Chessie breaks through

Chessie, the tunnel boring machine (TBM) tasked with constructing a 5,700-foot tunnel connecting the Chesapeake Bay Bridge-Tunnel’s (CBBT) Island 1 to Island 2, achieved a significant milestone Monday evening, breaking through the concrete receiving wall.

According to CBBT officials, Chessie penetrated the lower half of the receiving wall at approximately 9:00 PM. The cutter head rotation has been paused as planned to allow for the removal of struts and the supporting steel beam. Once completed, the TBM will finish boring the remaining 43-foot diameter of the receiving wall.

The project, originally slated for completion in 2023, has faced delays due to unforeseen challenges, including striking a submerged anchor embedded in the bay’s seabed after Chessie had bored just 700 feet. This obstacle temporarily halted progress until tunneling operations resumed in April 2024. Since then, Chessie has advanced at an average rate of 50 feet per day. The new anticipated completion date for the tunnel is now May 2027.

Chessie, designed and built by Herrenknecht of Germany, is a massive machine with a cutter head measuring 43 feet in diameter and a total length of 308 feet. During its operation, it has removed approximately 500,000 cubic yards of soil and installed nearly 10,000 concrete segments, each weighing 10 tons. The machine has mined over a mile underground to date.

The $756 million Parallel Thimble Shoal Tunnel project is funded through revenue bonds, a Transportation Infrastructure Finance and Innovation Act (TIFIA) loan, a Virginia Transportation Infrastructure Bank (VTIB) loan, and allocations from the CBBT District’s General Fund. The new two-lane tunnel will improve traffic flow and safety by separating southbound and northbound traffic beneath the Thimble Shoal Channel.

When tunneling operations complete, efforts will then focus on finishing work. This includes paving, electrical and exhaust installations, tiling, vent construction, and replacing the curved trestle entrance with a straight one. Once completed, the Parallel Thimble Shoal Tunnel will significantly enhance the capacity and safety of the 17.6-mile CBBT, a vital transportation link connecting Virginia’s Eastern Shore to Virginia Beach.