Bertha might be to blame for Battery Street Tunnel’s bladder control issue

It happened again.

Seattle’s Battery Street Tunnel was shut down, again, after its fire-suppression system was activated for no apparent reason.

However, the sprinkler mishaps would not be an issue if the viaduct replacement project was on time.

The system is a series of sprinklers meant to douse flames within the tunnel. It has gone off, mistakenly, six times this year.

Related: Battery Street Tunnel has a bladder control problem

“The sprinkler systems have been malfunctioning in the Battery Street Tunnel for the last six months,” KIRO Radio’s Jason Rantz said. “On Sunday evening, for the fourth time, WSDOT had to close the tunnel because the sprinkler system had been going and no one could figure out why it was on. There was no real reason for it to be going.”

Battery Street Tunnel’s sprinklers are nearly 50 years old and are fed by a massive bladder that holds water. When a fire is sensed within the tunnel, the sprinklers are activated and the bladder empties. The problem is that the sprinklers cannot be shut off mid-stream, even for a false alarm. The bladder has to empty entirely.

Now, it seems the Washington Department of Transportation has diagnosed the problem: a broken regulator. A replacement part has been ordered. At least that was the issue for the most recent malfunction. In the past, mercury switches were to blame, according to KING 5.

The sprinklers are owned by WSDOT, but maintained by the Seattle Department of Transportation.

The sprinklers have been activated from time-to-time, and officials have been at a loss as to why &#8212 there was no fire in the tunnel during the activations. There are news reports of activations in October 2012 and January 2011. And an activation in May caused a three-car accident.

“Did the sprinklers cause the accident do you think?” the 9-1-1 dispatcher asked a caller who reported the accident while water rained down inside the tunnel in May.

“Yes,” the caller responded.

WSDOT also hired a consultant familiar with old tunnel systems who suggested a few improvements. The agency is implementing them and expects the tunnel to operate sufficiently over the next few years. WSDOT has not been thinking of long-term fixes for the tunnel because it doesn’t plan to use it for very long. In fact, it didn’t expect to be using the tunnel now at all.

“You know what should have been done by now … Bertha should have been done,” Rantz said. “Not completely done, but the tunneling machine should have been done enough to the point where they could have closed the Battery Street Tunnel. This is all being delayed because of the viaduct mess.”

“On the one hand I say this is not necessarily WSDOT’s fault. If you were told Bertha would be drilling away and this would be done by now, that’s different,” he said. “On the other hand, WSDOT is also partially to blame for the Bertha mess. They chose to go with Seattle Tunnel Partners choice … to drill this thing. They chose to take on the incredible risk of using a piece of equipment that had never been used before. That’s risky.”