A testament to Bangladesh's industrial prowess

A significant portion of the construction materials for the Bangabandhu Tunnel was sourced locally.

Although the main materials of the tunnel – the rings or segments – were imported from China, many other materials, including electric cables, were also procured from local suppliers for the tunnel.

Stakeholders say that the construction of the tunnel using domestic materials has added a new dimension to the country's industrial sector and highlighted the capabilities of Bangladeshi companies on the international stage.

Md Harunur Rashid, project director of the Bangabandhu Tunnel, said that the tunnel consists of two parts: the main tunnel and the approach road. The entire project is being implemented by China Communications Construction Company Limited.

"Due to Bangladesh's lack of capacity in tunnel construction, foreign contractors are implementing the project. However, the project has given priority to the use of domestic materials. As a result, local companies have supplied various materials to the project, including rods, cement, sand, and cables," he added.

The 3.315-kilometer-long tunnel, located 42.80 metres below the river's surface, is connecting Chattogram city with Anwara upazila.

3 local companies supplied 100% rods

According to sources, around 37,500 tonnes of steel were used in the entire Bangabandhu Tunnel project, all of which was supplied by three rod manufacturing companies in Bangladesh. BSRM, the country's top rod producer, supplied 72% (27,000 tonnes) of the rods, while KSRM supplied 7,000 tonnes and GPH Ispat supplied 3,500 tonnes.

Ameir Alihussain, managing director of BSRM, said, "We feel proud to be a part of all the important mega infrastructure projects in the country. We hope to continue our contribution and be a part of the country's growth. We are also proud to be a part of South Asia's first-ever underwater tunnel, which is a proud moment for the country."

"We maintain quality parameters from the beginning of the production process, starting with acquiring materials. The quality parameters we control are very consistent. Consistency is very important for this type of critical project," he added.

3 local companies supplied cement

A total of 215,000 tonnes of cement was used in the construction of the tunnel, all of which was supplied by local companies. Premier Cement supplied 85,000 tonnes, Ruby Cement supplied 75,000 tonnes, and Confidence Cement supplied 55,000 tonnes.

Mohammed Amirul Haque, managing director and CEO of Premier Cement Mills Limited, said, "Before the construction work began, the engineers of China Communications Construction Company collected samples of cement from our factory and sent them to China for testing. The samples passed the testing process, and the Chinese engineers visited our factory on the south bank of the Karnaphuli River.

"They were satisfied to see our state-of-art laboratory facilities for continuous quality control testing. Finally, they placed an order for us to supply three types of cement: AM, OPC, and BM, with three different compositions of clinker-fly ash-gypsum mixture," he added.

The testing and selection process for Ruby Cement and Confidence Cement was also similar. They also had to undergo a rigorous quality control process at each phase of production to comply with international standards.

Fakhrul Islam, head of corporate sales at Ruby Cement, a concern of Heidelberg Cement Group, said, "We mainly supplied PCC Composite 'A' Type cement to the tunnel project, which was used to construct the core infrastructure, such as tubes. This core infrastructure must withstand immense underground pressure, so it requires high-quality cement. Our PCC Composite 'A' Type cement has a special composition for this type of structure. The Chinese company was pleased with our consistent quality and services. We are also the nearest factory to the project site, which was another key factor in our selection as one of the major suppliers."

Mirajur Rahman, head of brands at Confidence Cement Limited, said that foreign construction companies used to import different materials, including cement, when implementing mega projects in the country. "However, the scenario has now changed," he said. "There are a number of local companies producing international-standard cement in the country, and we are among them."

Cables of 3 domestic companies

For the use of tunnel lighting, three local companies provided 750-degree-tolerant special cables. BBS Cables supplied 80% of the cables, with the remaining 20% supplied by BRB Cables and state-owned Eastern Cables Limited.

Rabiul Kamal, head of brand at BBS Cables, told TBS, "We have supplied 550,000 metres of different types of electric cables to the Bangabandhu Tunnel, with a market value of around Tk50 crore."

He also noted that the heat tolerance of cables typically used for electricity connections is 70 to 90 degrees Celsius, but the cables used in the Bangabandhu Tunnel can withstand temperatures up to 750 degrees. All cables had to be manufactured separately for use in the tunnel.

BBS Cables in its Gazipur factory manufactured these cables using copper imported from London. The tunnel authorities visited the factory three times, and all of their instructions were followed throughout the production process, he said.

In addition to rods, cement, and cables, domestic companies provided all the sand needed for the project, which was sourced from Moulvibazar, Sylhet.

Imported components

The segments of the two tunnels in the mega-structure were placed by excavating the riverbed. Eight segments, each weighing 11.5 tonnes, were placed to form a ring of 2 metres in diameter, which was then placed inside the tunnel. Each ring weighs about 88 tonnes. A total of 19,616 segments were used inside the two tunnels. The segments came from the Tunnel Segment Casting Plant in Zhenjiang City, Jiangsu Province, China.

The tunnel construction company imported the stone used in the project from Dubai. Lights, fire boards, and decorative boards for the project were also imported from different countries.

The Bangabandhu Tunnel project entails the construction of a four-lane road tunnel beneath the Karnaphuli River. The main tunnel is of twin-tube design, stretching over 3.315 km, with an additional 5.35 km of approach roads in the western and eastern sections, along with a 727-metre overpass (viaduct) linking Anwara upazila to Chattogram city.

The tunnel's entry point lies 2 km downstream from the Karnaphuli River near the airport and Navy College, while its exit is located at the Anwara end near the fertiliser factory. In its entirety, the project spans an impressive length of 9.392 km.

The maximum depth of the tunnel reaches an impressive 42.80 metres, with an outer diameter of 11.80 metres and an inner diameter of 10.80 metres. Inside the tunnel, there is a vertical clearance of 4.90 metres. The road within the tunnel consists of two lanes, with a maximum speed limit of 80 km per hour. The maximum slope within the tunnel is 4%.