In a significant step towards enhancing Singapore’s public transport infrastructure, the Land Transport Authority (LTA) has awarded a $242 million contract to a joint venture between two prominent Japanese construction firms, Nishimatsu Construction and Okumura Corporation Singapore Branch. This contract will facilitate the construction of deep tunnels for the second phase of the Cross Island Line (CRL), a crucial addition to the city-state’s MRT system.

The project involves the construction of twin bored tunnels, each measuring 2.4 kilometers in length and reaching depths of up to 40 meters—considerably deeper than the typical 30 meters for MRT stations in Singapore. These tunnels will connect the future stations in the West Coast area to the Jurong Lake District, traversing underneath vital infrastructure such as the Sungei Pandan canal, West Coast Highway, and Ayer Rajah Expressway.

The LTA announced on June 19 that construction is set to commence in the fourth quarter of 2024. Due to the challenging geological conditions in the area, characterized by weathered soil and hard sedimentary rock, the project will implement advanced engineering techniques and real-time monitoring to ensure safety and stability throughout the tunneling process.

Nishimatsu Construction has already made substantial contributions to the CRL, currently working on the bored tunnels connecting Tampines North and Defu MRT stations as part of the first phase. The firm also boasts a solid track record in tunneling projects, having completed work on the Keppel station for the Circle Line 6 extension and the Gardens by the Bay station on the Thomson-East Coast Line. Okumura Corporation, known for its extensive experience in tunneling both locally and internationally, has participated in significant projects, including the Deep Tunnel Sewerage System and the airport MRT line in Taipei.

The CRL, which is being developed in phases, will serve as Singapore’s eighth MRT line, covering the eastern, western, and north-eastern regions of the country. Announced in 2019, the first phase spans 29 kilometers with 12 stations, extending from Aviation Park in Changi to Bright Hill in Sin Ming. This segment is currently under construction and is projected to be completed by 2030.

The second phase of the CRL, stretching 15 kilometers and comprising six stations from Turf City to Jurong Lake District, is expected to be completed by 2032. Notably, this phase will involve tunneling directly beneath the Central Catchment Nature Reserve at a remarkable depth of 70 meters, marking it as the deepest MRT tunnel in Singapore. This depth was chosen to mitigate the ecological impact on the sensitive reserve, and a separate contract for these tunneling works was awarded in 2022 to a joint venture between Obayashi Corporation and Shanghai Tunnel Engineering (Singapore).

As engineering studies continue for the third phase of the CRL, which aims to serve the Jurong Industrial Estate with at least four stations between Jurong and Tuas, Singapore’s commitment to developing a robust and efficient public transport system remains evident. The ongoing enhancements to the MRT network are crucial for accommodating the growing population and improving connectivity across the city-state.