DESIGN AND CONSTRUCTION OF WESTMINSTER STATION ON THE JUBILEE LINE EXTENSION.

Creating Westminster station on the Jubilee Line Extension involved construction of the deepest box excavation in London and complete renewal of an operational Underground station with only minor disruptions to service. The task was further complicated by the need to provide foundations for a New Parliamentary Building above the station, which required lowering the District and Circle Line tracks by 300 mm. The control of ground movements was also of paramount importance since one of the world's most famous landmarks—Big Ben clock tower—is within 30 m of the 39 m deep station.