In June 2000 , The MTR Corporation proceeded with its plans to retrofit 2,960 pairs of platform screen doors at all 30 underground stations on the Kwun Tong Line , Tsuen Wan Line , and Island Line in a six year program . In June 2000 , MTRCL proceeded with its plans to retrofit 2,960 pairs of platform screen doors at all 30 underground stations on the Kwun Tong Line , Tsuen Wan Line , and Island Line in a six year program .