Cutting Concrete, Not Corners, In an Explosive Environment

PCL faced a potentially explosive challenge when completing expansion work on the Cargill Grain Terminal in 2016.
PCL’s Track Expansion Project set out to increase
the grain receiving capacity of the
Cargill Grain Terminal.

The Cargill Grain Terminal in North Vancouver
receives grain from the prairies and ships it to
the rest of the world.​

As one of Canada’s largest agricultural processers, the Cargill Grain Terminal is located in North Vancouver along a major export corridor for grains from the prairies. The terminal has a big job–processing and exporting a major Canadian resource to make it available to the rest of the world. To increase the rate at which the facility can unload shipments from Western Canada’s grain farmers, the Track Expansion Project at the Cargill Grain Terminal set out to expand the grain-receiving capacity of the terminal.

The dangerous challenge came from the volatile nature of the resource itself. Highly concentrated grain dust can be combustible when exposed to spark or flame, a difficult risk to avoid when a team is tasked with cutting new concrete openings. Because of the explosive nature of grain dust, any concrete cutting completed in the terminal historically required a full plant shutdown. The estimated financial and logistical impact of a lengthy shutdown on Cargill and Western Canadian farmers was deemed too great, however. So how did PCL and our partners complete the job in a facility that was required to remain in operation 24 hours a day, seven days a week?

The Spark Zone

Since a complete plant shutdown was out of the question, discussions with Cargill’s plant safety committee and our partners resulted in an alternative solution.

All heat-generating equipment was kept away from the grain receiving area, and a hydraulic wire saw surrounded by fire-resistant hoarding was used in the cutting areas. Created by wrapping plywood with fire blankets and using fans to provide positive pressure, the enclosure encapsulated the “spark potential” zone and kept the plant operational during cutting. A significant volume of water was required to prevent any sparks and reduce wire friction, which was cleaned up using an intrinsically safe vacuum. The project team was able to eliminate the potential for explosion by eliminating any sparks that would have been caused by concrete cutting.

Cargill’s fire watch team was present throughout the entire process, but because of rigorous safety procedures PCL created in partnership with Westcoast Cutting & Coring and Cargill, the entire concrete cutting process was completed without incident.

The project was recently awarded a Vancouver Regional Construction Association 2017 Silver Award in the General Contractors $20 million to $45 million category.

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