In 2015, Apex Steel was brought in as a trade partner and tasked with the challenge of how to get 2,000 lbs. glass panels to the observation deck and restaurant level at the Century Project as part of the scope for the $100 Million dollar renovation to the iconic landmark in Seattle, that was built in 1962. Options considered were; tower crane, conventional hoist, helicopter, and ultimately, Apex proposed a custom built gantry crane designed, engineered, fabricated and erected by Apex Steel.
First consideration when designing the unit was that it has to be used for construction but also be erectable in the future if glass needed to be replaced. Second consideration was that no hoisting was available on the roof, so the unit had to be able to be built with pieces that could go up the elevator and assembled in place by hand. Third consideration was weather, so the unit was constructed out of galvanized steel.
Ultimately the custom hoist used a winch that was modified with all safety measures of a hoist so that Apex could get speed and stopping safety features. The hoist was designed with a 3,000 lb. load capacity so that it had a safety factor over the required limit.
No expense was spared in parts, including the wire rope that has a special anti-twist feature.
The entire crane was bought into our yard for a complete mock up to ensure all parts and pieces fit and to determine if any modifications needed to be made to ensure ease of assembly and dismantle in the field. Ultimately a few modifications were made to ease assembly in the field.
The crane was certified and load tested prior to use and no breakdowns, mechanical failures or time loss incidents took place during the entire job. We employ a Washington State licensed elevator mechanic that wired the unit and serviced it weekly. We also mocked up and tested a wind sock for use as needed.
The crane was designed with temporary platforms to receive the glass. The crane was placed on top of the observation deck and Apex designed a custom landing platform on the restaurant level for a secondary stop that hung off the bottom of the hoist.
The crane used a pennant controller to control the hoist and we went with 50 feet of wire versus a remote to eliminate communication failure.
The crane had an additional safety feature of an anti-two block to act as an emergency shut off if the ball got too close to the sheave.
The hoist has 3 gears so it could be run in high gear mid travel, mid gear within 10 feet and low gear for the last 2 feet.