A Tacoma Tideflats engineering and steel fabication company is rebuilding a tunnel boring machine that will help dig an underground extension of Sound Transit's Link light rail line to Northgate.
Jeff Gellert, Jesse Engineering president, said the used machine arrived two months ago at Jesse's Hylebos Waterway plant from Singapore where it was last used to bore a tunnel. Replacement parts for the machine have recently arrived from China.
Jesse's workers are rewiring and rehabilitating the machine to equip it for its new job, to create a transit tunnel from the University of Washington to Northgate in Seattle.
Two years ago, Jesse assembled and upgraded a boring machine that was used to create a Sound Transit tunnel from downtown Seattle under Capital Hill to the University of Washington.
The boring machine now being renewed is scheduled to go to Seattle in June to begin its work there.
Gellert said one boring machine Jesse won't be working on is "Bertha," the world's largest tunnel boring machined that stalled beneath downtown Seattle five months ago.
"I don't think that's something that we want to get near," he said.
The Japanese-built boring machine stalled after it hit an underground pipe. After the pipe was removed, the machine overheated after it was restarted. Now experts from the state, the tunnel contractors and the boring machine builders say it may be a year until the machine gets moving again.
Those experts are trying to find why the borer is failing and to repair it. Costs for that repair could amount to more than $125 million.
Bertha's 57-foot bore is far larger than the 21-foot bore of the machine that Jesse is rehabilitating.
In other business at Jesse, the company is building a maintenance barge for the Corps of Engineers for use at the Hiram Chittenden Locks in Seattle. That barge will be used to keep the two parallel locks working smoothly.
Jesse's other major project, tower-like steel fabrications painted in gray and yellow, is a confidential assignment from a client whose name Jesse couldn't reveal.
The steel, box-shaped sections are scattered about Jesse's plant site and mounted on barges moored just north of the 11th Street drawbridge on the Hylebos Waterway.
"Our contract with our customer requires us to keep the details confidential," said Gellert.
He said he expects construction on the mystery structures to continue into 2015.