new infrastructures

NEW STARS FOR
LOS ANGELES

The underworld of Los Angeles holds surprises in store. If you bore tunnels here, you primarily cut through well-known clay and siltstone. But repeatedly, football-sized boulders get in the way: hard work for the cutter of a cutting wheel. “You have to be careful when you encounter explosive gases – or oil- and tar-bearing sand,” says Chris Hebert, who heads the tunneling division of US contractor Traylor Bros. Inc. His currently most important projects contribute to the expansion of the Los Angeles Metro Rail.

HERRENKNECHT DOESN‘T JUST DELIVER A MACHINE, BUT WORKS WITH THE CUSTOMER TO FIND A SOLUTION TO EVERY CHALLENGE.”

Chris Hebert, Vice President, Division Manager Underground, Traylor Bros. Inc.

The second largest city in the US, with around four million inhabitants, is famous for two things: Hollywood movies and congested roads. So the expansion of the metro network has had highest priority for some years now. One of the underground projects is the Crenshaw-LAX Corridor, a north-south link completed in 2017. Then there is the Regional Connector Transit Corridor, an east-west axis due to be operational in 2021. Finally the extension of the Purple Line, which will open up the bustling business and residential areas in the west of the city. “Hardly any other construction project is as popular as the new metros,” says Hebert, who as part of Traylor Bros. is involved in two joint ventures for the construction of the Regional Connector Transit Corridor as well as the Purple Line Extension.

Jobsite in Downtown: the Regional Connector Transit Corridor links the center of L.A. to the metro network. The east-west connection is due to go into operation in 2021.

Until the new metro lines go into operation, there is plenty for him and his people to do – and for the three Herrenknecht TBMs Traylor Bros. is using. “The machines are tailored exactly to our requirements,” says Chris Hebert. “They are explosion-proof in case we encounter gas. Moreover, they are equipped with tools and systems to assist us in handling all the types of ground we will encounter, including the sticky tar sands “says Hebert. “Our partners at Herrenknecht don‘t just deliver a machine. Together with the customer, they find a solution to every challenge.”

  • Projects: Regional Connector Transit Corridor, Purple Line Extension Section 1 + 2, Crenshaw/LAX Corridor; Los Angeles (USA)
  • Client: Los Angeles Metropolitan Transportation Authority
  • Contractors: Regional Connector Constructors, Skanska/Traylor/Shea JV, Tutor Perini/O&G JV,Walsh/Shea Corridor Constructors
  • TBM diameter: 6,560 mm, 6,620 mm,
    6,514 mm
  • Tunnel length: 2 x 1,700 m,
    2 x 5,250 m, 2 x 3,200 m, 2 x 1,600 m