Seattle Municipal Tower
Building Maintenance Unit Installation
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The city of Seattle is replacing obsolete and out-of-compliance façade maintenance systems on the Seattle Municipal Tower with a building maintenance unit (BMU) that will allow maintenance of all exterior surfaces of the glass and granite building. A 52-ton crane will hoist the unit in pieces to the rooftop where it will be assembled, scheduled for March. Columbia Street between Fifth and Sixth Avenues will be closed during installation.
The existing system is out of compliance with Washington State Labor and Industries and the U.S. Department of Labor’s Occupational Safety and Health Administration (OSHA).
In late 2007, a team was hired to oversee a project leading to the design, preparation and installation of the new BMU. To prepare for the rooftop unit, 45 tons of steel reinforcement have been added to floors 60 through 63. An extra 15 tons of temporary steel supports are currently being installed in preparation for the March installation of the BMU. The new BMU was manufactured by Manntech, a German company.
With the BMU in place, costs to maintain the building will be substantially reduced compared to costs using the obsolete system or costs of maintaining the building with no system in place.
The BMU will sit in a well on the roof of the building and will allow access to all sides of the building all the way to the ground. It includes a crane with an arm that telescopes from the base of the unit with a reach of 112 feet. The personnel basket is 16 feet wide, can hold two to three people, and up to 750 pounds. The BMU has an additional equipment unit that can hold another 750 pounds.
The city of Seattle purchased the former KeyBank Tower in 1996 and officially changed its name to the Seattle Municipal Tower, now home to primarily city of Seattle offices. In 2005, the city and national experts analyzed the maintenance systems for the façade of the building, concluding the existing systems were obsolete and out of compliance.
- Original name: AT&T Gateway Tower.
- Constructed in 1988-89, occupied in 1990.
- 62 stories; granite and glass exterior; located at 700 Fifth Avenue.
- When the city purchased the building in 1996, it was known as Key Tower. In 2004, the city officially changed the building’s name to the Seattle Municipal Tower.
- In 2005, the city of Seattle, with building manager CB Richard Ellis and national experts, conducted a peer review study and analysis of the façade maintenance system that concluded the existing system was obsolete and out of compliance.
The Façade Maintenance Project
- Late 2007, the city initiated contact with likely firms and selected an experienced team to design the replacement of the façade maintenance equipment.
- Team: Architectural lead – Zimmer Gunsel Frasca; Structural firm – Magnusson Klemencic
- Project replaces out-of-date and out-of-compliance systems with one Building Maintenance Unit (BMU).
- Full design of project started in summer of 2007 and was completed in fall 2008.
- 45 tons of new steel reinforcement were added to floors 60 through 63 in preparation for BMU.
- Project was bid in December 2008. Contract awarded to Andersen Construction. BMU manufactured by Manntech.
- Construction of BMU was more than half completed by end of August 2009.
- Final phase of project involves lifting the BMU in pieces to the roof of the building using a 52-ton crane. BMU will be assembled atop the roof.
- BMU will be hoisted to the tower on two or three consecutive days, including a weekend. Loading will be done at Sixth and Columbia; Columbia Street will be closed between Fifth and Sixth Avenues during installation.
- Project is scheduled for completion March 2010.
- Project cost: $9.4 million.
Building Maintenance Unit Features
- Can access all sides of the Tower all the way to the ground.
- Sits in a well on the roof of the Tower. When retracted, the profile of the BMU is approximately 4 feet above the roofline.
- Unit includes a crane with an arm that telescopes from the base of the unit with a reach of 112 feet.
- Personnel basket is 16 feet wide and can hold 750 pounds (two to three people); BMU has additional equipment unit that can hold another 750 pounds.
- Personnel basket has swing arm feature allowing access to cantilevered projections on building.
- Weight: 123,500 lbs.
- Load capacity: 1,000 lbs
- Lifting speed: 30 feet per minute
- Traversing speed: 26 feet per minute
- Length when fully extended: 111 feet
- Length when collapsed: 63 feet