Stationkeeping in Solid Drift Ice (original) (raw)

Propulsion Machinery Operating In Ice – A Modelling And Simulation Approach

ECMS 2013 Proceedings edited by: Webjorn Rekdalsbakken, Robin T. Bye, Houxiang Zhang, 2013

Shipping activity and offshore operations in Arctic areas are increasing as a result of more effective transportation routes and oil/gas exploration. Vessels navigating in ice covered areas are exposed to additional loads from different ice conditions. In this paper the dynamic loads on propellers are investigated to better understand the impact on propeller, power transmission elements and engine. An ice-propeller interaction model is implemented with a full propulsion machinery to simulate the systems response to ice loads. The ice load models are developed based on the DNV and IACS rules for ice-propellers. Modelling and simulation of interactive multi body systems is a rather complex task, involving hydrodynamics, mechanics, electronics and control systems. This paper describes an approach to link the different models to simulate the overall system response and the interactions between the sub-systems. Therein, the rule-based ice loads are implemented in two ways for comparison: a) a coupled and b) an uncoupled treatment of the ice load and system response. The simulation results show that the dynamic peak loads are 10-20% lower than the maximum peaks predicted by the uncoupled simulation, i.e. conventional rule-based. Simulations also show that the peak loads are damped through the transmission elements, and therefore reducing the load on critical machinery components.

Sea Ice Engineering

Ice engineering covers a variety of subjects, mainly involving the interaction of ice with marine structures, as well as the use of ice as a construction material. The focus of this presentation is on ocean and offshore applications. While much of the material on ice properties and mechanics also applies to other ice engineering topics (such as river ice and coastal ice problems), the applications focus here will be on the action of ice on offshore structures and the interaction of ships and ice.

Full-scale ice impact to an azimuthing thruster in laboratory conditions

2017

Ships navigating in winter conditions frequently come in contact with ice blocks floating on the waterways. The ice blocks can collide with the propulsion machinery of the ship. Especially the interaction between ice and ship azimuthing propulsion call for greater understanding. Ice blocks can collide with the azimuthing propulsion units in many different ways, one of them being the propulsion unit hitting the ice block as the ship advances. This is an impact type loading case and the dynamics of the thruster and ship hull affect to the load response level obtained in this case. In a dynamic system, the damping is greatly affecting to the response level. To study the dynamics and damping in an ice impact event, a full-scale test opportunity was found in an azimuthing thruster test bench. An impact test with a full-scale thruster and ice blocks was carried out in the laboratory with velocities corresponding to realistic ship operating speeds. In addition, numerical analyses of the ic...

Station Keeping in Ice – Challenges and Possibilities

2013

Station keeping in ice covered waters must react to forces caused by drifting ice. The reaction forces from a station keeping system can be generated by dynamic positioning (DP) in light ice conditions. In more severe ice conditions, only mooring can create large enough forces to counteract the ice forces. An intermediate system is DP assisted mooring where DP controls the heading towards ice drift. The paper describes various station keeping methods and their operational envelopes in terms of ice conditions. Further, methods to estimate the operational envelopes are described. The effect of ice management on the operational envelope is considered. Finally, the future development of methods to estimate the operational envelopes of station keeping systems are described as well as development in station keeping systems.

North Pole ice-resistant self-propelled platform as an innovative complex for research in the Arctic

E3S Web of Conferences

The Russian presence in the Arctic Region and the development of the Arctic is one of the most important geopolitical interests of Russia. At the beginning of the 21st century, the problem of using innovative methods in Arctic research came to the fore. Based on the analysis of the unique work experience of drifting stations “Severniy Polus” (“North Pole”) (1937-2015), Arctic and Antarctic Research Institute specialists have concluded that the stations should be replaced by a modern scientific complex, capable of solving a wider range of problems. As a result, it was proposed to create an ice-resistant self-propelled platform (IRSPP) – an engineering structure for permanent basing of scientific observatories. The IRSPP is designed to conduct year-round comprehensive scientific research in the high latitudes of the Arctic Ocean and should make a long drift of at least one year together with the surrounding ice massive. The scientific complex of the IRSPP includes 16 different laborat...