This is a seasonal operation of Limited Express Okhotsk that connect Sapporo (札幌) and Abashiri (網走) in Hokkaido. This train is operated from late January to early March for Ryuhyo (流氷=Drift ice) viewing. The operation, like time required and route, is completely same as Limited Express Okhotsk. But this seasonal train is operated by specialized car. The accommodation is much better than regular train of Limited Express Okhotsk.
Ryuhyo Norokko train has been stopped operation because of carriage was too old. Other train replaced Ryuhyo Norokko train but it is operated by common fleet.
Ryuhyo (Drift Ice=流氷) viewing is most popular things to do in Hokkaido during the winter time. This sea ice reach around Abashiri from late January to late March. The best season to view this ice is mid February. This train, Ryuhyo Norokko train is operated in this Ryuhyo season between Abashiri (網走) and Shiretoko-Shari (知床斜里) where is the gate town to Shiretoko peninsula. This train goes on Senmo line (釧網本線) along the coast of Sea of Okhotsk. You have lots of change to see the sea ice from the train. And also Abashiri can be reached by Limited Express Okhotsk or seasonal tran, Ryuhyo Limited Express Okhotsk no Kaze from Sapporo. Both express train from Sapporo and Ryuhyo Norokko train are fully covered by Japan Rail Pass.
Limited Express Okhotsk and Taisetsu take you to Abashiri from Sapporo and Asahikawa. Abashiri is well known as drift ice viewing in winter time. And also when you go to the world heritage site, Shiretoko, you may use this train to Abashiri and transfer to the local train to Shiretoko-Shari. If you need the information about the access to Shiretoko, please see one of my posts, “How to get Shiretoko“.