PIPA Pipescout™ & PLUTO S™ successfully completes first tethered line submerged siphon inspection project in Dublin, Ireland on 3 locations
Scope of Works
PIPA & Service partner API were recently contacted by a pipeline contractor GMC based in Ireland. The client working with water utility Irish Water has several siphon mains located below river crossing that are always fully submerged with high velocity flows, and required a method to assess current condition. The pipelines being submerged containing wastewater could not use traditional inspection systems like CCTV devices and other ROV traditional techniques as the client could not get the results required.
Project location
The Liffey Siphon was constructed in circa 1900 as part of the original Dublin City Drainage Scheme that removed untreated wastewater discharges from the River Liffey. The siphon runs from Eden Quay (north bank of River Liffey) to Burgh Quay (south bank of River Liffey) and is within the Dublin City centre catchment.
The Rosie Hackett Bridge is a Luas and Bus transport corridor. The bridge was constructed directly over the siphon in 2012 under an NTA/DCC Transport Project. The siphon structure is considered a critical wastewater asset within the Greater Dublin Area (GDA).
The Liffey Siphon, which is an inverted siphon (always submerged with flow), is a single cast-iron pipeline. It is brick lined with an internal diameter of 3 feet 4 inches (1m) and is 210 feet long (64 m).
GMC Utilities Group on behalf of Uisce Eireann decided to undertake a detailed survey of the siphon, including confined space entry to carry out a sonar and an acoustic survey using PIPA Technology delivered by pipe inspection experts API. This will be one of the first occasions in Ireland where this method will be used to survey a wastewater siphon. The results will indicate the condition of the aging structure and the need for remedial works.
Project Challenges
The pipelines are located under river crossings with entry via grid covered chambers.
The pipes are carrying untreated waste water lines supporting a large area of Dublin, Ireland.
The pipelines are cast iron and brick lined pipes.
The water content is not clear and contains many contaminants so CCTV was not an option.
The pipelines discharged large amounts of water with a very high velocity identified.
Due to pipe location and entry points located close to a traffic carrying bridge a short working window was available at night only.
The submerged pipes had not been inspected in many years so current condition was unknown.
PIPA Technology used on project
The Pipescout™ and PLUTO™ system offers long range tethered pressurised floating pipe assessments that include CCTV, Sonar, Leak location and pipe tracing up to a range of 5km.
API Successfully delivered the project using PIPA Technology that includes a high strength umbilical cable, pressure rated hydrophone capsule and buoyant sonar pod system tethered to a cable to give the operator live scan data during an inspection. The system enters a pipeline via a predetermined riser. The system works on a live basis, with no interruptions to the client’s services.
The unique water safe cable can be installed and left inside pipelines as part of an ongoing monitoring process. This means that the lines can be inspected every year to quickly identify all new leaks as they occur. The system also offers pipe contractors a failsafe on all new pipe installations.
The technology is the latest live main inspection system on the market being fully battery powered and only requires a 2-person team for its Implementation.
Survey results
API successfully surveyed 3 pipelines
Tethered insertion technology system allowed for precise location of the leaks to be identified
Acoustic system is very sensitive and able to pick up small and large leaks
The cable has been left installed for future inspections and monitoring
System is portable and was easily carried out of vehicle to the entry points, and is self-powered via batteries for silent operation during a night shift in a sound sensitive residential area
Complete sonar scan survey and pipe acoustic evaluation completed in one insertion
Conclusion
It would have been very difficult and expensive for contractor to find the remaining issues within the pipelines if they had to dewater the lines. The long range tethered acoustic and sonar capability proved indispensable for locating issues and troubleshooting pipelines even with multiple bend configurations prior to rehabilitation projects.
API completed the pipe inspections in 1 working week including travel from and to the UK.
The utility client was impressed by the quick procedure to float down and install a monitoring cable and complete a tethered sonar and leakage inspection undertaken by API.
All cables are now left and safely secured at each end of the pipelines for future pipe analysis.
PIPA representative Fabio Orlandi Director said- The project was a great success, Ideal due to pipe location and water type with a high flow and also a great case study for our company. The contractor had exhausted all other pipeline inspection avenues, and was more than relieved when we offered a solution.
API representative Carl Read Operations Manager said- The project turned out to be a great job for the team in Ireland. We will be promoting this inspection service to our wide client base in 2024.
PIPA through API has also delivered successful projects with the majority of the UK water utility companies, and is now seeking partner operators for the Pipescout™ & PLUTO S™ technology globally.
For more information contact sales@pipa-uk.com
