Only Train Controllers may approve ASB for Track under their control.
If a Safety Assessment shows that it is safe, some kinds of work may be done in the
Danger Zone without a Work on Track Authority. ASB is one of those methods of
working.
WARNING
If the Safety Assessment shows that a Work on Track Authority is
necessary, work must not be done using the ASB method.
ASB may be used only:
for station staff to access the Track;
for work using equipment which can be removed from the Track by Workers without
mechanical assistance;
at Network Access Level Crossings, to allow Vehicles to cross the Track; or
to allow Vehicles to directly cross the Track.
If ASB is used, then a Worker may work alone. In this case, that Worker is also the
Protection Officer (PO):
the ASB method of Protection must be applied to Controlled Absolute Signals;
and/or
where the Signal has more than one Route available apply Blocking Facilities to
protect all entry points to the Worksite.
The ASB method must not be used for work that breaks the Track or affects
Infrastructure integrity