NR TWI 3B015 ISSUE 1 PDF

Introduction

This Track Work Instruction covers the gluing of ballast, sometimes referred to as ‘ballast bonding’.

Ballast gluing is a technique used to increase the stability of the track at locations where any lateral movement is particularly undesirable. The technique can also be used in order to create quasi-slab track, or as a medium for reducing the impact where the track support changes from ballast to a more rigid type of support e.g. longitudinal timbers, a bridge with minimum ballast depths, etc. The technique uses chemical resins to stick the individual pieces of (clean) ballast together. This makes the ballast act as a solid mass.

The pieces of ballast only stick to each other at the points where they touch. Thus, there remains an open structure to the ballast which allows surface water to pass through normally.

Ballast that has been glued is extremely hard when set. The only means of breaking it up is to use a heavy road breaker or some other form of heavy mechanical device. However, once broken it tends to be in relatively large lumps and should be removed. Re-gluing is impractical.

Gluing ballast at sleeper ends only will permit limited tamping operations.