Singapore’s Land Transport Authority (LTA) has awarded two substantial contracts for phase one of its new “Cross Island” mass rapid transit line, together worth S$766m ($568m).
Hock Lian Seng Infrastructure will design and build Aviation Park station, one of the new line’s termini, plus tunnels, in a contract valued at S$320m ($237m).
The second contract went to Nishimatsu Construction to design and build a 2.9-km-long tunnel between Tampines North and Defu stations for S$446m ($331m). It will use the biggest TBM ever seen in Singapore to bore the tunnel. The contract includes the construction of an electrical and mechanical facility building.
Both companies have experience delivering MRT projects in Singapore.
The 29km phase one of the Cross Island Line will be Singapore’s eighth MRT line with 12 stations between Aviation Park and Bright Hill, nearly half of them connecting with other lines. The line will serve future urban developments in the eastern, north-eastern and western corridors.
Work on the underground Aviation Park station next to Changi Coast Road and Aviation Park Road is expected to start in the first quarter of 2022, with passenger service expected in 2030.
The LTA said ground conditions at the site would be challenging because of thick layers of marine clay. It said safety measures would be needed in the deep excavation works to keep the ground and surrounding structures stable.
The project will also be subject to aviation height restrictions given its proximity to Changi Airport.
To bore its tunnel, which will house twin tracks, Nishimatsu Construction will deploy a TBM measuring some 12.6m in diameter, the largest TBM ever used in Singapore.
It will bore at depths ranging from 35m to 50m through predominantly Old Alluvium soil comprising sandy and silty clay, which is abrasive to the TBM’s cutting head.
Work on the tunnel is expected to start next month.