Sentosa Gateway Tunnel project in final stages, to open as early as April

A look at the Sentosa Gateway Tunnel.ST VIDEO: MARK CHEONG
A construction worker is seen inside the the Sentosa Gateway Tunnel on Jan 25, 2017.
A construction worker is seen inside the the Sentosa Gateway Tunnel on Jan 25, 2017. ST PHOTO: MARK CHEONG

SINGAPORE - A new one-way tunnel, which will connect vehicles leaving Sentosa island directly to Keppel Road and Lower Delta Road, will be opened to the public as early as April.

With the Sentosa Gateway Tunnel, motorists can bypass the busy junctions at Sentosa Gateway and Telok Blangah Road, as well as at Telok Blangah Road and Kampong Bahru Road. This would also ease traffic congestion at these spots.

The Land Transport Authority (LTA) said on Wednesday (Jan 25) that it has completed the structural, electrical and mechanical works for the project, and is "in the final stages of road pre-mixing and finishing works".

"The Sentosa Gateway Tunnel is scheduled for testing and commissioning works in the first quarter, and will be open to the public shortly thereafter," the LTA spokesman added.

The $160 million project was announced in 2008, as part of plans to enhance the area's road infrastructure.

This is to cope with the increase in traffic volume, brought about by the launch of Resorts World Sentosa in 2010, along with new residential and commercial developments on Sentosa.

The two-lane, 1.4km tunnel starts at the stretch between VivoCity and St James Power Station, and goes under Telok Blangah Road, before forking out into two single-lane roads - one connecting up onto Lower Delta Road, and the other onto Keppel Road.

While work started in 2010 and was targeted to finish at the end of 2015, the project was delayed for over a year due to construction challenges.

The new road tunnel is located just 1.6m above the North East Line MRT tunnels and about a metre away from the foundations of the West Coast Highway Viaduct.

The LTA said that to ensure the safety of the surrounding structures, a "piped-box tunnelling method" was used at two sites, below Telok Blangah Road and under Kampong Bahru Road.

The process involved the use of micro tunnel boring machines - about eight times smaller than the regular boring machines used for MRT tunnelling - to progressively tunnel and install steel pipes.

These interlocking pipes would form the perimeter of a tunnel box. Excavation follows in stages, and support frames are later installed to support the ground above and to minimise movement below. Concrete slabs are then cast to form the tunnel's structure.

Motorists said traffic along Sentosa Gateway can be clogged up in the evenings and during weekends, and they hope the new tunnel will help ease traffic flow.

Businessman Adrian Koh, 39, said: "When you exit the VivoCity carpark and get onto Sentosa Gateway, it's usually quite congested. I have to wait for two to three traffic light cycles before I can clear the junction."