Provision for duplication

To abate antecedent costs of a band that is assertive to see abundant cartage in the future, a band may be congenital as distinct clue but with earthworks and structures advised for accessible duplication. An archetype is the Strathfield to Hamilton band in New South Wales Australia which was complete as mainly distinct clue in the 1880s, with abounding duplication alone completed about 1910. All bridges, tunnels, stations, and earthworks were congenital for bifold track. The above Baltimore and Ohio Railroad (B&O) band amid Baltimore and Jersey City, now endemic by CSX and Conrail Shared Assets Operations, is an archetype of a duplication band that was bargain to distinct clue in best locations, but has back undergone duplication in abounding places amid Baltimore and Philadelphia, Pennsylvania back CSX added bales schedules in the backward 1990s.

Also Smardale Gill viaduct.