Civic Center Station in Denver, Colorado underwent drastic renovations last year. The station is one of the busiest regional bus transit centers, serving an average of 15,000 passengers a day according to RTD Denver. So, RTD and the City and County of Denver set off to revamp this station in 2015. As of December 17, 2017, passengers are enjoying this newly renovated station including a boomerang-shaped, curved structural steel canopy.
This curved structural steel canopy has an eye-catching design but also provides shelter and shade for passengers. To make this steel canopy, our customer provided the CAD design as seen here to Chicago Metal Rolled Products. CMRP used the CAD designs to take the canopy from conception to curved structural steel.
CMRP rolled 97,115 lb. of 10-inch and 12-inch square tube for the steel canopy. The curved structure is made from 60+ pieces of domestically-produced, architecturally-exposed structural steel (AESS). The square steel tubes seen in the picture here were curved to multiple radii that vary from 156 inches to 8052 inches. This large, varying range in radii means each piece of steel square tube had to be individually curved for accuracy.
The biggest challenge for CMRP and the fabricator was making sure all the square steel tube pieces fit together like a glove to prevent any mismatching and problems with fit up. To prevent any problems, the customer asked for very tight bending tolerances. All curvature at any point had to be within plus or minus 1/8 of an inch. The industry standard is 1/8” tolerance over a 10ft piece – this job required 1/8” tolerance over 30ft in some areas. No easy feat! The curved steel tubes also had to be held to maximum variation from flatness and tilt of plus or minus 1/8 of an inch. These tolerances were required to ensure that tarp canopy fit over the curved structural steel, resulting in the amazing canopy you see today.