Like the first flowers of spring – although substantially larger – the tunnel boring machine cutterhead arrival at the Metro yard this week is a harbinger of the future. In this case it’s a future of exciting Crenshaw/LAX construction to come. Although not particularly attractive to most of us, to subway experts it’s a thing of beauty because it means the process toward digging the tunnels needed for the underground portions of the line is proceeding.
The cutterhead is the circular rotating face with teeth that is attached to the front of the tunnel boring machine. It chews up the soil and pushes it backward through the boring machine to help create the subway tunnel. The soil is then collected and carried away.
Yesterday night’s cutterhead arrival, carried on a flatbed truck, was through the Port of Long Beach via ship from Germany, where it was manufactured.
Digging the tunnels between the three underground Crenshaw/LAX stations won’t begin for many months but the march of the cutterhead through darkened L.A. streets – accompanied by six CHP vehicles to ensure safety – was an exciting milestone, reminding us that massive projects like rail lines happen through hard work and a series of tiny steps, not through miracles.
For an explanation of subway construction, see this post.