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Suspension ships are a novel type of ships that utilize a suspension system as an integral part of their structure. One critical aspect of a suspension ship is its stability characteristics. The parameters that affect the initial transverse stability of these ships include the ship’s mass ratio, loaded height of suspension, placement location height of suspension, and beam. It is found that designing a suspension ship in monohull configuration is more difficult than in a catamaran configuration. Special attention is required when the static mass ratio is below 2 for both monohulls and catamarans.

The hydrodynamic noise of surface vessels has recently received significant attention. The unclear mechanism of the scale effect makes it challenging to accurately convert the hydrodynamic noise obtained from a scaled model to the actual ship scale. This paper introduces a dynamic towing method for a Wigley catamaran on the lake to eliminate the impact of propeller noise and mechanical noise. An annular hydrophone array was used to test the underwater radiation noise of the Wigley catamaran at various distances and directions at speeds of 4 knots and 6 knots. The experimental results show that the hydrodynamic noise is a broadband sound with a continuous spectral distribution. The hydrodynamic noise has the maximum energy contribution in the range from 100 Hz to 10 kHz, with the peak frequency 1600 Hz.

This study introduces a novel test bed, named the Maverick , which aims to advance the field of autonomous inland waterborne freight transportation and facilitate its eventual implementation. More specifically, the Maverick focuses on operating in small waterways within urban areas, aligning its application scenario with the European project AVATAR. The hull form of the Maverick was selected to be a catamaran, as it offers several advantages, including a large open deck area, high transverse stability, and excellent maneuverability at low speeds. The Maverick is equipped with two 360-degrees-steerable azimuth thrusters, one at the bow and one at the stern. This configuration makes the Maverick over-actuated, and offers more advanced motion control possibilities compared to conventional rudder-propeller actuated vessels. The Maverick is composed out of modular building blocks combined with a flexible interface, which enables it to accommodate diverse control terminals for future developments. Furthermore, to illustrate the feasibility of the Maverick within an urban context, this study also includes results of several trail tests. The interactive communication framework that was successfully employed in the autonomous sailing experiment is introduced. The Maverick offers a versatile platform for testing and developing a wide range of technologies in situation awareness, autonomous sailing, smart waterway logistics, and other interconnected domains. Therefore, this innovative research vessel can pave the way for the development of a new freight transport mode within European urban areas, contributing valuable experiences to the field.

At present, there is little research on the strength simulation calculation method of local steel structure at the joint between the fin stabilizer and hull of SWATH at home and abroad. Aiming at the problems of high-stress levels and difficult local strength of the local structure at the joint of SWATH submersible and stable fin, this paper, based on APDL language, takes a SWATH ship as an example, establishes a whole ship simulation model, analyses and studies the modeling scope, modeling requirements, boundary conditions, and loading methods of the local calculation model of stable fin, and puts forward an efficient simulation calculation and analysis method, namely sub-model method, which is suitable for the local strength calculation of stable fin, and provides guidance for the structural design method of the stable fin of SWATH catamaran.

The condition of the crew boat is good hull shape with good operational conditions when maneuvering. In this case, the condition of the waveform at sea will have a significant impact on the ship’s motion. To provide the optimal type of hull, it was developed by conducting several simulations on the ship’s motion. Several simulation conditions were carried out, including analyses of ship speed, the shape of the waves formed, and ship maneuvering. At the simulation stage, several types of hulls were carried out, including the single U-hull, the single V-hull, the trimaran, and the catamaran. The simulation limits the length of the ship but not the width of the ship because the conditions in the multi-hull require sufficient space for its width, so that it can be ascertained that it provides effective and efficient results for the selection of the shape of the hull. The simulation analysis carried out provides a recommendation that the single V hull model gives good results compared to other types of hull selection for crew boat hulls.

In this article, the calm water resistance and dynamic instabilities of a semi-displacement catamaran fitted with a stern wedge is investigated using an experimental method and numerical technique. This is accomplished in order to probe into the effects of aft geometry modification on semi-displacement ship dynamic characteristics, especially at medium and high speeds. An advanced 6-DOF model that takes into consideration the dynamic mesh method has been utilized in open source code OpenFOAM. Reynolds-Average Navier-Stokes (RANS) equations are solved using standard k-ε turbulence model and VOF method. The accuracy of the current numerical method is investigated by the calm water test in National Persian Gulf Towing Tank. The resistance, trim and sinkage of the ship were monitored during the experiments. The experimental analysis was performed on the initial model and a modified model with 8º wedge at different Froude numbers. After that, the wedges were mounted at different angles at the transom of the vessel and the effect of the angle change for 4 different angles was evaluated using numerical solution. The results show that fitting a stern wedge to this type of ship causes an intense pressure at the stern bottom. Also, it decreases the dynamic trimming and forward resistance of the craft. As well as, stern wedge causes increasing the lift force which affects the reduction of dynamic instabilities. It is concluded that numerical model presented here is quite suitable for accurately predicting dynamic characteristics of a semi-planing twin-hull ships at medium and high Froude numbers. As a result, 14% reduction in total resistance was observed due to the installation of a 6 degree stern wedge.

T-foil and stern tabs were installed on a wave-piercing catamaran (Incat Tasmania Hull 061) to improve ship motions and passenger comfort. More than 40 total effective hours of sea trials were conducted by the US Navy in 2004, encountering sea states 4–5 in the Atlantic Ocean near the United Kingdom. In this paper the influence of a ride-control system (RCS) on the heave and pitch response amplitude operator (RAO) of the full-scale high-speed catamaran was investigated using the sea trial data. The reduction in motion sickness incidence (MSI) was estimated in order to examine the effectiveness of the RCS in improving passenger comfort. With the existing control algorithm, the vertical accelerations were found to be best controlled by the active T-foil working together with the active stern tabs, while the pitch RAO was mainly mitigated by deploying only the stern tabs. About a 23% reduction was observed in the peak heave RAO with deployment of an active T-foil. The MSI can be reduced by up to 23% with respect to the cases with stern tabs only, depending on the encountered wave conditions, based on ISO recommendation for MSI calculation of a 2-h seaway passage.

Modern ship designs are being developed for various purposes in uncrewed operation. In particular, low-speed uncrewed surface vehicle (USV) catamarans have been applied as rescued boats in recent years. Therefore, predicting the performance of this ship type in calm water and waves is necessary. This study investigates the response, shear force, and bending moment of a low-speed USV catamaran operating in regular and irregular waves. Numerical simulations are conducted using the Ansys AQWA solver, which employs the boundary element method to model inviscid flow. The catamaran’s responses in regular waves, with the ratio of wavelength to ship length ranging from 0.4 to 2.0, are compared with the experimental data. The catamaran’s behavior in irregular waves is then determined from integrating its responses in regular waves over the encounter wave spectrum. Additionally, the catamaran’s responses and the wave-induced vertical shear force and the bending moment at the x- and y-axes within a frequency range of 0.2 to 3.0 rad/s are analyzed. We demonstrated that the heave, roll, and pitch of the catamaran align well with the corresponding experimental data. Significant vertical shear forces are observed at a wavelength-to-ship-length ratio of 1.0, particularly at one-fourth of the ship's length from either end. The transverse bending moment is significant in a wide range of wave frequencies for the ship in beam seas. The findings show that the maximum midship vertical bending moment in the frequency range of 1.5 to 3.0 when the ship moves in head waves should be considered. The vertical shear force and transverse midship bending moment in the whole frequency domain should be assessed when the catamaran operates in beam waves.

The estimation of fatigue life in the design process is particularly important for weight-optimised ships such as high-speed aluminium craft, but to date no research has been published on the fatigue accumulation on large wave-piercing catamarans, focusing on long-term operations. This paper assesses the applicability of classification society rules for high-speed catamarans with respect to fatigue design. This was achieved by comparing the long-term distributions of stress, measured on a 111m long wave-piercing catamaran ferry whilst operating in the Canary Islands and during the delivery voyage, with load spectra estimated using a method accepted by the classification society, DNV. The paper also proposes an improved distribution fitment method for fatigue analysis. A detailed method to convert measured stress histories in the time domain into an appropriate stress-spectrum and fitment of Weibull parameters is presented. Results show that the simplified method accepted by the classification society is highly conservative regarding fatigue estimation compared to fatigue results based on measured data. The proposed combined Weibull fitment method substantially improves the accuracy of simplified fatigue analysis methods.

Traditional boats are vital for many Indonesians, particularly river and lake passenger boats, which are essential transportation links in specific regions. However, the absence of regulated passenger capacity limits has compromised safety standards. This study aims to determine safe passenger capacities for river and lake boats through shipping risk and stability analyses. Using the minimum passenger area requirements from the Indonesian National Standard (SNI) and stability criteria from the Indonesian Classification Bureau (BKI), passenger capacities were calculated for various boat types across four waters: Lake Matano, the Mahakam River, the Indragiri River, and the Musi River. Boat lengths varied from 3 to 15 meters, and widths varied from 1 to 4.5 meters. The analysis of 15x4.5 meter boats shows that the speed boat is the most stable (134.7 kN.m) and accommodates the most passengers (56 people), the trimaran offers the most significant space despite having the lowest stability (62.0 kN.m), the long boat has the largest passenger area, and the catamaran has the lowest capacity (36 people). This research provides a framework for determining minimum passenger capacities based on boat dimensions and types, contributing to improved river and lake transportation safety standards in Indonesia.