The new completion date for consumer use of the Parallel Thimble Shoal Tunnel Crossing is anticipated to be in 2027 according to representatives from the Chesapeake Bay Bridge Tunnel(CBBT) and Chesapeake Joint Tunnel Venture(CJTV).
Initially predicted to be finished this year, the start of the project was held up due to delays in acquiring the necessary permits and then by the issues stemming from the COVID-19 pandemic.
The Chesapeake Joint Tunnel Venture, a partnership with the Dragados USA and Schiavone Construction Company, LLC, began the tunneling process this past spring. Recently, the tunnel boring machine(TBM) struck and anchor believed to be from a 1920s frigate, which has stopped the tunneling. Workers on the TBM noticed pieces of metal in the material coming through the TBM’s conveyor belt, which prompted a stop work order for investigation.
Construction crews are now working on grouting a safe zone on the front of the TBM, so inspections and repairs can take place. The tunneling is expected to resume in February 2024.
However, the striking of the anchor by the TBM should not delay the final completion of the project too badly according to CBBT Executive Director Jeff Holland. Construction crews anticipated a five to six month delay in boring while the receiving pit on the second island was finished.
“Net, I anticipate this will back up the final completion date three months,” he said.
The TBM is just now getting through the bay bottom, about 13% of the total length. The state of the art machine bores in the front and constructs the tunnel as it goes, propelling itself forward with hydraulic jacks which also tighten the tunnel sections, which are then bolted together by hand.
Before the anchor, the TBM was moving at approximately 35 millimeters a minute.
“At this time, because we are at the beginning of the tunneling, we are moving slower,” said Juan “Jr.” Lopez, the Deputy Project Safety Director of the CTJV. “We can cause damage… because we don’t have much coverage right now. As we get deeper, that’s when we can increase the pressure and go a bit faster.”
Lopez said at the maximum speed, the TBM will likely be moving at 45 millimeters a minute, which is approximately 35-40 feet every 12 hours.
Currently, the TBM is 11 millimeters off its intended path, just shy of a half inch. Lore states when the initial Chesapeake Bay Bridge Tunnel was completed in 1964, the bridge landed a quarter inch off its intended mark.
If the project interests you, Lopez said they are still looking to hire approximately 20 people to complete the construction.