As conduits of fundamental heating and cooling utilities for critically important government buildings, the “G” tunnels are vital infrastructure for government operations, including the Supreme Court. The tunnels had not received upgrades since their construction and were susceptible to break downs and other malfunctions. The Architect of the Capitol required specialized utility upgrade construction in a unique, challenging and high security environment.

Conti Federal worked through very difficult conditions, such as extreme heat, tight underground spaces and ever-changing windows of work to deliver this design-build project to the Architect of the Capitol. The project team constructed two new emergency egress structures after demolishing an obsolete one, repaired structural concrete along 652 feet of steam tunnel (including structural support to the entire tunnel during this phase), replaced the tunnel’s existing lighting, installed a new exhaust fan to improve temperature cooling requirements and restored the site with new landscaping. Key aspects of the project included extensive safety training for all personnel, close coordination with subcontractors and enormous flexibility to work around the schedules of each Supreme Court Justice. The team worked around the clock on a fast tracked timetable to respond to the Justices’ schedules. Due to heightened security, Conti Federal performed in cooperative collaboration with the Supreme Court police.

Key features of the project included:

  • Design-Build
  • Constructed egress structures
  • Demolished former egress structure
  • Formed and installed rebar
  • Implemented side-rail system
  • Repaired structural concrete
  • Installed exhaust fan
  • Restored site

The Architect of the Capitol gave Conti Federal an “Outstanding” performance rating for the quality of the work delivered.