青函トンネル
Neither JR East nor JR Hokkaido owns electric locomotives capable of operating through the Seikan Tunnel to and from Hokkaido after the overhead line voltage was raised from 20 kV to 25 kV AC with the opening of the Hokkaido Shinkansen on 26 March 2016, but JR East leases JR Freight electric locomotives to haul the "Cassiopeia" trainset on seasonal services through the Seikan Tunnel after the Hokkaido Shinkansen opened. The coaches are also used on cruise train services to other destinations within the JR East region.