Multipurpose Polar Icebreaking Subsea Work Vessel Niko Kantonen

Multipurpose Polar Icebreaking Subsea Work Vessel Niko Kantonen Santeri Ihalainen

Hull structure • First round of calculations for the hull structure done in the structural design course • We have the first sketch of the main frame, plates, stiffeners and web frames defined • All the difinitions need to be updated • Checking the compatibility of structure with GA

Main Frame

Work flow • • • The process is started by estimating the pressures on different structural components After that calculating the still water bending moment (SWBM) and wave induced moment, especially the cases where the moment gets the highest values (hogging and sagging) • • To estimate the ships response in irregular sea, the Bonjean curves are utilized For the wave loads the North-Atlantic wave spectrum -> ship response After the loads are estimated the plate thicknesses can calculated according to the classification society rules

Work flow • After the plates the tertiary level response -> defining stiffener sizes • Moving on to secondary level response -> web frames and girders • Finally the hull girder response -> longitudinal strength • Check the critical buckling stresses and make sure those are not exceeded • Check the vibratory response

Problem area - Moonpool • The moonpool is located in the mid ship area • Space reserved around the pool for the hull structures • How should we take the moonpool in consideration in the calculations?

Schedule and work breakdown • First week updating the calculations done in the ship structural course • A more specific estimation of the loads will be carried out • Adding more attention to problem points including the moonpool and other discontinuity points of the ship • Checking the compatibility of structure with GA