Together with client, Nishimatsu Construction Ltd, Cowi has won a package of work on Singapore LTA’s Cross Island Line that includes 2.9km of bored tunnel, 300m of cut and cover tunnels, a 2-storey facility building with 5 level of basement to provide electrical and mechanical service. A large-diameter TBM, measuring 12.6m in diameter, will be used to construct the single tunnel with two tracks. This will be one of the largest TBMs ever deployed in Singapore. The cut and cover tunnels will extend 45m deep and the bored tunnel depth will vary from almost 50m underground at its deepest to less than 12m cover at its shallowest.
Expected to open in 2030, the Cross Island Line (CRL) will be Singapore’s longest fully underground line at more than 50km and is expected to carry over 600,000 commuters each a day. CRL will ease travelling across eastern and western parts of Singapore and reduce traffic congestion on the existing East-West Line while providing an alternative option to commuters.
Jotham Vizard, Senior Vice President in COWI’s international transportation unit, is super excited about this opportunity: “We are immensely proud to be able to assist Nishimatsu in creating this state-of-the-art metro in Singapore. As TBM technology improves, large diameter tunnels are becoming more common, and this project maintains our leading position in the large diameter market.”
Vince Goh, Managing Director for COWI in Singapore, adds: “This project involves a number of exciting technical challenges other than the large diameter tunnel itself. Among others, the tunnel will go underneath a military airport with sensitive fibre reinforced pipe (FRP), runway, taxiway, apron, airport structures which increase limitation in ground movement during both bored and mined tunnelling operation. Moreover, any TBM cutterhead intervention beneath the airbase will need to be pre-planned and in hyperbaric environment due to the depth. Multiple closely spaced adits for future underground infrastructure is also part of the challenge. The
tunnel will also go under public roads and will under cross the Sungei Serangoon vehicular bridge and Kallang-Paya Lebar Expressway viaduct.”
Construction works are expected to start in June 2022.
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