The vertical shaft at Whitehall is the largest European shaft built to date and has resulted in the excavation of over 84,000m³ of earth. The launching point for the two TBMs that are drilling the majority of the Dublin Port Tunnel, the shaft is 33m deep, 56.6m in diameter and has walls 1.6m thick. Over 16,000m³ and 1,332t of reinforcing steel were used in the construction of the walls and the base slab of the shaft.
A shaft with a diameter of 56.6m has been sunk some 33m into the ground from which two Tunnel Boring Machines (TBMs) are setting off to drill the two-lane, 11m-wide traffic tunnels. When TBM 1 (travelling south through hard rock) reaches Fairview Park it will turn around and drill the northbound route. The same procedure will occur for TBM 2 (travelling north through boulder clay) which will turn around at a reception area at Swords Road. Cut and cover tunnel construction will be used from Swords Road to the M1 entrance and from Fairview Park to the Alfie Byrne Road, a short overground drive from the port itself.