New Delhi, Nov 24 : The National High Speed Rail Corporation Limited (NHSRCL) said that 100 km of viaducts were ready for the 508 km of the mega Mumbai-Ahmedabad High Speed Rail Corridor project while 250 km of pier work has been completed. The NHSRCL said that on November 25, 2021 first girder was launched while the first km of viaduct was completed on June 30, 2022 in a span of six months. The completion of 50 km of viaduct was completed in a span of 10 months on April 22, 2023 and 100 km in the next six months, it said. It said that the project achieved this milestone of construction of cumulative 100 km of viaducts through launching of 40 m long full span box girders and segmental girders. The corporation said the full span launching technique (FSLM), where 40 meters long box girders are launched through state-of-the-art launching equipment, are being used along with Span by Span launching of segments. "FSLM is 10 times faster than the launching through Span by Span method, which is normally used for constructing metro viaducts," the NHSRCL said, which is looking at the construction of India's first Bullet train project. The NHSRCL also said that the 250 km of pier work has also been completed for the project "The viaducts include bridges over Six rivers -- Par in Valsad district, Purna in Navsari district, Mindhola in Navsari district, Ambika in Navsari district, Auranga in Valsad district and Venganiya Navsari district, all in Gujarat. "Even the installation of noise barriers has already started on the constructed viaduct." The NHSRCL also said that the laying of first Reinforced Concrete (RC) track bed for the MAHSR corridor track system as used in Japanese Shinkansen has also started in Gujarat's Surat. "This is for the first time, the J-slab ballastless track system is being used in India," it said. Giving more update on the project, the corporation said, "Breakthrough of first mountain tunnel of 350 metre has been completed in Gujarat's Valsad district and even the first steel bridge of 70 m length has been erected in Gujarat's Surat. "This is the first of the 28 steel bridges which will be part of the MAHSR corridor," the NHSRCL said. The foundation stone for India's first Mumbai-Ahmedabad High Speed Rail Project was laid in September 2017 by Prime Minister Narendra Modi and his then Japanese counterpart Shinzo Abe. The project is scheduled to be completed by 2026. /IANS