Boring of Karnaphuli tunnel’s tubes finished

The boring of Bangabandhu Tunnel’s two tubes, built under 18-32 metres of the Karnaphuli River bed in Chattogram, was completed on Thursday.

With this, 72 per cent of the tunnel had been completed, Bangladesh Bridge Authority officials said.

Bangabandhu Tunnel Project Director Md Harunur Rashid Chowdhury said the tunnel’s basic construction had been done.

“We hope the tunnel can be opened to traffic by December 2022. Now road construction, electrical, and safety work inside the tunnel have to be completed,” he added.

The four-lane tunnel extends from near Bangladesh Naval Academy in Patenga to near Karnaphuli Fertiliser Company in Anwara.

In February 2019, Prime Minister Sheikh Hasina inaugurated the boring of the first tube.

The work was completed in August last year, and the boring of the second tube began in December.

Each tube is 1,228m long, and 614 rings have been installed in each.

The tunnel is 3.4km long, 11.4m wide, and 4.9m high.

The rest of the tunnel without the tubes has been built on both sides of the river.

Bangladesh Bridge Authority sources said the tunnel boring machine is 97m long and has the size of a capsule.

The main equipment to build the tunnel consists of a shield (a large metal cylinder) and trailing support mechanisms.

The distance between the two tubes is about 12 metres inside the tunnel. There will be three cross passages between them.

Emergency exits will be built in seven places in each tube.

There will be enough air and oxygen ventilation systems inside the tunnel along with rescue teams, modern equipment, and special fire control systems.

Harunur said in addition to the tubes, an important part of the project is installing safety measures and connecting roads and other infrastructure, which is about 30 per cent of the work.

To turn Chattogram into “one city two towns” like China’s Shanghai, China Communication Construction Company and China Road and Bridge Corporation are building the tunnel at a cost of Tk 9,880 crore.

The underground passageway is a significant part of the Marine Drive from Mirsharai to Teknaf and the Asian Highway connecting the Chattogram port and the Matarbari deep-sea port.

Some 13.9 million vehicles are expected to run annually through the tunnel by 2030, 32.9 million by 2050, and 50.5 million by 2062, according to the project’s feasibility study.

Of them, 50 per cent will be goods-carrying trucks.