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The Dublin Port Tunnel comprises approximately 5.6 km of dual carriageway, which includes 2.1 km of twin cut & cover tunnels and 2.4 km of twin bored tunnels, with associated interchanges and infrastructure.
The scheme follows a broad north-south path in its route from Santry to Dublin Port. The route of the proposed scheme commences on the M1 Dublin-Belfast Motorway at Coolock Lane Interchange. The route would be constructed in cut & cover tunnel from the portals at Santry, under the M1 and Swords Road, down to Collins Avenue. (A cut & cover tunnel is created by excavating a trench from the surface down, constructing the tunnel inside the trench, and filling in the trench afterwards.)
From this point the route would then continue southwards towards Fairview in bored tunnel. (A bored tunnel is constructed completely underground, with openings only at the ends of the tunnel.) The depth of the bored tunnel section, from existing ground level to the roof of the tunnel, would be approximately 19.0m to 24.0m under residential houses.
Passing beneath Griffith Avenue the route swings eastwards, travelling beneath the mainly residential area of Marino, and part of Fairview. At Fairview Park the bored tunnel construction would end, and a cut & cover tunnel would be constructed through the park.
The route would pass beneath the Dublin-Belfast and DART railway lines and Alfie Byrne Road to the southern portals located to the east of Alfie Byrne Road. Crossing the Tolka River at ground level on a bridge, the route would end at a North Port Interchange, set in open ground to the north of East Wall Road and west of Bond Road. A Toll Plaza, which would utilise electronic tolling technology, would be constructed at the North Port.
The scheme would be linked to the East Wall Road at Tolka Quay Road. The current entrance to the Port would be then be relocated from Tolka Quay Road to Promenade Road.
Motorway Scheme Details
- Two tunnel tubes, each approximately 11 metres in diameter;
- One tube carries northbound traffic - the other tube carries southbound traffic. Each tube has two traffic lanes;
- Approximately half of the tunnel length will be constructed by underground boring. The other half will be constructed from the surface down using "cut and cover" methods;
- Overall scheme length is 5.6 km of which the tunnel section will be 4.5 km (bored=2.4km, cut&cover=2.1km, and surface road=1.1km);
- Construction Contract Cost is £353 million;
- 3_ year construction period;
- Opening date - December 2004;
- Contractor : Nishimatsu Mowlem Irishenco;
- Construction of the two main tunnel bores will be by means of two Tunnel Boring Machines;
- Traffic flow in the tunnel is projected to be 20,000 vehicles per day in opening year, rising to 31,000 in 2018;
- Travel time from the M50 (at the M1) to Dublin Port will be approximately 6 to 7 minutes;
- There are 315 private residential properties, and 13 institutional properties situated above the tunnel;
- The geology along the bored tunnel section mainly comprises a stiff boulder clay along sections underneath open lands, and strong limestone rock along the residential housing section;
- On average the tunnel crown is located approximately 20m below ground level under residential properties.
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