Song Da No. 10 JSC is a Vietnam-based construction and engineering enterprise primarily engaged in underground excavation, tunneling, and civil infrastructure development for the energy, industrial, and transportation sectors. Established in 1983 as a specialized underground works enterprise under Song Da Corporation and headquartered in Hanoi, Vietnam, the company operates across key business segments comprising Construction and Engineering, Building Materials and Fabrication, and Ancillary Services and Power Generation. Its core offerings include underground tunneling, shaft sinking, and cavern excavation for hydroelectric power plants, railway networks, and vehicular transit; construction of civil, industrial, transportation, and irrigation facilities; quarrying and processing of construction stone, sand, and gravel aggregates; manufacturing and distribution of commercial ready-mix concrete, precast concrete elements, and fabricated steel structures; mechanical and electrical equipment installation for industrial and energy installations; leasing, maintenance, and repair of specialized tunneling equipment and heavy construction machinery; real estate investment, office leasing, and property management; and the development and operation of small-to-medium hydropower generation projects. The company executes major construction contracts across Vietnam and extends its engineering capabilities to regional markets in Southeast Asia, notably Lao People's Democratic Republic. In recent developments, Song Da No. 10 JSC transitioned its equity listing from the Hanoi Stock Exchange to the Unlisted Public Company Market under the ticker symbol SDT and initiated comprehensive corporate and financial restructuring under the strategic direction of Song Da Corporation. The company has focused its operational expansion on secured bidding for major national infrastructure projects, including tunnel packages for the North-South Expressway and strategic capacity expansions at major hydroelectric facilities such as the Hoa Binh and Ialy power projects, while continuing to upgrade its specialized mechanized tunneling fleet and divest non-core assets to strengthen working capital and operational efficiency.