The job
Perfect Concrete Care was engaged by the John Holland Laing O'Rourke Joint Venture (JHLOR JV) to locate and mark reinforcement in the platform coping along the Sydenham to Bankstown rail corridor. The JV needed to know exactly where the N16 U-bars sat in the coping face at every non-mechanical gap filler location before any drilling or fixing went ahead, so nothing would hit steel.
The brief was 190 locations across both platforms at ten stations: Marrickville, Dulwich Hill, Hurlstone Park, Canterbury, Campsie, Belmore, Lakemba, Wiley Park, Punchbowl and Bankstown. At each one the bars were expected at roughly 200 millimetre centres for two metres either side of the door centre, and the JV wanted them found and marked on the concrete, not estimated off the drawings.
What made it hard
This was live rail corridor work. The scanning could only happen inside track access windows with the traction power isolated, so the programme was set by the possession dates, not by us. The first window opened at short notice: the JV asked on the Monday whether we could start the next day, and we had a technician at Marrickville Station at 7 am on the Tuesday.
Then the power was due back on. With the corridor re-energising on the following Monday, the last three stations dropped out of the first window and had to wait for the next isolation. That kind of stop and restart is normal on rail and the job has to be set up so it does not lose anything when it happens.
How it was done
One GPR scanning technician, Nelson Gallo, ran the whole job with our handheld GPR gear on the coping face. Each gap filler location was scanned across the two metre zone either side of the door centre and the U-bars were marked directly on the concrete for the JV's crews to work to. Working through both platforms at each station and then moving along the line kept the shifts productive inside a window that could close early.
The first window ran from 25 to 28 March 2025 and covered Marrickville, Dulwich Hill, Hurlstone Park, Canterbury, Campsie, Belmore and Lakemba. Wiley Park, Punchbowl and Bankstown were scanned in the May 2025 isolation once the JV had the track back.
Outcome
All 190 locations were scanned and marked across the two access windows. The JV's project engineer confirmed afterwards that the works were carried out safely and professionally and that our technician was reliable on site access, attendance and finishing the works as scheduled.
Rail corridor scanning is a small part of a big project but it is the part that stops a drill hitting a bar. If you need reinforcement located before drilling, coring or anchoring on a live asset, talk to us about GPR scanning in Sydney and Brisbane.
Perfect Concrete Care acknowledges the Aboriginal and Torres Strait Islander people as Traditional Custodians of the country on which we live and work. We pay our respects to the Traditional Custodians and Elders past, present and future, and honour their connection to the land and ongoing contribution to society.