PHOX Skyshaft relocation
- Project: PHOX Skyshaft Relocation
- Client: M2P Engineering
- Sector: Mining & Resources
- Year: 2024–2025
Fraser-Lever provided the temporary works engineering and structural verification required to enable a substantially completed Skyshaft structure to be assembled away from the shaft collar and relocated to its permanent position using Self-Propelled Modular Transporters (SPMTs).
Project overview
The project developed the temporary works and structural verification required to support the off-shaft assembly and relocation of a 616.8-tonne Skyshaft structure at Prominent Hill Mine.
The Skyshaft was designed to be pre-assembled on temporary foundations in a dedicated laydown area approximately 400–500 metres from its final location, before being transported to the Wira Shaft using SPMTs.
Fraser-Lever’s engineering covered the temporary assembly foundations, steel transport frame and connections, assessment of the loaded SPMT travel across the existing shaft collar, temporary propping beneath the collar slab and reinstatement of modified permanent steelwork following removal of the transport frame.
Fraser-Lever’s role
Fraser-Lever provided structural and civil engineering, temporary works design and engineering verification across the Skyshaft relocation methodology. The scope included:
- Independent mass and centre-of-gravity verification
- Temporary concrete assembly footing design
- Temporary steel transport frame design
- Connections between the transport frame and Skyshaft columns
- Structural assessment of the existing shaft collar under SPMT loading
- Temporary propping assessment and design input
- Structural analysis and finite-element assessment
- Column repair and reinstatement details following removal of temporary steelwork
- Civil foundation drawings and design reporting
- Review and coordination of shop details
- RPEQ design certification and sign-off
Fraser-Lever integrated client, vendor, geotechnical and SPMT information into a coordinated temporary works design basis, supported by structural modelling, first-principles connection checks and constructability review.
The engineering challenge
Relocating a structure of this scale required the temporary works, transport system and existing shaft infrastructure to be considered as a single engineering problem.
The design needed to accommodate the 616.8-tonne transport mass, the height and geometry of the Skyshaft, centre-of-gravity accuracy, temporary wind exposure and acceleration and braking loads generated during SPMT transport.
The transport route introduced further constraints, including strict grade limits and limited manoeuvring tolerance as the loaded transporters crossed the existing shaft collar. Ground and concrete bearing, shear and punching shear, local connection forces and modifications to the permanent columns also needed to be assessed.
The engineering required close coordination between M2P Engineering, the site and delivery teams, heavy-lift specialists, fabricators, detailers and other engineering consultants.
Engineering in practice
Fraser-Lever developed an integrated three-part structural solution comprising temporary reinforced-concrete assembly footings, a modular steel transport frame connected adjacent to the Skyshaft columns, and structural verification of the existing shaft collar for the loaded SPMTs.
The team independently checked the structure’s mass and centre of gravity, modelled temporary and transport load combinations, assessed footing bearing, shear and reinforcement requirements, extracted transport-frame actions and verified critical connections through structural analysis and hand calculations.
A key practical decision was the introduction of snug-tight temporary propping beneath the suspended collar roof slab along the SPMT travel path. While the structural assessment did not identify a general requirement for propping, its inclusion provided additional robustness where transporter positioning and manoeuvring tolerances could move loads further into the slab span.
Repair plates were also incorporated to reinstate column capacity following removal of the temporary transport connections.
Project outcomes
Fraser-Lever delivered the temporary works engineering basis, calculations and drawings required to support the proposed Skyshaft assembly and relocation methodology. The engineering package included:
- Temporary assembly foundations
- Transport frame design for the 616.8-tonne move
- Assessment of the existing shaft collar under SPMT loading
- Temporary propping requirements
- Permanent steelwork reinstatement details
- Design calculations and engineering documentation
- RPEQ certification and sign-off
The coordinated approach allowed the temporary foundations, transport steelwork and shaft-collar interfaces to be assessed as one engineering system, reducing uncertainty at critical interfaces and supporting constructability, fabrication, methodology and risk reviews.
Planning a complex brownfield installation?
Talk to our team about practical engineering, temporary works and design verification for complex site installations.