scope:

This SIN shall apply to all BS113A / CEN56 Vertical Full Depth & Shallow Depth (UIC54/CEN54) S&C and all RT/NR60 S&C fitted with adjustable stretcher bars (to RE/PW/814 or equivalent) installed on running lines, irrespective of point operating equipment or type of turnout.

Note: 'S&C' includes leads, crossovers, double junctions, catch points, switch diamonds, slips, scissors, and tandems

There are a small number of full depth switches with adjustable stretcher bars on the network, these installations are within the scope of this SIN.

All switches with adjustable stretcher bars shall be inspected and recorded under the scope of this SIN; this will include those which are believed to have Hard-Lock nuts already fitted.