J.F. Shea is to use a refurbished 6m diameter Robbins TBM to excavate the 5km long combined sewer overflow control tunnel beneath Fall River City in Massachusetts. The TBM is currently being overhauled by Shea at a workshop in Milwaukee with an increase in diameter from 5.6m. The machine was last used by Shea in New York on the Schiavone/Shea JV contract for the city’s Water Tunnel #3 project.
The TBM will work from a downstream portal. “We are currently excavating the portal cutting and the TBM is expected to arrive in October and be lauched in December,” Shemek Oginski, project engineer for Shea, said.
Shea was awarded the CSO contract by the City of Fall River Sewerage Department in May 2002 after submitting the lowest of three bids at $56M. Competing bids were submitted by the Shank/Balfour Beatty JV at $62M and Modern Continental at $64M.
Design and construction management for the design-bid-build contract is a team led by Camp Dresser & McKee. The engineer’s stimate was $59M.
The contract includes excavation of four small drill+blast adit tunnels to connect off-line drop shafts.
The hard granite rock beneath a maximum 36m overburden is predicted as highly abrasive. Cutter consumption will be high with frequent cutter changes. Mucking out through the portal access will be via trains of Mühlhäuser side-tipping muck cars.
From the portal access the CSO tunnel will connect via a 2.15m diameter conduit to the City’s central water treatment plant. “Our contract end date is January 2005,” Jeff Selai, project manager, said.
