50th anniversary of the slipforming of the CN-Tower

February 22, 2024 marks the 50th anniversary of the final lift of the slipform jacks to complete the CN-Tower’s main shaft. The slipform rig was then 446 meters above the ground where the process was initiated, June 26, 1973. Our technology had once again proven successful and reliable.
Together with the slipform rig, a tower crane was lifted on the journey up to the top using at most 54 nos slipform jacks type R72. As the slipform became narrower, the steel and wood were cut away from the outer ends (the number of jacks was reduced to 24) and lowered to the ground. Most of the slipform was gone when the shaft was completed at the 446m level.

When the observation deck “the SkyPod” began to be built later in the same year, the working platform, consisting of 12 brackets, was raised with the help of 45 nos of our steel rod climbers, type 2510-40-UD-W, specially equipped for strand lifting. This operation also took place without complications.
The CN Tower was built by Canada Cement Company (aka. the Cement Foundation Company of Canada at the time), a subsidiary of Sweden’s Skanska, a global project-development and construction group.
The slipform was designed and supplied by Scanada (aka. Heede International at the time) who then and now use our jack technology.

We still use the R72 jack, albeit in a revised version, but nowadays we use our T15 Strand climber for strand/wire liftings exclusively.
Completed in 1976, the CN-Tower held the record for the world’s tallest free-standing structure for 31 years, until 2007, when it was surpassed by the Burj Khalifa, and was the world’s tallest tower until 2009 when it was surpassed by the Canton Tower.

Read more about our achievements over the years here!

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