SmartPly Precision
After serious consideration and an exhaustive environmental impact study, it was agreed that a tunnel
under the river Shannon was needed to offer necessary and long term socio-economic benefits to
Limerick and the surrounding area. The tunnel will be capable of handling up to 40,000 vehicles per
day and the removal of this many vehicles from the city centre will eliminate traffic congestion,
improve air quality, lower CO2 emissions and allow for further pedestrianisation and greater public
transport facilities for Limerick city centre.
The construction of the new Limerick Tunnel is one of the largest projects undertaken in the west of
Ireland, at a cost of over €500 million, and use of locally sourced sustainable materials is of particular
importance. The Limerick Tunnel Project is Phase II of the Limerick South Ring road project with an
estimated completion date of 2010.
Tunnel construction began in August 2006 with the tunnel being the
major element of the project, the
immersed tube tunnel measuring 675m in length. The tube will consist of
two bores, one for
southbound traffic and the other for northbound traffic. Each of the
two bores comprises two lanes
with emergency walkways on each side. Capita Symonds design for the
tunnel called for a completely
flat timber platform on which the concrete formwork for the tunnel base
would be constructed.
Precision was an essential requirement as with such exact engineering,
deviation of even a few
millimetres would cause problems. After assessment and evaluation,
German construction company Strabag International selected Waterford
based and FSC certified OSB from manufacturer SmartPly over other panel
product alternatives. Their specification
was tested and met with Capita Symonds approval. Thousands of stainless
steel screws protrude up through the 18mm SmartPly OSB3 to attach
15,000m2 of panels to the under-side of the concrete base elements of
the tunnel where the structural SmartPly OSB3 takes the weight of the
concrete during construction. The tunnel is constructed in five Tunnel
Units which
will be floated out and sunk into a pre-dredged channel across the
river. The SmartPly OSB panels
will be permanently beneath the tunnel elements on the river-bed once
the tunnel units are completed
and sunk in July 2008, where, with their unique task complete, the
non-toxic panels will safely
degrade over time.
Mr. Uli Holt, commercial manager for Strabag says "In this tunnel base application, SmartPly OSB
met all our needs in respect of both our quality and cost requirements. The structural capability of the
product was vital. We have been impressed with SmartPly's technical performance and intend to use
it again on our future projects."
Tunnel base timber sheathing for a major civil engineering project is just one of a wide range of
construction and design applications for Irish manufactured SmartPly OSB - from timber frame
construction to site hoarding, and from boarding up windows to robust modern architecture.
SmartPly OSB is part of Coillte Panel Products, a division of Coillte, the Irish Forestry Board.
Key Facts
Start Date - August 2006
Completion Date - September 2010
Overall Length - 10Km
Major Interchanges - 4
Number of Structures - 17
Length of Tunnel - 675m
Toll Collection Locations - 2
Volume of Excavation - 300,000 m3
Volume of Fill - 3,100,000 m3
The Limerick Tunnel consists of:
9.75km of two lane dual carriageway
2.3km of single lane dual carriageway
675m long tunnel under the River Shannon
750m causeway across Bunlicky lake
11 Bridges
6 Underpasses and 8 Culverts
2 Toll Plazas
Design Company - Capita Symonds, UK
Construction Company - Strabag International GMBH, Germany
OSB Supplier - Heiton Buckley Ltd, Limerick, Ireland
24 June 2008