(1) An electrical block instrument for granting or obtaining Line Clear and at least one of the means of communication shall be provided at every station for obtaining or granting Line Clear.
(2) (a) electrical block Instruments for granting or obtaining Line Clear provided at any station shall be of a type approved by the Commissioner of Railway Safety and shall not be brought into use in the first instance unless they have been passed by him.
(b) the official incharge of maintenance of block instrument shall not, without the approval of the said authority, permit the substitution for the instruments and installation brought into use in the first instance or any other instruments or installation which do or does not satisfy the conditions prescribed in clause 2(a).