Rapid Assessment of Hull Girder Collapse for Corroded Double Hull Oil Tanker After Collision

Author(s):  
Sung Hwan Noh ◽  
Jung Kwan Seo ◽  
Jeom Kee Paik ◽  
Samy A. M. Youssef

Corroded tankers might be subjected to a very serious structural damage if involved in collision accidents. For understanding or preventing the collision accidents, various studies are being proposed by researchers to improve the analysis method. In this paper, four types of double hull oil tankers (Panamax, Aframax, Suezmax and VLCC) are used. Probabilistic approach is used to create ship-ship collision scenarios for each target structure and the ultimate longitudinal hull girder strength of the hypothetical oil tanker’s hull cross-section. The ALPS/HULL is used to simulate and is intelligent supersize finite element method (ISFEM) software. A relevant probability density function (PDF) is introduced using the results from finite element simulations of the ship-ship collisions, which is commonly used to predict residual strength.

Author(s):  
Seung Jun Baek ◽  
Jung Min Sohn ◽  
Jeom Kee Paik ◽  
Sang Jin Kim

Collision and grounding accidents account for more than half of all accident cases in most cases. Such marine accidents cause severe structural damage to the ship and lead to marine pollution as well as life and financial loss. For preventing the loss of property and pollution, and preparing a countermeasure, it is needed to predict a residual hull girder strength after accident regardless of someone’s special skill. The aims of this study are to i) investigate the residual hull girder strength by quantitative approach with collision location (height and penetration), ii) develop an empirical formula for calculating a residual hull girder strength which whoever can calculate in association with collision locations. In this study, three kinds of ships such as very large crude oil carrier, Suezmax, and Aframax class double hull oil tankers are selected as target struck vessels. And, the Intelligent Supersize Finite Element Method (ISFEM) is applied to assess the residual hull girder strength of damaged structures after collisions. Based on the ISFEM results, an empirical formula for calculation of residual hull girder strength is developed as a function of the collision depth and penetration. The developed formula in this study can be applied by anyone, and rapidly calculate its strength for preventing sequential events (collapse, fuel spill, etc.) after collision.


2009 ◽  
Vol 46 (04) ◽  
pp. 183-191
Author(s):  
Jeom kee Paik ◽  
Jae Hyung Park ◽  
Emmanuel Samuelides

To mitigate the impact of consequences of ship collisions in terms of health, safety, and the environment, it has been made mandatory that hull structures of all oil tankers have double sides and double bottoms. In recent years, International Association of Classification Societies (IACS) has developed Common Structural Rules (CSR) for structural design of double-hull oil tankers on the basis of limit states, together with the traditional approach using the allowable working stress that has been a basis of pre-CSR. The application of CSR may result in some differences in terms of structural performance, among other aspects. The main objective of the present paper is to investigate the structural performance of CSRdesigned tankers associated with ship collisions. This aspect might be interesting, although CSR are not intended specifically to improve collision performance. As an illustrative example, an AFRAMAX-class double-hull oil tanker structure with same deadweight designed by both pre-CSR and CSR methods is studied by comparing their collision energy-absorption capabilities as obtained by nonlinear finite element methods. It is found that the collision performance of the CSR design could be improved by 5% to 25% compared with that of the pre-CSR design, depending on the accidental limit state criteria. However, it is concluded that the strength performance of the CSR vessel is similar to that of the pre-CSR vessel in terms of collision-accidental limit states, considering the uncertainties involved in conjunction with collision scenarios and nonlinear finite element method modeling techniques. Although the present study deals with some very specific scenarios of collisions, the insights and conclusions developed will still be useful for recognizing a structural design trend related to collision-accidental limit states


1995 ◽  
Vol 32 (04) ◽  
pp. 277-296
Author(s):  
David J. Witmer ◽  
Jack W. Lewis

BP Oil Company time-charters a fleet of American-flag tankers for the ocean transportation of crude oil and petroleum products to the East, West and Gulf Coasts of the United States. Commencing in 1991, ship response and structural monitoring instrumentation was installed on the four ships of the Atigun Pass-class. These crude carriers are operated in the Trans-Alaska Pipeline Service, or "TAPS" trade, sailing the waters of the North Pacific Ocean and Gulf of Alaska. The structural monitoring systems were designed to measure the effects of subjecting a ship to the typical loads and forces encountered while at sea: hogging, sagging, slamming, hydrostatic pressure, and hull girder springing. Additionally, BP was interested in developing a system that could provide shiphandling guidance to the master or watch officer so that the detrimental effects of prolonged exposure to such loads and forces could be effectively minimized. The paper describes in detail the physical arrangement of the BP Oil Tanker Structural Monitoring System (BPSMS), including the suite of sensors employed to measure ship responses and hull girder stresses. It explains how the response data collected by the sensors is analyzed by the onboard computer located on the ship's bridge and how ship response data are presented back to the deck officers via a family of display monitor screens. These displays provide the officers with a "tool" that can be used to effectively monitor the physical and structural response of their ship to waves, and to quantify, in terms of lowering the wave bending moment and reducing the risk of slamming, the result of an action or actions taken to minimize the risk of incurring structural damage. Onboard ship response and structural monitoring is now an integral part of BP's tanker fleet structural management program. The units have greatly increased the awareness of the ship's officers regarding their role in helping to control the amount of structural damage done to the ships. Data from the units have also helped management make more informed decisions regarding operational requirements placed on the ships.


2018 ◽  
Vol 177 ◽  
pp. 01030
Author(s):  
Muhammad Zubair Muis Alie ◽  
Juswan ◽  
Wahyuddin ◽  
Taufiqur Rachman

The objective of the present research is to study the ultimate strength of ship’s hull considering cross section and beam finite element under longitudinal bending. The single hull bulk carrier and double hull oil tanker are taken to be analysed. The one-frame space of ship is considered in the calculation. The cross section of ship’s hull is divided into element composed plate and stiffened plate. The cross section is assumed to be remained plane and the simply supported is imposed to both side of the cross section. The longitudinal bending moment is applied to the cross section for hogging and sagging condition. The Smith’s method is adopted and implemented into the in-house program of the cross section and beam finite element to calculate the ultimate strength of ship’s hull. The result of the ultimate strength for hogging and sagging condition obtained by considering the cross section and beam finite element is compared with one another.


2021 ◽  
Vol 156 (A2) ◽  
Author(s):  
S A M Youssef ◽  
S T Ince ◽  
Y S Kim ◽  
J K Paik ◽  
F Chang ◽  
...  

In recent decades, the safety of ships at sea has become a major concern of the global maritime industries. Ships are rarely subject to severe accidents during their life cycle. Collision is one of the most hazardous accidents, with potentially serious consequences such as the loss of human life, structural damage and environmental damage, especially if large tankers, LNG and/or nuclear-powered vessels are involved. This study presents a Quantitative Risk Assessment (QRA) for double hull oil tankers that have collided with different types of ships. The methodology used to perform the QRA is based on the International Maritime Organization’s (IMO) definition of a Formal Safety Assessment (FSA). Using probabilistic approaches, ship-ship collision scenarios are randomly selected to create a representative sample of all possible scenarios. The collision frequency is then calculated for each scenario. As this is a virtual experiment, the LS-DYNA nonlinear finite element method (NLFEM) is used to predict the structural consequences of each scenario selected. In addition, the environmental consequences are estimated by calculating the size of each scenario’s oil spill. To assess the economic consequences, the property and environmental damages are calculated in terms of monetary units. The total risk is then calculated as the sum of the resultant structural and environmental damages. Exceedance curves are established that can be used to define the collision design loads in association with various design criteria.


2018 ◽  
Vol 25 (s2) ◽  
pp. 42-48
Author(s):  
Wenfeng Wu ◽  
Yubin Yang ◽  
Jianwei Zhang ◽  
Jinshu Lu

Abstract Due to the great danger of the collision of oil tankers, lots of research on the collision of oil tankers has been carried out. But, at present, the research on the collision of oil tankers mainly focuses on the loading condition of the struck ship, ignores the impact on the loading condition of the striking ship. However, during the actual oil tanker collision, the striking ship is generally in the state of loading. Therefore, it is necessary to carry out the analysis of the impact of the loading condition of the striking ship on the collision damage of the oil tanker. In this paper, the effect of striking ship with loading on the impact performance of the side structure during the collision of the cargo double hull oil tanker has been investigated. The ship collision model was established by using the finite element software ANSYS/LS-DYNA which is based on 7000 tons of double hull oil tankers. Based on the analysis of the collision force, impact of striking speed changes, impact of striking deep changes and structural energy absorption during the collision process, the influence of the striking ship with loading on the damage mechanism and the impact performance of the double shell oil ship side structure was expounded. The results show that the influence of the striking ship with loading can be great to the damage to side hull during the research of the collision performance of the oil tanker.


2020 ◽  
Vol 8 (12) ◽  
pp. 988
Author(s):  
Burak Can Cerik ◽  
Joonmo Choung

This study examined the hull girder strength of intact and damaged ships by adopting the incremental-iterative method for progressive collapse analysis, which was extended to the general case of the unsymmetrical bending of beams with an arbitrary cross-section. The sources of an unsymmetrical loading, including rotation of the loading plane and section asymmetry caused by structural damage, are described. A fast and robust procedure is presented to determine the translation and rotation of the instantaneous neutral axis at each curvature increment when applying Smith’s progressive collapse analysis method. A series of analyses were conducted on a double hull VLCC and a bulk carrier, considering various loading plane angles and damage conditions. The decrease in ultimate strength and the influences of rotation of the instantaneous neutral axis and ship heeling are discussed. The proposed method can be used for a rapid and rational assessment of the hull girder strength under adverse conditions.


1993 ◽  
Vol 1993 (1) ◽  
pp. 745-751
Author(s):  
Virgil F. Keith

ABSTRACT The groundings of the Exxon Valdez on Bligh Reef in Prince William Sound, spilling more than 10 million gallons of Alaska North Slope crude, and the American Trader off Huntington Beach, spilling almost 400,000 gallons of Alaska North Slope crude, suggest that the construction of oil tankers be re-examined with respect to a design which could reduce both the number and magnitude of oil spills. This paper discusses state-of-the-art tanker technology with respect to spill prevention, effectiveness, and cost. The design features include double hulls, centralized bunker tankers, vacuum-retaining valves, cargo control systems, auxiliary thrusters, electronic charting, and the retransmission of the ship's position. Double hulls provide the highest probability of surviving damage, either from a collision or grounding, with no loss of cargo. Use of double hulls can reduce oil spill incidence by 90 percent in grounding situations and by 75 percent in collisions. The oil spill from the American Trader could have been completely avoided by double hull construction. The arrangement provides spaces below the cargo tanks and on the vessel's sides solely for the carriage of ballast water when the tanker is in ballast condition. These tanks are empty when the tanker is loaded and then also act as the first line of defense in the event of structural damage to the cargo tanks. Tanker design is integrated with port safety measures, including vessel monitoring systems, in this total spill prevention analysis. All aspects of the tanker transportation system are considered.


Author(s):  
Huirong Jia ◽  
Torgeir Moan

This paper deals with conditional risk assessment considering hull girder failure of damaged vessels. Only damages amidships are investigated. Conditional risk in this paper is defined as the probability of a given damage multiplied by the probability of hull girder failure conditioned upon the given damage. Taking a double hull oil tanker at full load condition as an example, the 3-hour’s failure probabilities conditioned upon damage properties are estimated. The statistical database for collision event in the HARDER project is adopted to assess the probability of sea state and damage. The sensitivity of 3-hour’s failure probability to the sea state and damage properties is investigated. Furthermore, the conditional risk is also assessed.


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