Middlebury Rail Line Improvements

Project Details

• Owner: Vermont Agency of Transportation and Town of Middlebury, VT
• Contractor: Kubricky Construction Corp.
• Engineer of Record: VHB
• Completion Date: 2019
• Scope: U-Wall sections, Upper-Wall Units, Fast-Tracked, Tunnel

Project Overview

Administered through a Construction Manager / General Contractor (CM/GC) contract by The Vermont Agency of Transportation (VTrans) and Town of Middlebury, two nearly 100-year-old bridges over railroad tracks are being replaced by a 345-foot-long precast concrete tunnel, which is part of a 1,736-foot-long precast concrete rail trench in the center of Middlebury, Vermont. In 2017, the two bridges were removed due to severe deterioration and temporary bridges were installed to maintain traffic. According to a VTrans report, the bridges did not have enough vertical clearance for double-stack rail cars. This project lowers the vertical rail bed for more than 3,000 linear feet, thus allowing vertical clearance to be extended from less than 18 ft to 21 ft without impacting final grade of the streets and sidewalks above. Lastly, the new tunnel and trench improves the rail alignment by reducing a sharp horizontal curve.

Fast forward to 2019 when The Fort Miller Co., Inc. commenced fabrication on 423 total precast concrete elements; 295 U-Wall sections and 127 Upper-Wall units. The heaviest U-Wall pieces weigh approximately 80,000 lbs. and the average weight of the precast is approximately 70,000 lbs. The completed 4-sided tunnel section will be 17 ft-9 in. wide and 24 ft.- in.” high (inside dimensions).This project was completed in an aggressive 10-week construction / installation schedule.