[1] [1] BIRD K J, PENTIER R R, GAUTIER D L, et al. Circumarctic resource appraisal: estimates of undiscovered oil gas nth of the arctic circle[R]. [S. l. ]: U. S. Geological Survey, 2008.

[2] PEROVICH D K, RICHTER M J A. Loss of sea ice in the Arctic[J]. Annual Review of Marine Science, 1, 417-441(2009).

[3] PAKASTE R, LAUKIA K, WILHELMSON M et al. Experience with Azipod propulsion systems on board marine vessels[J]. ABB Review, 2, 12-18(1999).

[9] [9] ISLAM M, JAHRA F, MOLYNEUX D, et al. Numerical research on usage of podded propulss in ice management[C]OTC Arctic Technology Conference. Copenhagen, Denmark: Offshe Technology Conference, 2015.

[10] [10] DOBRODEEV A, SAZONOV K, RYUSHIN A, et al. Experimental studies of ice loads on pod propulss of icegoing suppt ships[C]Proceedings of the 24th International Conference on Pt Ocean Engineering under Arctic Conditions. Busan, South Kea: POAC, 2017.

[12] [12] International Association of Classification Societies. Requirements concerning polar class[S]. [S.l.]: IACS, 2011.

[13] [13] Wld Meteological ganization. WMO seaice nomenclature: terminology, codes, illustrated glossary symbols[S]. [S.l.]: Secretariat of the Wld Meteological ganization, 2014.

[14] TIMCO G W, WEEKS W F. A review of the engineering properties of sea ice[J]. Cold Regions Science and Technology, 60, 107-129(2010).

[15] [15] Finnish Maritime Administration. FinnishSwedish ice class rules[S]. [S.l.]: Finnish Transpt Safety Agency, 2017.

[18] [18] Arctic Council. Arctic marine shipping assessment 2009 rept[R]. Tromsø: Arctic Council, 2009.

[19] JEONG S Y, CHOI K, KANG K J et al. Prediction of ship resistance in level ice based on empirical approach[J]. International Journal of Naval Architecture and Ocean Engineering, 9, 613-623(2017).

[20] [20] JONES S J. Resistance propulsion model tests of the USCGC Healy (model 546) in ice[R]. St. John''s, NL, Canada: Institute f Ocean Technology, National Research Council of Canada, 2005.

[21] [21] LINDQVIST G. A straightfward method f calculation of ice resistance of ships[C]Proceedings of the 10th International Conference on Pt Ocean Engineering under Arctic Conditions. Lulea, Sweden: POAC, 1989.

[22] ERCEG S, EHLERS S. Semi-empirical level ice resistance prediction methods[J]. Ship Technology Research, 64, 1-14(2017).

[23] [23] KOKKILA M. Polar expedition ships: ultimate passenger safety comft with Azipod propulsion[EBOL]. [20210126].https:new.abb.comdocslibrariesprovider91leafletsbrochuresabb_whitepaper_polar_cruise_kokkila.pdf.

[24] [24] American Bureau of Shipping. Guidance notes on ice loads on azimuthing propulsion units [EBOL]. [20210126].https:ww2.eagle.gcontentdameaglerulesguidescurrentspecial_service235_Guidance_Notes_on_Ice_Loads_on_Azimuthing_Propulsion_Unitsapuiceloadsgnaug20.pdf.