Experimental study of Stability Limits for Semisubmersibe Drilling Platforms

Naval Engineers JournalVolume 83, Issue 3 p. 36-38 The Jimmie Hamilton Award JOHN J. NACHTSHEIM, JOHN J. NACHTSHEIM John J. Nachtsheim: is currently the Deputy Assistant Administrator for Research & Development for the Maritime Administration. His duties are the planning, coordinating, organizing, evaluating and directing of the R&D activities of MarAd. His past experiences include: Naval Architect for the Naval Ship Engineering Center, 1959; Deputy Chief Design Engineer for the Puget Sound Naval Shipyard, 1958 to 1959; and Naval Architect, the former Bureau of Ships, 1948 to 1958. His education is comprised of a B.S. degree from the Webb Institute of Naval Architecture, an L.L.B. degree from the George Washington University Law School, completion of the Advanced Management Program at Harvard University and current study of Transportation at the American University. He is a Registered Professional Engineer in the District of Columbia and a Member of the Bar in the District of Columbia and the State of Maryland. In addition to ASNE, his other professional memberships include the Society of Naval Architects and Marine Engineers, the Society of Aeronautical Weight Engineers and the Association of Senior Engineers of the Naval Ships Systems Command (Honorary).Search for more papers by this authorCOMMANDER L. DENNIS BALLOU, COMMANDER L. DENNIS BALLOU USN Commander L. Dennis Ballou: , USN, is the Head of the Engineering Service Office, Naval Ship Engineering Center. He is involved in computer hardware and software services to support engineering design, automatic data processing systems, design work study, and quality assurance. Prior to NavSec duty, Commander Ballou served in various billets afloat and ashore: tours on the USS Skagit and Tang; supervision of the USS Skipjack's first overhul; construction of the USS Nathanael Greene and helping to establish the Polaris overhaul program. He is a graduate of the U.S. Naval Academy, Officers' Submarine School and the Webb Institute of Naval Architecture. He holds BS and MS degrees in marine engineering and naval architecture, respectively. He has also completed many graduateSearch for more papers by this author JOHN J. NACHTSHEIM, JOHN J. NACHTSHEIM John J. Nachtsheim: is currently the Deputy Assistant Administrator for Research & Development for the Maritime Administration. His duties are the planning, coordinating, organizing, evaluating and directing of the R&D activities of MarAd. His past experiences include: Naval Architect for the Naval Ship Engineering Center, 1959; Deputy Chief Design Engineer for the Puget Sound Naval Shipyard, 1958 to 1959; and Naval Architect, the former Bureau of Ships, 1948 to 1958. His education is comprised of a B.S. degree from the Webb Institute of Naval Architecture, an L.L.B. degree from the George Washington University Law School, completion of the Advanced Management Program at Harvard University and current study of Transportation at the American University. He is a Registered Professional Engineer in the District of Columbia and a Member of the Bar in the District of Columbia and the State of Maryland. In addition to ASNE, his other professional memberships include the Society of Naval Architects and Marine Engineers, the Society of Aeronautical Weight Engineers and the Association of Senior Engineers of the Naval Ships Systems Command (Honorary).Search for more papers by this authorCOMMANDER L. DENNIS BALLOU, COMMANDER L. DENNIS BALLOU USN Commander L. Dennis Ballou: , USN, is the Head of the Engineering Service Office, Naval Ship Engineering Center. He is involved in computer hardware and software services to support engineering design, automatic data processing systems, design work study, and quality assurance. Prior to NavSec duty, Commander Ballou served in various billets afloat and ashore: tours on the USS Skagit and Tang; supervision of the USS Skipjack's first overhul; construction of the USS Nathanael Greene and helping to establish the Polaris overhaul program. He is a graduate of the U.S. Naval Academy, Officers' Submarine School and the Webb Institute of Naval Architecture. He holds BS and MS degrees in marine engineering and naval architecture, respectively. He has also completed many graduateSearch for more papers by this author First published: June 1971 https://doi.org/10.1111/j.1559-3584.1971.tb03628.x AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume83, Issue3June 1971Pages 36-38 RelatedInformation

A new approach to assessing the on-bottom stability of jack-up rigs during preloading is presented. A leaning Instability IS described, which may appear similar to a punch through, but is associated with soil stiffness and rig flexure. Suggestions for avoiding this instability are given. INTRODUCTION Jack-up foundation failures during preloading are generally associated with a so-called "punch through". When a strong soil layer overlies a weak layer punch through may occur. The typical example is a sand layer, or sand lens, above a weak clay. If spud can load exceeds the bearing capacity of the sand layer, the spud can will penetrate into the weaker layer. This may happen suddenly and penetration into the weaker layer may be deep. Buoyancy support on the hull may eventually prevent further spud can penetration. In soft uniform soils, where bearing capacity increases continuously With depth, punch through failures are not expected. However, there have been foundation failures in such conditions, which appear to be punch through, but cannot be explained geotechnical by the normal punch through model. Ingram & Dutt (Reference 1) describe such an event in the Gulf of Mexico in 1982. This paper describes a new method for calculating elevated stability of jack-ups during preload where spud can loads are steadily increased. It shows how unstable leaning, leading to rapid leg penetration, can occur in soft soils where punch through cannot be the failure mechanism. For the purposes of this paper, the term rapid leg penetration is used to describe leg penetration rates which are faster than the rig's jacking rate. This typically means 1.5 feet per minute. As will become evident in the paper, the speed at which events take place is a critical factor. STABILITY REQUIREMENTS Stability requirements (Operations Elevated) for Mobile Offshore. Drilling units are normally addressed by classification societies along with governmental regulatory bodies. These requirements vary from being quite extensive as pertains to Environmental Forces, Soil Particulars, Overturning moments, Air Gaps and various Safety Factors, to being Just a general statement in regards to these variables. The U.S. Coast Guard (USCG) and the American Bureau of Shipping (ABS) make a general statement in regards to operations. Elevated/Stability On Bottom. The ABS, in their publication Rules for Building and Classing Mobile Offshore Drilling Units, Section 3' Part 3.13 state : Units Resting on the Sea Bed "Units which are to rest on the sea bed are to have sufficient positive downward gravity loadings on the support footings or mat to withstand the overturning moment of the combined environmental forces from any direction. Realistic variable loads are to be considered." Underwriter-approved Marine Surveyors can provide Location Approvals for Mobile Offshore Drilling Units Operations Elevated. ' It is standard in the industry that these location approvals be based on compliance with the approved Rig Operations Manual.

Safety standards applying to the development and operation of Lockheed's subsea production system are discussed. Past and future actions to meet safety standards, and a review of performed operations with the impact of these operations on safety improvements are included. Introduction The Lockheed one-atmosphere subsea completion system, when fully developed, will comprise permanent subsea chambers and mobile service permanent subsea chambers and mobile service systems. The subsea chambers, called wellhead cellars, manifold centers, and pumping stations, will contain wellhead equipment, control systems, machinery and pumps, manifolds, instrumentation, and other equipment essential for the controlled production of oil and gas. Flowlines and control production of oil and gas. Flowlines and control cables will interconnect the subsea chambers to facilitate transport of oil and gas and transmission of control data. The service system transports men and equipment to the subsea chambers using a service capsule with a surface-connected umbilical providing electric power, life support, and other services required for work in the subsea chambers. This work initially consists of installing production and control equipment, pulling in flowlines, and testing pressure and drift, followed by maintenance, repair, pressure and drift, followed by maintenance, repair, and service of subsea chambers, production and control equipment, flowlines, and control cables. Operational hardware includes a wellhead cellar installed in the Gulf of Mexico in the summer of 1972 at a water depth of 375 ft; and a Gulf of Mexico service system based in Houma, La., used for the 1972 well installation and a subsequent routine re-entry in 1973. Several standard wellhead cellars have been engineered:non-TFL cellars (for applications not using pump-down tools),TFL cellars (for pumpdown tool application), andsplit cellars for wet tree installation. The development of the first manifold center is well under way. The manifold center is being landtested and is scheduled for installation in the Gulf of Mexico later this year. To meet the needs of the off shore industry in the North Sea area, a second service system is now being built. It is scheduled to be operational by July 1, 1976. It is the intent of this paper to discuss the safety principles of Lockheed's subsea production system principles of Lockheed's subsea production system and to describe actions already taken and safety features being implemented. Safety Standards There are a considerable number of safety regulations, standards, guidelines, principles, etc., established and controlled by several government agencies and private societies. The U. S. Coast Guard (USCG) private societies. The U. S. Coast Guard (USCG) and the U. S. Geological Survey (USGS) are examples of regulatory bodies, and the American Bureau of Shipping (ABS) and the American Society of Mechanical Engineers (ASME) are typical certifying societies. In addition, insurance companies may have specific safety requirements that must be met before insurance coverage can be obtained at reasonable rates. The design engineer, the project engineer, and the operations superintendent are responsible for compliance with all these regulations, standards, guidelines, and requirements. JPT P. 427

The general layout of 6th generation semi-submersible drilling platforms is the main factor impacting the efficiency of their drilling operations. This paper provides a compound/integrated algorithm based on process flow that is aimed at improving efficiency, while giving attention to stability and safety at the same time. The paper describes the process flow of dual drilling centers and a hierarchical division of rigs based on the different modes of transportation of various drilling support systems. The general layout-centripetal overall arrangement spatially was determined based on drilling efficiency. We derived our modules according to drilling functionality; the modules became our basic layout units. We applied different layout algorithm to mark out the upper and lower decks. That is, the upper deck was designed based on the lowest transportation cost while the lower deck’s calculations were based on the best-fit scope. Storage configurations in columns and pontoons were also considered for the layout design. Finally the center of gravity was taken into consideration and the general layout was adjusted accordingly, to result in an optimal center of gravity. The methodology of the general layout can provide a reference for implementation of domestic designs of semi-submersible rigs.

Journal of the American Society for Naval EngineersVolume 64, Issue 4 p. 869-871 THE ASSOCIATION OF SENIOR ENGINEERS OF THE BUREAU OF SHIPS DAVID J. BARRY, DAVID J. BARRY The Author Early training consisted of five years shipbuilding apprenticeship in Workman, Clark, and Company, Belfast, combined with the regular Naval Architectural Course in the Municipal College of Technology. From 1924 to 1938, he worked on hull design in Newport News S. B. and D. D. Company and Bethlehem Shipbuilding Corporation, Quincy, Massachusetts. From 1938 to date he has been in Civil Service with the Navy, Principal Naval Architect in charge of Design Arrangements until 1948, and since then Head Civilian in the Conversion Design Branch. He is a Registered Professional Engineer, a member of The Society of Naval Architects and Marine Engineers in addition to holding membership in The American Society of Naval Engineers.Search for more papers by this author DAVID J. BARRY, DAVID J. BARRY The Author Early training consisted of five years shipbuilding apprenticeship in Workman, Clark, and Company, Belfast, combined with the regular Naval Architectural Course in the Municipal College of Technology. From 1924 to 1938, he worked on hull design in Newport News S. B. and D. D. Company and Bethlehem Shipbuilding Corporation, Quincy, Massachusetts. From 1938 to date he has been in Civil Service with the Navy, Principal Naval Architect in charge of Design Arrangements until 1948, and since then Head Civilian in the Conversion Design Branch. He is a Registered Professional Engineer, a member of The Society of Naval Architects and Marine Engineers in addition to holding membership in The American Society of Naval Engineers.Search for more papers by this author First published: November 1952 https://doi.org/10.1111/j.1559-3584.1952.tb03019.x AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume64, Issue4November 1952Pages 869-871 RelatedInformation

Oil drilling and extraction platforms are currently being used in many offshore areas around the world. Whilst those operating in shallow seas are secured to the seabed, for deeper water operations, Dynamic Positioning (DP) is essential for the platforms to maintain their position within a safe zone. Operating DP requires intelligent and reliable control systems. Nearly all DP accidents have been caused by a combination of technical and human failures; however, according to the International Marine Contractors Association (IMCA) DP Incidents Analysis, DP control and thruster system failures have been the leading causes of incidents over the last ten years. This paper will investigate potential operational improvements for DP system accuracy by adding a Predictive Neural Network (PNN) control algorithm in the thruster allocation along with a nonlinear Proportional Integral derivative (PID) motion control system. A DP system’s performance on a drilling platform in oil and gas deep-water fields and subject to real weather conditions is simulated with these advanced control methods. The techniques are developed for enhancing the safety and reliability of DP operations to improve the positioning accuracy, which may allow faster response to a critical situation during DP drilling operations. The semisubmersible drilling platform’s simulation results using the PNN strategy show improved control of the platform’s positioning.

After the marine disaster of the semi submersible platform "Aleksander L. Kielland", the Norwegian Maritime Directorate (NMD) launched a number of research projects on safety of mobile offshore structures. One of these was the Mobile Platform Stability project, or the MOPS project. Seven subprojects have been carried out: Icing, Motion Response, Model Tests, Education, Estimation of Damage Conditions, Hydrostatics, and a Project Synthesis. The present paper summarizes each technical subproject, and describes in more details the proceedings made during the project synthesis. The main conclusion from the MOPS project is that the present stability regulations of NMD are adequate for the majority of the existing platform types. However, the MOPS project recommends that more rational regulations based on risk analyses, inviting technical flexibility, should be developed in order to increase the overall safety of mobile drilling units in general. INTRODUCTION The philosophy of the existing regulations regarding stability of mobile platforms is mainly adopted from the stability rules for ships. The present regulations are primarily based on hydrostatic calculations, and the environmental forces are mainly included as a steady wind heeling moment. The dynamic loads are incorporated by a safety factor. One of the main objectives of the MOPS project has been to investigate the technical validity of the present stability regulations, and one important aspect has been to study the dynamics of damaged platforms, both by theoretical means and by use of model test results. The stability regulations of today have been updated as the rig concepts have changed and as a consequence of increased offshore experience. Another main objective for the MOPS project has therefore been to suggest an outline for possible new stability regulations, allowing for technical flexibility at an early design stage, and also increased safety. The project has been carried out as a collaboration between several Norwegian research institutions. The project synthesis has been carried out after the closure of all technical subprojects. In addition to the information from the various subprojects, other projects and institutions have been consulted in order to achieve state-of-the-art. The main objectives of the project synthesis have been as follows: To draw the final conclusions from the technical work carried out in the various subprojects in relation to the stability rules for mobile offshore platforms. As far as possible give recommendations on practical use of the results as suggestions for revision of the rules. Suggest future research and development projects which can improve the safety level for mobile offshore platforms. The project synthesis has been carried out by establishing a project synthesis group, consisting of all the subproject leaders and personnel from The Norwegian Institute of Technology and the offshore industry.

The Marine Forensics Panel of the Society of Naval Architects and Marine Engineers (SNAME) grew out of analyses of the shipwrecks of the German battleshipBismarck and the passenger shipsTitanic andLusitania. It is now co-sponsored by five other professional societies on both sides of the Atlantic. A number of ship losses have been investigated, and lessons have been learned relevant both to marine technology and history.

From April through October, 1977, a series of oil spill skimmer performance tests were conducted at the United States Environmental Protection Agency's (EPA) Oil and Hazardous Materials Simulated Environmental Test Tank (OHMSETT), Leonardo, New Jersey. This program was sponsored by EPA, the Coast Guard, Navy, and Department of Energy combined as the OHMSETT Interagency Test Committee (OITC). The test devices selected were the commercially-available Oil Mop, Inc. Dynamic Skimmer, the Cyclonet 050 mounted on a Zodiac Inflatable boat, the Anti-Pollution, Inc. Clowsor Skimmer, and the Bennett Pollution Controls, LTD., Mark 6E Skimmer. A total of 198 test runs were performed during which each device was evaluated for recovery of two test oils through a wide range of simulated environmental conditions of waves and currents. The performance indicating parameters were: (1) throughput efficiency, the percentage of oil encountered which is collected; (2) recovery efficiency, the percent oil in the oil/water mixture collected; and (3) oil recovery rate, the volume of oil collected per unit time. The Oil Mop Dynamic Skimmer produced its highest average throughput efficiency (78 percent) with light oil (9 centistokes—cst) at a tow speed of 200 feet per minute (fpm) in calm water. Highest recovery efficiency (77 percent) was observed with heavy oil (3,000 cst) at 200 fpm in calm water, and maximum recovery rate was established with light oil at a tow speed of 400 fpm. The Cyclonet 050 showed its highest average performance with heavy oil (550 cst) at a tow speed of 150 fpm. Throughput efficiency was 34 percent in calm water, recovery efficiency was 27 percent in the 0.6 by 26.2 ft (height by length) wave and recovery rate was 14 gallons per minute (gpm) in calm water. The Clowsor Skimmer was tested as an advancing and stationary system. Highest average results occurred in the stationary mode with heavy oil (1,900 cst) and recovery efficiency was 91 percent. Maximum recovery rate observed was 95 gpm. The Bennett Mark 6E Skimmer performed best with heavy oil (3,200 cst). Throughput efficiency was 95 percent at a tow speed of 300 fpm, recovery efficiency was 88 percent at 100 fpm, and maximum oil recovery rate occurred at 200 fpm and was measured at 108 gpm. The general trend of performance for all devices tested showed diminishing performance with increased tow speeds and wave conditions.

There are 32 arctic offshore oil/gas projects already in operation or having confirmed development plan. Seven offshore engineering patterns have been applied, including "gravity based structure (GBS) + shipping pipeline", "subsea production system + onshore terminal", "artificial island + shipping pipeline", "jacket platform +shipping pipeline + onshore terminal", "floating platform + subsea system", "FPSO + subsea system" and "offshore oil produced from land". Gravity based structure is the most widely used production platform, followed by FPSO/FSO, subsea production system, floating platforms and artificial islands. Arctic offshore wells have been mainly drilled from anti-ice floating drilling platform, ice-resistant fixed drilling platform and artificial island. In future, arctic petroleum exploration & production will move to deeper water area; natural gas development will play more important role. In arctic offshore E&P area Tremendous facilities and technologies will be developed and applied, including anti-ice floating concrete Spar, fully enclosed production platform, "subsea factory", round semi-submersible drilling platform, seafloor drilling rig, GBS LNG facility, free hanging solid ballast semi (FHSB Semi) platform and so on. Advantages & disadvantages, application conditions of main arctic offshore engineering patterns, facilities & technologies are described, which shall be helpful for arctic project investment opportunity study, screening and evaluation.

In this paper, we outline a risk-based decision-making (RBDM) approach for, and some examples of, review of novel concepts for gas transportation and handling. In its more complex applications, an RBDM review process may call for full-scale application of risk assessment methodologies, including quantitative frequency assessment, detailed consequence analysis, and comprehensive risk evaluation. However, at the novel concept stage, there is generally not enough information to provide the input those methods require. This paper addresses performing the kind of review needed at early stages in development of a conceptual design. The basis for an effective RBDM application is to perform as little analysis as is necessary to provide the information needed by decision makers. This leads to very focused risk analysis efforts, including the use of approaches such as change analysis, relative ranking, and other qualitative techniques in many cases. If required, more detailed quantitative studies can be performed; however, this is seldom necessary (or even possible) at the conceptual stage. Those studies are reserved for when they are more valuable (i.e., when detailed engineering efforts have developed adequate information to consider). The process outlined in this paper is consistent with the United States Coast Guard's (USCG's) Risk Based Decision-Making Guidelines [1.] (referred to as the RBDM Guidelines) that was documented for the USCG by ABSG Consulting Inc. (ABS Consulting). The specific novel concept process is documented in the American Bureau of Shipping's Guidance Notes on Review and Approval of Novel Concepts [2] (referred to as the Novel Concepts Guide). Introduction The development of deepwater gas resources is an on-going process involving innovative solutions to to develop, produce, process, transport, and handle natural gas. In many cases, these approaches involve "novel concepts," which are defined as applications or processes that have previous experience in the environment being proposed. In working with novel concepts these classes of concepts have been defined:Existing design / process / procedures in new or novel applicationsAn example of this could be a proposed first use of an existing onshore technology (e.g., a chemical process or storage medium) on floating structures.Existing design / process / procedures challenging the present boundaries/envelope of current offshore or marine applicationsAn example of this could be a proposed use of an existing type of floating structure, typically only used for drilling and processing hydrocarbons that would also include hydrocarbon storage.An example of this could be a new type of offshore floating structure that has not been used before in the industry.New or novel design / process / procedures in new or novel applicationAn example of this could be a proposed use of a new technology application such as the use of a new hydrocarbon process on a new type of floating structure. Novel concepts are not inherently more risky, in fact, in many cases, they may prove in operation to pose less risk than prior technologies.

This article is intended to provide a basic understanding and overview of the critical factors controlling habitability noise onboard vessels. It is intended to assist the marine community—shipyards, naval architects, marine engineers, regulators, and owners—in addressing issues and important design parameters related to generation and control of shipboard noise. It includes a description of noise‐generating mechanism, specifics on noise sources in ships, information regarding noise transmission through the hull structure, an overview of methods used for noise analysis, and noise control during the design stage or during modernization. There is a discussion of inspection and compliance testing. With the proper understanding of how noise is generated, controlled, and measured, ships can be delivered to various noise criteria in a straightforward, economic, and optimal manner.

Towing tank tests in calm water were performed on a trimaran planing hull to verify its navigational properties with different displacements and centres of gravity, as well as to assess the effects of air jets and bilge keels on the hull’s planing capabilities, and to increase the longitudinal stability of the hull. Hydrostatic roll tests, zero speed tests, and sea trials in the presence of regular waves were conducted to investigate the hull’s seakeeping ability. The test results indicate that the influence of the location of the centre of gravity on the hull resistance is similar to that of a normal trimaran planing hull; namely, moving the centre of gravity backward will reduce the resistance but lower the stability. Bilge keels improve the longitudinal stability but slightly affect the resistance, and the presence of air jets in the hull’s channels decreases the trim angle and increases heaving but has little effect on the resistance. Frequent small-angle rolling occurs in waves. The heaving and pitching motions peak at the encounter frequency of , and the peaks increase with velocity and move towards greater encounter frequencies. When the encounter frequency exceeds, the hull motion decreases, which leads to changes in the navigation speed and frequency.

Physical properties and roll decay of David Taylor Model Basin (DTMB) Model 5720, a 23rd scale free running model of the research vessel (R/V) Melville, are documented with uncertainty estimates. Properties include mass, vertical center of gravity (VCG), longitudinal center of gravity (LCG), and transverse center of gravity (TCG), and moments of inertia (MOI) for roll and pitch, transverse metacentric height (GMT), and natural roll period, Tn. Previous analysis has been expanded with additional details and uncertainty estimates. Results are based on measurements with the latest technology. The significant results for model properties are as follows: length 3.3652 ±0.0010 m (±0.030 %), mass 233.21 ±0.46 kg (±0.20 %), LCG 1.6061 ±0.0011 m (±0.067 %) aft of bow, VCG 0.2640 ±0.0017 m (±0.63 %) above keel, GMT 47.76 ±0.61 mm (±1.3 %), roll radius of gyration 0.2329 ±0.0042 m (±1.8 %), and pitch radius of gyration 0.8434 ±0.0024 m (±0.28 %). The roll period in calm water was independent of the Froude number (Fr) and initial roll angle (a). At Fr = 0, 0.15, 0.22, the average roll period was 2.2298 ±0.0040 s (±0.18 %) for 76 runs, all Fr, and all initial roll angles. The initial roll angle variation was 3° to 25°. The natural roll period was 2.139 ±0.041 s (±1.9 %). The decay coefficient data were accurately approximated by a plane in three dimensions with Fr and initial roll amplitudes (a) as the independent variables. Examples are provided that show the average values for a single roll decay event from the logdecrement method are the same as the values by the curve fitting method within the uncertainty estimates.

Mathematical modeling of planing hulls and determination of their characteristics are the most important subjects in hydrodynamic study of planing vessels. In this paper, a new mathematical model has been developed based on pressure distribution. This model has been provided for two different situations: (1) for a situation in which all forces pass through the center of gravity and (2) for a situation in which forces don not necessarily pass through the center of gravity. Two algorithms have been designed for the governing equations. Computational results have been presented in the form of trim angle, total pressure, hydrodynamic and hydrostatic lift coefficients, spray apex and total resistance which includes frictional, spray and induced resistances. Accuracy of the model has been verified by comparing the numerical findings against the results of Savitsky's method and available experimental data. Good accuracy is displayed. Furthermore, effects of deadrise angle on trim angle of the craft, position of spray apex and resistance have been investigated.