Simplex Infrastructures Limited operates as a diversified infrastructure company in India and internationally. It offers construction and engineering services for the piling, energy and power, building and housing, marine, roads and highways, railways, urban infrastructure, real estate, and other sectors. The company builds rail infrastructure, including rail tracks, station buildings, bridges, and culverts; and designs and constructs high-rise infrastructure, such as multi-storeyed residential towers, institutional/IT buildings, hotels, hospitals, and mass housing projects. It also builds industrial structures comprising steel and power plants; and undertakes projects for cement, aluminum, copper, engineering, automobiles, petrochemicals, fertilizers, paper textiles, pharmaceuticals, chemicals, and other industrial plants. In addition, the company engages in erecting various types of power infrastructures that include thermal, hydel, and nuclear, as well as ultra-mega power projects; underwater piling, which comprise steel piling; and building bridges across rivers. Further, it undertakes ground engineering projects, including pre-cast piling and jointed piling, cast-in-situ, driven, and bored piling, as well as soil investigation, soil compaction, diaphragm walls, grouting, and stone columns. Additionally, it offers airport renovation and modernization; and oil drilling services, as well as engages in the equipment hire business activities. The company was incorporated in 1924 and is headquartered in Kolkata, India.