Balfour Beatty Rail has started construction on the new Canal Tunnel Junction project on behalf of Network Rail.
The project involves the installation of two new turnouts in the existing up and down Moorgate Lines to allow East Coast Main Line trains from Peterborough and Kings Lynn to travel further south of the Thames.
The southern end connection with the existing Thameslink system, situated just north of St Pancras International low level platforms A & B, will create the new junction.
The project is constrained by the old infrastructure and the existing track form will need to be broken out and the turnouts installed during key possessions taking place around Christmas.
The initial works will comprise of demolition and preparation, followed by diamond wire cutting and support.
Structural concrete and preparation work will enable the project team to lift out existing track slabs and place the new turnout sections with minimum disruption to the infrastructure.
Concrete infill and finishing works will complete the project which is due to be handed over on 30th December 2011.