Convention Centre – pile driving to be complete by Dec. ’05

Saturday, August 27th, 2005

Michael Scott

CREDIT: Steve Bosch, Vancouver Sun There will be about 900 piles — about 49 kilometres worth — holding up the expanded convention centre.

The good news is that the pile driving at the convention centre expansion, the first major part of the $565- million project, is going pretty well — about 195 piles have been completed since the job began April 22.

The bad news is that there are another 690 to go.

The whump-whump-whump of the pile driving — audible to anyone working or living along the shore of Coal Harbour — is definitely the sound of progress, (however irritating it may be to the construction site’s neighbours).

It starts up early, around 7:30 each workday and continues with clock-like regularity until supper time. The only time during the day that the pile driving stops is when the large steel tubes hit what construction executive John Stewart politely calls “obstructions.”

Unlike the marine piles at the northern edge of the site which are driven down through endless layers of silt, the landlocked piles must pass through several metres of fill and construction refuse from decades past, before they hit the homogenous underlying strata.

Stewart’s obstructions include boulders excavated from other downtown building sites, that were carted to the water’s edge and dumped; as well as bits of old buildings torn down in the middle of the last century to make way for new office towers. The biggest piece the pile drivers have hit was a boulder about the size of two refrigerators side by side.

When a pile hits an obstruction, usually three to five metres down, it has to be yanked out and the offending boulder or chunk of Edwardian office building excavated, before the process can start again.

The completed piles are 55 metres long, which means that the convention centre will one day be seated atop almost 49 kilometres of steel stilts. The piles are milled to order in Japan and delivered in 12-metre and 18-metre lengths.

Sometimes the piles are spliced to the right length in advance at the contractor’s yard in North Vancouver and then barged across Burrard Inlet. This is the preferred method: standing up a 55-metre steel tube, about a metre in diameter, and banging it in. Sometimes that’s not practical, so the contractor, Vancouver Pile Drivers Ltd., has its crews install the piles in shorter sections welding new pieces on at the top as the work progresses.

That operation, known as a field splice, takes two welders the better part of a day, working on the seam at chest height in the middle of the site, with the new portion of the pile towering above them.

But even when one driving rig is idle — waiting for an obstruction to be cleared or for a field splice to be completed — there are three others on site to keep on bang-bang-banging away.

If the work stays on schedule, pile driving will be complete by Christmas, a modest consolation for all the Coal Harbour condo residents and hotel guests (and maybe even the odd business executive) who yearn to slumber undisturbed.

© The Vancouver Sun 2005

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