It has been developed large mooring fittings having the capacity of 160 tons and 180 tons installed on 170K LNG FSRU. The finite element analysis for the mooring fittings was carried out in order to check the structural integrity and to confirm satisfaction of the rule requirements. The 3 kinds of mooring fittings such as chock, bollard and universal fairlead are selected for FE analysis and load test. According to the FE analysis results, all the stress levels satisfied the acceptance criteria guided by the IACS UR A2, ISO standard, ship rules and OCIMF. As test results under design load, no structural defects were found.

The rolled carbon steel plate has anisotropic property in Z-direction(thickness direction). This is induced by cooling rate difference of Z-direction and sulfur which make non-metallic inclusion(MnS) at center line of thickness direction. Z-directional mechanical properties of normal steel plate are not generally specified and it is defined for Z-Quality steel only through tensile test in Z-direction. If Z-quality steel is not applied for cruciform joint, the lamella tearing will be occurred by tensile stress after welding & during operation of the structure. In this research, one equation estimating Z-directional(orthogonal to plate) stress was developed to prevent lamella tearing by welding. This equation deals with plate thickness & joint configuration(eccentricity, angle and curvature). Analyses were done by strain boundary method using sectional FE modeling and FE 3D models are also used for some cases. Designers can predict the possibility of lamella tearing by adequately applying the result and can appropriately minimize the application of Z-quality steel by revising welding design to some extent.

The Lashing bridge and radar mast of ship are upright structures so they are generally exposed to excessive vibration. Recently, the use of low speed main engines for improving fuel efficiency has been increasing, and the excitation frequencies of the main engine are moving to the low frequency band. If the excitation frequencies are coincident with the natural frequencies of the local structure, excessive vibration occurs during main engine operating condition. The modal test is to experimentally determine resonance frequency, mode shape, and damping, which are vibration characteristics of a mechanical structure under dynamic external force. Through this study, the vibration characteristics of the structure are obtained by modal tests and the low vibration measure is applied to the local structures.

In spite of adoption of Intact Stability Code Part A as mandatory, the accidents have been occurred frequently caused by dynamic stability. Therefore International Maritime Organization (IMO) is revising the Intact Stability Code to prevent the cause of accidents. The result of 4th meeting of Sub-committee on Ship Design and Construction (SDC), five mode of the cause was defined and establishing each draft regulations. We consider physical background, mathematical description, draft regulations for five failure mode and sample calculations for ships built by STX Offshore & Shipbuilding.

The independent tank surface create formation consists of repetitive tasks, but this study deletes the existing manual and repetitive tasks and facilitate the create formation of tank surface.

Due to the nature of semi-submergible drilling rig, various equipments are arranged in a limited space, and therefore the many types of outfitting holes passing through the hull structure are densely arranged and that is required the detailed structural strength evaluation in terms of ULS and FLS by class or client. Particularly, semi-submergible drilling rig has a variety of global load which affects the structure strength around holes compared to general commercial ship, and its response of stress is also complicated, so it is difficult to carry out the prediction design of structural strength evaluation and reinforcement. In this regard, this paper presents a case study on the evaluation of structural strength for the various holes and large openings of semi-submergible drilling rig conducted by our company, as well as an established hole verification procedure.

FPSO is widely used to develop deep sea oil fields and HHI has constructed ten(10) FPSOs. During these constructions, relevant structural design criteria such as yielding, buckling, fatigue, collision and impact strength were applied to verify structural safety. To apply the buckling strength evaluation for structures, the critical buckling stresses and applied stresses of relevant panels should be calculated. The plate and stiffened panels are to be idealized, which are needed much time and efforts by designers. Therefore, program development is necessary in order to evaluate the buckling strength conveniently and accurately. In this study, the buckling strength assessment system by using offshore code, DNV-RP-C201 was developed under MSC/PATRAN, pre-post program of finite element method. Graphic user interface program is written in MSC/PATRAN PCL functions. Source program to evaluate the buckling strength is developed in FORTRAN programming languages. The developed program is verified by comparing with the results of the Nauticus Hull developed by DNV Classification Society, and applied to the marine construction project conducted by Hyundai Heavy Industries LTD.

We work for big offshore project in the Korean shipyards as a EPC contract. There are a lot of risks even though the FEED Engineering was taken in the famous engineering company. In case of ICHTHYS CPF, it worked on the FEED activity for several years. Here is mention that design modification was carried how to modify material and specification according to shipyards human resource and yard practice for your reference. Furthermore, I expect that this paper is used for Korean engineer for their reference.

The vessels which are operated in ECA (Emission Control Area) after $1^{st}$ January 2016 shall be complied with revised NOx emission requirement (Tier III). Effective solutions for NOx emission requirement are SCR (Selective Catalytic Reduction), EGR (Exhaust Gas Recirculation) and Installation of LNG Dual Fuel Engine. This study is considered the design modification as per application of LNG Ready notation. In case of LNG Ready - S notation, the vessel shall be retrofitted the Main engine with Dual fuel engine and LNG Fuel system after delivery. On this paper, the entire process for design modification was explained to meet the requirement for LNG Ready notation.

Recently oil price has got lower, but energy efficiency has been considered as an important factor to minimize ship operational costs and reduce greenhouse gas emissions. For the reason, it is necessary that energy efficiency improvement for hull form design and operational performance reflect an understanding of the vessel's operational profile. Throughout the life of the vessel, this can lead to important economies of fuel, even if, in some cases, a small penalty can be taken for design condition. In the present paper, hull form was developed for 5,000TEU class container carrier at given operation profile. As a CFD result at several design point, optimized hull form has improved resistance performance in comparison with the basis hull form. To reducing the viscosity and the wave resistance at multi draft and multi speed, the hull form was investigated for Cp-curve, frame and local shape. Numerical study has been performed using WAVIS & Star-CCM+ and verified by model test in the towing tank.

All passenger ships aboard more than 36 passengers are to be able to easily find escape routes when the escape way by fire with flame spread were onboard vessel (incl. Ferry, Passenger, Ro-pax, Inland Ferry) It should be impossible by ordinary emergency lights. The international Maritime Organization (IMO) gives special requirement for luminescent evaluation onboard test procedure and applicable location of low location lighting. In order to maintain the residual light source for a certain time in the low location lighting with a strip-shaped light source, the light source material must be sufficiently exposed to the light due to the proper placement of the escape route. The lighting arrangement influence how maintain low location lighting strip luminescent which measured onboard in connection with what elements are mainly sustain luminescent.

This paper presents on the evaluation of thermal comfort in office on offshore. In living quarter of offshore, strict air conditioning performance is required to office on offshore and displacement ventilation is applied to office space which rooms are required to confirm the thermal environment. The computational fluid dynamics (CFD) is performed to calculate the temperature, air velocity in office and thermal comfort such as PPM & PPD is evaluated by the CFD result.

IACS enacted Harmonized CSR(CSR-H) to meet the IMO GBS applied from 1 July 2016. CSR-H is clearly complement and integrate than present CSR-BC & CSR-OT. One of the biggest issue in new rule is structural analysis. In CSR-H, structural analysis must carried out entire each cargo area including the aft bulkhead of the aftermost cargo hold and the collision bulkhead. Accordingly, new load and boundary conditions are present, an additional structural reinforcement is required by the structural analysis result for each cargo hold. In this study, we applied CSR-H to existing 158K DWT CLASS CRUDE OIL TANKER in order to compare and analyze the hull changes. It is useful for the application of the CSR-H to the similar vessel and helpful in finding the optimized structural design.

This paper is related to structural assessment considering the hydroelastic response of ultra large container ships, especially from whipping (bow or stern impacts) and from springing (resonance). In general, whipping contributes both to increased fatigue and extreme loading, while springing does mainly contribute to increased fatigue loading. To evaluate the hydroelastic response quantitatively with high accuracy, numerical code considering hydro-structure coupling was applied and fatigue strength of a 13,100 TEU class containership was verified. The segmented model test and full scale measurement were also needed to assess the effect of whipping and springing on the fatigue and extreme capacity in more realistic way and for verification of the numerical tools. With reference to class rule, fatigue assessment considering springing effect and extreme assessment considering whipping effect were introduced.

As the considerable request of the fast and accurate way of the selection of circuit breaker is increased, we introduce the development of software of circuit breaker selection for the marine use. Originally, the selection of circuit breaker has been carried out by manual in the marine project. It is not the easy work to select the proper type of circuit breaker to check the time-current characteristic curves of each type of circuit breakers for the various type of loads. In this regards, we developed the software to select the proper type of circuit breaker to confirm fast and accurately. And, we introduce the course of the development of the software for the selection of circuit breaker.

IMO type C independent tank is one of the cargo containment system specified on IGC code. It is normally adopted for small and medium size liquefied gas carrier's cargo containment system and it can be applied to fuel tank of LNG fueled vessel. This study focuses on rule scantling process and evaluation methods in early design stage of type C independent tank. Actual design results of 22K LPG/Ammonia/VCM carrier's No.2 cargo tank are demonstrated. This paper presents the calculation methods of design acceleration and liquid height for internal design pressure as defined on IGC code. And this paper shows the applied results of classification rules about shell thickness requirement and buckling strength. Additionally this paper deals with evaluation methods of structural strength and cumulative fatigue damage using FE analysis.

Condensation is one of the common issues which we can easily see in everyday life. For example, the surface of glasses with cold water is easily moisturized. This wet surface gives us uncomfortable feeling and is sometimes dangerous because it is slippery. As the safety on working space is one of the most important issue on offshore project, condensation is also important matter to take care of with precaution. Since the bottom of vessel or offshore facility is submersed in the water, the risk of having condensate on the steel surface is getting higher because sea water temperature is normally lower than ambient temperature. And if there is any electric equipment or person working in that space, condensation is normally not allowed. The pontoon of semi-submersible drilling rig is such a space which is submersed, with electric and mechanical equipments and person working periodically. To prevent condensation in pontoon, study was conducted by checking several cases.