Hamburgische Schiffbau-Versuchsanstalt (Germany)

Abstract The main topics discussed in this paper are icebreaking capacity estimation methods and an introduction to the hull form development of Arctic container ships. The first topic is the estimation of ice resistance and pod propeller net thrust curve based on numerical analysis, the second topic is a discussion of the key performance of the 8K Arctic container ship from a hydrodynamic point of view and its relationship with hull form shape characteristics. As is well known, a precise and scientific approach for ice resistance and propeller net thrust estimation is essential to obtain accurate icebreaking capacity prediction. In this paper, the prediction of pod propeller overload curve through a numerical analysis approach and the ice resistance by Simulator for Arctic Marine Structure were conducted, and these estimation results were evaluated by comparing with the model test results. The accuracy of ice resistance prediction based on the Simulator of Arctic Marine Structures (SAMS) performed in this paper showed an error rate of 10% in the ahead going condition, while in the astern going condition, the error rate was found to be about 40% and 10% in the high and low speed regions, respectively. The reason for the somewhat larger deviation between the model and experimental results in the low-speed case is that the SAMS-based ice resistance analysis does not take into account the pod thrusters. For this reason, the ice-hull interaction is simulated differently from the actual ice behavior, and it is recognized that this effect is more significant at low speeds than at high speeds. On the other hand, the results of the overload curve estimation of the pod propeller through the numerical analysis method showed high accuracy within 4% compared to the model experimental results in both the ahead and astern going conditions. This paper also describes important considerations for designing Arctic vessels, especially from a hydrodynamic performance perspective. For example, balanced open and ice performance in the Arctic, maneuvering ability in ice conditions, and pod propeller cavitation problems are discussed and introduced the application of twin plates, which are relatively free from the risk of pod propeller cavitation. Based on these research activities and experiences, Samsung 8K-class Arctic container ship was developed, and icebreaking performance of Arc7 ice-class and open sea performance of more than 20.0 knots were validated through the model testing in 2024.

_ The paper describes the implementation of state-of-the-art “Industry 4.0” methods and tools, of a holistic ship design optimization and of modular production methods, as well as of advanced battery technologies in the development of an innovative, fully electrical, fast zero-emission catamaran for waterborne urban transport. The design of a fast catamaran passenger ferry prototype (Medstraum), planned for operation as a waterborne shuttle in the Stavanger/Norway area, and of a replicator for operation at the Thames River/London are elaborated, including on land infrastructural issues that are necessary for their operation. The presented research is in the frame of the H2020 funded project “TrAM—Transport: Advanced andModular” (www.tramproject.eu). Introduction The international maritime community is amassing momentum in its efforts towards a drastic reduction of greenhouse gas (GHG) emissions. This is expected to be further accelerated after the upcoming COP261 (COP26: UN Climate Change Conference of Parties) in Glasgow in autumn 2021. The maritime industry is examining alternative ways to contribute actively to this endeavor, despite the additional challenges posed by the COVID-19 pandemic.

This article addresses the problem of the scale effect for an Ultra Large Container Ship (ULCS) with the novel twin-crp-pod propulsion system.Twin-crp-pod propulsion arrangement is an innovative solution that gains from three well-known systems: twin-propeller, contra-rotating propellers and pod propulsor.It is well-known, that the scale effect has been widely investigated for ships with conventional propulsion systems.Nevertheless for ships with the crp-pod propulsion arrangement, due to the combination of shaft propeller and pod propulsor, the problem is a cutting-edge challenge and as such has never been investigated in detail.To address this knowledge gap, CFD numerical simulations in various scales were performed, and this article presents the results of these calculations.The scope of simulations covered self-propulsion tests for a full-scale and model-scale Ultra Large Container Ship in calm water conditions.The model-scale calculations performed at scale 1: 37.416 were validated using towing test results.The self-propulsion simulations have been carried out similarly to towing tank tests following the British method.Calculations were performed for vessel design speed, the constant revolution of the shaft propeller and two different revolutions of the pod propeller.CFD simulations were performed using an unsteady RANS approach.The finite volume method was applied to solve the governing equations of mass and momentum conservation, and STAR-CCM+ software was used.The sliding mesh approach with a rotating region around the local coordinate system was used to model the propeller directly.The flow was turbulent with the k-ω SST turbulence model applied.The second-order implicit temporal discretization scheme was applied.The full-scale simulations have been compared with towing tank extrapolated results.The comparison covered the total resistance of the bare hull, wake fraction, relative rotational efficiency, thrust deduction and propeller revolution required to achieve the self-propulsion point.

Abstract A study is performed to establish and enlarge the knowledge on the factors influencing the friction between ice and ship hulls. A set of experimental friction tests with a newly designed testing apparatus with computer controlled stroke, speed and acceleration is conducted. The testing involves the determination of the friction coefficient between an ice sample and a reference plate representing a ship hull with ice resistant coating. Results show a characterized, mostly decreasing evolution of the friction coefficient with an increasing number of testing cycles, especially at medium to large testing speed values. The influence of the normal load is significantly smaller and varies with the sliding speed. The friction coefficient tends to increase with a decreasing ice temperature. Finally the paper gives the basis to transfer the influence of these parameters (or others) at the laboratory level to the total ship resistance in ice.

Survivability of damaged ships, especially ro-ro/passenger (ropax) vessels, is of paramount interest. Nowadays, time-domain simulation of flooding and motions of damaged ships are more frequently performed to obtain a more realistic overview of the actual survivability in case of a flooding accident. An international benchmark study on simulation of flooding and motions of damaged ropax vessels was conducted within the EU Horizon 2020 project FLARE, using new dedicated model tests as a reference. The test cases include transient flooding in both calm water and in irregular beam seas, as well as gradual flooding and capsizing in beam seas. The studied damage case is a two-compartment collision damage, and the studied intact metacentric height values were lower than the statutory requirements to achieve also capsize cases. Numerical results were carefully compared against measurement data from the model tests. In transient flooding cases the capsize conditions were generally detected well by most codes. However, much variation was observed in the internal flooding and capsize mechanisms. For gradual flooding in beam seas, the results for capsize rate and time-to-capsize were characterized by significant variability among the codes. Results indicate that more research is needed to further improve the time-domain flooding simulation methods to correctly capture both transient flooding phenomena and motions of damaged ship in high waves.

150 years ago, the first modern icebreaker in the world was designed by the naval architect Carl Ferdinand Steinhaus and built for purpose of removing ice barriers on the river Elbe in Hamburg, Germany. No model tests were performed at that time. Later, in the first half of the 20th century, “model tests” for ships were carried out in natural ice on lakes. In the 1950th the first-generation ice model basins were put in operation and ice model testing became a standard method in the icebreaker design process. This paper discusses the influence of the economic and environmental development in arctic regions, driven by shipping and offshore activities in environmental changing Arctic Waters, on the ice model basin design, equipment and testing methods. The developments will be presented with examples from The Hamburg Ship Model Basin (HSVA). To complete the overview, an outlook to future trends is attempted.

Abstract Sea ice pressure ridges have been recognized as important locations for both physical and biological processes. Thus, understanding the associated light‐field is crucial, but their complex structure and internal geometry render them hard to study by field methods. To calculate the in‐ and under‐ridge light field, we combined output from an ice mechanical model with a Monte‐Carlo ray tracing simulation. This results in realistic light fields showing that light levels within the ridge itself are significantly higher than under the surrounding level ice. Light guided through ridge cavities and scattering in between ridge blocks also results in a more isotropic ridge‐internal light field. While the true variability of light transmittance through a ridge can only be represented in ray tracing models, we show that simple parameterizations based on ice thickness and macro‐porosity allow accurate estimation of mean light levels available for photosynthesis underneath ridges in field studies and large‐scale models.