Energy utility company SP Group has announced that a 40 km network of deep tunnels, which started in 2012 and costs $2.4 billion, that will carry power transmission cables to help ensure a reliable supply of electricity will be ready by next June.
The company said that the tunnels will be able to house around 1,200km of extra high-voltage cables, more than three times the distance from Singapore to Kuala Lumpur, adding that most will be about 60m beneath the earth - the height of a 20-storey Housing Board building - but some will be at 80m, the deepest of any tunnels here.
According to the company, the tunnels will also be among the deepest cable transmission tunnels in the world.
It said the high-voltage cables, which are planned to last 120 years and costs additional $700 million, will mainly replace eight circuits running north and south or east and west across the country.
"These eight circuits are the oldest transmission cables still in use here," it noted.
SP Group said that about 500km of cables will be laid, which is less than half the capacity of the tunnels, and is slated to be completed by 2022.
Mr Michael Chin, SP Group's managing director of infrastructure and projects, said, "We had to build 60m deep because Singapore lacks space. We had no choice."
"If you look at the profile of Singapore, we have the MRT which is 30m to 40m deep, then you have your Deep Tunnel Sewerage System, which is between 40m to 70m, so we 'choped' (saved) our space at 60m," he said.