Crews have  launched tunnel boring operations on the $5.6-billion Blue Line metro expansion, beginning excavation on a 15.5-km underground corridor that will extend Dubai's automated rail network into nine districts currently without metro service. Sheikh Mohammed bin Rashid Al Maktoum, vice president and prime minister of the United Arab Emirates and ruler of Dubai, activated the first tunnel boring machine May 3, according to state news agency WAM. Construction began in June 2025, as ENR previously reported , and the project is now 20% complete and on track to reach 30% by year’s end. The line is set to open Sept. 9, 2029—the 20th anniversary of Dubai Metro’s original launch. “Our projects in Dubai are … guided by clear plans, precise timelines and national talent capable of turning vision into tangible achievements in practice,” Sheikh Mohammed told state media. The design-build contract was awarded in December 2024 to the MAPA–Limak–CRRC consortium.…