Tony Dempsey Profile Photo with Grey Background

Tony Dempsey

Chief Bridge Engineer
Meath County Council


Roughan & O’Donovan brought this high level, cable stayed bridge through every phase of the planning and design process, including:

  • Feasibility
  • Preliminary design
  • Public consultation
  • Detailed design
  • Contract document and administration
  • Construction supervision


The bridge won the ACEI’s President’s Award and Engineers Ireland’s Morgan Sheehy Medal in 2005.

  • 96m

    Height of the Y-shaped tower pylon
  • 370m

    Overall length of the bridge
  • €35m

    Total value of the bridge


This landmark, asymmetrical cable-stayed bridge structure carries the M1 northern motorway (Dublin-Belfast) across the River Boyne to the west of Drogheda.

With an overall length of 370 metres and a 35 metre wide deck comprising two longitudinal steel plate girders, it features transverse girders at 3.3 metres centres supporting an insitu reinforced concrete slab.

A steel composite deck, clad in a GRP enclosure, is supported from a 95 metre high reinforced insitu concrete pylon by 14 pairs of stay cables consisting between 32 and 68 No. 15.7mm diameter 7-wire strands.


To design a bridge over the Boyne, without impacting either the river or its banks, was the principal challenge. 

The solution lay in the bridge’s long main span, which eliminated the need for supports in the river, thus protecting it and the estuary from environmental impact.

Services provided:


Learn more about our long-span bridge projects