scope:

This product specification applies to TPWS FIUs for TPWS trackside subsystems when the associated TPWS fitted signal is mechanically operated and controlled i.e. a signal without the ability for the signal in rear to be replaced to danger automatically in the event of TPWS failure. It may also be used for failure reporting of TPWS at Permanent Speed Restrictions (PSRs) or buffer stops in areas where signals are mechanically operated and controlled.

This product specification should be read in conjunction with RAILTRACK COMPANY Specification RT/E/S/10133 TPWS Signalling Interface Design Requirements.

PURPOSE

The purpose of this product specification is to define the performance requirements for a Train Protection and Warning System (TPWS) Failure Indication Unit (FIU) that will be used for reporting of failed TPWS track subsystem in mechanically signalled areas where there are no existing circuits for the proving of lamp alight in the signal in rear.