scope:

Introduction

This Track Work Instruction covers how to manage maintenance on a single line. It should be remembered that single lines can carry traffic of all speeds - they are not just slow speed rural railways.

The term "single line" is usually understood to mean one track that can carry traffic in either direction. However some single lines, particularly those associated with flyover type junctions, normally carry traffic in one direction only.

See also the separate instruction:

TWI 3G089 How to relay on a single line