Projects > Design Build
Portumna, Co. Galway.
|Replacement/refurbishment of the vehicular crossing of the
navigation span of the River Shannon previously provided by the
existing Portumna opening Swing Bridge
The new welded steel bridge structure was delivered to site in
sections and assembled on site; it was lifted in using a 500t
mobile crane. Elements of the existing bridge were removed,
refurbished and reinstalled; these included the rack, stabilising
and slewing wheels. The refurbishment involved, shot blasting,
non-destructive testing, repair and application of specialist
The existing bridge hydraulic, mechanical and electrical systems
were decommissioned. Due to the environmentally sensitive
nature of the River Shannon the decommissioning of these
components was carefully planned to avoid any contamination of
the water course and its environs. A new plant room was
constructed to house the replacement components.
The electrical, hydraulic and control systems were contractor
designed and installed. The moving structure was PLC controlled
into a HMI interface on site. Automatic traffic barriers and CCTV
were integrated into the works.
All of the onsite work was carried out over or adjacent to water.
These included the demolition of the existing steel bridge
structure, installation of the new structure, abutment repair,
bearing installation, electrical installation, submarine duct
placement on river bed and fender installation. Significant works
were carried out on the masonry abutments in the form of
vegetation removal, cleaning and repointing using traditional
techniques ensuring structural integrity prior to placement of the
Upon completion the structure was CE Certified in accordance
with the EU machinery Directive.
As the route is a main traffic artery, traffic management was of
the upmost importance. L & M Keating designed and
implemented a Traffic Management Plan for the project. This
Traffic Management Plan had a significant bearing on the design
of the new structure which was modified to ensure the
replacement was completed during a 9-day road closure of the
N65. The road was re-opened ahead of schedule. The road
closure was planned and agreed 10 months ahead of the
proposed closure date with the involvement of three Local
Authorities and the NRA. A diversion was put in place for the
closure; a traffic management plan was implemented according
to Chapter 8 of the Traffic Signs Manual.
2 Sligo Road,
10 Bernard Street,
Edinburgh, EH6 6PP.
|Date of Completion||December, 2008.|