State transportation workers found 26 loose wall panels inside the Sumner Tunnel during an inspection late Sunday night into Monday morning and removed them, after an examination last week in the Callahan Tunnel found 121 loose panels.
“Overall, the condition of the wall panels in the Sumner is much better than what we found in the Callahan,’’ said Frank DePaola, highway administrator for the state Department of Transportation, during a press conference at the department’s headquarters in downtown Boston Monday.
Each enamel-coated metal panel measures 4 feet by 9 feet and weighs approximately 100 pounds. About three dozen workers performed pull tests on all 2,400 panels lining the Sumner and found that 26 were loose because the stainless-steel bolted connections holding them in place were corroded, DePaola said.
The inspection of the Sumner, which lasted from 9 p.m. Sunday night until 1 a.m. Monday, was triggered by findings inside the Callahan, which runs parallel to it. The Callahan was shut down Dec. 21 as an emergency precaution after a single panel fell at 6 p.m. that day. There are 2,800 panels in the Callahan. No commuters were injured in that incident.
Annual inspections of all tunnels were prompted by a 2006 ceiling-tile collapse in the connector that links the Ted Williams Tunnel with other sections of the Big Dig, killing grandmother Milena Del Valle.
You have reached the limit of 5 free articles in a month
Stay informed with unlimited access to Boston’s trusted news source.
- High-quality journalism from the region’s largest newsroom
- Convenient access across all of your devices
- Today’s Headlines daily newsletter
- Subscriber-only access to exclusive offers, events, contests, eBooks, and more
- Less than 25¢ a week