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Cliff-hanger swings dizzyingly over Capilano precipice Walkway |
 Cliff-hanger
swings dizzyingly over Capilano precipice
Walkway suspended 30 storeys above canyon
John Stibbard, vice president of operations for
Capilano Suspension
Bridge,
peers over the edge of the company's partially complete Cliffhanger attraction.
The $3.6-million suspended walkway went through 12 redesigns before it was
finally installed on the east side of Capilano Canyon, Monday, October, 11,
2010.John Stibbard stands on a plank perched over the Capilano Canyon abyss and
marvels at the cost of the new Cliffhanger walkway. "$3.6 million," says
Stibbard, vice-president of operations for Capilano Suspension Bridge, on a
recent tour of the private park's latest expansion. "A good portion of that was
figuring out how the hell to build this thing."
The 50-centimetre-wide wood-and-steel platform, which hangs precariously over a
90-metre drop just north of the main visitor centre, is still missing the
railings. Wandering out onto a suspended walkway is easy, he explains. Building
it, it seems, is the hard part.
 Stibbard came up with the idea for the Cliffhanger project when he and a friend
rappelled into that portion of the canyon on an excursion three years ago. The
ferny cliff environment appealed to him, he said. Stibbard decided there must be
a way to allow the public access.
After consultation with engineers, an environmental consultant and District of
North Vancouver staff, the company put a proposal before council in July 2009.
The idea, its backers explained, was to give visitors a close-up view of an area
they would otherwise never see, teach them something about that part of the
ecosystem, and, in essence, to scare the bejesus out of them.
Councillors ultimately gave the project the green light.
The original concept was to build the walkway significantly closer to the
ground, but engineers advised against the idea, pointing out that it would have
to incorporate a huge number of steps, and that building the walkway with so
much cliff face above it would expose it to rock fall.
The company resolved to move the walkway closer to the top of the cliff, but
then it had to figure out how to make it stay there.
Designers also had to consider the danger of falling rock, avoid connecting
supports to weak surfaces and somehow fit largely straight-edged components to
an irregular surface.
The first step was to survey the rock face along the selected route. This in
itself was a challenge, because the survey couldn't be performed from the base
of the canyon -- the easiest option -- since the face was obscured by trees.
Instead, managers sought out workers with experience in mountain climbing and
sent them down the cliff on ropes. The surveyors took measurements using lasers
and other devices while dangling 30 storeys off the ground.
The data they gathered were used to create a 3-D computer model of the rock
face, which was in turn passed on to geotechnical engineers for analysis.
In all, Cliffhanger was redesigned 12 times before it reached its current form.
What resulted was a 213-metre-long series of wooden walkways, steel stairs and
suspended viewing platforms, portions of which swing dizzyingly out over the
canyon to avoid areas where the rock is unstable.
Most of the structure is now in place. The company is just waiting for a spiral
staircase, wire mesh guard, handrails -- at the moment cables strung along its
length provide the only hand-hold -- and some thick pieces of glass that will
form the floor of certain viewing platforms.
In the meantime, crews are working to build a nature walk that leads from the
main visitor centre to the walkway. The area, formerly a gravel works yard, is
being remediated as part of the requirement to reduce the net environmental
impact of the project.
Cliffhanger is due to open in April. Admission will be included in the cost of
entering the park. |
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