Soil contamination prompted construction of a 7-km-long extension of Cairo Metro’s Line 3 on a viaduct instead of below ground, as first planned. A major challenge overcome by the Egyptian joint venture stemmed from the line’s location along the median of one of Cairo’s main highways. To minimize disruption to the utilities and nearly halve the amount of foundation concrete, the team built the viaduct on a single row of 2-m-dia concrete columns up to 16 m tall. Each column was founded on a 2.4-m-dia monopile.

As well as its six new stations, the project included a 65-acre workshop area with 32 buildings, which is said to be the largest depot in the Middle East and Africa. Despite congested urban conditions, the metro’s third line’s phase 4B was completed on time and budget, according to the team. 

Although the all-Egyptian joint venture employed French subcontractors for the line’s railroad systems, it believes experience from its overall project management will reduce future reliance on foreign expertise. Until then, French contractors and designers had led all the main work on what was the African continent’s first metro system, which crosses central Cairo below ground.

The project team says it performed more than 5.7 million worker hours without a lost-time incident. Line 3’s first 4.3-km phase, with five underground stations, began operation in 2012. Its 7.7-km second phase with four stations followed two years later. Work on the 17.7-km third phase of Line 3 continues. Meanwhile, the first part of the line’s nearly 16-km-long fourth phase was completed in 2019. Phase 4B was inaugurated by Egyptian President Abdel Fattah el-Sisi in August 2020.