NR NR/L2/SIG/30009/P060 ISSUE 2 PDF

This module primarily reflects multiple aspect signalling to which Track Circuit Block Regulations apply, controlled from a route setting panel or VDU system. The concepts also apply to other interlocking and block systems. Any significantly different / additional considerations to other forms of signalling are specifically identified. 

This Module and those directly associated with it equally apply to railway which is ETCS fitted unless there are no applicable lineside signals.

NOTE: The principles appropriate to Modular Signalling are as specified within the functional requirements of NR/L2/SIG/30097/Appx C which references those standards extant in April 2014 and therefore is not affected by the publication of this module.

This module applies to all command and control equipments (see the typical listing in NR/L2/SIG/30009/A060 Section C1.2) for new provision and, subject to consideration of "using reasonable opportunity" and practicability, all alterations to signalling where the changes appreciably alter the risk associated with the layout and with any of the signals within the scheme.

Changes to layout risk are likely when any of the following apply:

a) alterations are made to a layout;

b) lines become designated as passenger;

c) layouts are re-signalled or relocked (or re-controlled, though it is recognised that the opportunity to mitigate existing risk is generally limited);

d) additional routes are provided;

e) platforms are added;

f) permissible or attainable speeds are changed, whether raised or lowered;

g) an overrun or timetable risk assessment (or similar) identifies the need to review protection. 

Where the content of application standards (such as NR/L2/SIG/11201, SSI8003, NR/GN/SIG/CAT0005) are different to the requirements described in this standard this standard takes precedence.

This section describes controls between signals and commissioned points and movable infrastructure:

• facing and trailing points (combining to form crossovers, tandem points, single and double slips, etc.); 

• swing nose crossings; 

• switch diamond crossings (effectively two point ends); 

• trap points and catch points; 

• derailers and scotch blocks;

• movable bridges.

NOTE: The implication being that points not yet commissioned and the means by which risk is mitigated is not included; see NR/L2/SIG/11704.

The following items of movable infrastructure do not require control by the signalling system but may (in prescribed layout situations) be required to be detected:

i) train operated points (including spring points); 

ii) hand points; 

iii) non-powered derailers and scotch blocks.

This module comprises mandatory sections, statements of best practice (to be followed unless an alternative can be demonstrated to be beneficial to the company and no less safe), and guidance.

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 but in particular NR/L2/SIG/30009/A060. 

The SPH details Network Rail’s requirements for the provision of functional logic between signals, movable infrastructure such as points and other parts of the signalling system to control the risk of: 

 a) failure of moving infrastructure to establish a wheeled path; 

 b) collision between a train and another train legitimately present; 

 c) the issuing of a movement authority to the train driver and its subsequent removal. 

The SPH comprises mandatory sections and guidance. The guidance is to be followed unless an alternative can be demonstrated to be beneficial and no less safe. It satisfies the relevant parts of the IRSE Fundamental Requirements for Train Control Systems.