disambiguation ) ▁ ▁Thomas ▁By r nes ▁( disambiguation ) <0x0A> </s> ▁The ▁ ▁is ▁a ▁limited ▁express ▁train ▁service ▁in ▁Japan ▁operated ▁by ▁the ▁H ok ka ido ▁Railway ▁Company ▁( J R ▁H ok ka ido ), ▁which ▁runs ▁between ▁ ▁and ▁. ▁As ▁of ▁March ▁ 2 0 1 2 , ▁there ▁are ▁four ▁services ▁per ▁day ▁running ▁in ▁both ▁directions , ▁with ▁the ▁journey ▁time ▁taking ▁approximately ▁ 5 ▁hours ▁ 3 0 ▁minutes . ▁Tra ins ▁operate ▁at ▁a ▁maximum ▁speed ▁of ▁ 1 1 0   km / h . ▁It ▁is ▁named ▁after ▁the ▁Sea ▁of ▁Ok hot sk . ▁ ▁Rol ling ▁stock ▁Ok hot sk ▁services ▁are ▁normally ▁formed ▁of ▁ 4 - car ▁Ki Ha ▁ 1 8 3 ▁series ▁dies el ▁multiple ▁unit ▁( DM U ) ▁trains ▁as ▁shown ▁below , ▁with ▁car ▁ 1 ▁at ▁the ▁S app oro ▁and ▁Ab ash iri ▁end ▁( train ▁revers es ▁at ▁Eng aru ▁Station ). ▁ ▁Form ations ▁All ▁cars ▁are ▁no - sm oking . ▁ ▁Past ▁ ▁Ki Ha ▁ 2 2 ▁DM Us ▁( Se ptember ▁ 1 9 5 9 ▁– ▁October ▁ 1 9 6 1 ) ▁ ▁Ki Ha ▁ 5 6 ▁DM Us ▁( Oct ober ▁ 1 9 6 1 ▁– ▁October ▁ 1 9 7 2 ) ▁ ▁Ki Ha ▁ 8 0 ▁DM Us ▁( Oct ober ▁ 1 9 7 2 ▁– ▁November ▁ 1 9 8 6 ) ▁ ▁History