Dec. 15 project update: Operations buildings nearly complete

Posted on Dec 15 2016 4:29 PM
As Bertha continues mining toward the north portal, crews are nearing completion on what will ultimately be the most recognizable features of the SR 99 tunnel: the operations buildings at each portal. If you’ve driven on SR 99 through Seattle, you’ve seen them – who could miss the bright yellow ventilation stacks?
The stacks are central to the tunnel’s ventilation system, which will be capable of removing 1.4 million cubic feet of air per minute should it be necessary. In addition to ventilation, the buildings will house operating systems, including safety, lighting and communications. They’ll also provide space and access for the very thing that inspired the colorful stacks – WSDOT’s yellow maintenance vehicles. 
Both buildings will be mostly complete by next year, although a portion of the north operations building will be completed after the tunneling machine is removed from the ground. Crews have installed the stacks and main ventilation fans, as well as all exterior glass, in both buildings. The focus now is on completing the remaining interior work. 
Permanent power was recently connected to the north operations building, which is located at the corner of Harrison Street and Sixth Avenue North. The building’s interior, as well as the plaza that’s taking shape outside, are now lit up at night.
The south operations building, which is located on the south side of South King Street, will be connected to the electrical grid in 2017.  
Both buildings were designed to be beacons of light rather than blocks of cold concrete. The ventilation rooms of both operations buildings will stay lit throughout the night, acting as luminous bookends to the bored tunnel.
North operations building
North plaza
The plaza outside the north operations building takes shape.
North roof
Looking north from the roof of the north operations building.
South operations building 
South operations interior
A look inside the south operations building.
South building exterior
The glassy exterior of the south operations building is visible beyond stacks of tunnel segments. 
It's been nearly one year since the SR 99 tunneling machine resumed mining following the tunneling delay. We're highlighting a different aspect of the program each day this week to illustrate the progress we've made to date. Yesterday’s post highlighted #BalloonsOverBertha, one of many ways to track progress.