26.—(1) The undertaker may compulsorily acquire such rights, and impose such restrictions, in the subsoil of, or the air-space of, the land referred to in article 21 (compulsory acquisition of rights) as may be required for any purpose for which such rights or restrictions may be acquired in land under that provision instead of acquiring the rights or imposing restrictions over the whole of the land.
(2) Where the undertaker acquires any right or imposes any restriction in the subsoil of, or the air-space over, land under paragraph (1), the undertaker is not required to acquire an interest in any other part of the land.