July 11, 2023, saw the 8.54m diameter “CREC 1148” EPBM designed and manufactured by China Railway Engineering Equipment Group Co. Ltd. (CREG) begin boring on the shield driven section of the Halkali-Ispartakule high-speed railway project in Turkey.
The shield section includes twin bores, with each TBM drive some 6km with a maximum depth of 55m. The geology consists mainly of clay, silt, sandstone, conglomerate, claystone and marlstone, and the EPBM will underpass the Küçükçekmece lake and proposed Istanbul canal.
Focusing on the drives’ considerable depth and high-pressure water conditions, CREG has customized two EPBMs (“CREC 1148” and “CREC 1149”) to the same diameter. The two TBMs have the total lengths of 135m and maximum thrust speeds of 80mm/min and meet the requirements of Conformité Européenne (CE) certification. In addition, CREG has designed a double screw conveyor system and carried out ground reinforcements to help overcome the high-water pressures.
Sister machine “CREC 1149” is currently being assembled and will be launched in September 2023.
Upon completion, the Halkali-Ispartakule high-speed railway project will ease the significant pressures on local transport systems, improve the level of local passenger and freight transport and promote exchanges between the two areas in the region of Istanbul.