Modjeski and Masters Wins Awards from Association for Bridge Construction and Design
MECHANICSBURG, PA Modjeski and Masters (M&M) announces its selection as winner of two Association for Bridge Construction and Design (ABCD) Susquehanna Chapter awards. The firm was recognized with the Outstanding Rehabilitated Bridge Award for its work on the Portage Lake Lift Bridge in Michigan, and won the Outstanding New Medium Span Bridge Award for the Elizabeth City Bascule Bridge in North Carolina.
"We're humbled that our prestigious group of peers in the Susquehanna Chapter recognized the innovation and value of our work on both the Portage Lake and Elizabeth City Bridge projects," said Mike Britt, President of M&M. "Winning these awards demonstrates the type of work that our firm provides across the country, benefiting communities like those in Michigan and North Carolina for many years to come."
The Portage Lake Lift Bridge, which connects the cities of Houghton and Hancock, is the heaviest and widest double-deck bridge in the world and only one of its kind in the state of Michigan. The lift span, which can be raised up to 100 feet, features an upper and lower deck. The upper deck carries four lanes of US Highway 41 and M-26. The lower deck originally carried railroad traffic and currently is used for permit vehicles in the summer and as part of the statewide snowmobile trail system in the winter. It is the only bridge in the region connecting Copper Island in the north with the rest of the Keweenaw Peninsula to the south. In an effort to preserve and maintain this vital crossing, the Michigan Department of Transportion (MDOT) turned to trusted bridge engineering firm M&M to lead the structural, electrical and mechanical rehabilitation of the massive 269-foot-long, 54-foot-wide lift span.
The project focused primarily on the replacement of the wire ropes which connect the lift span to the counterweight. To successfully accomplish this, M&M performed work during winter months when the bridge could be left in the fully lowered position, with traffic maintained on the upper deck. This also helped to accommodate snow mobile traffic which commonly uses the lower deck during the same season. M&M also implemented homeland security recommendations, provide structural repairs to the operator's house, and design upgrades to the barrier gates. Implementing the repairs and retrofits with minimal disruption to traffic was very important as this is the only connector for emergency services on each side of the lake.
Preservation of this historic structure is a high priority. The Portage Lake Lift Bridge was completed in 1959 and is the fourth bridge crossing to be built at the site. The bridge replaces two steel swing bridges before it, and supersedes the original 1875 wooden swing bridge. The Portage Lake Lift Bridge is no doubt an iconic structure due to its sheer size, but also its history of connecting two communities. The bridge is a focal point of both communities and is celebrated yearly at the annual Bridgefest which is held on the anniversary of the bridge being opened to traffic. This project also serves as a continuation of M&M's long-term relationship with MDOT and is representative of our expertise in the preservation, maintenance and rehabilitation of movable bridges.
The Elizabeth City Bascule Bridge project completely replaced both the superstructure and substructure of the eastbound bridge of US 158 over the Pasquotank River in North Carolina. Built in 1931, the eastbound span was one of 838 bridges identified by the North Carolina DOT to be replaced after determining it had reached the end of its expected life span. M&M designed the replacement bridge with a 430-foot approach and a new 146-foot double-leaf trunnion bascule span, accommodating the highway, bicycle and pedestrian traffic the bridge sees.
Known as the "Harbor of Hospitality," Elizabeth City has been a historic player in the shipping industry due to its location at the narrowing of the Pasquotank River. In the early part of the 20th century, engineers determined that building a bascule bridge would be the most efficient way to span the river without impacting maritime activity. The bridge was later twinned to alleviate traffic congestion resulting from the region's economic growth.
However, after nearly 80 years of continuous use, the original eastbound bridge started to show its age. NCDOT was faced with a dilemma; continue to use the existing bridge and face constant repairs and traffic interruptions, or replace the bridge all-together. When the NCDOT determined it was time to replace the aging structure, the project was put on an accelerated design and construction schedule. NCDOT needed a bridge design firm with proven bascule bridge engineering experience, a sensitivity to stakeholder needs, and the capacity to develop the design in a shortened time frame; they found these qualities in Modjeski and Masters.
M&M provided preliminary and final design services for structural, mechanical, and electrical design for the bridge replacement. Also part of this project, the westbound bridge was temporarily closed to traffic and rehabilitated when the new eastbound bridge was completed. Both bridges are now operated from a new control tower located on the new eastbound bridge.