Steel Shots: Jacks of All Trades

Richmond Center Jack FramesThe 70-ft-tall architecturally exposed structural steel (AESS) delta frame assemblies for Toronto’s Queen Richmond Centre West building project were inspired by children’s jacks. Photo: Courtesy of Cast Connex

Suspending the new 11-story reinforced concrete office tower above two heritage structures - as part of the Queen Richmond Centre West building project in Toronto - are three, 70-ft-tall architecturally exposed structural steel (AESS) delta frames connected by 35,000-lb cast steel nodes engineered, detailed and supplied by Cast Connex (an AISC member).

Each delta frame is an hourglass-shaped frame comprised of steel pipes - four rising from the foundation, meeting at approximately the mid-height of the frame, and continuing through to the tabletop to frame directly below the centerlines of the tower’s columns, which are placed on a 9-m by 11.25-m (29.5-ft by 37-ft) grid. This configuration halved the unbraced length of the inclined pipe columns, significantly reducing their required member size to provide a slim aesthetic. The result was a support concept that was far less obtrusive to the building’s soaring atrium and which would be a distinctive feature of the iconic development.

A tour of Queen Richmond Centre West will take place the Wednesday of NASCC: The Steel Conference (March 26); the project is located just a few blocks from the Metro Toronto Convention Centre, NASCC’s home in Toronto. Visit  for more information.

You can read more about the project in the March 2014 issue of Modern Steel (available now!).