Original scientific paper
https://doi.org/10.21278/brod67303
INFLUENCE OF OPERABILITY CRITERIA LIMITING VALUES ON SHIP SPEED
Jasna Prpić-Oršić
; Faculty of Engineering, University of Rijeka, Vukovarska 58, 51000 Rijeka
Odd Magnus Faltinsen
; Centre for Autonomous Marine Operations and Systems (AMOS), Department of Marine Technology, NTNU, Trondheim, Norway
Joško Parunov
; Faculty of Mechanical engineering and Naval Architecture, University of Zagreb, Croatia
Abstract
When the ship is caught in heavy seas, there are two manoeuvres that the shipmaster can undertake to avoid excessive ship motion and hull damage: changing course or voluntary speed reduction. This paper presents a study of the effect of the various voluntary speed reduction criteria to attainable speed of ship on seaway. The speed loss is calculated by taking into account wind and wave effect on ship speed, the engine and propeller performance in actual seas as well as the mass inertia of the ship. The attainable ship speed for ship in head, following and beam waves by accounting for voluntary speed reduction is estimated for various significant wave height. The criteria of slamming, deck wetness, propeller emergence, excessive accelerations and roll are taken into account. The impact of variations of the limiting values of certain criteria due to which the captain intentionally reduces the ship speed is analysed and discussed.
Keywords
Operability criteria; Seakeeping; Voluntary speed reduction
Hrčak ID:
161987
URI
Publication date:
30.9.2016.
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