▁S - class ▁sub mar ines ▁( 1 9 3 1 ) ▁Category : Miss ing ▁sub mar ines ▁of ▁World ▁War ▁II ▁Category : 1 9 4 2 ▁ships ▁Category : World ▁War ▁II ▁sub mar ines ▁of ▁the ▁United ▁Kingdom ▁Category : L ost ▁sub mar ines ▁of ▁the ▁United ▁Kingdom ▁Category : Sh ips ▁lost ▁with ▁all ▁hands ▁Category : Mar itime ▁inc idents ▁in ▁June ▁ 1 9 4 4 ▁Category : World ▁War ▁II ▁ship w re cks ▁in ▁the ▁Mediter rane an ▁Category : Sh ips ▁s unk ▁by ▁mines <0x0A> </s> ▁The ▁ ▁was ▁an ▁ice bre aker ▁of ▁the ▁Imperial ▁Japanese ▁Navy ▁( I J N ) ▁serving ▁during ▁the ▁ 1 9 2 0 s ▁through ▁World ▁War ▁II , ▁the ▁only ▁ship ▁of ▁her ▁class . ▁She ▁was ▁the ▁only ▁ice bre aker ▁war ship ▁in ▁the ▁I J N . ▁ ▁Background ▁▁ Ō tom ari ▁was ▁planned ▁as ▁one ▁of ▁the ▁Kam oi - class ▁oil ers ▁under ▁the ▁E ight - e ight ▁fleet ▁plan ▁at ▁first . ▁The ▁Nikol ay ev sk ▁Inc ident ▁( 1 2 ▁March ▁ 1 9 2 0 ▁– ▁ 3 ▁June ▁ 1 9 2 0 ) ▁changed ▁the ▁plan . ▁The ▁Imperial ▁Japanese ▁Navy ▁was ▁not ▁able ▁to ▁dispatch ▁their ▁war ship ▁to ▁Nikol ay ev sk ▁which ▁fro ze , ▁because ▁they ▁did ▁not ▁have ▁an ▁ice bre aker . ▁Japanese ▁civ ili ans ▁were ▁killed ▁by ▁terror ists ▁in ▁this