How to - SKS Blocking

An updated cue card for NWT 320 - Signal Key Switch Blocking is now available.

The cue card outlines the important steps and safety critical communication assurances to follow.

An e-learn refresher training for SKS Blocking – Communication protocols will also be rolled out in May 2022.

The Signal Key Switch (SKS) Blocking Rule introduced in 2019 allows the use of an automatic signal fitted with a signal key switch to exclude rail traffic from a portion of the track.

There are currently 14 Signal Key Switches fitted across the Network and another 44 priority signals have been selected for an SKS installation over the next three years.

Training is available for Protection Officers and Handsignallers.

For more information please email

Using a Signal Key Switch

SKS Blocking - General Overview

Establishing SKS Blocking

SKS Blocking - Managing Rail Traffic

SKS Blocking - Ending SKS Blocking