During the past 5 years the Arctic Technology Department was involved and coordinated several public funded research projects. The following links provide more information on Arctic Technology related research projects at HSVA:

ONR: Investigations on the Level Ice Resistance of Ships with Non-typical Icebreaking Bow Shapes

Project period from June 2018 to May 2021

For typical icebreaker shaped vessels with an inclined bow and low flare angles the major components of the hull-ice interaction process are quite well understood. Analytical methods exist to predict the average resistance based on few inputs for the hull shape characteristic and ice properties. For non-typical icebreaking ships the interaction process includes many unknown phenomena like cracking, splitting and crushing, which are difficult to be described by straightforward approaches. Furthermore, the accumulation and clearing of the broken ice floes is completely different. Finally, the database (e.g. from model tests) of performance records for such vessels in solid ice is very limited.

The demand for a more profound understanding of ice interaction with non-icebreaker shaped vessels results from an increasing number of those ships accessing Arctic and Antarctic waters. Examples are cruise expedition vessels and government vessels with multiple missions (coast guard, rescue and salvage). Even if the sailing time of those vessels in ice is limited to few weeks in a year, a detailed assessment of their capabilities in ice is required to optimize their design and operational profile.

A study to investigate and understand the basic process of sea-ice interaction with ships of open-water or moderate icebreaking shape is currently ongoing at HSVA. The objective is to identify the major process phenomena and to find correlations between parameters, especially those between the hull geometry, ice properties and motion characteristics of a vessel. The study is supported by the Office of Naval Research (ONR) and includes theoretic investigation and physical model tests conducted in the large ice model basin of HSVA. The aims are as follows:
•    improve principal understanding of the hull-ice interaction process, ice failure and the components contributing to the ice resistance
•    find methods to evaluate the ice performance (ice resistance, attainable speed) as well as the factors of major influence
•    enhance quantity and quality of ship-ice interaction observations
•    provide a database of results obtained under controlled conditions

FATICE: Fatigue damage from dynamic ice action

After completion of the DYPIC project, HSVA is again involved in a big European Research Project. FATICE is a MarTERA ERA-NET COFUND Project that started in 2018. The duration is 36 months again with seven international partners involved (listed below). HSVA’s contribution is funded the Federal Ministry of Economic Affairs and Energy while the other partners are funded by their individual national bodies.

FATICE deals with assessment of fatigue damage on fixed offshore structures exposed to drifting sea ice. Offshore structures are important for European industry and society with respect to exploitation of oil and gas, other mineral resources, aids for navigation and development of offshore wind. Fatigue is one of the main challenges for these structures and the present guidelines include large uncertainties that may give very heavy and expensive structures. This has three main reasons:

a) Ice conditions are poorly defined,
b) ice loads and structural response are estimated independently and
c) the assumption of linear (or independent) damage accumulations found in fatigue estimation. In FATICE the two fields of Ice-induced Vibrations (IIV) and Fatigue assessment will be combined to a) define time-series of load cycles and structural response (occurrence of IIV + coupled ice-structure interaction model) and b) develop a new method to assess fatigue life through Variable Amplitude Loading (VAL). This allows for the first time for the design of reliable and thus cost-efficient fixed offshore structures exposed to drifting sea ice and consequently for recommendations for novel guidelines.

HSVA will be involved in four Phases of Ice model testing with special focus on developing a new kind of model ice that is optimized to represent crushing failure. The new model ice will mainly be applied in ice-structure interaction tests but can also be used for ship tests in which local crushing failure occurs.

Partners:

NTNU – Norwegian University of Science and Technology (Coordinator), Trondheim, Norway
HSVA –The Hamburg Ship Model Basin, Hamburg, Germany
TUHH – Hamburg University of Technology, Institute for design and analysis of ships, Hamburg, Germany
DIMB Engineering, Trondheim, Norway
Siemens Wind Power B.V., Den Haag, Netherlands

Subcontractors:

TU-Delft – Delft University of Technology, Delft, Netherlands

Contributors:

TÜV Nord EnSys GmbH & Co. KG, Hamburg, Germany