshore Technology Conference. The vertical reel, with the adjustable stern ramp, will allow the lay angle to be increased or decreased depending on water depth and pipe properties. The preliminary design basis is for the laying of 16-inch, 12-inch, and smaller pipes in approximately 2,000, 2,500, and 3,000 feet of water, respectively. This system constitutes one of the Apache's major advantages over existing equipment.
The concept of laying pipe with a reel is not unique, having been used successfully for many years in the Gulf of Mexico from both portable and barge mounted reels. The pipelay barge, Chickasaw, (Figure 2) equipped with a horizontally mounted reel has installed nearly five million feet of pipe up to 12-inches in diameter in water as deep as 350 feet. Using a special stinger attachment, the barge has demonstrated the ability to lay pipe to a depth of 1,000 feet in a test conducted in 1975.
Hawser System Design For Single Point Moorings
Authors: Woehleke Steven P. , Flory John F. , Sherrard James R. 
Published: October 2008

ABSTRACT
This paper presents design information for mooring hawsers for single point moorings. It is based on a recent study, conducted by Exxon Research and Engineering for the U.S. Coast Guard, which will serve as a guide for the evaluation of SPMs used at U.S. deepwater ports. Information from many sources has been drawn together and analyzed to present a comprehensive study of synthetic rope properties of interest in SPM design. Much of the information has not been published before.
Properties of nylon, polypropylene, and polyester fibers, and the types of rope construction used at SPMs are discussed. The elasticities of ropes of various materials and constructions are compared. The methods which are used to rate large-rope breaking strengths are evaluated. Factors which affect new and used SPM hawser strength are discussed. Chafing chains, hawser floatation devices, and the methods by which hawsers are attached to the tanker are also discussed.
Recommendations are made for SPM hawser material and construction. Factors of safety for SPM hawser design for U.S. deepwater ports are also recommended. These factors of safety are higher than those previously adopted by the industry.
The data and findings presented in this paper will be of interest to SPM designers and operators and to other users of large-diameter synthetic rope.

Introduction
During 1977, Exxon Research and Engineering Company conducted a study for the U.S. Coast Guard to prepare guidelines for evaluating Single Point Moorings (SPMs) for U.S. Deepwater Ports. As part of the study, SPM hawser systems were examined, and this paper covers the major findings pertaining to hawsers.
The hawser system serves to moor tankers to the SPM. An SPM hawser assembly consists of a large synthetic rope spliced to form eyes at both ends or end-to-end spliced to form a loop, referred to as a strop. The eyes or ends of the strop are placed on thimbles, and chafing chains are attached to the thimbles. Floatation devices are provided to keep the chafing chains and hawsers afloat when a tanker is not moored. A typical SPM and hawser system with a tanker moored is shown in Figure 1.
The examination of SPM hawser systems focused mainly on their design. Information from many sources was drawn together and analyzed in a comprehensive study of synthetic rope properties of interest in SPM hawser design. Information was also gathered and analyzed on the associated hawser components, such as thimbles, floatation units, and chafing chains. Based on the study, guidelines were prepared for the design of SPM hawser systems. The complete study of SPM hawser systems, along with studies on other aspects of SPM design, is presented in "Guidelines For Deepwater Port Single Point Mooring Design" (l) available to the public through the National Technical Information Service, Springfield, Virginia 22151.
Dynamic Tow Motion Of a Platform In a Seaway
Authors: Chung Jin S. 
Published: October 2008

ABSTRACT
An analytical method for the prediction and analysis of the motion and stability of a platform under tow in a seaway has been developed. Equations of motion and hydrodynamic coefficients are derived, which account for the effect, on plat form motion and stability, of tow speed, waves and heading relative to the prevailing wave direction. This method is an extension of a previous simple method of prediction for zero tow speed. Predicted motion is presented for a multihull platform subjected to the wave frequency of interest. The results show that heave is increasingly coupled with pitch as tow speed into a head sea increases, whereas there is little heave pitch coupling at zero tow speed. Surge, sway, roll and yaw show little coupling effect compared with heave-pitch coupling. As speed increases in a head sea, amplitude increases near the resonant heave period, possibly reducing longitudinal stability. Heave pitch coupling effects are strongly dependent upon tow speed or damping. At tow speeds above certain critical values, reduction in pitching moment or decrease of longitudinal stability may require damping devices such as fins.
There has been renewed interest or concern following the recent capsize of several jacket platforms when under tow in a seaway. Conventional analytical prediction or analysis of stability has not taken into account the effect of speed in the equation of motion. Present analytical prediction of motion is based on solution of coupled six degrees-of-freedom motion for a multihull platform at tow draft. The analytically predicted speed effects on the motion of the present semi submersible platform under tow in a seaway are qualitatively compared with model test results of a jacket platform under tow. The comparison shows good agreement in the trend of the speed effect.
This method can be used to aid in the analysis of dynamic stability or to establish requirements for towing a jacket plaltform in the actual ocean environment, given prevailing weather or wave conditions along the tow route. Also, it can be used to aid in deciding the tow-out date by analyzing weather and sea state forecasts, and in predicting platform motion and stability at various times of the month or year. Towing of semi submersible platforms, semi submersible-type offshore supply vessels or similar floating structures can be analyzed directly by the present method.

INTRODUCTION
Renewed interest or concern has been developed following several recent capsizing incidents of platforms or tall jacket platforms under tow at sea as a whole or in pieces. Floating structures such as semi submersible or jacket platforms designed for stationary operation in the ocean have usually been towed to operational or installation sites. Safe towing depends largely on local weather conditions prevailing along the tow route. That is as much a question of halting the tow during bad weather, as it is of getting to the site a few hours earlier.
Variations Of Waves And Currents In Storms In The North Sea
Authors: Freeman John C. 
Published: October 2008

ABSTRACT
The North Sea has great variations in width and depth. These physical characteristics and the direction of the prevailing strong winds lead to a great geographical variation in the expected extreme values of waves and currents. Further variation is caused by the fact that an extreme storm in the middle latitudes has a typical small scale variation that is usually ignored. This feature has some of the characteristics of a hurricane in that it is an intense vortex caused by strong convergence and rising moist air. Since this vortex is embedded in an already well developed low cell in middle latitudes and is cold it is not isolated and easy to identify like a hurricane. The affect of this intense embedded vortex on maximum wind and maximum wave statistics for the North Sea (or any other middle latitude stormy area) is very important. In summary there is the same low probability at a middle latitude station of a hit by one of the intense vortices as there is at a semi-tropical station of a hit by a hurricane or typhoon.
This means that extreme wind and wave statistics for a middle latitude station must be based on studies of the eight or ten worst storms in a few decades rather than on the more readily obtainable history of thirty to forty storms in two or three years.
Examples of winds and waves in the North Sea in extreme storms are presented in this study.

INTRODUCTION
In temperate latitude locations such as the North Sea the usual practice of developing design conditions is to find a series of measurements for a (necessarily short) time and to project (by probability theory) the probability of extreme events by graphical or analytic means.
It is well known that this process will not work for an area such as the Gulf Coast of the United States where the extreme storm (the hurricane) is a rare event in itself.
The purpose of this paper is to show that the likely cause of extreme conditions in the North Sea is a rare event (once every 3 years as opposed to once every 10-15 years for a hurricane on the Gulf Coast) and that the same general type of analysis should be used.
Quite by coincidence the rare event in the North Sea has some of the same meteorological Characteristics as a hurricane. The appearance of the disturbance is modified by the fact that it is embedded in a large deep middle latitude low cell and because it is moving fast it is difficult to capture the extreme values by ordinary reporting systems.

THEORY OF COMPENSATION
We begin the discussion by showing the similarity with a hurricane and then investigate the effects of such a rare small disturbance on estimates of extreme conditions.
Critical State Soil Mechanics Model Of Soil Consolidation Stresses Around a Driven Pile
Authors: Miller Terrell W. , Murff James D. , Kraft Leland M. 
Published: October 2008

ABSTRACT
This paper discusses results of a study investigating the radial, plane-strain consolidation of soil around a pile using a Critical State soi1 Mechanics [1, 2] model of the soil The study was conducted to assess the assumption that the stress path of the soil during radial consolidation would occur along the critical state line as a basis for developing an effective stress pile capacity formulation [3, 4].
The study showed that predicted stress paths deviated significantly from the critical state line. Furthermore, the results indicated that if initial pore pressures are high enough, consolidation of the soil at the pile wall occurs along a stress path characterized by a radial-Ko condition (Available in full paper). The implications of these results are that consolidalion pressures are model dependent and that excess pore-pressures are likely to be generated during pile loading. It therefore appears appropriate to modify effective stress pile capacity formulations [3] that are based on the soil being at the critical state at initial pile loading.

INTRODUCTION
Developing improved methods of predicting axial pile response has been an area of active interest by the offshore industry and the geotechnical community for some time. Until recently, the methods developed have been based on a total stress approach to soil behavior although it is widely appreciated that an effective stress approach is more fundamentally sound. The preference for total stress methods exists because effective stress analysis introduces major experimental and analytical difficulties. As a result, use of effective stress methods require many simplifying assumptions and it has not been clear they provide a real advantage. Furthermore, the total stress methods have proven to be sound, workable engineering tools, however many engineers feel that they have been extended to their limits and that further improvements can only be achieved through the more fundamental approach.
Recently several efforts have been made to develop axial pile capacity prediction techniques that are based on an effective stress representation of soil strength (e.g. Burland [5], Parry and Swain [6], Esrig, et al. [3]). Burland assumed that pile installation and loading did not change the soil's stress state. Parry attempted to remove an important assumption by considering changes in stress state due to pile loading. Although these methods do constitute important background work and have indicated some promise they do not demonstrate a clear advantage over total stress approaches when compared with available pile test data. In order to improve on these methods, the in-situ stress state and stress history of the soil around the in-place pile must be determined. This exercise requires several important tools; chief among these are accurate constitutive models of soil behavior, models of pile insertion and loading, and a means of solving difficult nonlinear equations.
Sedimentation In Coastal Embayments, Northeastern Gulf Of Alaska
Authors: Molnia B.F. 
Published: October 2008

ABSTRACT
During the last two centuries, glacial-fluvial, glacial-marine, and littoral sedimentation have completely filled at least three major embayments in the coastline of the northern Gulf of Alaska. In addition, the same processes are presently responsible for significant shoaling in Controller Bay, Icy Bay, Yakutat Bay, Dry Bay, Lituya Bay and Taylor Bay. The three filled embayments are Tsivat Bay, Kaliakh Bay and Vancouver's Icy Bay. To document the depositional histories of these nine coastal embayments, comparisons of shoreline configuration and depth were made from eighteenth century maps of exploration, nineteenth and twentieth century nautical charts and maps, and numerous ground and aerial photographs. These comparisons often permit calculation of volumes of sediment accumulated and rates of sedimentation.
Sedimentation rates in the nine Gulf of Alaska coastal embayments vary, but may be as high as 2 - 3.75 m/yr. Icy Bay, Yakutat Bay, and Lituya Bay all have areas that accumulate more than one meter of sediment annually. Planning and development of harbor facilities in coastal embayments of the Gulf of Alaska must include consideration of long term deposition patterns in the selection of harbor sites. Without careful analysis of sedimentation patterns, harbors may be selected which could fill with sediment before the completion of development.

INTRODUCTION
The- Gulf of Alaska coastline has been mapped and explored since 1741. Numerous maps and charts, and more recently, ground and aerial photographs have been made which depict parts of the coastline and which serve as permanent records of the configuration of the coastline at specific points in time. Maps of exploration, early ground photographs, seismic surveys, recent nautical charts and maps, and 1926-1979 aerial photography document many significant changes in the configuration of the coastline of the Gulf of Alaska and in the depth of specific coastal embayments.
This paper will describe changes in nine Gulf of Alaska coastal embayments and discuss the implications of sedimentation on the onshore siting of resource development facilities. The nine enbayments, (Fig. 1) from west to east are:Controller BayTsivat BayKaliakh BayIcy BayVancouver's Icy BayYakutat BayDry BayLituya BayTaylor Bay
Many of the early maps of exploration are printed or drawn at scales that make it difficult to tell what is cartographic imagination and what is real. Others however, are accompanied by narratives of exploration complete with soundings and descriptions of positions. Detailed accounts of the voyages of Bering (Davidson, 1901), 0 Cook (Ellis, 1782), La Perouse (1798), and Vancouver (1798) form the basis for many of the earliest shoreline comparisons made in this paper. A detailed atlas by Tebenkov (1852), which incorporates many of the earlier maps of exploration, includes data compiled by the Russian American Company in the early nineteenth century and serves as a basis for comparison with the modern data.
Development of a New Welding Gun for Underwater Welding
Authors: Coriatt G. , Roggen R. 
Published: October 2008

ABSTRACT
A new semi-automatic welding gun has been developed for underwater welding. The principle consists of producing a water-free zone within a rapidly rotating bell-shaped transparent cavity. A protective gas environment can thus be maintained within the vortex zone, providing suitable conditions for performing the welding operation in all positions. Butt and fillet welds on plates up to 1" thickness have been made. The encouraging results obtained indicate the possibility of a large field of application on offshore structures and in shipyards, where manual or automated welding of good quality is required.
The paper describes the conceptual design of the system, the test procedures which have been adopted and summarizes the most pertinent results obtained in the laboratory and under hyperbaric testing conditions.

INTRODUCTION
The technique of underwater wet welding has made some progress within the last few years, mainly by the development of new coated electrodes; suitable for operation in the presence of water. Nevertheless, the water in the welding zone limits the quality of welds for the following reasons:–the dissociation of the water in the arc zone yields atomic and molecular hydrogen, which increases the hydrogen level and hence the risk of hydrogen cracks;–the rapid cooling of the weld in the presence of water results in additional local quenching effects, which may increase the hardness, in the weld and the heat affected zone;–the presence and the rapid evaporation of water affects the stability of the arc which may cause the occurence of porosity.
For these reasons, large underwater dry welding operations, as for instance on pipelines in the offshore oil and gas industries, are generally carried out in dry habitat welding. The installation of such chambers around pipeline sections to be welded is a time-consuming and expensive operation.
In recent years, a number of devices have been developed and used with different degrees of success. These consist of carrying out the weld in a small welding chamber supplied with a protective gas environment and sealed either by means of flexible or spongy seals or else by discharging a water jet through an annular nozzle surrounding the gun. As will be explained below, none of these systems has proved to be truly successful in every day underwater welding applications, a fact which has led us to consider new approaches for underwater welding in suitably dry conditions, with a robust, reliable, light-weight hand-held tool.
The principle consists of producing a water-free zone within a rapidly rotating bell-shaped transparent cavity. A protective gas environment can thus be maintained within the vortex zone, providing suitable conditions for performing the welding operation in all positions (see Fig. 1).
Patents for this process have been applied for in several industrialized countries.
Deployment and Operation of the 50KW Mini-OTEC Plant
Authors: McHale Frank A. , Jones W. Lloyd , Horn Henry M. 
Published: October 2008

ABSTRACT
In 1979, the world's first successful at-sea closed cycle OI'EC plant was moored offshore of Kona, Hawaii and produced the first net useful electricity from the solar heat resource stored in ocean surface waters. The unique mooring combined the Ocean Thermal Energy Conversion (OI'EC) mId water pipe and mooring" tension leg in one polyethylene pipe. Operation of the electrical generating process was successful in waves up to 15-20 feet.

Introduction
The State of Hawaii, Lockheed Missiles and Space Company, and the Dillingham Corporation agreed in lq78 to design and build a demonstration Ocean Thermal Energy Conversion (OI'EC) plant to be installed on a floating platform. By August 1978 a Navy barge had been obtained. The actual instruction of the plant took place between December 1978 and June 1979, and the barge was placed on station in July 1979. On August 3, 1979, Hawaii's Governor George Ariyoshi was able to announce the world's first successful generation of net useful OTEC power from a closed cycle plant operating at sea. The plant continued operating successfully until November 1979, when available funds had been depleted, and at that time the Mini-OTEC returned triumphantly to Honolulu Harbor.

MOORING DESIGN REQUIREMENTS
The underlying requirements for Mini-OTEC were to supply 3200 GPM of 40°F. water from 2200 feet to a surface barge and to moor this surface barge, a 103 × 34 ft. rake-ended hull, in currents which were known to exceed two knots. Winds of 30 knots and waves of 25 foot significant height were assumed to be acting in the same direction with the ocean current. A system was required which mold be deployed within a weather window of only one day. The sea bed at the required mooring site (a State-sponsored, environmentally blessed research area) is a steep rocky volcanic slope with very rough topography. There are essentially no bottom sediments that would allow an anchor to "grab". The seabed slopes so -steeply that there was concern that an anchor might simply slide down the underwater hill, which is merely a continuation of the shoulder of the volcano above.
Research on candidate materials for the Mini-OTEC cold water pipe (CWP) had led to consideration of fiberglass, polyethylene, polyvinylchloride, rubber and polypropylene. Polyethylene was attractive as a CWP material due to its very smooth interior for flow characteristics and low susceptible to befouling. In addition, a fusion welding process was available that provided reliable joints. The polyethylene is very flexible and rugged and is not brittle even at low temperatures.
After selecting ultra high molecular weight polyethylene pipe as the CWP material, and in looking at the polyethylene properties, it was soon realized that the breaking strength of the pipe was quite high and a most attractive solution was to use the cold water pipe itself as the mooring line. This was considered to be a rather daring step at the time and much discussion ensued.