Summary of Working Paper No. 62-1996

III.11.1: New Concepts of Removing Ice. Investigation of the efficiency and advisability to use non-traditional shape of hull lines for icebreakers and icebreaking cargo ships of Arctic navigation.

By Alexander V. Ierusalimsky, S.M. Ponomarev and T.M. Semanova, Central Marine Research and Design Institute (CNIIMF), St. Petersburg, Russia.

Analysis was carried out of the results of full-scale trials of icebreakers "Mudyug" and "Kapitan Sorokin" with barge-like forebody after their conversion by the Thyssen-Nordseewerke as well as of the icebreaker "Kapitan Nikolaev" of the same type as the latter for which the Masa-Yard Company has built a new forebody with conical lines. Comparison was made with the results of similar tests of all three icebreakers prior to the conversion when they had modern icebreaking forebody lines of traditional type having a wedge-like waterline and stem. Analysis was carried out using the results of tests and experimental operation of pushed icebreaking - icecleaning attachments realizing the principle of ice destruction similar to the Thyssen-Waas conception. To estimate the efficiency of non-traditional lines, a comparison is made in this report on the basis of the results of trials and experience of operation of icebreakers of "Kapitan Sorokin" type prior to and after conversion. Preliminary conclusions on the advantages and disadvantages of non-traditional hull lines were formulated.