Préfabrication Béton - Voussoirs de tunnels

Anacostia River Tunnel Washington DC	Number 7 Line Extension Manhattan, New York, NY	North Shore Connector Pittsburgh, PA
University Link Tunnel U220 Seattle, WA	Beacon Hill Station and Tunnels Seattle, WA	MSP LRT Tunnel and Station Project Minneapolis - St Paul, MN
Blue Plains Tunnel Washington DC	Queens Bored Tunnels and Structures Queens, New-York, NY