Emergency repairs to Stanwell Park viaduct

Some of you would be aware that the Viaduct was constructed as part of the Stanwell Park Deviation between 1916 and 1920. The purpose of the line deviation was to ease the 1 in 40 rising grade in the Up direction, and eliminate the notorious Otford tunnel. Almost one and a half kilometres in length, and on 1 in 40 grade, Otford tunnel was not only a bottleneck to the expansion of rail traffic to the South Coast, but was also the cause of severe discomfort to passengers and crews alike. Prevailing winds in the area filled the tunnel with smoke and steam. Drivers and firemen working heavy coal trains were sometimes scalded and overcome by smoke. During the last years of its operation a blower system was installed to alleviate the problem. However, it was not until the deviation was opened on 10 October 1920, that public and staff could look forward to a trip on the lllawarra Line without trepidation. The Deviation took the form of a duplicated track around the amphitheatre at the rear of the beach, and is on a grade of 1 in 80. Although 1 kilometre longer than the old line, there was no loss in running time. The Viaduct is/was? a magnificent structure of 8 arches and has an overall length of 148 metres, minus 235mm. It is built on a 240 metre radius curve and the track is some 45 metres above ground level at its centre as it passes over Stanwell Creek. The Viaduct is of brick skin construction (bricks being manufactured on site) with rubble infill and then stone parapets. Arches are 13 metres in diameter. Up until August 1985, the Viaduct was in very good condition with no visible evidence of any major deterioration. On 14.8.85 cracking was noted in the floor of No. 3 arch. Remedial works were carried out to this span. Work included lowering of both tracks to relieve the spandrel walls of side pressure and installation of tie bolts· with vertical supports to brace the span. These works were completed in September, 1985. Regular monitoring of the structure continued and on 8 December 1985 the Up track was closed due to Joss of brickwork from the arch in span 6. On 12 December 1985 only 3 days before the proposed opening of the lllawarra Electrification, the Viaduct was closed to allow repairs and further investigations as to the cause of the damage. The immediate problem became how to repair the Viaduct as quickly as possible, without knowing the real cause of the failure and what further damage was likely to occur. This was later expanded as to how to investigate, design and construct a "bridge" in under 8 weeks with no plans, materials, information and when manufacturers and contractors are closed for the Christmas holidays. While the task may sound daunting, staff and contractors on the 1llawarra Electrification Project were used to such challenges and suitably rose to the occasion.

• Record URL:
  • https://railknowledgebank.com/Presto/content/Detail.aspx?ctID=MTk4MTRjNDUtNWQ0My00OTBmLTllYWUtZWFjM2U2OTE0ZDY3&rID=NDg2OA==&qrs=RmFsc2U=&ph=VHJ1ZQ==&bckToL=VHJ1ZQ==&rrtc=VHJ1ZQ==
• Authors:
  • Allen J
  • Hickey M
• Conference:
  • Permanent Way Institution (PWI) NSW 1986 Annual Convention: More than just a Pretty Track
• Publication Date: 1986

Media Info

• Pagination: 23p. ; PDF
• Monograph Title: Permanent Way Institution (PWI) NSW, 1986 annual convention

Subject/Index Terms

• TRT Terms: Repairing; Safety
• ATRI Terms: Repair; Structural safety
• Subject Areas: Safety and Human Factors;

Filing Info

• Accession Number: 01711535
• Record Type: Publication
• Source Agency: ARRB
• Files: ATRI
• Created Date: Jul 19 2019 2:28PM