Top 10 Technical Challenges of Ropax and the Countermeasures

 

TIAN Zhengjun, JI Chunzheng, WU Lin, YU Jian, ZHAO Yong, ZHAO Zibing

（China Merchants Cruise Research Institute (Shanghai) Co., Ltd., Shanghai 200137, China）

 

Abstract: Ropax has its own unique features which combine the characteristics of Ro-Ro ships and passenger ships, but there are many challenges in design and construction. This paper presents ten technical challenges including speed performance, damage stability, weight control, structural design, vibration and noise reduction, Ro-Ro equipment, interior decoration engineering, propulsion system, air-conditioning and ventilation, and safe return to port. It also elaborates the reasons behind the challenges and the countermeasures to deal with the challenges to provide reference for the design, construction and operation of subsequent ships of the same type.

Key words: Ropax; technical challenge; countermeasure

 

 

 

A Study on the Swing Motion and Living Comfort of

Semi-submersible Offshore Living Platform

 

HU Kaiye¹, WANG Shoujun², HAN Ronggui², CHEN Mo¹

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

2. CIMC Offshore Engineering Institute Ltd., Yantai 264000, China）

 

Abstract: Swing motions have important impact on the comfort level of living platform, therefore the ANSYS software is used to create the numerical analysis model for a semi-submersible offshore living platform and the AQWA-LINE module is used to carry out the hydrodynamic calculations, where the motion responses of the platform are obtained based on three-dimensional potential flow theory. The AQWA-DRIFT module is used to predict the acceleration responses of the platform in all three directions under the ocean wave environment, and to carry out the motion comfort level analysis. The limiting wave conditions that satisfy the platform motion comfort requirements are obtained via calculations and analysis. The result shows that the platform has excellent comfort performance, which can provide reference for the design and comfort level assessment of similar platforms.

Key words: semi-submersible living platform; three-dimensional potential flow theory; swing motion; hydrodynamic performance; comfort level

 

 

 

Design and Installation of Bulk/Mud System for

8000kW Rescue and Salvage Tug

 

XIAO Zuguang，PENG Jianwen, HUANG Guangxiong

(CSSC Huangpu Wenchong Shipbuilding Co., Ltd., Guangzhou 511462, China)

 

Abstract: This study puts the emphasis on the design and installation of the bulk and mud system of an 8 000 kW rescue and salvage tug with the purpose of keeping the economic performance of the tug on the premise of not affecting its major operation functions, and at the same time meeting the demand of the ship owner on the volume of bulk and mud tanks so as to avoid the design problems encountered by the ship owner during the usage of the bulk and mud system onboard other ships. Based on the equipment profile, the 3D model and the system principle, the bulk tank dimensions, installation form and equipment layout are optimized for the bulk system, and some of the equipment layout and installation are optimized for the mud system. In this way the bulk and mud system works well and satisfies the ship owner.

Key words: bulk system; mud system; system principle; installation

 

 

 

A Study on the Full Frequency Domain Noise Analysis of

Semi-submersible Platform Based on Octave Estimation

 

MEI Huadong¹, XU Qinliang², SHEN Zhiheng¹, MA Bangyong¹, LI Yanhua¹

（1. Offshore Oil Engineering Co., Ltd., Tianjin 300452, China;

 2. Yantai CIMC Raffles Offshore Limited, Yantai 264000, China）

 

Abstract: The noise of deep water semi-submersible production platform is sourced from the machinery working year round including the main engine, pumps, compressors, distribution boards in the living area, fans, air-conditioners and other vibration equipment, as well as the pumps inside the pump compartment of hull columns, the hydraulic units and the air-conditioners at the column top (serving the hull control room). According to the principles of statistical energy analysis, the noises of the HVAC (heating and ventilation air conditioner) are estimated based on empirical formula, while the aerodynamic noise, the frequency of the plate structure and the noise of HVAC are simulated and analyzed with the finite element method and the numerical analytical method for the semi-submersible platform. The overall noise value is thus predicted, which satisfies the on-site measurement requirement. On this basis, the full frequency domain noise analysis and evaluation results and design suggestions are produced, which provides technical support for the noise control of semi-submersible production platforms.

Key words: semi-submersible production platform; octave range; structural noise; aerodynamic noise; noise analysis

 

 

 

Analysis of Key Design Points for the Sliding Bow Door of

Ropax Vessel

 

ZHAO Yong, LI Baogong, YIN Xingjie, ZHAO Tonghui

（China Merchants Cruise Research Institute (Shanghai) Co., Ltd., Shanghai 200137, China）

 

Abstract: There are many coordination points and factors for consideration in the structural design of sliding bow door with arms for Ropax vessels, which leads to challenges and difficulties in the structural design, structural calculations and technical management. This paper summarizes the existing problems in the technical management of a series Ropax vessel, and analyzes in detail the key points of bow door structural design according to the relevant rules and regulations. Meanwhile, the technical management process is summarized based on the experience to provide reference for the designer to solve similar problems.

Key words: Ropax vessel; sliding bow door; structural design; structural analysis; technical management process

 

 

 

Design and Test of High Speed and Large Depth Towing System

 

TAO Guangyong

（Zhong Ke Great Wall Ocean Information System Co., Ltd., Changsha 410100, China）

 

Abstract:In order to meet the need of high speed and large depth towing systems for ocean survey, Fluent is used to design the upstream lines for towline and towed body. The shape of the towline is a combination of ellipse line and straight line, while the lines for towed body are combinations of ellipse lines and arc lines. Both are made of stainless steel frame with glass fiber resin. The towline resistance coefficient obtained via simulations and analysis is as small as 0.26 and that of the towed body is 0.24. The fluid dynamics of the towing system in towing motion are analyzed, and the towing forces, water entrance angles, lagging distances and submerged depths under different speeds are calculated based on the analysis model. The result shows that the towing system can meet the application demand under a speed of 15 kn and a working depth not smaller than 100 m. According to the sea trial, the measured values well agree with the design values, so the method has high engineering reference for the design of similar systems.

Key words: high speed towing; low flow resistance; tension; submergence depth

 

 

 

A Health Diagnostic Method for Marine Diesel Generator Set

 

ZHAO Junchao, WANG Jiabiao, Aimaiti Bulading, WANG Qishuo, MAO Donglin

（Shanghai Marine Equipment Research Institute, Shanghai 200030, China）

 

Abstract:In order to improve the performance of marine equipment and increase the cruising ability of marine power generators, an experimental system for marine diesel generator set is developed. Huge amount of system operational parameters are collected. The data characteristics are analyzed using statistical analysis method, and the health of generator set is scored using the analytic hierarchy process (AHP). On this basis, the abnormal data are analyzed to develop a fault recognition algorithm based on machine learning, and a health diagnostic system is then set up, which can realize the real-time fault diagnosis of the generator set.

Key words:diesel engine generator set; fault prediction; machine learning; health diagnosis

 

 

 

Optimized Design for Pressure Water Spray System

in Ro-Ro Space of Inland Ships

 

GONG Xucheng, YU Yun

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

 

Abstract:Analysis and comparison of several commonly used design methods for the water spray system in ro-ro space are carried out to calculate and compare the system weights of various schemes, which takes into account the nozzle selection, zone partition, pipeline arrangement, pipe material selection and etc. On the premise that the system functions are guaranteed, the design optimization schemes for the system are discussed. The result shows that it is possible to significantly reduce the system weight and improve the ship's loading capacity by using optimized pipeline design concept, zone partition and other measures in the design of the water spray system for the ro-ro space.

Key words:ro-ro space; water spray; light weight design; pipeline arrangement

 

 

 

Circuit Design for a High Power and

High Frequency Sonar Transmitter

 

WEI Pingfen¹, LAI Duoming², ZHANG Chaoming²

(1. Navy Military Representative Office in Guangzhou, Guangzhou 510260, China；

2. Kunming Branch of the 705 Research Institute, CSIC, Kunming 650106, China)

 

Abstract: This paper introduces a method that can implement the circuit design of a high power and high frequency sonar transmitter, including the driving circuit design of single integrated chip IR21844 for power devices, the design of power MOS transistor driving transformer circuit, the design of transformer characteristics and parameters, the impedance matching design of transducer and etc. The design of high power and high frequency sonar transmitter is finally completed with all these designs.

Key words:high power; high frequency; sonar transmitter; chip IR21844

 

 

 

A Practical Study on the Measurement of

Black Carbon in Ship Exhaust Gas

 

LOU Chunjing

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

 

Abstract:Black carbon in the exhaust gas of vessels is a harmful substance to the environment. In order to find out the pattern of the black carbon in ship emission so as to work out effective measures to reduce black carbon, it is necessary to measure the black carbon in the exhaust gas of existing vessels. A 180 000 dwt bulk carrier is taken as the object to design the practical black carbon measuring method of minimum workload on the premise of not modifying the pipelines and the facilities. Sea trial measured the black carbon in the ship’ emission from the main engine and generators, and the practice result shows that the method can be applied to other ships.

Key words: black carbon; main engine; generator; boiler; exhaust gas; emission

 

 

 

A Study on the Installation of

Integrated Rudder & Propeller System

 

WANG Zhongqiang, ZHAO Zhihua, JIANG Zhiqiang

（LNG Technology Research Institute, Hudong-Zhonghua Shipbuilding (Group) Co., Ltd., Shanghai 200129, China）

 

Abstract: This paper elaborates the study on the precision requirement, erection deformation control and construction procedures of the rudder system and the propeller system during the installation process to ensure that the rudder well matches the propeller with high accuracy, and to realize the installation of rudder system and the shaft system at the sectional construction stage. It is expected that the installation technology can reach the advanced level and effectively reduce the dock construction period.

Key words:high efficient rudder; shafting; integrated system of rudder & propeller; precision

 

 

 

Rapid Creation and Onboard Application of

Marine Outfitting Basic Database

 

DAI Fenfen, LIU Yongzhen, WANG Yan, QIAN Liping, ZHANG Zhenning

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

 

Abstract: The outfitting basic database is created for rapid maintenance and modification of marine outfitting units in batches. It includes pipelines, ventilation pipes, electrical equipment, iron tan, interior fitting and other equipment, whose feature information can also be rapidly modified in batches. Based on the marine material attributes and classification principles, VB.NET is used to assign CAD software for data reading and writing, and SQL Server technology is used for material attribute information management. PYTHON is used to integrate the program into CAD software platform to realize rapid integration of marine outfitting material database and CAD software platform, which ensures the accuracy and uniqueness of the data source. The application onboard several ships has shown excellent results which has proved that the method is feasible.

Key words:production design; outfitting basic database; material classification

 

 

 

A Study on Conversion of CATIA Automatic Cutting Instruction

 

LI Jin, WANG Shaohua, ZHANG Qiang, GUO Wenzhong, LIU Ya

（CSCC Huangpu Wenchong Shipping Co., Ltd., Guangzhou 510000, China）

 

Abstract: In order to solve the problem that CATIA software can’t generate automatic cutting instructions, a study on the conversion of automatic cutting instructions is carried out to produce a method that can convert XLS files into LST files. The method compiles the convert rules to turn the profile files designed by CATIA into the automatic cutting instructions based on the analysis of LST files and XLS files and then checks each cutting instruction. The examination result shows that the cutting instructions can be converted with high efficiency and reliability. The CATIA automatic cutting can not only ensure the product quality, but also improve the production efficiency and reduce the cost.

Key words:profile cutting instruction; conversion; CATIA profile

 

 

 

Analysis of Simplified Evacuation for an Antique Replica Vessel

 

ZHANG Fan, MIAO Aiqin, CHEN Qiong, LI Xiaoling

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

 

Abstract:According to the demand, an antique vessel built in the 1920s is replicated and exhibited at the port. It is found during the vessel design process that the vessel was built prior to all of the existing rules and regulations, and the inner space of the ship is quite small, so evacuation analysis is carried out to ensure the safety of visitors on board, which is of great help for the designer to find out the potential problems of the evacuation in advance, so as to avoid the risk and ensure the life safety at sea. This work can provide design reference for passenger vessels.

Key words:antique vessel; evacuation analysis; travel duration; flow duration