 Between late 1962 and early 1964 the east ends of the platforms were extended to allow longer 8 @-@ car trains to be operated . This involved carefully enlarging the tunnels under the Metropolitan Police 's original headquarters at New Scotland Yard ( now Norman Shaw Buildings ) . The station was completely rebuilt to incorporate new deep @-@ level platforms for the Jubilee line when it was extended to the London Docklands in the 1990s . During the works , the level of the sub @-@ surface platforms was lowered to enable ground level access to Portcullis House . This was achieved in small increments which were carried out when the line was closed at night . 
