HEXHAM TRACK RECONDITIONING
Finalist – Category 1 CCF Earth Awards NSW 2019
Abergeldie was engaged by ARTC to carry out a 400m track reconditioning project at Hexham. The Hexham project was just one of the package of works delivered across a number of track reconditioning sites throughout the Hunter Valley. Works included 1.7m deep excavation of the track-supporting ground formation, filled with 900mm rock and geofabric/ geogrid layers with 400mm ballast on top.
The works were completed in wetland conditions under a Track Work Authority (TWA) arrangement for working adjacent to the live up-and-down mains. Although no rail traffic was permitted on the two lines on which Abergeldie was working during the possession period, live rail traffic continued on the two lines immediately adjacent.
SCOPE OF WORKS
- temporary traffic management for overland haul routes and interfaces with public roads;
- detailed, round the clock works programming on an hour by hour basis;
- preparation of site and amenities;
- transport, delivery, receipt and inspection of materials supplied by ARTC;
- survey set out;
- signals infrastructure disconnection;
- track removal;
- underlying formation excavation and reconditioning;
- cess drain regrading;
- track reinstatement;
- signals infrastructure reconnection; and
- testing and certification.
COMPLEXITY AND INNOVATION
The major on-site elements of the works could only be carried out during a strictly limited, pre-scheduled weekday period of “rail possession” with a 96-hour timeframe. To address time constraints, each critical step was thoroughly planned to meet the project’s completion time.
Works were being carried out during the summer when NSW was having a heat wave, which affected the overall progression of the project. To work within these extreme conditions, fatigue management was required to be maintained to an adequate standard, dust control was stepped up using spray from a large watercart, and alternative construction methods for clipping
up were implemented to mitigate negative impacts from the
Groundwater ingress was a constant challenge during excavation as the rail corridor stretches through the Hunter Wetlands National Park, through swamp land with a high groundwater table and subject flooding. A temporary coffer dam was established to provide the crew with a dry worksite and the ability to maintain productivity levels throughout all stages of the program.
A project-specific Environmental Management Plan was developed for the Hexham site, to address all environmental obligations and requirements.