Protection of Bridge Piers Against Ship Collision

in Deep Water Channels

 

CHEN Guoyu

（Shanghai Ship and Shipping Research Institute, Shanghai 200135, China)

 

Abstract: This paper analyses the “anti-ship-bridge-collision” methods used in the past 30 years to solve the problem of protecting bridge piers against ship collision caused by 50000 to 100000 tonnage ships sailing in Yangtze River downstream channels, Ling Ding Yang Channel of the Pearl River estuary, Hu Men Channel, Zhan Jiang Bay Channels, Xiang Shan Port channel and the channels between some costal harbors and islands. The analysis comes to a conclusion that indirect anti-collision devices could be used when the water is shallow or there are rocks; and direct anti-collision devices should be chosen if the water is deep. The “flexible anti-collision device with a steel wire ring to support the steel periphery of piers” is a kind of direct anti-collision device. Compared with other existing devices, this new device can reduce the collision force acting on the bridge piers, double increase the pier’s collision resistance ability, and protect both the bridge and the ship at the same time. In addition to this, the device has a long service time without obstructing the channels. It has already been applied to bridges in Zhan Jiang Bay and Xiang Shan Port, where 50000 tonnage ships pass through.

Key words:deep water channel; direct anti-ship—bridge-collision device; collision force on bridge pier; steel wire anti-collision ring; steel periphery; flexible anti-collision device

 

 

 

Hydrodynamic Load and Structural Analysis of a Fin Stabilizer

Based on Fin Shell Model

 

WEI Jianqing¹, CAO Anxi^2a, JIN Yongxing^2b, FU Chongbo^2b

(1. Shanghai Composites Science & Technology Co., Ltd., Shanghai 201112, China;

a. Marine Science and Engineering College; b. Merchant Marine College;

Shanghai Maritime University, Shanghai 201306, China)

 

Abstract: In order to improve the efficiency and accuracy of fin stabilizer simulation, a shell model for the fin is established based on the ANSYS Workbench-component systems, and the fluid-structure interaction analysis is performed by combining Fluent with ANSYS. Fluent is used for the hydrodynamic analysis of the fin to obtain its lift and drag forces in the flow field; and the fin structural response analysis is then performed by applying these forces to the solid body elements and the shell elements of the fin structure. The result shows that the finite element analysis of the fin structure based on the shell model needs less modeling work and less computation time but provides higher simulation accuracy when compared with the solid body model. For fins, it is more suitable to use the shell model for finite element analysis both from the structural and mechanical property point of view.

Key words:shell model; fin stabilizer; fluid-structure interaction; finite element analysis

 

 

 

Hydrostatic Pressure Test Technology for

Deep-Sea Equipment

 

ZHANG Hailong, ZHONG Guorui, ZHU Zhiwei

（Institute of Deep-Sea Science and Engineering, CAS, Sanya 572000, China)

 

Abstract: Traditional hydrostatic pressure test methods for ocean equipment can no longer meet the demand of ocean equipment development today as there were some problems encountered in the tests. This paper briefly introduces the hydrostatic pressure test device and methods for deep-sea equipment in China, and analyzes how to select technical parameters for the hydrostatic pressure test including test pressure, test duration under pressure, pressurization and relief rate. The procedures for deep-sea high-pressure hydrostatic pressure test are summarized based on three typical test examples, and the problems existing in deep-sea equipment hydrostatic pressure test are discussed, which provides support for the hydrostatic pressure test standards of deep-sea equipment.

Key words:hydrostatic pressure test; pressure cylinder; test pressure; pressure coefficient

 

 

 

Design and Application of Derrick Stress Test Tooling for

Offshore Workover Rig

 

ZHANG Shichao

（CNOOC Safety Technology Services Co., Ltd., Tianjin 300450, China)

 

Abstract: Tooling is a necessary auxiliary loading device for derrick stress test of offshore workover rigs, whose structural form and bearing capacity will directly affect the safety and efficiency of the stress test of the derrick. In order to develop a derrick stress testing tooling with strong universality, the main structure forms of offshore workover rigs in service are investigated, and two working conditions of the tooling are calculated and analyzed with the ABAQUS finite element software according to the standard stress test requirements. The analysis results show that the maximum stress of the tooling is 260.9MPa which meets the strength requirement; the maximum deformation is as small as 3.37mm . Field application shows that the designed tooling can meet the requirement of field derrick stress test, which is convenient to use and is of good applicability.

Key words:workover rig; derrick; tooling; stress test; finite element software ABAQUS

 

 

 

Conversion Design of a Multipurpose Ship with Large Opening

 

MA Min, JIN Yangbo

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

 

Abstract: In order to meet ship owners’ demand of carrying extra-long cargoes to raise ships’ competitive ability, a conversion design is accomplished for a 17300t multipurpose ship with large opening, where the ship length is increased while the breadth, depth and twin cargo tanks of the original design remain unchanged. Meantime the watertight subdivisions are adjusted and the watertight opening interpretation for Dutch flag ships is well adopted to comply with the damage stability requirements. The ship structure is properly designed with finite element analysis method, and the carrying capacity is guaranteed by lightweight control, despite of increased global bending moment.

Key words:multipurpose ship with large opening; general conversion design; damage stability; structural optimization design

 

 

 

Seal Technology of Stern Shaft for Deep-Sea Manned Submersible

 

XU Ke¹, CAO Haijian², WANG Rui¹, FAN Huatao¹

(1. State Key Laboratory of Deep-sea Manned Vehicles, China Ship Scientific Research Center, Wuxi 214082, China;

2. Dongtai Marine Fittings Co., Ltd., Dongtai 224200, China)

 

Abstract: Stern shaft sealing device is the key equipment to determine the technical feasibility of the shaft passing through the compressive cabin of deep-sea manned submersible. This paper analyzes the composition and arrangement of the shafting for deep-sea manned submersible and also the composition and working principle of the conventional stern shaft sealing device; summarizes the technical scheme of the stern shaft sealing device and its enclosed cooling water system; then proposes the technical scheme of the test system for stern shaft sealing device. The evaluation of the technical scheme proves that the seal technology of the stern shaft for manned submersible is feasible.

Key words:high submergence depth; manned submersible; stern shaft sealing device; end face seal

 

 

 

Application of Improved Composite Weight TOPSIS Method

in Comprehensive Evaluation of Ships

 

ZHANG Mingxia¹, JIANG Zhelun¹, XU Xiaoli²

(1. School of Naval Architecture and Ocean Engineering, Dalian University of Technology, Dalian 116024, China;

2. China Shipbuilding Industry Corporation Economic Research Center, Beijing, 100120, China)

 

Abstract: To solve the problems existing in traditional multi-object evaluation of ship performance, the composite weight is improved by dynamic combination of subjective weighting method and objective weighting method according to their characteristics. The composite weights of each evaluation index are integrated with the TOPSIS conception to establish the improved composite weight TOPSIS (ICW-TOPSIS) evaluation model, which is used to evaluate seven workover vessels. The result shows that the ICW-TOPSIS evaluation model has the feature of simple calculation principle, which is suitable for the evaluation of large quantity of ships with uneven performances. The evaluation indexes are influenced by both the subjective wills and the information that the data carries. Therefore the sensitivity of subjective wills is lower than the AHP-TOPSIS method, which can effectively avoid the problems of improper selection of subjective weights and inaccurate evaluation caused by inexperienced decision maker. The proposed method can objectively combine the subjective wills of the decision maker and the objective information of evaluation index to improve the accuracy of the evaluation model.

Key words:improved composite weight; Analytic Hierarchy Process (AHP); Entropy Weight Method (EWM);  comprehensive ship evaluation

 

 

 

Research on the Application of Fuel Gas Supply System on

Super Large Dual Fuel Container Ships

 

XU Annan, TIAN Dabing, SONG Lijun

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

 

Abstract: This paper discusses the natural gas consumptions of a super large dual fuel container ship both at sea and under bunkering. Dual fuel low speed engines one each from WinGD and MAN are compared to find out the advantages and disadvantages of the two fuel gas supply systems in terms of holistic function, cost, operation, control and so on. This study provides reference for the BOG treatment of LNG fuel gas supply system.

Key words:fuel gas supply system; natural gas consumption; dual fuel; super large container ship

 

 

 

Predictive Control of the Reversing System for

Water-jet Propulsion

 

SONG Chenwei¹, LIN Hui², QIN Feilong², ZHOU Guanze², XIE Haichuan², YUAN Jingqi¹

（1. Department of automation, Shanghai Jiaotong University, Shanghai 200240, China;

2. Laboratory of Waterjet Propulsion, Shanghai 200011, China)

 

Abstract: This paper establishes a transfer function model of water-jet propulsion reversing device for an example ship through analyzing the working principles of the reversing device of water-jet propulsion. The model-based disturbance observer and the model predictive controller are designed and simulated with MATLAB SIMULINK platform. The result shows that the model predictive controller with inner circle observer has the excellent reversing control tracking performance and good robustness.

Key words:water-jet propulsion; reversing device; model predictive control; disturbance observer

 

 

 

Design of the Control System for Reliquefaction Plant

on Very Large Liquefied Petroleum Gas Carrier

 

YANG Sen, FAN Fan, Zhang Mingyao

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

 

Abstract: Taking the reliquefaction plant installed on an 85000 m³ Very Large Liquefied Petroleum Gas Carrier (VLGC) as the research subject, this paper elaborates the basic concept, the operational principles, the equipment configuration and the operating modes of the reliquefaction plant in accordance with the intended purpose of the ship and the requirements of handling and transportation. According to the foreign process principles for compression, liquefaction and cooling of petroleum gas, this study analyses the major components of the reliquefaction plant, such as vapor suction separator, compressor, condenser, cooler and accumulator, with the emphasis on safe operation and reliability of the system. It elaborates the functions of the components in the reliquefaction process, the corresponding means of control and monitoring, and the alarm and interlock performance. Then the liquefaction cycle of cargo propane (8 mol% ethane in liquid phase) on the VLGC is explained based on the cargo condensation and the forced reflux of the reliquefaction plant, which provides references for the design of the control system for reliquefaction plant in China.

Key words:liquefied petroleum gas (LPG); reliquefaction plant; process flow; operating mode; alarm and interlock

 

 

 

Influence of Ventilation on Other Technical Items and

Its Treatment Method

 

LI Aihua, DAI Huiyang

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

 

Abstract: This paper gives five practical examples in design of a ship, which demonstrates the mutual influence between ventilation and other technical items. It explains the importance of coordination of different technical items in the preliminary design stage. Some influence may directly affect the system design and the equipment choice. Different forms of Class B division for internal outfitting will affect the selection of air distributors for ventilation and the selection of accessories such as special electrical lamps and alarms which may damage the ceiling. The regulations on sound insulation of cabin walls and doors for interior outfitting indirectly affects the balance design of the cabin’s air-conditioning ventilation system; the general arrangement and entrance/exit positions of the pipe tunnels directly affect the relevant ventilation designs of exterior outfitting and electrical equipment; and the cargo type in the cargo tank not only influences the ventilation design, but also directly influence the selection of hatch covers for large cargo tanks. Loading of hazardous cargo requires a 3m extension of the hazardous area for ventilation inlet and outlet, which directly affects the layout of breathable heads for oil tanks, void tanks and etc.

Key words:class B division; air distributor; system balance; pipe tunnel; natural ventilation; hazardous area

 

 

 

Research and Application of Precision Control Techniques to

380t Rudder Blade Installation Platform

 

CHEN Feng, TIAN Xiaoxiong

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

 

Abstract:This study analyzes the key points and hard points of the precision control in construction of a 380t rudder blade installation platform based on the construction experience, the high precision requirements and difficulties in the precision control of the platform construction. It proposes a set of precision control techniques for the construction of support legs, the main frame and etc.

Key words:rudder installation platform; precision control; support leg; main frame

 

 

 

Pallet Tracking Technology for the Logistics of

Ship Curved Block Parts

 

WU Zhaohui, HU Chengcheng, WANG Xuanping, YU Feng

（Jiangnan Shipbuilding（Group）Co., Ltd., Shanghai 201913, China)

 

Abstract: Pallet tracking technology for the logistics of ship curved block parts is an important method to ensure timely and orderly construction of ship blocks. A multi-step pallet logistics tracking solution is proposed based on the analysis of the distribution of ship curved block parts. It uses digital technology in tracking the movement of pallet during the entire process of curved block construction. The result of application shows that the technology can effectively raise the level of delicacy management of ship parts pallets, which brings a favorable effect on ship production and materials management.

Key words:curved block; pallet; logistics tracking

 

 

 

Control Technology of Lane Separation Logistics for Ship Parts

 

LIU Qiaomei, SHEN Aihua, CAO Hengling

（Jiangnan Research Institute, Jiangnan Shipyard Co., Ltd., Shanghai 201913, China)

 

Abstract: The analysis of lane separation logistics control technologies for ship parts compares the advantages and disadvantages of the traditional management and the lane separation management, and proposes a set of rules and methods that meets the lane separation production requirements of ship parts. Then the lane separation logistics control scheme for ship parts is established based on the existing steel plate spray printing equipment, and a holistic digital management control platform for the lane separation logistics is developed. Its application shows that the platform can expedite the logistics process, reduce the occurrence of lack material and invalid picking, and raise the utility efficiency of the site.

Key words:lane separation of parts; lane separation rule; logistics control