22 JANUARY 2022 WorldWide Drilling Resource® Troubled Bridge Over Water Gets New Life Compiled by the Editorial Staff of WorldWide Drilling Resource® A troubled bridge over water, the Gloucester Drawbridge was built in 1911, reconstructed in 1932, and updated in 1984; until a state safety study designated it as the worst structural condition of any bridge across the Massachusetts Bay Transportation Authority (MBTA) system. Due to its age and condition, the MBTA decided it needed to be replaced. The contract was awarded to Framingham-based J. F. White Contracting Company to replace this vital link for the Newburyport/Rockport Commuter Rail service over the Annisquam River in Gloucester. Plans are for complete replacement of the southern barrel to open it to train traffic in mid-2021, with the northern barrel opening in 2022. Gloucester Drawbridge is a steel single-leaf trunnion bascule drawbridge. A bascule bridge is a moveable bridge, opening to provide clearance for boat traffic, using a counterweight continuously balancing a span, or leaf, throughout its upward swing to provide the opening. The original bridge was a single-leaf bridge with two tracks, one of the most common drawbridge types in the world since it opens quickly and requires little energy to operate. MBTA’s original plan was to keep the bridge in service during construction, but service was suspended in mid-2020 due to unexpected site conditions.Threatening settlement of the slope and track, the northwest retaining wall was failing. Excavation of the east abutment also revealed foundation problems. MBTA decided to employ a service diversion, stopping train service around construction and providing full bus service to give the contractor unencumbered access to the site and mitigate the schedule risks and passenger inconvenience. Initial project demolition and testing were completed during the six-week service diversion. Demolition of the bridge’s moveable bascule span, as well as the timber fender system with timber docking system, steel cross-framing, steel girders, and the steel west approach span was completed. The east abutment - which supported the lateral pressure of the arch at the end of the bridge - was demolished, and 66 micropiles were installed to support the new abutment. Pier 1 was demolished as workers removed the existing steel trunnion tower, while construction of the southern half of the new Pier 2 began. When finished, Pier 2 will hold the trunnion tower and machinery for the new moveable bascule span over the river channel. Two southern drilled shafts supporting the pier, along with the concrete pier cap and machinery slab platform were put into place. With the drilled shaft, pier cap, control house, first-floor base slab, and exterior concrete walls completed, the new control tower located at Pier 3 will operate the new bridge. A foundation slab supporting the new generator and automatic transfer switch were placed east of the bridge. Submarine cables and submersed conduits carrying power to operate the bridge were installed in the channel. Other installations included conduits and innerducts to support future upgrades, as well as the addition of a new signal gate and signal instrument houses east of the bridge. Construction is ongoing with a total project cost of $100 million The new drawbridge will include new side-by-side, single-track moveable bridges, an updated east approach trestle with box beams on top of drilled shafts, and a relocated control tower on the Gloucester Station side. This will provide more resilient and reliable Newburyport/Rockport line service, eliminate current bridge-related speed restrictions, bring the bridge into a state of good repair, reduce maintenance costs and service impacts, and improve right-of-way access for boats. Old Gloucester Drawbridge. C&G Rendering of new Gloucester Drawbridge. Images courtesy of MBTA. eranhenderson@gmail.com New & Used Tricones PDCs Drag & Claw Bits Drill Collars Bit Tipping Subs & Stabilizers HDD Bits & Reamers DTH Hammer & Bits Custom Fabrication Junk Mills / Fishing Tools Rod Henderson 661-201-6259 Eran Henderson 661-330-0790 Editorial: (Focus ~ Hammers/Bits/Tool ing) January 15 Ja u tth See Doc’s Buyers’ Guide for Drillers™ for Classified Deadlines Advertising Space Reservation: Januaary 25tthh Ad Copy: February 1st WorldWide r March Issue Deadlines
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