5Any hereditament occupied by the Post Office by any such property as follows, namely—
(a)posts, wires, underground cables and ducts, telephone kiosks and other equipment not within a building, being property used for the purposes of telecommunication services ; and
(b)the railway constructed, and the works executed, by the Postmaster General in exercise of the powers conferred by the [1913 c. cxvi.] Post Office (London) Railway Act 1913, and the railway constructed, and the works associated therewith executed, by him in exercise of the powers conferred by the [1954 c. xxix.] Post Office (Site and Railway) Act 1954.