South 10th Street Bridge Project Brings Home More Awards

South 10th Street Bridge Project Brings Home More Awards 150 150 American Bridge

It was a little delayed, but on Saturday, April 30th, the South 10th Street Bridge Dehumidification project accepted the 2020 Outstanding Highway Engineering Award – Category C (Projects Greater than $20M) from the American Society of Highway Engineers, Pittsburgh Section.

In 2017, AB served as the general contractor for the South 10th Street Bridge, also known as the Phillip Murray Bridge in Pittsburgh, PA. At 84 years of age, the Allegheny County Department of Public Works determined a main cable dehumidification system was the appropriate course of preservation for the city’s only conventional suspension bridge.

After a successful bid, AB collaborated with AECOM, WSP USA, and SAI Consulting Engineers on this project. AECOM worked as the lead designers, WSP was brought on as the contractor’s engineer and structural engineer, and SAI provided construction management and inspection.

After a rigorous submission process and judging panel, representatives from Allegheny County, American Bridge, AECOM, WSP, and SAI were present to accept the award.

On May 19th, the South 10th Street Bridge team collected yet another belated award, collecting the 2019 Association for Bridge Construction and Design (ABCD) Award for Outstanding Rehabilitation Bridge.

Preserving and upgrading structures like the Philip Murray Bridge is such an important part of what we do in Public Works. It is an honor to be part of a great team, and we’re very pleased with how this project came together.
– Steve Shanley, PE, Public Works Director

More on the South 10th Street Bridge Project

Dehumidification is a preservation technique gaining popularity in North America after successful utilization in Europe and the United Kingdom. This innovative technique involves dehumidified air being prepared by and monitored from equipment in a plant room within the anchorage. The unique challenge faced by the team on this project was the Murray Phillip Bridge having unusually small anchorages that did not support a separate, fully enclosed plant room. After brainstorming different solutions to overcome this challenge, AB’s team proposed an innovative design that converted the entire north anchorage into a plant room.

AB’s proposal solved the issue but posed two significant challenges. First, the dehumidification plant room equipment must be sized to fit in the anchorage and still supply the appropriate percentage of relative humidity (RH) at multiple locations to dry out the cables and maintain the proper RH. Second, the anchorage needed to be air and watertight to run the system effectively.

The team used epoxy coating (typically applied to a bridge’s exterior to protect steel), to seal the interior anchorage walls. Additional coating was used by the sidewalk area where the cables enter the anchorage. To further protect the main system equipment in the north vault, the area was sealed off and special doors were installed to create a tighter seal for the dehumidified air.

Cables were addressed one at a time to keep traffic moving. The east side cable dehumidification system and structural repairs had to be completed prior to moving the traffic and beginning the west side work. To keep the project on schedule, the team developed a temporary blower system to active the east side system until the west side could be synched. The blower prepared the air at the same level as the final dehumidification system to confirm the eastern cable was fully sealed. This was all done without needing the permanent dehumidification equipment to be in place. With all hands-on deck, the AB team was able to install the system and get it operational in less than 20 months.

AB and our team members are extremely honored to add another recognition of the hard work and innovation required for this project to the shelf. The South 10th Street Bridge Rehabilitation and Main Cable Dehumidification also received:

  • Outstanding Engineering Achievement Award, Pennsylvania Society of Professional Engineers, 2020
  • National Recognition Award, American Council of Engineering Companies, 2020
  • Diamond Award for Engineering Excellence – Structural Systems, American Council of Engineering Companies of Pennsylvania, 2020

Find Out More About the South 10th Street Project