ST. LOUIS (KSDK) - Since the end of February, the Metropolitan Sewer District has been working almost ceaselessly beneath the city streets), digging a tunnel underneath the River Des Peres with the aid of a 300,000-pound tunnel boring machine (TBM).
The machine, named 'Chelsea the Chomper,' is digging the 3,028 feet long Lemay Redundant Force Main, which will not only permit the Lemay Wastewater Treatment Plant to handle a greater volume of wastewater, but give MSD engineers an opportunity to inspect the original main tunnel for the first since its construction in the 1960s.
MSD began the project, titled Project Clear, by digging a 175-foot starter shaft in January 2014 and then lowering Chelsea and her massive cutting head down to the beginning of the tunnel. After 26 days of digging (March 27), Chelsea traveled approximately 556 feet. Workers will then dig a 128-foot shaft at the end of the tunnel to lift Chelsea out.
At least 23 MSD workers will be on site at any given moment, operating Chelsea's cutting head in two shifts, totaling 16 hours every day. When finished, the redundant force main line will be 11 ¼ feet in diameter.
The work is expected to be completed in Spring 2014, weather and construction delays permitting.