The SCL comprises two sections of new railway: the 11km six-station NSL between Tai Wai and Hung Hom in Kowloon, due to be completed in 2018, and a 6km, four-station extension of the East Rail Line between Hung Hom and Admiralty on Hong Kong Island, which will open in 2020. This will create a 57km east-west rail corridor linking Wu Kai Sha with Tuen Mun.

As part of the project, Thales will modernise the CBTC systems it originally installed in 2003-04 on the Ma On Shan and West Rail lines.

MTR also expects to invite bids in January for the replacement of existing signalling systems with CBTC on the Island Line, Kwun Tong Line, Tsuen Wan Line, Tseung Kwan O Line, Airport Express, Tung Chung Line, and Disneyland Resort Line.