The Army engineers have begun piling and foundation work for FOBs at Elphinstone Road on the Western Railway, and Currey Road and Ambivli on the Central Railway after obtaining necessary approvals from the transport PSU, said the Railway official.
The official said the permission from the Commissioner of Railway Safety (CRS) for the FOB at Elphinstone Road was expected "any moment".
He said the General Arrangement Drawing (GAD) of the Elphinstone Road FOB was submitted by the Army engineers yesterday.
The under-construction bridge at Elphinstone is an extension of the current north-end FOB at Parel station and will land at the west side of the Elphinstone Road station. It is estimated to cost Rs 11 crore, officials said.
Railway Minister Piyush Goyal, Defence Minister Nirmala Sitaraman and Maharashtra Chief Minister Devendra Fadnavis had visited the Elphinstone Road station a few weeks ago and announced the January 31 deadline for completing the three FOBs.