The development and introduction of early warning monitoring devices for the Illawarra railway

In the autumn of 1988 the Illawarra region received unusually heavy rainfall which resulted in many major geotechnical problems along the Illawarra Escarpment. This caused extensive damage to the rail line and adjoining property, due to embankment failures, and also the deaths of 2 residents at Coledale. Extensive embankment reconstruction and culvert installation was undertaken in an effort to ensure the safety of rail traffic and nearby residents on the Illawarra Line. In conjunction with these major earthworks, consultants advised that some system of detection was needed to monitor embankment movement. This was required on both reconstructed and suspect embankments, which may not be able to be upgraded for some time. While earth movement measuring devices were available, a system was not then developed for movement monitoring, to immediately produce remote alarms for embankment failure. A joint effort between the Signals and Civil Engineering Sections developed a system which would fulfil all requirements to keep the rail line safe. Signals Engineering already had the infrastructure to handle the circuit design, protection of the site by existing signals, and transmission of alarm indication to remote location. The slip detector was developed with contributions from consultants, Civil and Signals personnel and geotechnical equipment suppliers. There was also a need for an automatic measuring device for rainfall. Recent hydrological studies completed in December 1989 had shown that many culverts were under capacity, or could provide the necessary capacity only under high water head pressure. This meant the railway embankment was acting as a dam, something for which the embankments were not designed. The study showed that, based on a 1 in 100 years storm, more than 50% of culverts were under capacity. In many cases this meant increasing the culvert size from .4 metre to 3.2 metres diameter.

Media Info

  • Pagination: 16p. ; PDF
  • Monograph Title: Permanent Way Institution (PWI) NSW, 1990 annual convention

Subject/Index Terms

Filing Info

  • Accession Number: 01711381
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ATRI
  • Created Date: Jul 19 2019 2:23PM