Time Lapse Video: Watch as we install and assemble tunnel boring machine Mom Chung
This time lapse video — our first ever — shows the first steps of installing and assembling tunnel boring machine Mom Chung.
For the past few weeks, Central Subway crews have worked day and night to install and assemble our first tunnel boring machine, Mom Chung, underground beneath 4th Street.
We’ve documented the process on three time lapse cameras installed at this major construction site. The cameras took photos every two minutes, and we compiled and edited the images to create the video above.
In it, you’ll see our crews construct a specialized crane, called a gantry crane, over 4th Street to prepare for Mom Chung’s arrival. Then hundreds of tons of massive Mom Chung are lowered underground and assembled by Central Subway workers. The segments seen here make up Mom Chung’s shield (the part that builds the tunnel) and cutter head (the part that excavates). At the end of the video, we install an auger screw, which is used to transport dirt and spoils through the front of the TBM and onto a series of conveyors.
Taken from April 22 to May 3, the video contains 1,917 images. Check it out here or on our YouTube channel. (And be sure to check out our construction videos, too.)
We’ll post more time lapse videos soon, including one of the entire TBM assembly process, as we continue to document construction of this essential improvement to San Francisco’s public transportation system.
