The house flag of British Rail. A pale blue rectangular flag with an applied motif of two parallel rails and arrows pointing in opposite directions. The flag is made of a wool and synthetic fibre bunting; the hoist and central motif are made of cotton. It is machine sewn with a rope and toggle attached.

The shipping services of Britain’s railway companies were born out of a desire to continue services beyond the end of the line and coordinating rail and sea traffic for passengers, cargo and mail. Routes were operated to the Continent, Ireland, the Channel Islands, the Western Isles of Scotland, and the Isle of Wight as well as numerous estuarial ferry crossings. After nationalization, the various railway companies were amalgamated into a single organization called British Railways (although control of the shipping side of the business was still regionalized). Further reorganization in 1963 saw the creation of British Rail, and with it came the new double arrow logo.

The 1960s saw the gradual transformation from steamships to diesel roll-on roll-off vessels; although the company was initially slow to see their benefit. The carrying of vehicles and road freight became the main function of the company.

The regions finally lost the control of shipping on 1 January 1968 when British Rail Shipping and International Services was formed. It became responsible for all British Rail shipping services, railway owned ports and the development of traffic and liaison with continental and Irish railway administrations. Links to continental rail and maritime companies brought about the formation of Sealink in 1970, a consortium including British Rail and the SNCF, along with other continental companies.

British Rail Shipping and International Services ceased to exist in 1979, and its function, assets and staff were transferred to a new company wholly owned by the British Rail Board named Sealink UK Ltd, still part of the Sealink consortium.
The service was sold to Sea Containers Ltd in 1984, becoming Sealink British Ferries. In 1991 it was sold to Stena Line, becoming Sealink Stena Line, then Stena Sealink. It was finally rebranded to Stena Line in 1995.