Lima Metro tunnelling is complete, after a tunnel boring machine broke through at the future Carmen de la Legua station in Peru, finishing excavation on the country’s first underground metro lines. According to International Railway Journal, the breakthrough completed a 7.5 kilometre drive southwards from Gambetta and closed out tunnelling for Line 4, while tunnelling on Line 2 had already finished in July.
What happened at Carmen de la Legua
The breakthrough was marked by a ceremony at Carmen de la Legua earlier in October, attended by the president of Peru, Keiko Fujimori Higuchi, transport and communications minister Angello Tangherlini, Line 2 general manager Carmen Deulofeu, and David Hernandez Salazar, executive president of the Lima and Callao Urban Transport Authority. According to Webuild, the machine that made the breakthrough, TBM Micaela, arrived at the eighth and final station of the Line 4 section, which will become the interchange between Lines 2 and 4.
Line 4 runs for 8 kilometres from Gambetta to Carmen de la Legua via Jorge Chavez International Airport, serving six intermediate stations, and it is being built under the same concession as Line 2. Line 2 itself runs for 27 kilometres from Ate in the east of the city to Callao in the west, serving 27 stations. Together the two lines form a 35 kilometre underground network, the first of its kind for Lima and Callao.
Lima Metro tunnelling: how the digging was done
Tunnelling on Line 2 was completed in July using two tunnel boring machines with cutter heads 10 metres in diameter, according to International Railway Journal. The Line 4 drive reused one of those machines: the tunnel boring machine used to excavate Line 4 had previously completed a 4 kilometre drive on the western section of Line 2, from Callao to Insurgentes, in October 2023, before it was dismantled and moved to the launch site at Gambetta.
According to Webuild, Micaela and a second machine, Delia, together excavated more than 20 kilometres of tunnels beneath the city. Reusing a machine that had already proved itself in Lima ground, rather than commissioning a new one for the shorter Line 4 section, is the kind of practical decision that keeps a long programme moving: the crew, the logistics and the ground behaviour were already known quantities.
Why it matters
When operational, Lines 2 and 4 will directly serve 10 districts of the Peruvian capital, benefitting around 2.5 million residents, according to International Railway Journal. The two lines are expected to carry 660,000 passengers each day, with capacity for up to 1.2 million passengers a day. The headline benefit for commuters is time: Line 2 will cut the journey between Ate and Callao from 2 hours and 45 minutes to 45 minutes, which the project says will deliver benefits in social inclusion, economic competitiveness and reduced emissions.
The scale of the investment matches the scale of the digging. The project is valued at 5.8 billion US dollars, financed under a 35 year public private partnership concession awarded in 2014 to a consortium of ACS Dragados, FCC, Salini Impregilo (now Webuild), Hitachi Rail, Ansaldo STS (now part of Hitachi) and Cosapi.
According to International Railway Journal, the consortium has provided 1.2 billion US dollars in financing, and the Peruvian government has recently approved an additional budget appropriation of more than 8 billion soles (2.3 billion US dollars), part of which will go to station and commissioning work on Lines 2 and 4.
What happens next
With Lima Metro tunnelling complete, the programme shifts from digging to finishing. According to International Railway Journal, work is now focused on tracklaying, installing railway systems and station fit-out. The first section of Line 2, stage 1A from Evitamiento to Mercado Santa Anita, opened in December 2023, and the ministry and the concessionaire have agreed to accelerate work to commission stage 1B, from Mercado Santa Anita to Ate via Vista Alegre and Javier Prado. According to Webuild, TBM Micaela will now proceed to a shaft where it is expected to be dismantled in November, closing the excavation chapter of Peru’s first underground metro.
Source: International Railway Journal, “Metro tunnelling completed in Lima”: https://www.railjournal.com/passenger/metros/metro-tunnelling-completed-in-lima/