The railway line between Knockmore (south of Lisburn) and Lurgan consists of a twin-track railway with a maximum line speed of 90mph. In areas, actual speeds were reduced by Permanent Speed Restrictions (PSRs) and further Temporary Speed Restrictions (TSR’s).
The primary objective of the Track Ballast Rehabilitation Programme was to return and maintain the operational line speed on the network to the design speed as a result of rehabilitated permanent way ballast.
NIR proposed to undertake these works by use of a Ballast Cleaner and new ballast to rehabilitate the existing track ballast. The Ballast Cleaner is an on-track machine which excavates ballast below the sleepers, screens the excavated material and returns suitable size stone to the trackbed together with the addition and distribution of imported virgin ballast into the Permanent Way to replace the removed unsuitable material.
The Enabling Works scheme was undertaken in advance of the ballast cleaning site works. One of the aims of this scheme was to ensure that the Ballast Cleaner was able to work in a cleared zone free from infrastructure.