Gandhinagar: A 6.5 km long twin underground tunnel of 5.8 diameter size each upline and downline has been completed on Apparel Park – Shahpur – Sabarmati river route of 40-km Ahmedabad Metro rail project phase-1 according to a note released by Gujarat government today. This tunnel is 18 meter below the surface. The works were completed using four tunnel boring machines. The company involved had called skilled laborers back from Odisha by air, to continue the works during Covid19 pandemic.