Joint Operation of Tension Leg Platform

Assisted by Drilling Tender Vessels

 

DU Zhong¹, LIU Yong-gang¹, BI Tie-man¹, LI Wei¹, WANG Jin-guang²

(1. Dalian Shipbuilding Industry Co., Ltd., Dalian 116000, China;

2. Technip MHB Hull Engineering Sdn. Bhd, Kuala Lumpur 50400, Malaysia)

 

Abstract: This paper introduces the major advantages and service conditions of joint drilling operation supported by drilling tender vessels. Based on the application of drilling tender vessels on the tension leg platform, the challenges and major precautions to be considered in the early design stage for the multibody coupling mooring system in operation are summarized. This study demonstrates that the floating body selection in the concept design stage should consider the overall economical efficiency and applicability of the tender assist drilling operation mode.

Key words:Drilling Tender Vessel (DTV); Tension Leg Platform (TLP); Tender Assist Drilling (TAD); multibody coupling mooring system

 

 

 

Shallow Water Effect on Ships and

Its Empirical Calculation Method

 

ZHANG Wei

(Wison Offshore & Marine Limited,Shanghai 201210, China)

 

Abstract: When sailing from deepwater into restricted sea routes in shallow waters, inland rivers and port areas, ship always encounters the shallow water effect caused by limited channel dimensions, which will affect ship's navigation safety and maneuvering performance. This paper analyzes the concept of shallow water effect, its occurrence conditions and its influence on navigation safety. The empirical formula commonly used for estimating the sinkage and the resistance-added is introduced to quantitatively analyze the shallow water effect. The empirical calculation method can help the captain respond quickly when his ship encounters shallow water effect, thus ensuring safe navigation.

Key words:shallow water effect; channel limitation; sinkage and change of trim; resistance increase; UKC; empirical formula method

 

 

 

Application of Cycloidal Propeller on

Scientific Research Vessels

 

ZHANG Hong-bing

(Shanghai LingYao Marine Engineering Co., Ltd., China Ship Development and Design Center, Shanghai 201108, China)

 

Abstract: This paper elaborates the propulsion principles of cycloidal propeller, its performance advantages and the application practice based on the model experiments of a survey ship and a law enforcement ship. The actual application onboard an ocean-going fishery resource survey vessel showed that the ship's maneuvering performance with cycloidal propeller is better than that of the conventional propellers, and the excellent roll stabilization effect is achieved. Cycloidal propeller is suitable for ships requiring high maneuverability and high sea-keeping performance. It would have good application prospect for ocean-going scientific research vessels and offshore support vessels.

Key words:cycloidal propeller; powering performance; maneuverability; seakeeping; research vessel

 

 

 

General Arrangement Design of 5000t Pipe Laying and Crane Vessel

 

GAO Fei, HU Min

(Shanghai Bestway Marine Engineering Design Co., Ltd., Shanghai 201612, China)

 

Abstract: In order toenhance the ability of marine rescue and salvage, a self-propelled lifting & pipe-laying vessel is designed with the capacity of 3000m deep-water pipe laying and 5000t full revolving lifting. This paper introduces its design principles, general arrangement, key technologies and systems.

Key words: lifting system; pipe laying system; dynamic positioning system; cabin division

 

 

 

Influence of Initial Welding Imperfections on the Ultimate Strength of Offshore Platform Lateral Brace

 

CUI Zhen, CHEN Zhen

(State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai 200240, China)

 

Abstract: To investigate the influence of initial welding imperfections on the ultimate strength of offshore platform structures, the thermal elasto-plastic finite element method is used to simulate the welding process of lateral braces on a semi-submersible offshore platform with different welding sequences, so as to obtain the residual stress and deformation of the structure. On this basis, the Riks method is used to calculate the ultimate strength of the lateral braces under axial compression in account of the initial welding imperfections. The results from the two different welding sequences show that the difference of axial compression loads which lead to local bulking of the lateral brace is about 11%; and the buckling compression load with the initial welding imperfects is about 18.45% which is smaller than that under perfect conditions. As the structure is of high overall stiffness, the initial welding imperfections and welding sequences have little effect on the ultimate strength of the structure.

Key words:welding sequence; welding initial imperfection; lateral brace; ultimate strength

 

 

 

The Technology for Self-Floating Cofferdam Underwater

 

FU Fang-chao, CAI Chang-song, HAO Jing

(COOEC Subsea Technology Co., Ltd., Shenzhen 518067,China)

 

Abstract: A method of cofferdam installation is proposed for the repair of hull structure with FPSO (Floating Production Storage and Offloading) unmoved in place to keep the production unstopped and to provide data for the certificate of ABS (American Bureau of Shipping). The underwater loads of the cofferdam are analyzed, and its structural strength is verified so that proper structure forms can be designed and make the underwater operations easier for the divers. Successful application of the underwater self-floating cofferdam technology also makes it possible for the repair of outer plate longitudinal stiffeners with production unstopped. This technology is appropriate for the structural repair of FPSO, FSO (Floating Storage and Offloading) and other ship types so as to reduce the frequency of ship docking, realizeuninterrupted production and save the repairing cost in dock. It can also realize the underwater hull structure repair without water-back welding.

Key words:FPSO; self-floating; cofferdam; non-stop production; water-back welding

 

 

 

An Analysis on the Holding Capacity of

Marine Steel Anchors in Fine Sand

 

LI Shuan¹, NI Fu-sheng^1,2, YUAN Wan-qing¹, XU Li-qun^1,2, SHI Shun-kai¹

 (1. Department of Mechanical and Electrical Engineering, Hohai University，Changzhou 213001, China；

2. Engineering Research Center of Dredging Technology, Ministry of Education, Changzhou 213001, China)

 

Abstract: In order to investigate the holding capacity of marine steel anchors, the Flipper Delta anchor is used as the prototype to design an anchor model with 1:5 scale ratio for anchor dragging experiment in fine sand under different inclination angles. The experiment result shows that the inclination angle of anchor has large influence on the holding capacity, the gnaw depth in soil and the dragging distance. When the inclination angle is 35°, the holding power coefficient of Delta steel anchor can reach 13, which indicates that the Delta steel anchor has a good holding performance.

Key words:steel anchor; holding power; holding performance in soil; inclination angle of anchor

 

 

 

The Construction Equipment for Offshore Foundation

Reinforcement Based on Deep Mixing Method

 

XIE Ji-wei

(China Railway Engineering Machinery Research & Design Institute Co., Ltd., Wuhan 430066, China)

 

Abstract: This research uses the deep mixing and reinforcement technology to develop a new type of marine construction equipment tailor-designed for offshore foundation reinforcement with an engineering ship as the carrier. The equipment is capable of large depth reinforcement and multiple pile-forming in one mixing, and has the function of pile-forming dispersion adjustment, which can realize not only the discrete mixing pile reinforcement for underwater foundations with adjustable spacing, but also the continuous wall-forming reinforcement underwater.

Key words:offshore foundation reinforcement; deep mixing method; four-shaft and one-jet; discrete reinforcement; continuous reinforcement

 

 

 

Design of Induced Ventilation System Distributed in Engine Room

 

YANG Yong

(CSSC Cruise Technology Development Co., Ltd., Shanghai 200439, China)

 

Abstract: Distributed layout of induced ventilation fans can realize accurate control of engine room equipment and ventilators to meet the requirements for intelligent control and energy saving. This paper introduces the design of induced ventilation system distributed in the engine room, including calculation of blowing rate for the equipment in the engine room, design and calculation of the induced jet nozzle, and selection of the induced ventilation fans. The advantages of distributed induced ventilation system are evident when compared with the conventional ventilation systems for engine room, which provides reference for the engine room ventilation design.

Key words:engine room induced ventilation; distributed induced ventilation fan; jet nozzle; air distribution

 

 

 

Geometric Element Design of Large Full Spade Rudder

 

GUAN Qing-xiang, WANG Hai-bo, ZHANG Li

(Merchant Ship and Offshore Design and Research Institute,

Dalian Shipbuilding Industry Design & Research Institute, Dalian 116005, China)

 

Abstract: This study deduces the mathematical expressions of rudder force, rudder torque, rudder stock diameter and rudder trunk diameter for full spade rudders on the basis that the rudder trunk inserting depth ratio with rudder blade height and the rudder blade aspect ratio are taken as variables. The preferred rudder geometric elements such as rudder trunk inserting depth ratio and aspect ratio are determined according to the function property, the extreme values of the function and the function curves. This method can serve as the design reference basis for large full spade rudders.

Key words:full spade rudder; aspect ratio; rudder trunk inserting depth ratio

 

 

 

Design of Hydraulic Jack Lifting Salvage Ship

 

LI Bing¹, LIU Yu-kun²

（1. Shanghai Bestway Marin Engineering Design Co., Ltd., Shanghai 201612, China;

2. Yantai Salvage Bureau of the Ministry of Transport, Yantai 264012, China)

 

Abstract: This paper introduces the design of a hydraulic jack lifting salvage ship, elaborates traditional salvage methods and the principles and pros and cons of the hydraulic jack lifting salvage method, and demonstrates the general arrangement and positioning system of the 12000t lifting salvage ship, to provide reference for the development and design of similar ship types.

Key words:salvage ship; hydraulic jack; lifting; general arrangement; positioning system

 

 

 

Design of Expansion Bending Loop for Marine Pipes

 

CAO Yun, SHAO Kai

（New Century Ship Design & Research (Shanghai) Co., Ltd., Shanghai201203, China)

 

Abstract: This paper proposes a check method for design of expansion bending loop based on the analysis of the factors that cause ship deck pipeline deformation. The method simplifies the hull deformation caused by transferred loads into the maximum deflection at the free end of a cantilever beam under the concentrated load, and adds to it the maximum deformation of the pipeline under extreme temperature difference during operation. The result obtained is compared with the pipeline material's maximum allowable elastic deformation to determine whether the expansion bending loop design can meet the requirement. On this basis, the reference values for common pipeline expansion bending loop design are put forward.

Key words:ship pipeline arrangement; expansion bending loop; deformation

 

 

 

Fuel Injection Technology for Marine Low Speed Diesel Engine

with Self-Owned Brand

 

WEN Li-ming, ZHANG Zhi-yong

(China Shipbuilding Power Engine Institute Co., Ltd., Shanghai 200120, China)

 

Abstract: As an example of Electronic Fuel Injection（EFI）technology applied on low speed engines, the latest developed electronic high pressure common rail fuel injection technology is applied to the self-designed and self-developed “HHM-6EX340EF” small bore diesel engine. This paper elaborates in detail the basic structure, the working principles, and the results of experiments and integrated engine test. It shows that the engine meets Tier II emission requirements and the fuel consumption rates at some load points are slightly better than other engines with equivalent power.

Key words:low speed engine; electronically-controlled; high pressure common rail; fuel injection

 

 

 

Research on Shipbuilding Berth Pulling Technology of

Subsea Supply Vessel

 

YIN Long, YU Fu-you, SUN Ming-yuan

（COSCO Shipping Heavy Industry (Dalian) Co., Ltd., Dalian 116113, China)

 

Abstract: Taking a subsea supply vessel (SSV) as the example, this paper proposes a tandem construction method in berth with pulling technology in order to solve the problem of limited berth space. The technical difficulties regarding the pulling and skidding technology are solved via research, which ensures the successful implementation of the tandem construction and pulling of the SSV project. The successful application of the proposed pulling technology can significantly improve shipyards’ delivery ability and berth efficiency.

Key words:tandem shipbuilding method; pulling technology; skidding technology

 

 

 

Procedure of Pressure Measurement for

Air Cushion Vehicle

 

YUAN Chao, SUN Hong-kun

（Naval Representative Office in Guangzhou Region, Guangzhou 510260, China）

 

Abstract: The pressures of air cushion, air sac and air passage are measured accurately for the air cushion vehicle. As there isn’t established pressure measurement regulation for air cushion vehicles at present, this study discusses the pressure measurement procedures for air cushion vehicles based on the features and actual measurement operations, so as to propose the basic requirements on the measurement conditions, systems and procedures. The air cushion, air passage and air sac pressure measurement of an air cushion vehicle under different loading conditions and cushion working conditions have been successfully completed based on the proposed requirements.

Key words:air cushion vehicle; pressure measurement; basic requirement

 

 

 

Measurement of Production Resources Capacity of Shipbuilding Enterprises

 

JIN Yu-heng

（Shanghai Waigaoqiao Shipbuilding & Offshore Co., Ltd., Shanghai 201306, China)

 

Abstract: In order to improve the management level and increase the profit of shipbuilding enterprises, it is necessary to study the management of production site resources. Therefore, the production site resource capacity is studied according to the actual practice of shipbuilding enterprise’s production site resource management, and the shipbuilding enterprise production site resource management methods are developed via the studies of rational division of production site function, the assembly jig frame capacity measurement, the block storage site capacity measurement and so on.

Key words:production site; site capability; assembly jig frame; block storage site