• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.25 no.11
• /
• pp.1612-1618
• /
• 2021

The telegraph controller is a device used to control the speed of a ship, and it is a device that has a very direct effect on the safety of the crew. Accordingly, ship owners demand very high reliability of the telegraph controller, and the classification trend is to introduce HILS (hardware in loop system) test as a method to verify reliability. Therefore, in this paper, an electric propulsion ship was modeled to perform the HILS test of the Telegraph controller. For modeling, the specifications of the electric propulsion tug boat were defined, and the battery parts, propulsion motor parts, and ship model parts were modeled. In addition, various operation scenarios were defined and the Telegraph controller was modeled accordingly. Finally, the results of the integrated model were confirmed through simulation.

• Journal of Korea Port Economic Association
• /
• v.25 no.3
• /
• pp.67-92
• /
• 2009

A tugboat (tug) is a boat that maneuvers vessels by pushing or towing them. Tugs move vessels that should not move themselves alone, such as ships in a crowded harbor or a narrow canal, or those that cannot move themselves, such as barges, disabled ships, or oil platforms. Tugboats are powerful for their size and strongly built, some are ocean-going. Historically tugboats were the first seagoing vessels to receive steam propulsion, freedom from the restraint of the wind, and capability of going in any direction. As such, they were employed in harbors to assist ships in docking and departure. Towage is in essence a service by one vessel to another vessel for a fixed remuneration. The most common reason for requiring this service is the lack of its own motive power. Conventionally, towage is defined as "the employment of one vessel to expedite the voyage of another, when nothing more is required than the accelerating of her progress". Apart from accelerating vessels, acquiring towage service is a common practice for towing barges, platform of drilling oil, floating ship yards, etc.

• Journal of Navigation and Port Research
• /
• v.44 no.6
• /
• pp.439-446
• /
• 2020

The IMO has adopted emission standards through Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL) that strictly prohibit the use of bunker C oil for vessels. In this study, we have adopted the turret-moored Floating LNG-Bunkering Terminal (FLBT) which is designed to receive the LNG from LNGCs and transfer it to LNG-bunkering shuttles in side-by-side moored condition. Numerical analyses were carried out using the high-order boundary-element method for four vessels at various relative distances. Mean wave drift forces were compared in an operational sea state. A model test was performed in the ocean engineering basin at the Korea Research Institute of Ships & Ocean Engineering (KRISO) to verify the safety of the berthing/unberthing operation. In the model test, a jig was designed to simulate tug boats pushing or pulling the bunkering vessels, so that the friction force of the g operation was not affected. Safety depended on the environmental direction, with more stable operation possible if the heading-control function of FLBT is applied to avoid beam-sea conditions.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2021.11a
• /
• pp.127-128
• /
• 2021

This study suggests surface wave communication, which uses a metal surface as a medium, to provide wireless communication in the extreme environment due to surrounding metal materials on vessels. The test was conducted on a G/T 265 tons tug boat, and to confirm the possibility of surface wave communication between a bridge and each designated space in the boat. As a result, the transmission speed was 13Mbps in average. For the test case between the bridge and the engine room, transmission speed was 4.3Mbps while the engine was on, and 1.2Mbps during sailing. It was able to be overcome by partially changing the equipment installation location. Surface wave communication in a bow storage, a fully enclosed space, had 8Mbps better transmission speed than wireless communication; this confirmed the superiority of surface wave communication in confined spaces on a vessel. Additional surface wave generators were designed and applied to resolve the paint issue. It is expected to apply surface wave communication to implement the new wireless solution on vessels.

• Journal of Navigation and Port Research
• /
• v.27 no.3
• /
• pp.259-266
• /
• 2003

Due to the growth of population and industrial development at the coastal cities, there has been much increase in necessity to effective control of the wastes into the coastal water and river. The amount of disposal at those waters has been increased rapidly ana it is necessary for us to track of it in order to keep the waterway safe and the water clean. The investigation and research in terms of water quality in these regions have been conducted frequently but the systematic survey of the disposed wastes at the bottom was neglected and/or minor. In this study we surveyed the status of disposed waste distribution at the bottom of coastal water and river from the scanned images. The intensity of sound received by the side scan sonar tow fish from the sea floor provides information as to the general distribution and characteristics of the superficial wastes. The port and starboard side scanned images produced from two arrays of transducers borne on a tow fish connected by tow cable to a tug boat have the area with width of 22m~112m and band of 44m~224m. All data are displayed in real-time on a high-resolution color display ($1280{\times}1024$ pixels) together with position information by DGPS. From the field measurement and analysis of the recorded images, we could draw the location and distribution of bottom disposals. Furthermore, we could make a database system which might be useful for navigation and fundamental for planning the waste reception and process control system.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.18 no.4
• /
• pp.298-303
• /
• 2015

When a disabled ship is being towed in a seaway, the resistance increase of the towed ship caused by both the external conditions such as wave and wind and the hull conditions such as drifting angle, should be accurately predicted. Most of the disabled ships cannot be towed in the front direction of hull, but they are usually towed in drifted direction with some drifting angle. In this sense, the resistance increase caused by the drifting angle is not an element to be ignored. In this paper, various methods for prediction of the resistance increase caused by the drifting angle are studied. In addition, new prediction methods such as front-lateral projected ratio method and empirical formula method by multiple regression analysis have been derived. The front-lateral projected area ratio method has been applied to a computer program for prediction of the towing condition, and this method has been approved to be a useful method in practical situations.

• Journal of Navigation and Port Research
• /
• v.32 no.8
• /
• pp.597-602
• /
• 2008

T.S. HANBADA has a relatively large hull and superstructures above the water line, so she has much of leeway or turning of bow with the effect of winds. Especially on berthing, unberthing and/or sailing on low speed, these effects take place more significant. Therefore, it was carried out the numerical calculation of the wind force and moments acting on the T.S. HANBADA, and then calculated the leeway angle and counter rudder angle with the relative wind direction and velocity. Also, it was suggested the maximum wind velocity which could be berthed or unberthed used by bow thruster and the tugboat operations in strong winds. These results will be great helpful to the vessels with large superstructures on ship's handling in harbour or tugboat operations.

• Journal of Navigation and Port Research
• /
• v.29 no.8 s.104
• /
• pp.673-678
• /
• 2005

In order to improve the safety of ship berthing and the efficiency of berth operation in the harbour, the berthing energy acting on a ship in berthing maneuver need to be estimated properly. The berthing energy is used as one of the criteria to determine the maximum permissible load q{ fender as well as important factors to establish the berthing speed and the required power of tug-boat for pilot and ship operator. Some problems of berthing energy are discussed on the basis of the hydrodynamic aspects. Then, series calculations of berthing energy are carried out considering the effect of water depth on added mass and the ship shape for container series from 1,600TEU to 12,000TEU.

• Journal of the Society of Naval Architects of Korea
• /
• v.34 no.4
• /
• pp.1-11
• /
• 1997

When a barge is towed by a tug boat using a tow line, the barge is frequently subject to a large sway motion induced from its inherent yaw motions. This large sway motion combined with external forces due to winds and waves may makes the towing to be difficult or even dangerous. It has been reported that in worse situations, barges or tugs are capsized. In addition, the large sway motion of the towed barge gives a menace to the safety of ships navigating nearby. This paper is the results of the experimental investigation into the course stability of an 8,000 DWT barge using a Towing Tank and a Circulating Water Channel. Various skegs are designed and course stability tests for the barge with skegs are conducted in calm water and in irregular waves. It is observed that an effective skeg attached to the barge enables the sway motion to be zero while the sway amplitude of the bare hull is around 10 times its breadth.

• Aerospace Engineering and Technology
• /
• v.5 no.2
• /
• pp.143-148
• /
• 2006

This article summarizes the results of sea transportation load measurements, which will be used as the reference to the sea transportation environment condition for the launch vehicle of KSLV-I. KSLV-I will be transported by Sea from Pusan to the NARO space center in Gohung, Chunnam province. Since the vibration load condition during sea transportation is considered as one of the important design parameters of KSLV-I and its transportation means, it is necessary to directly measure the environmental condition of sea transportation loads prior to establish the sea transportation plan in detail. This material includes the measured data of 3-axis linear accelerations and 3-axis angular rates on the board of a barge-ship, which is towed by a tug boat during shipping operation. This barge-ship is same class with one which will actually carry KSLV-I. The results show that the measured load condition during sea transportation is not severer than the reference data of MIL-STD-810F and Zenit-3SL launch system.