Session: 07-01-01 Operations in ice

Submission Number: 153256

Propeller Ice Interaction – Theory and Practise 

Propeller ice loads refer to the forces exerted on ship's propeller when it comes into contact with ice. This interaction is particularly relevant where ships frequently encounter ice floes and ridges. The forces generated during ice impacts can be quite significant compared to open water operation and can affect the structural integrity of the propeller and the entire propulsion system. The ice properties such as thickness, strength, salinity and temperature play major role in determining the magnitude of ice induced propeller loads. Understanding the propeller ice loads is essential for ensuring the safety and efficiencyof ships operating in ice covered waters.

This paper describes the basic principles regarding the design of ice-strengtened propellers.The design principles evolved from experience-based knowledge to analytical calculations of ice loads on the propeller blade.

The different methods will be presented and evaluated by comparing to practical experience and measurements. Constraints and shortcomings with different methodologies will be discussed. In addition propeller damages induced by ice will be discussed. Comparison will be made between different classification rule requirements.

This paper will also discuss the differences on ice loading on pushing type propellers with conventional shaft line icebreakers and modern pulling propellers used in azimuth type thrusters. 

Presenting Author: Samuli Hanninen ABB OY

Presenting Author Biography: Mr. Hänninen works for ABB Marine and Ports business unit in Helsinki, Finland. His position is in ABB global sales team as responsible for icebreaking vessels. Mr. Hänninen is specialized in podded electric propulsion for icebreakers. He has a M.Sc. (Nav. Arch.) degree in Mechanical Engineering, Ship Building department from the Helsinki University of Technology, Finland. He has also worked for Helsinki University Ship laboratory as research scientist and assistant lecturer in courses of ships ice loads and winter navigation. In the last 25 years he has published more than 40 conference papers and reports related to arctic marine technology.