Prepare for a street closure at Tacoma City Hall this weekend — and an awfully large crane.
Contractors will remove a 40-year-old heating and ventilation system from the top of the 15-story building and replace it with a 240-square-foot heat recovery unit.
To move such heavy equipment, contractors will enlist a 550-ton crane and close Market Street to through traffic from St. Helens Avenue to South Ninth Street.
Josh Clarke, project manager with the city, said crews will begin setting up in the early morning, and dismantle and remove the old equipment from the building's roof 250 feet from the ground.
Installing the heat recovery unit "is part of a larger project we are doing in the building," Clarke said. "We are looking at getting up to 30-percent energy efficiency in the building by all of the things we are doing."
The cost of the work is about $1.1 million, and the city says it will save about $60,000 each year. That means the upgrade will pay for itself in a little over 18 years at current energy usage. Grants and utility rebates will pay for half of the cost.
Those interested in watching the progress of the crane can get a decent vantage point from Court D, the alleyway just west of City Hall.
The Tacoma Municipal Building, at 747 Market St., was built in 1930. City Manager T.C. Broadnax said Tuesday that the work should be completed Saturday, unless the weather doesn’t cooperate. The Saturday forecast calls for a 60-percent chance of rain, with possible storms.