Narrandera to Yanco Rail Project

Client: John Holland

Project: Narrandera to Yanco Cutting and Embankment Works

Description: Improve drainage and access to a rail line cutting to allow ongoing maintenance

Barnson’s Role: Surveying of the site, geotechnical assessment of cuttings, civil design of drainage and new cutting profiles

Time frame: Project planning carried out in 2014, with works to be completed in April 2015

Two rail line cuttings between Narrandera and Yanco, on the Junee to Yanco rail corridor were presenting a challenge to John Holland. Poor drainage within the cuttings was causing formation issues and making it difficult to access the sites to perform routine maintenance. There was evidence of sink holes and blowouts and a significant amount of rock needed removing. There was also the potential need for speed restrictions on this area of track if the work was not carried out.

This project presented a number of challenges, including:

  • Limited access
  • No access on the downside – access needed to be re-instated.
  • Water running ponding in the ballast of the track causing subgrade failures
  • Rock infringing on rail corridor clearances.


The Barnson team was involved in the geotechnical assessment of the cutting rock and soil stability. The site was then surveyed by Barnson to determine the current cutting profiles, track location and current drainage paths. A sub-consultant track designer, Lycopodium was engaged to confirm the curved section of track was within curve alignment tolerances.


Barnson’s civil engineers produced drainage calculations and applied the geotechnical cutting parameters to then provide design drawings for the cutting re-shaping and drainage improvements. Once the works are complete, Barnson’s surveyors will re-peg the track control marks and re-check the track horizontal alignment.