Progress of the Research on Motion Performance of

Ship Surface Towing System

 

LIU Yan-min^1,2, XING Fu^1,2, ZHOU Jia^1,2

(1. China Ship Scientific Research Center, Wuxi 214082, China;

2. State Key Laboratory of Deep-Sea Manned Vehicles, Wuxi 214082, China)

 

Abstract: This paper reviews the progress of the research on the motion performance of ship surface towing system, and categorized them into three methods, i.e. empirical formula and diagram method, experimental method and numerical simulation method. The technological status regarding the calculation methods for towing forces, the experimental techniques of the towing system, the hydrodynamic loads and motion of the tugs and the maneuvering simulation methods for the towing system are elaborated, which may provide references for study of the motion performance of towing system.

Key words:surface towing system; motion performance; empirical diagram; tank experiment; numerical simulation

 

 

 

Experimental Study on Fatigue Behavior of Grouted Connections under Bending Moment in Monopile Offshore Wind Turbines

 

WANG Xian¹, CHEN Tao¹, YUAN Guo-kai², LIU Jin-chao²

（1.Department of Structural Engineering, Tongji University, Shanghai 200092, China；

2. China Energy Engineering Group Guangdong Electric Power Design Institute Co., Ltd., Guangzhou 510663, China）

 

Abstract: This paper presents the test results of five cylindrical monopile grouted connection specimens with shear keys, which have the same external diameter of 612 mm but different lengths of 4365 mm, 4475 mm, and 4585 mm. The specimens are tested under a constant range of fatigue cyclic bending moments, where the load ranges are established on the ultimate bending capacity of each specimen. It leads to the result that the grouted connection can survive two million load cycles without obvious degeneracy in bending capacity although local degradation exists, and the residual displacement could be negligible after the test. Nevertheless, some test procedures stopped as the longest specimen has the welded structure cracked due to the maximum load they had after approximate 1.28 million load cycles carried out, but no destruction was found in the grouted connection. Furthermore, the specimens of different lengths are compared. It is found that the minimum length of the specimen specified in the common design rules for grouted connections with shear keys is somewhat conservative.

Key words: offshore wind turbine; monopile foundation; grouted connection; fatigue under bending moment; shear keys

 

 

 

Comparative Study on the Performance of Tensioned and Semi-Tensioned Mooring Systems for a SPAR Platform

 

KANG Zhuang¹，FU Sen¹，YUAN Hong-tao²，WANG Yu-han²

(1. College of Shipbuilding Engineering, Harbin Engineering University, Harbin 150001 China;

2. Shanghai Waigaoqiao Shipbuilding Co., Ltd., Shanghai 200137, China)

 

Abstract: This study focuses on the tensioned and semi-tensioned mooring systems used for the operation of SPAR platform. The dynamic response characteristics, forces and displacements of the two mooring systems are compared under the same initial vertical force conditions. The result shows that the tensioned mooring system performs better than the semi-tensioned one in terms of displacement and drift motion control.

Key words:SPAR platform; semi-tensioned mooring; tensioned mooring; scheme comparison

 

 

 

Effect of Hogging Correction on the Lightweight of

170000m³ LNG Carriers

 

YU Xin, WENG Zhen-yong, WU Si-wei, CHEN Sheng-lan, YANG Chun-hua

（Hudong-Zhonghua Shipbuilding (Group) Co., Ltd., Shanghai 200129, China）

 

Abstract: Taking the 170000m³ series Liquefied Natural Gas (LNG) carriers as the research object, this paper analyzes the effect of hogging correction on ship’s lightweight in consideration of the hogging phenomenon happened in the inclining test/deadweight measurement test and the calculation result from NAPA. The result shows that the lightweight calculated with Simpson’s second method is closer to that of the real ship compared with the correction coefficient method.

Key words:170000m³ LNG series carriers; hogging correction; lightweight; correction coefficient method; Simpson’s second method

 

 

 

Strength Analysis on the Tank Structure of a Type B LNG Carrier

 

ZHANG Yu-kui, ZHENG Wen-qing

（Marine Design and Research Institute of China, Shanghai 200011, China）

 

Abstract: This paper performed strength analysis on the tank structure of a 170000m³ Liquefied Natural Gas (LNG) carrier with type B cargo containment system. A feature of the ship is its liquid tanks are self-supporting and connected to the hull only by means of the seat. To ensure the safety of LNG cargo, the finite element method is adopted to check the structure strength of the liquid cargo tanks in accordance with the requirements of American Bureau of Shipping (ABS) to determine the high stress regions that require major attention, to provide suggestions for optimization and to obtain the distribution characteristics of the seat supporting forces.

Key words:LNG carrier; type B cargo containment system; finite element method; strength

 

 

 

Computational Analysis on the Vibration and

Structure Strength of Aluminum Alloy Mast

 

WANG Zao-chun, MA Xiao-feng, CHEN Ji

（Hudong-Zhonghua Shipbuilding (Group) Co., Ltd., Shanghai 200129, China）

 

Abstract: Taking the mast of a refitted ship as example, a finite element analysis is performed on the vibration and structure strength of the truss type aluminum alloy mast under different conditions to elaborate the general method for the strength check and vibration prediction of this type of mast, which provides the theoretical basis for the design and application of the mast structure. The computational method can provide reference for the finite element analysis of other truss type masts.

Key words:aluminum alloy mast; truss type structure; strength and vibration computation; finite element analysis

 

 

 

Escape Channel Design for Passenger Ships

 

XU Rong

(Shanghai Merchant Ship Design and Research Institute, Shanghai 201203, China)

 

Abstract: Passenger ship design must include escape channels which enable the people on board to evacuate to the lifeboat and life raft embarkation area safely and swiftly. The International Maritime Organization (IMO) continuously updates and complements the rules and regulations to improve and optimize the escape channel design system for passenger ships. This paper elaborates the major rules, regulations, resolutions and communications related to the escape channel design and introduces the escape channel design of the ARANUI 5 luxury passenger ship, with a detailed discussion on the key design points for the accommodation area and the service area.

Key words:passenger ship; passenger-cargo ship; escape; escape channel

 

 

 

General Design of the Semi-Submersible Barge

with 10000t Lifting Capacity

 

WANG Hui

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

 

Abstract: This paper analyzes and introduces the general design of a semi-submersible barge with 10000t lifting capacity from the aspects of the determination of main dimensions, the general arrangement and structural design, and the designs for anchor mooring system and ballasting system, which provides reference for the design and development of subsequent ships of the same type.

Key words:semi-submersible barge; main dimensions; anchor mooring system; ballasting system; general design

 

 

 

Application of Power Station Protection and Power Management Module in Offshore Platform

 

YU Dong-liang，CHU Wei

(Shanghai Waigaoqiao Shipbuilding Co., Ltd., Shanghai 200137, China)

 

Abstract: Based on the hardware of the power station management system and the traditional power stations in an offshore platform, this paper introduces the way to realize the control and management of power station with DEIF company’s Protection and Power Management-3 (PPM-3) module. The main functions of PPM-3 are introduced, including the power station protection, power distribution and power station automation. The new application of PPM-3 in offshore platform power station is also briefly introduced.

Key words:offshore platform; power station management system; PPM-3; power station automation

 

 

 

Robotic Milling and Grinding System for Marine Propellers

 

LI Ming, YANG Pei-pei

(Shanghai Marine Diesel Engine Research Institute, Shanghai 201108, China)

 

Abstract: This paper studies the robotic milling and grinding system for marine propellers and elaborates the system composition, system principles and key technologies. The propeller blade shape parameters are obtained with the photographic 3D scanner, and then the data is fitted to create the 3D blank model of the propeller. A professional software is used to compare the blank model with the target model and to draw the cutting curves, so as to achieve the optimal cutting amount. After that, the data is transferred to the robotic system where the milling and grinding program is generated for the robot to mill and grind the propeller with the optimal cutting amount. This robotic milling and grinding system can solve the problem of interference between blades when the whole propeller is under grinding, and avoid the defect of low quality of manual grinding, which is very important for the fast and high quality manufacturing of the whole propeller.

Key words:whole propeller; robot; milling and grinding;photographic 3D scanning

 

 

 

Fixing of Grounding Screws

Based on Gunpowder-Driven System

 

ZHU Wan-lin¹，LI Ji¹，MENG Xiang-ting¹，GAO Ji-ning²

（Offshore Oil Engineering Co., Ltd., Tianjin 300450, China）

 

Abstract: Comparison shows that the system grounding fixation by welding is simple and cost-effective, but it will damage the coating and is labor-intensive, while gunpowder-driven installation can easily realize a rapid grounding point fixation with less work-load. It can effectively reduce the working procedures and significantly increase the work efficiency. Compared with traditional fixed branch cable method, this method is convenient and flexible. It can greatly reduce raw materials and eliminate the procedures of anti-corrosion and welding. The experiment result demonstrates that the gunpowder-driven method has large advantages in reducing workload, work procedures and overall cost, compared with traditional grounding fixation method.

Key words:grounding point; gunpowder-driven; direct fastening; grounding screw; nailing connection; quick installation

 

 

 

Research and Application of LNG Subsea

Cryogenic Pipeline Technology

 

YANG Liang¹，LIU Yun²，LIU Miao-er¹，XU Jia-wei¹，FAN Jia-kun¹

（1. Research and Development Center, CNOOC Gas & Power Group Co., Ltd., Beijing 100028, China；

2. CNOOC Research Institute Ltd., Beijing 100028, China）

 

Abstract: The subsea cryogenic pipeline technology has emerged to conform to the trend that Liquefied Natural Gas (LNG) receiving terminals are moving to offshore. Considering the engineering cost and the technological feasibility, the LNG subsea cryogenic pipeline system is superior to the trestle pipeline system. As LNG storage and transportation requires low temperature, there are higher requirements on the subsea cryogenic pipeline than the land based cryogenic pipelines regarding structure composition, pipeline material, thermal insulation materials, pipeline axial stress absorbing devices, detection system and constructions. Researches are carried out and the result shows that the requirements on practical application of the LNG subsea cryogenic pipelines could be met when 9% Ni steel is used as the inner pipe material, aerogel is used as the thermal insulation layer, the fender technology is adopted to overcome the axial stress on the pipeline and the optical fiber sensing technology is introduced to monitor the pipeline operation status in real time.

Key words:liquefied natural gas; subsea cryogenic pipeline; axial stress; aerogel; online leak monitoring

 

 

 

The Re-Socketing Technology for Anchor Leg

 

YU Jin-lin, GAO Yuan, ZHANG Ren-gong, LIU Zhen-fei, LIU Song, LI Dong-sheng

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

 

Abstract: This paper introduces the project background and technical difficulties, select the appropriate equipment, detailedlydescribe calculate anchor leg cutting point, wire cleaning, re-socketing procedure and the test of the sample. Besides, it introduces possible risks in the process of actual construction, combining with theoretical analysis and taking effective measures to cope with the situation, so as to safely and efficiently complete the wire re-socketing operations.

Key words:select the appropriate equipment; calculate cutting point; wire cleaning; re-socketing; sample test

 

 

 

Innovating Progress Mode to

Promote Shipbuilding Modeling 2.0

 

WENG Hong-bing¹, QIE Jin-bo²

(1. Hudong-Zhonghua Shipbuilding (Group) Co., Ltd., Shanghai 200129, China;

2. Shanghai Shipbuilding Technology Research Institute, Shanghai 200023, China )

 

Abstract: In order to speed up the modernization of shipbuilding, China State Shipbuilding Corporation (CSSC) put forward the strategy of “modern shipbuilding mode 2.0” in 2016 and decided to implement it as the programmatic document that guides the company’s shipbuilding modeling in the next ten years. As a response, Hudong-Zhonghua Shipbuilding (Group) Co., Ltd. quickly started the deployment to promote the modeling 2.0 through setting up organizations, conference platform, management system and key tactics, which has led to fruitful outcomes.

Key words:shipbuilding modeling 2.0; intermediate product integrity; refined work dispatching; new technique and technology; business process management