Why There's a Crane on Top of Seattle Municipal Tower

Well, aren't you curious about every little thing?

It's a 52-ton crane, and it's there to hoist a "building maintenance unit" to the rooftop of the Seattle Municipal Tower. The BMU, as we're calling it now, sounds like something you might be able to charge admission to.

It sits in a well on the roof, and gives maintenance workers access to all sides of the tower, from floor 62 to the first floor. Most excitingly, it comes with a crane itself, a telescoping arm with a reach of 112 feet, that holds a personnel basket (16 feet wide, 2-3 people, up to 750 pounds).

The tower's current "façade maintenance systems" is out of compliance with Washington State Labor and Industries and the U.S. Department of Labor’s Occupational Safety and Health Administration (OSHA).

The city's BMU fact sheet explains that preparation for this began in 2007. "To prepare for the rooftop unit, 45 tons of steel reinforcement have been added to floors 60 through 63." A further 15 tons of steel supports were added temporarily as part of the installation process.