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Plane Train Tunnel West Extension

City of Atlanta

Hartsfield- Jackson Atlanta International Airport is the world’s busiest airport and is currently undergoing a $6-billion capital improvement program, which includes the Plane Train Tunnel West Extension Project (PTTWE). The PTTWE project includes construction of a 900-ft long SEM tunnel and bifurcation that will extend the airport’s existing automated people mover system tunnel west from its existing endpoint. The extension will improve the train turn-back operation, reducing train headway and increasing passenger capacity.

Peer Review Services:

Gall Zeidler Consultants (GZ) provided a formal constructability review of the respective Sequential Excavation Method (SEM) tunnel design packages, including an assessment of excavation sequencing, initial support, instrumentation and monitoring, and contingency measures. GZ has provided on-site support during construction of the SEM tunnels including the Senior SEM Engineer and SEM Superintendents.


Hartsfield-Jackson Atlanta International Airport, Atlanta, Georgia


2019 - Present


Automated People Mover System Tunnel Extension


900 ft (247 meters)


~20.5 ft height x 19 ft width


Fill, Residuum/Saprolite, Partially Weathered to Fresh Gneiss


Approximately $331 million


Clark/Atkinson/Technique (CAT) JV


City of Atlanta