Before a rail safety officer enters railway premises (which are not a public place) under section 77, the officer must give the occupier of the premises reasonable notice of the intention to enter unless:
(a) giving the notice would be reasonably likely to defeat the purpose for which it is intended to enter the premises; or
(b) entry to the premises is made with the consent of the occupier of the premises; or
(c) entry is required in circumstances where the officer reasonably believes there is an immediate risk to safety or another form of emergency; or
(d) entry is authorised by a warrant issued under section 86.