Time-lapse video: Truckee’s Mini Mousehole bores through railroad tunnel
TRUCKEE, Calif. — The town of Truckee and Caltrans this week announced that crews successfully bored through the Highway 89 Mousehole undercrossing to reach the next phase of the long-awaited pedestrian tunnel project.
The structure — dubbed the “Mini Mousehole” — is now completely through the Union Pacific railroad embankment at the crossing between Deerfield Drive and West River Street.
Crews spent several weeks this summer building the tunnel structure and retaining walls on the south side of the railroad, using more than 1,500 cubic yards of concrete, according to Caltrans.
“Then the jacking began to insert the tunnel structure into the hole dug into the railroad embankment by a ‘road header’ machine, which removed more than 900 cubic yards of soil and rock,” Caltrans officials said.
On Monday, the ‘road header’ — which is a grinder on the end of an excavator — dug through to the northern side of the embankment, “with the concrete tunnel structure nearly all in place,” officials said.
Work began in March on the project to create a pedestrian/bicycle railroad undercrossing east of the existing Mousehole tunnel.
Alamo, Calif.-based Gordon N. Ball Inc. is the contractor on the roughly $14 million project. Funding is covered by a mix of local, state and federal dollars, including $7.5 million approved last July by the California Transportation Commission.
While the tunnel has been bored, officials say much work needs to be done before it is safe for the public to travel through.
“Over the next months, portal wall construction and finish work will continue … that will provide a safer route for pedestrians and bicyclists along the heavily traveled Highway 89 between Truckee and Tahoe City,” according to Caltrans.
According to Caltrans, while most of the work is expected to finish this fall, some will continue before it’s fully finished in spring 2016.
Travel disruptions on 89 will continue to be intermittent, according to previous reports, with up to 10-minute delays possible.