3-D modelling brings high-tech accuracy to heritage conservation
To help preserve the red grain elevator in Creston, Leslie Boyer used innovative technology to ensure the elevator will be accessible, virtually and physically, for future generations to come. State-of-the-art laser scanning equipment has completely captured the existing image of the elevator and now the team working on preserving the historic building has the meticulous specifications it needs to perform vital next steps and future generations will always have virtual image.
Boyer, who owns SiteBIM, based in Edmonton, used the laser scanning equipment on the Alberta Wheat Pool (red) grain elevator to obtain incredibly accurate and detailed measurements that are “exponentially” better than what other types of manual equipment can obtain, he says. The scanner—which turns on a tripod while also using a spinning mirror—captures 976,000 measurements per second, all accurate to within one millimetre. Boyer then oversees as a computer meshes the scans together into one digital 3-D model, called a point cloud.
Colourized photographs are also stitched together in three-dimensional space to create a panoramic walkthrough of the building—think Google Maps, but specific to this site and every floor of the building. This enables the consultant team to revisit the site virtually at any time.
While Boyer has scanned heritage buildings before, this was his first time in a grain elevator. “This was fun,” he says. When in functioning order, the main focus of the building is the vertical conveyer belt, also known as the elevator leg, which uses gravity to load and unload bins and deliver the grain into rail cars. “Technically, they’re wonderful structures.”
The technology he uses is also impressive. Boyer has been in the business almost nine years and was one of the first in Canada to use the FARO Laser Scanner. The technology and software have seen a lot of improvements over the last couple of years alone. When it comes to conserving historic buildings, “it’s becoming more and more necessary,” he says.
Now, the information he obtained on the red elevator is in the hands of architects. Summer Bourgon is the Designer and Heritage Conservation Specialist at Next Architecture. “The level of detail is amazing,” she says. “Because it’s so accurate and it captures so much detail, we were actually able to trace the faded lettering on the side of the elevator.”
This precision will result in hands-on action, when the measurements will be used to guide exterior repair work. “We’re refinishing the siding on the elevator,” she says. “We’re putting a new roof on it, but it’s going to be the same style of roof as before, with the cedar shingles. We’re basically preserving it in its current design so it doesn’t deteriorate further.”
Inside will see a structural enhancements, safety features installed, such as a fire alarm system, exit lighting, safety railings, and a lifeline on the ladder in the middle of the building. The work should wrap up by the end of this year.
Soon, passers-by will see this elevator in much closer condition to its glory days. Part of this will include freshly painted lettering, which, with the aid of high-tech efforts, will be nearly identical to the original. Future generations will also have a digital legacy of this iconic landmark.
In 2018, the Trust purchased this iconic grain elevator—and the neighbouring Midland & Pacific (white) one—to help preserve the region’s history and share it with future generations. Approximately six storeys high, the elevators were built in 1935 (the white one) and 1936 (the red one) and were used to collect, store and ship locally grown wheat, barley, oats and rye. They closed to public use in 1971 and were sold to a private business person, who used the premises to sell seed and feed and purchase grain from local farmers for shipment to Alberta and Vancouver and eventually ceased operations in the mid 80’s.