A technical methodology for establishing structural limitations of ships in pack ice

Abstract

This thesis presents a technical methodology for determining operational limitations for ships in pack ice from a structural risk perspective. The methodology relies on mechanics of ship-ice interaction and direct analysis of structural response. The limitations are presented in the form of so-called “safe speed” curves derived by a set of calculations under specific technical assumptions. These operational envelopes are useful in understanding a ship’s structural capability in a variety of ice types beyond the notional description of an ice class notation or lack thereof. The work focuses on hull forms and structural arrangements which are not necessarily intended for dedicated or aggressive ice operations and explores consequences of different operational demands. Non-ice strengthened and light ice class structures that may operate in light to medium pack ice present new technical challenges that require modifications to the conventional mechanics that form the basis of existing models and approaches. This thesis proposes several modifications and offers two case studies to demonstrate the methodology and highlight the influence of key parameters.