INVESTIGATION OF OIL TANKER ACCIDENTS BY USING GIS

This study focuses on marine accident data regarding accidents that occurred between the years 1998-2010 for ships within the oil tanker category. Data in the study include accident reports, which are recorded in the Global Integrated Shipping Information System (GISIS) and country reports. Textual accident data in the GISIS database were tabulated, thus creating a systematic database. By using accident data from this database, a marine accidents map for oil tankers was developed via the ArcGIS 10 program, the areas with the highest accident incident rates were determined, and reasons for oil tanker accidents were revealed through the assessment of factors such as accident type, accident incident number, accident scope, ship tonnage, navigational sea area type, and accident’s impacts on the environment, economy and personnel. The study showed that very high risk areas for oil tanker marine accidents include the Singapore Strait and Oresund, and high risk areas are the Bristol Channel, Suez Channel, Strait of Hormuz, Great Belt, Piraeus, Hull, İstanbul Strait, and Amsterdam, respectively. The study also established that oil tanker accidents are related to ship tonnage and navigational sea area type.

QUANTITATIVE RISK ASSESSMENT FOR COLLISIONS INVOLVING DOUBLE HULL OIL TANKERS

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.

DESIGN OF COMPLETELY AUTOMATIC ODMCS

This paper presents a novel approach for designing a completely automatic Oil Discharge Monitoring and Control System (ODMCS) for the discharge of oily mixtures/effluents from cargo area and slop tank of oil tankers. The Global Positioning System (GPS) and modified World Vector Shorelines (WVS) data are used for the development of a system, which completely automates the working of ODMCS to comply with Marine Pollution (MARPOL) regulations. The system level hardware and software design for the same is discussed. An animated simulator for the completely automatic ODMCS is developed. The developed system may also be used as ODMCS emulator when main ODMCS fails. The results obtained by applying the test inputs to such a system have been presented and verified against the requirements of MARPOL regulations.

FATIGUE ASSESSMENT OF CORRODED DECK LONGITUDINALS OF TANKERS

Fatigue life of deck longitudinals of oil tankers is analysed based on linear elastic fracture mechanics. A parametric formulation for the estimation of stress intensity factors and the Paris-Erdogan law are applied. Long-term effects of corrosion are modelled based on regression equations fitted to thickness measurements made during inspections of two tankers. Parametric studies are performed in order to investigate the importance of the governing parameters of crack propagation. A comparison of the fatigue analyses performed by linear fracture mechanics and S-N approaches is presented.

A NEW METHOD FOR ASSESSING THE SAFETY OF SHIPS DAMAGED BY GROUNDING

The primary aim of the present study is to propose an innovative method for assessing the safety of ships which have suffered accidental or in-service damages. Only a small number of probable scenarios for accidental or in-service damage representing all possible damage scenarios are selected using a sampling technique in which the random variables affecting the damage are probabilistically characterized. A damage index for the corresponding damage scenario is defined as a function of damage characteristics such as location and extent of the damage. The residual strength performance of a ship with the corresponding damage scenario can then be calculated by analytical or numerical methods. Once this process has been carried out for each of the damage scenarios selected, a diagram relating the residual strength performance to the damage index (abbreviated as the R-D diagram) can be established. This diagram will be very useful for a first-cut assessment of a ship’s safety immediately after it has suffered structural damage. The diagram can also be used to determine acceptance criteria for a ship’s safety against accidental or in-service damage. An applied example is shown to demonstrate the applicability of the proposed method in terms of developing a diagram between the ultimate longitudinal strength versus grounding damage index for four types of double-hull oil tankers – VLCC, Suezmax, Aframax, and Panamax.

PeTroShare: Blockchain-Managed, Logistics-Aware, Privacy-Friendly, Comparative, and Efficient Petroleum Transportation

Crude oil is one of the critically needed resources. It is the main pillar supporting almost everything we rely on in daily life. Unfortunately, due to many factors, crude oil costs too much. Transportation is one of the critical factors that affect such costs. Due to many environmental risks attached to the transportation process, many countries added very high tariffs to cover any hazards during the transportation, loading, and unloading process. Logistics concerns and political conflicts are the other key factors that can massively impact the transportation cost. This paper presents an Industry 4.0-compliant PeTroShare (PTS), a blockchain-powered trustworthy, logistics-friendly, and cost-efficient crude oil trading platform. PTS is a novel ride-sharing platform that enables an anonymous exchange of crude oil between oil producers and customers, focusing mainly on the product quality, not the source of origin. In our scenario, floating crude oil tankers will hold the cargo to an intermediate position in the open ocean. PTS will match the product availability based on the location and the needed quality of the customer requests. Consequently, the time and distance travelled are minimized. Our simulation results show that enabling the anonymous sharing of crude oil products can significantly enhance system efficiency and cost-effectiveness.

Full-Scale Measurements of the Propeller Thrust during Speed Trials Using Electrical and Optical Sensors

Full-scale sea trials demonstrate a ship’s performance under real operating conditions to confirm whether a ship meets its specifications and requirements. The determination of the performance through a sea trial is the most important stage in the ship design cycle. If one is relying on measurements of propeller shaft power or fuel consumption, the distinction between the propeller and hull efficiencies may not be made. In order to be able to identify the propeller efficiency separate from the hull, full-scale propeller thrust should be accurately measured. In this study, full-scale measurements of the propeller thrust, torque, and revolution for a series of crude oil tankers and twin-skeg LNG carrier were conducted during the speed trials. Two different measuring systems, strain gauge and optical type, were implemented to compare the performance of sensors. As a result, it was shown that the strain gauge type-measuring device matched the model test results relatively well compared to the optical device. Above all, in the case of the optical device, it has been demonstrated that the zero setting is important to increase the accuracy of the full-scale measurements.

Proposed Design Criteria for a Bilge Pumping System for Large Container Ships

The IMO’s Goal-Based Standards (GBS) in the Safety of Life at Sea Convention (SOLAS) sets the high-level goals (GBS Tier 1 and 2) and classification societies acting as recognized organizations (ROs) should develop detailed rules and regulations in order to meet the goals (GBS Tier 4). Even though the GBS requirements are applicable to new build construction standards of bulk carriers and oil tankers at present, given that IMO may develop goal-based standards for other safety areas, it will be meaningful to examine the bilge pumping system requirements in the context of principles of Goal-Based Standards. The bilge pumping system is one of the most important systems in ships but there is no requirement for its performance except for the 2 m/s speed of water requirement and the internal diameter of bilge main prescribed in SOLAS. The purpose of this study is to quantitatively evaluate bilge pumping performance of actual ships in service and to propose an alternative set of performance standards. The rules of Classification Societies were investigated, and the bilge pumping performance was quantitatively evaluated using specifications of a 14,000 TEU class container ship. As a result of the investigation, it was found that satisfying the 2 m/s requirement under many operating conditions was impossible, and the rules and regulations to determine the internal diameter of bilge main and the capacity of bilge pump did not meet intended purpose of the 2 m/s speed of water requirement. Finally, a set of design criteria are proposed to fulfil the intended purpose of the 2 m/s requirement of SOLAS.