Construction Update Volume 3
August 26th, 2010
August 26, 2010
Retractable Roof Construction Underway
BC Place is already starting to take on its new look, and you’ll notice some dramatic changes in the next few weeks.
Following the deflation of the old air-supported roof on May 4th and several weeks of site preparation, the large temporary (yes, temporary) steel tower at centre field was erected. This 200+ foot tower holds aloft the white centre “node” - the actual centre point of the new roof.
Meanwhile, on the outer edge of the building, the first of 36 new masts have already been installed on the ring beam - each one standing 14 stories tall. The rest will be installed in sequence over the coming months, followed by final painting and removal of the temporary platforms and attachments. Cables will run from each outer mast to the node in the centre, creating a cable suspension grid that will support the new retractable fabric roof to be installed. Visit bcplace.com and click on the timeline pictures at the bottom of the “Construction” menu to watch an animation video of how it will all come together.
The Jig is Up...and Running
Each of the 36 masts for the new retractable roof stands 14 stories tall in its completed form. Clearly that’s too long to ship in one piece, so they’ve all been shipped to the construction site in three pieces, which then go into a “rotator-jig” to hold the pieces in place for welding, assembly and finishing. This jig allows each mast assembly to rotate slowly on its axis, so that workers can access all parts of the mast while it’s being put together.
Beefing Up the Building is Part of the Job
The new roof is much heavier than the previous air-supported fabric roof, so extra rebar and concrete support is being added to the existing concrete support pillars. As well, the building’s foundations are being upgraded to improve seismic standards, and allow BC Place to operate as a centrally located emergency shelter for the Vancouver area, in case of an earthquake or other major disaster. Construction technology and materials have changed dramatically since 1983 when BC Place first opened, and the advanced engineering being used to upgrade BC Place will ensure the building’s future for decades to come.
Why Are All the Cranes Working fromthe Inside?
Quite simply, the outer plaza surrounding BC Place is not capable of supporting the massive cranes and other heavy equipment being used to lift the masts and other components into place. As well, the plaza will be updated and improved as part of the overall revitalization of BC Place, and need to remain clear for this work.
Redefining "Big"
BC Place is a "big" building, which needs a "big" roof, consisting of some pretty "big" parts. Check out these numbers, to put things in perspective:
- 220 tons - approx. weight of each mast and its attachments
- 120 tons - weight of the centre node alone
- 600 tons - lifting capacity of the crane in the configuration used for BC Place
- 85 - number of semi trailers needed to bring in the components needed to build the giant red crane now lifting the masts to the building's ring beam
- 18,000 tons - combined weight of all of the steel used in construction of the retractable roof
- 76,000 square metres - area of fabric used to cover the roof
- 90mm (3.5 inches) - diameter of individual cables used in the spans between masts (compare that to Whistler’s Peak to Peak gondola, which uses primary cables that are 56mm in diameter)
- 35 kilometres - total length of all cabling