scope:

Requirements in this module apply to layouts when infrastructure layout changes take place: 

a) resignalling; 

b) alterations are made to an existing layout; 

c) renewals of infrastructure where there are points or derailers that provide trapping protection; 

d) the designated purpose of lines and sidings are changed including   

  • when changes are made to the use of reception lines, sidings and adjacent facilities, especially at the boundary with other administrations   

  • when the change of use relates to the stabling of trains.

Purpose 

This module forms part of the Signalling Principles Handbook (NR/L2/SIG/30009)and is to be read in conjunction with the other modules of the handbook. See especially Module A060, and A200 which refers to legacy practices. 

It describes appropriate measures for the detection of trains at trap points buffer stops and arrestors to control the consequences of vehicles running away or exceeding the movement authority at these infrastructure features. 

This SPH comprises mandatory sections, statements of good practice (which shall be followed unless an alternative can be demonstrated to be beneficial to the company and no less safe), and guidance on historical practices (which are not to be applied to new works but provide information on previous standards or their interpretation.