Main tunnel works connecting future Changi Airport T5 to existing T2 completed

Key Concepts

• Changi East Development: Expansion project of Changi Airport, centered around Terminal 5.
• Integrated Airport Concept: Operating all terminals as a unified system for seamless passenger and baggage flow.
• Tunnel Boring Machine (TBM): Machinery used to excavate tunnels through various ground conditions.
• Passenger Automated People Mover (APM) System: Underground train system for rapid inter-terminal passenger transport.
• Baggage Handling System (BHS): Automated system for efficient baggage transfer between terminals.

Completion of Main Tunnel Works for Changi East Development

The primary tunnel connecting the future Terminal 5 to existing Terminal 2 has been completed, marking a significant milestone in the Changi East development project. This completion, achieved as of October last year, covers 1.7 kilometers of the total 2.5-kilometer tunnel stretch. Construction on the remaining 0.8 kilometers is currently in progress, with overall project completion targeted for the mid-2030s. The overarching goal is to establish Changi Airport as a fully integrated airport system upon the opening of Terminal 5.

Tunnel Infrastructure and Functionality

The tunnel system comprises three distinct tunnels. The completed main tunnel will house a passenger train system – an Automated People Mover (APM) – designed to facilitate rapid and seamless transfers between Terminal 5 and Terminal 2. This APM system is projected to carry approximately 100 passengers per train, operating at intervals of around 4 minutes. Two additional tunnels are under construction, dedicated to the automated transfer of baggage between the terminals. These tunnels will run beneath the airport’s second runway. Furthermore, work is underway on a passenger train depot and station located at Terminal 2, alongside tunnels to support internal passenger and baggage movement within Terminal 5 itself.

Construction Challenges and Mitigation Strategies

The tunnel construction presented significant engineering challenges, primarily due to the need to avoid disruption to ongoing airport operations. A key difficulty was the requirement to build all three tunnels directly underneath operating taxiways. Engineers implemented meticulous planning and precise control of the Tunnel Boring Machine (TBM) parameters to ensure no impact on aircraft movements or airport functionality. As stated by an engineer involved in the project, “The engineers had to be very careful in planning the parameters and in the operation of the tunning machine to make sure there's no impact on the airport operation at all.” The main tunnel works commenced in early 2022.

Terminal 5 Capacity and Associated Works

Terminal 5 is designed to effectively double the overall capacity of Changi Airport. Once operational, it will be capable of handling approximately 50 million passengers annually. Concurrent with the tunnel construction, work is also progressing on the construction of new aircraft stands and connecting taxi lanes to support the increased operational demands of the expanded airport.

Public Engagement and Future Outlook

In 2026, the public will have the opportunity to view a free exhibition showcasing the behind-the-scenes planning and development of the new terminal. This exhibition aims to provide insight into the complexities and innovations involved in the Changi East project.

Synthesis

The completion of the main tunnel represents a crucial step forward in the Changi East development. The project’s success hinges on the integration of advanced infrastructure, including the APM and BHS systems, and the careful mitigation of operational disruptions during construction. The expansion, centered around Terminal 5, will significantly increase Changi Airport’s capacity and solidify its position as a leading global aviation hub.