Day by day, piece by piece, Darrell Bay Rock is slowly disappearing.
The huge granite bulge just south of Shannon Falls near Squamish, B.C., 45 kilometres north of Vancouver, causes the Sea to Sky Highway to turn at a sharp, treacherous angle. Now it is halfway pulverized, thanks to the careful use of explosives and a portable on-site crusher that turns mountains into hills of gravel.
It is just one small section of the ramped-up level of construction taking place this summer on this 100-kilometre-long connector between Whistler and Greater Vancouver, arguably one of the most scenic drives in the country and one of the more dangerous.
The Darrell Bay Cut, as it is known to the project's engineers and builders alike, will result in a smoother curve and a safer sightline of traffic for drivers, said Rob Ahola, who was hired by British Columbia's Transportation Ministry as chief construction director for the Sea to Sky Highway Improvement Project, the largest such project of his career.
Between May and November this year, 800 workers from Kiewit Construction - the contractor overseeing the work - will have completed 35 per cent of the $600-million expansion that was undertaken in anticipation of the 2010 Winter Olympics.
With construction crews at work about 20 hours a day, 70 per cent of the entire project will be completed by this fall and, unlike other Olympics-connected projects, on budget, Mr. Ahola said.
The result of the work will be an additional 80 kilometres of passing lanes, traffic lights through communities adjacent to the highway and more pull-out spots that will, among other things, allow police greater access to the highway. Bridges are being widened and reinforced to withstand potential damage from debris brought down the mountain in bad weather, and new electronic weather stations will improve highway maintenance response time in the winter.
Overall, two million cubic metres of rock, trees and debris will be removed by the time the expansion is completed, Mr. Ahola said.
One of the most technically complicated sections of the Sea to Sky Highway expansion - the Darrell Bay Cut - involves blowing up 80,000 cubic metres of solid granite, enough to fill 500 railway boxcars, and will be completed next summer, after 18 months of work. Mr. Ahola explained that a flat shelf, or "bench," was blasted out of the top of the rock, providing enough room for an excavator to sit on top and push the boulders created by the blasts onto the highway 20 metres below. A second excavator lifts the boulders onto trucks that then take them to the rock crusher.
This is repeated level by level, bringing the bench closer and closer to highway level. Mr. Ahola said that at several tight points along the highway, blasting out solid rock was the only option, since they could not expand out over the railway, the main line linking Vancouver with Whistler and Squamish, which runs alongside the highway.
Traffic, both rail and road, is stopped when the explosives are detonated, though with large hydro towers above, there isn't much room for error. One miscalculation earlier this year led to the corridor having its Telus Internet link severed for almost a day.
"Blasting adjacent to that [hydro tower]has probably given some people some heartburn," Mr. Ahola said. "[Blasting]is quite a planned event - you've got to look at geological conditions, the size of the explosive in each hole. It's just about the largest excavation on the project, certainly the largest through solid granite." The highway from Horseshoe Bay in West Vancouver northward runs through a wide variety of landscapes: mud, forest and fractured rock, solid portions of granite and even through the ancient paths of lava that once streamed down from volcanoes between Whistler and Squamish.
And for the first 45 kilometres there is the high, treacherous drop-off from the highway down to Howe Sound.
Where possible, the rock that has been pulverized by crushers has been turned into fill in the Howe Sound section of the project, in some parts packed with reinforced steel cages and mixed with concrete, to provide the necessary support for roads and bridges. Mr. Ahola said the pulverized mountainsides will also be used as aggregate beneath the asphalt now being laid on the highway, and larger boulders will be used to stabilize earth walls.
The only material that leaves the construction zone, he said, is an acid-generating rock that is being barged to a federal ocean disposal site off the B.C. coast and dumped.
As for the many trees that have been chopped down to make way for the widened highway, Mr. Ahola said members of the first nations take them away.
"As part of the agreement with the Squamish Nation, they receive the usable timber. Wood waste, like branches and stumps, are chipped for use in regional parks," he said.
Ironically, despite the expected safety improvements being wrought because of the 2010 Olympics, when the Games finally roll into the region most vehicles will not be allowed on the highway for its duration. Instead, a fleet of 800 buses will take participants and spectators up and down to event venues. Local residents along the corridor will get special passes to allow them to move around.
With the Sea to Sky having had the reputation as one of the most dangerous stretches of highway in the province, Mr. Ahola said it was important for the design to ensure a smoother drive and lower accident rates.
Doug Henderson of the Insurance Corporation of British Columbia said that while it was too early to tell how much safer the Sea to Sky will be once construction was completed, the figures for 2003 and 2005 - the most recent available - show a drop in vehicle accidents. Between West Vancouver and Whistler, there were 450 crashes in 2003, 430 in 2004, and 380 in 2005.
"It's obviously good news that there is a trend of declining crashes, but I'm hesitant to say there is a link," Mr. Henderson said. "We will be able to measure any changes once the highway expansion is finished."