Part of the Bradfield Plan, St James station was originally intended to be a major interchange with the Eastern Suburbs line on Sydney's underground rail system. Plans for the construction of St James included railway lines in four directions, but the original plan was never completed due to disagreements over the routes. Four platforms were completed, but the two inner platforms, intended to support Bradfield's proposed eastern and western suburbs lines, were never put into service. When the Eastern Suburbs line was eventually built it was done so via a different route via Town Hall. In the 1990s, the two island platforms were connected by filling in the space between the two inner platforms, resulting in the single, large island platform seen today.