Work begins on S'pore's 10th expressway

Completion due 2013; it is first road tunnel under the sea

(SINGAPORE) The Land Transport Authority (LTA) broke ground yesterday on the construction of Singapore's first road tunnel under the sea, the Marina Coastal Expressway (MCE).

The new expressway, slated for completion in 2013, will connect the Kallang-Paya Lebar Expressway (KPE) and the East Coast Parkway (ECP) to the Ayer Rajah Expressway (AYE).

'The MCE underscores the government's commitment to continue investing in Singapore's road network,' Transport Minister Raymond Lim said at the ground-breaking ceremony.

'The MCE will be our 10th expressway, after the KPE which opened last year. We will continue to invest in road infrastructure for the future, within the constraints of our limited land space. By 2020, we will complete the North South Expressway (NSE), which will provide an additional route from the north to the city.'

The 5 km MCE is the most ambitious project undertaken by the LTA and involves the widest road tunnel in Singapore, with five lanes going in each direction.

A 420 m section of the expressway will be beneath the sea bed. At its deepest point, it will be about 20 m below mean sea level. Some 13.1 ha of land will be reclaimed for the project - 9.1 ha at Marina Wharf and 4 ha at Marina East.

Singapore's 10th expressway is also notable for another superlative - it will be the country's most expensive expressway, with the value of contracts awarded so far coming up to $4.1 billion.

Exceeding a budgeted figure of $2.5 billion, based on lower construction and engineering costs in 2006, the contracts awarded so far comprise six major civil contracts and four major system-wide contracts. One minor civil contract and three other system-wide contracts are still to be awarded.

In comparison, Singapore's second most expensive expressway, the KPE, cost $1.8 billion to build.

According to LTA, some of cost of the MCE may be recovered if the prices of materials fall, due to a price fluctuation clause in contracts.

Apart from higher tender prices, construction of the MCE in difficult ground and soil conditions, as well as additional safety requirements for the sub-sea tunnel, added to the overall cost.

Construction will take place in soft clay that runs as deep as 60 m in some places.

'Soft clay is not very good for construction,' said Chuah Han Leong, LTA's director of the MCE project. 'It is like working with toothpaste. So we have to conduct extensive ground improvement to enhance the safety of the excavation.'

Planning for the MCE was done with an eye on property values. To increase the development potential of prime land in Marina Bay, the section of the ECP that runs through Marina South will be realigned and downgraded to an arterial road.

'The MCE will add to the long-term growth of Singapore and increase accessibility to the Marina Bay downtown area,' said LTA chief executive Yam Ah Mee.

Source: Business Times, 29 April 2009