May 28, 2010

STURGESS ARCHITECTURE

Similar to a walkway over the Grand Canyon, the Brewster Discovery Walkway at Jasper National Park will jut out 400 metres to offer a spectacular view. It is being built with private funds and will operate as a paid attraction.

FEATURE | Steel

Alberta’s Jasper National Park to feature a steel walkway offering tourists a bird’s eye view

PETER KENTER

correspondent

Alberta’s Jasper National Park has plans for a futuristic 400-metre glass and steel bridge to allow tourists and visitors to walk suspended above the Sunwapta Valley and the Columbia Ice Fields.

Brewster’s Discovery Walkway will be a privately owned and operated attraction carefully designed to work with the goals of Parks Canada in connecting people with the natural environment in a respectful and sustainable manner.

The cantilevered steel frame project, composed of irregular shapes designed to work with the natural setting, was the winning entry of a competition submitted by the team of Sturgess Architecture of Calgary, RJC Consulting Engineers and PCL Builders Inc.

The design follows the natural landscape of the mountainside, then juts 30 metres outward, providing a bridge with transparent glass floor that will allow visitors a one-of-a-kind viewing experience.

While tourists can enjoy the visitor centre at no cost, the extended walkway will require the purchase of an admission ticket.

The design is intended to encourage viewers to explore the dizzying heights of the outlook while providing them with a sense of safety that encourages them to explore further.

Architecture firm Sturgess Architecture provides a wide variety of designs, ranging from urban designs, to historic restorations, churches and rapid transit.

“We like to work on projects that are more on the edge,” says Jeremy Sturgess, principal architect with the firm.

“On this project, we were invited by structural engineer RJC to become part of the team for the design-build project organized by Brewster Travel Canada. The client had seen the cantilevered overlook at the Grand Canyon designed to allow visitors to look at the gorge. By going to a structural steel cantilevered design, we were able to avoid using a tall-masted structure and instead provide a more subtle design that worked within the mountain context without creating a major impact on the visible landscape.”

Sturgess says that the structure will be bridge-like, but is not actually a bridge. Structural steel members will be anchored deep in the rock face of the mountain to provide support for the cantilevered structure.

Sheets of Corten steel, which will weather to provide a protective rusty patina, will provide the planar faces of the structure. It will quickly take on an earthy tone and texture designed to blend with the natural environment.

“We’re not being pretentious and suggesting that people will see the structure as part of the mountain,” says Sturgess. “However, the design is very congruent with the mountain landscape and the glacial fields below.”

Sturgess notes that typically few visitors to the park will actually visit the valley floor and creek bed to look up at the walkway — virtually all eyes will be focused on the valley below.

“There has been some concern from the public that the attraction will be too visible,” says Sturgess. “However, the existing road is already much more visible and this is just an appendage to that road. We’re actually improving the site by removing the existing parking lot from the viewing area. Visitors will park out of sight and be brought to the viewing area by bus at no charge.”

The project will be built on land leased from Parks Canada and construction will be privately funded.

“We’re just going through the approvals process with Parks Canada, including public consultation, and we hope to be through that process by the end of May,” says Sturgess. “If all goes as planned we’ll be starting construction late this summer and we’ll hopefully be finished by summer 2012. By providing an inclusive visitor experience, we believe we’re meeting Parks Canada’s mandate for engaging visitors hands-down.”

“Once they had mapped out all of the utilities, the base of the support had extended far into St. Joseph Street,” says Love. “At that point they bumped it out just a little farther so that there was enough room in the lower portion for construction vehicles and delivery trucks to drive underneath the support.”

The support is made of steel girders and was constructed over the space of a month under the supervision of heritage masonry specialist Paul Goldsmith, president of Historic Restoration, Inc.

“There was a lot of tweaking of the design,” notes Weir.

“Movement can occur in the bricks over the length of the construction, so the steel was threaded through the wall in locations near the base and other areas where a single stone could be removed and later replaced. That limits the need for extensive repair when the structure is removed.”

The ultimate configuration was a structure 17 metres high and three metres deep. Diagonal members of the support reach out to the middle of the street where they’re anchored into a large concrete base.

Micropiles anchor the structure to the substrate below, small enough to negotiate the restricted spaces between gas, phone, cable, electric, water and sewage utilities. The back of the wall has been sandblasted, then draped with polyethylene sheeting to protect it from the weather and construction work.

As the condominium rises to the fifth floor, the east wall of the historic building will be rebuilt from material salvaged during demolition. As construction proceeds above the facade and the historic elements are tied into new construction, the steel support will be removed.

A row of retail buildings along Yonge Street was also purchased outright by the developers, Graywood Developments Ltd. and Mod Developments Inc., to ensure the condominium building would be flanked on the east side by heritage properties that will help retain the familiar streetscape.

“I think it’s a credit to the developers that they went through the effort and expense to preserve these historic elements with such care,” says Weir.

“Even the steel support structure is beautiful. It cost them a huge amount to pay for the support and the temporarily lost parking to the city, compared to simply demolishing the building, but the end product is a nice heritage project.”

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