The METRONET program represents Perth’s largest ever public transport investment, adding approximately 72 kilometres of new lines and 23 stations to the suburban network to increase capacity. The Thornlie-Cockburn Link will be Perth’s inaugural east-west crossline, enhancing travel flexibility and improving public transport access to the city’s southeastern suburbs.

BG&E’s scope included designing and documenting the relocation of Local Government Authority’s (LGA) and Water Corporation’s water distribution and reticulation mains, gravity sewer network, main drainage networks and Jandakot Airport’s critical sewer pressure main – all impacted by the rail infrastructure upgrade and duplication within the existing rail corridor.

The pipeline relocations included the design documentation of significant microtunnelled concrete pipe crossings under operating freeways, passenger and freight rail networks to facilitate the installation of new carrier pipework to be installed within the sleeves.

BG&E’s experience on the METRONET project highlights our expertise in designing Water Corporation distribution and reticulation mains within complex rail and urban environments while coordinating with major infrastructure projects. We excel in understanding the design, constructability, and maintenance of Water Corporation assets in close proximity to Western Power’s high voltage transmission lines and the PTA’s electrified rail environments.

The project ran from 2019 through to 2024 and comprised the following relocations

Water Reticulation – Rail Corridor Crossing

Leeming Road Crossing

Design of new microtunnelled sleeve and new pipeline across the rail corridor to replace existing water pipeline.

Clifton Road Crossing

Design of new microtunnelled sleeve and new pipeline across the rail corridor to replace existing water pipeline.

Ranford Road

Design of new sleeved rail corridor crossing within new bridge structure, including specialised bespoke details to address the differing bridge and water main movements across the bridge movement joints.

McLean Road Crossing

Design of a new multi-staged sleeve across the rail corridor to enable the installation of the final Water Corporation new water pipeline.

Water Distribution – Rail Corridor Crossing

Ranford Road

Design and documentation of new microtunnelled sleeve and new DN600 diameter steel pipeline under the rail corridor crossing to replace the existing crossing. Works undertaken with uninterrupted operations of the existing freight rail over the pipeline. Incorporated two separate sections of relocations in the pipe design – one addressing the rail corridor crossing and the second required to facilitate the installation of large retaining walls associated with the new Ranford Road bridge and roadworks.

Main Drainage

Hughes Street Main Drain (Water Corporation)

Design and documentation of the HughesStreet main drain network relocation affected by the proposed rail corridor works, including a new compensating basin and main pipe drainage with bespoke custom pits for the 200 metre siphonic main drain rail crossing to suit Water Corporation’s specific maintenance requirements. Coordination between design teams and stakeholders, including Water Corporation, ARC (Freight) Rail, Public Transport Authority, City of Gosnells and City of Canning, was essential due to the complexity of the combined gravity and hydraulic main drainage network that provides the flood protection to the overall precinct.  The design addressed the continuous operation of the existing ARC freight rail and constant flows within main drainage network – which required extensive interface with all stakeholders and the development of temporary works planning/documentation. This project also incorporated the detailed design of a custom inlet headwall structure to the Water Corporation’s specific requirements with cleanable safety screens and landings.

Amherst Street Main Drain (Water Corporation)

Designed the relocation of existing twin 1350 millimetre diameter main drainage pipe culverts under part of the rail corridor to a new continuous main drainage line under the track crossings over the full rail corridor extents.  With assistance from the Water Corporation’s precinct drainage modelling team, the stormwater flows across the rail corridor were reduced to enable the use of a single 900 millimetre diameter pipe in lieu of the existing twin 1350 millimetre pipes. The design documented the re-use the one of the existing 1350 millimetre diameter pipes as a sleeve for the new 900 millimetre diameter steel drainage pipe across the corridor. The section of the new 900 millimetre diameter steel pipeline beyond the existing 1350 millimetre diameter pipes was designed to be fully concrete encased across the rail corridor. This crossing anticipated and factored into design, the ground movements between existing 1350 millimetre diameter pipe sleeve and the new concrete- encased pipe crossing to ensure no detrimental effect on the rail tracks or the new 900 millimetre diameter steel pipe within the rail corridor.

Cameron Street & Elliot Road Main

Drainage (City of Gosnells-LGA) Designed the relocation of existing triple 1050 millimetre diameter drainage pipe culverts under the rail tracks to a new continuous main drainage system, spanning the entire corridor. This has required designing multiple rail crossings to suit constructability and to delineate the main drainage networks between the City of Gosnells, PTA, and ARC (Freight) Rail. The design incorporated new microtunnelled twin 1200 millimetre diameter pipes under the rail corridor, with the works undertaken with uninterrupted operations of the existing freight rail over the new microtunnelled pipes. In addition, the design documented the re-use the one of the existing 1050 millimetre diameter pipes as a sleeve for the new 700 millimetre diameter concrete drainage pipe across the corridor. The detailed design incorporated a large custom basin headwall/outlet structure with cleanable safety screens and landings, capable of peak flows in excess of four cubic metres per second.Greenway Avenue Main Drainage (City of Gosnells-LGA)

Designed the extension of existing twin 1050 millimetre diameter drainage pipe culverts under the existing freight rail tracks to new continuous main drainage pipes over the full rail corridor extents. This required the removal of the existing twin pipe headwalls within the rail corridor and continuing the twin 1050 millimetre diameter pipes to either side of the rail corridor to new custom City of Gosnells pits within their private lot drainage easements outside of the rail corridor.  This arrangement was developed to ensure that the City of Gosnells does not require access into the ARC (Freight) Rail or PTA electrified rail corridors for any regular maintenance works on their main drainage network.