News Release | Massive Tunnel Boring Machines Lowered into Ground for Eastside Light Rail Project

Massive Tunnel Boring Machines Lowered into Ground for Eastside Light Rail Project

Photos by Juan Ocampo

Ceremony is framed by pillars of historic Mariachi Plaza as officials gather to witness assembly of tunnel boring machines.

Mayor Antonio Villaraigosa leads ceremony to launch the tunnel excavation..

Machine is lowered into shaft at First and Boyle streets. Marachi Plaza is in the background.

Fully assembled underground, each tunnel boring machine will weigh more than 2 million pounds and stretch 344 feet. They will carve 21-foot diameter tunnels and install pre-cast concrete tunnel liners.

^Photo by Luis Inzunza

Today marked a major milestone for the Metro Gold line Eastside Extension light rail project as City of Los Angeles Mayor Antonio R. Villaraigosa, LA County Supervisor Gloria Molina and other elected officials and community leaders witnessed two massive tunnel boring machines being assembled in the station box at Mariachi Plaza at First and Boyle Streets.

Next month these machines, nicknamed Lola and Vicki, will begin boring twin 1.7 mile tunnels at an average depth of between 50 and 60 feet underground between Mariachi Plaza and First and Lorena in Boyle Heights where narrow surface streets cannot accommodate light rail trains. The tunnels are part of the six-mile extension of the Metro Gold Line that will link Union Station in downtown Los Angeles with Little Tokyo and the Arts District, Boyle Heights and East Los Angeles by late 2009.

"The City of Los Angeles, especially the Eastside, is moving forward now as we enter this critical tunneling phase," said Mayor Villaraigosa, who is also Metro Board chairman.

"It's a milestone that was achieved thanks to a united community, united local leaders and a united Congressional delegation," noted Supervisor Molina, who also serves on the Metro Board. "It won't be long before we can all see the light at the end of the tunnel and that will be a welcome sight, indeed."

"The federal government has committed nearly $500 million for the Metro Gold Line Eastside Extension that will provide a critically needed safe, affordable and efficient mode of transportation to the residents of East Los Angeles," said Congresswoman Lucille Roybal-Allard (CA-34) who represents Boyle Heights. "I want to, again, thank my fellow Members of Congress and all the local officials over the years who worked tirelessly with me to make this historic project a reality. For the families of the East Los Angeles community whose transportation needs have been ignored for far too long, this is truly a day to celebrate. Next stop: East LA."

The amount of earth excavated from the two tunnels could cover an entire football field from sideline to sideline and end-zone to end-zone 15 stories high.

Closed-faced earth pressure balance machines (EPB) will be used on the Eastside rather than open face machines such as those used in building the Metro Red Line subway. The EPB machines have been widely used in Europe including construction of the English Chunnel. The machines are better capable of handling the excavation by providing increased ground support during tunneling to reduce the risk of excessive ground settlement.

Lola and Vicki were custom built in Germany for Metro by Herrenknecht at a cost of $10 million each. Construction of the Metro Gold Line Eastside Extension is being done by Eastside LRT Constructors, a joint venture of Washington Group International, Obayashi Corporation and Shimmick Construction Corporation.