Westshore Terminals Limited Partnership Inc. (Westshore) operates the busiest single coal export terminal in North America. As part of a plan to diversify their product base, Westshore engaged CWA as the lead consultant in a consulting group (consisting of RF Binnie & Associates Ltd., enCompass Solutions Group, Braun Geotechnical Ltd., and Naesgaard-Amini Geotechnical Ltd.) to conduct a comprehensive study to expand their existing coal export facility by integrating new potash-handling infrastructure that will allow a Stage 1 throughput of 4.5 Mt/y of potash. A planned future Stage 2 will increase Westshore’s potash export capacity to up to 9.2 Mt/y.
The installation of new potash-handling infrastructure and related modifications to existing infrastructure need to be completed in time to receive the first potash train from the BHP Billiton – Jansen Mine, which is currently under construction in Saskatchewan, Canada.
Key requirements from Westshore and the Producer include maintaining the quality of the potash product, minimizing temporary disruptions during construction and permanent impacts on the existing coal operations, and preventing cross-contamination between the two products.
The existing structures at WTLP’s Berth No. 2 will be repurposed for the new dual-product shiploading system and the 50+-year-old foundations will need to be brought into alignment with current seismic codes. Developing concepts to address this presented a significant challenge due to liquefaction and flow slides that occur under the design seismic events.
The seismic design of upland structures was also challenging due to very large displacements that made a standard conveyor truss design infeasible.
CWA developed the layout of the new potash-handling infrastructure and performed the preliminary structural and mechanical design of:
- A new bottom-dump, electrically-indexed railcar unloading system.
- A new 1,200+ metre inbound conveyor network.
- A new 200,000-tonne (Phase 1) potash storage building with a dual-boom portal reclaimer.
- A new 1,300+ metre outbound conveyor network.
- A new dual-product shiploading system including two new dual-product quadrant shiploaders.
- An automatic sampling system.
- Dust collection systems.
- Seismic retrofits to existing Berth 2 foundations.
Where possible, the new potash-handling system will parallel the existing coal-handling system to minimize impacts to the coal operations and stockyard. Tower footprints will be minimized and conveyor bent locations will be optimized to maintain existing site services and access roads as much as possible. The modularization of conveyor galleries and towers will limit the need for onsite laydown areas and reduce installation time during construction.
The study team employed complex geotechnical and structural analyses to investigate several different concepts to retrofit the existing berth structures to align with current seismic standards. The study team developed a concept that will be constructed in short annual shutdowns to minimize the overall impact to ongoing berth operations.
To accommodate seismic considerations for the materials handling infrastructure without requiring disruptive ground improvements on a space-constrained brownfield site, elevated conveyor systems will use an innovative design employing a combination of sliding connections, spherical bearings, and pinned connections at the gallery support locations such that large displacements in a seismic event will not result in structural collapse.
CWA also had an oversight and contributory role in performing overall project execution planning including the development of an AACE Class 4 capital cost estimate and schedule, the development and management of a project risk register, including mitigation measure identification and enaction, and a project procurement strategy.