Abstract
For their mooring on the sea, ships are equipped with mooring utilities such as anchors, anchor chains, and winches. To determine the specifications of these equipment, the equipment number of each ship must be calculated, and the formula used for calculating this number is provided by the classification society. However, as the equipment number formula was derived based on the tanker at the time of development, it may not be suitable for relatively recent types of ships, such as container ships and liquefied natural gas carriers. Therefore, in this study, the suitability of the equipment number formula was verified, and modified coefficients are proposed for the types of ships. First, the formula for calculating the drag force acting on the ship due to the wind and current was derived and compared with the equipment number formula. The meaning of each coefficient in the equipment number formula was analyzed using this process. Additionally, the mooring equipment, such as anchor and anchor chain, was selected based on the equipment number, and the holding power of the mooring equipment and the drag force acting on the ship was compared to verify the suitability of the equipment number formula for each type of ship. Based on this verification result, a modified coefficient was proposed for each term in the equipment number formula.
Highlights
For mooring a ship on the sea to prevent unexpected movement, specific equipment, such as anchors, anchor chains, and ropes, are needed
It is reasonable to assume that the equipment number calculation formula is generally derived based on when the ship is anchored or moored near a port, so that Oil Companies International Marine Forum (OCIMF), which refers to the ship moored in port, is used to calculate drag force
The formula for calculating the drag force acting on the ship due to the wind and current was derived and compared with the equipment number formula
Summary
For mooring a ship on the sea to prevent unexpected movement, specific equipment, such as anchors, anchor chains, and ropes, are needed. When designing a ship, it is necessary to determine the appropriate specifications of these equipment. The specification of these equipment should be determined by considering the drag force due to the current and wind acting on the ship. As it is not efficient to calculate the drag force whenever an equipment is designed, the specifications of the equipment are generally determined by referring to the equipment number of each ship. Owing to changes in the marine environment; the development of various types of ships, such as container ships, liquefied natural gas carriers (LNGCs), and drill ships; and the emergence of new technologies, it is necessary to verify whether the current formula for equipment number calculation is still suitable. In this study, the suitability of the existing equipment number formula was verified, and a modified coefficient is proposed for each term
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
