Client: Blackburn with Darwen Borough
Start / completion dates: 2006 - 2008
Contractor: Balfour Beatty Civil Engineering
Project construction value: £12,000,000
Services provided: Bridge Design, Project
Management, Civil Engineering, Landscape Architecture
Blackburn with Darwen Borough Council
benefited from an unrivalled multi-disciplinary approach to the
redesign of this key transportation route within Blackburn town
centre and the assurance that fundamental issues within the area
masterplan were considered.
Our client required an effective and
aesthetically appealing structure which could be delivered with
minimal disruption to road and rail users. The bridge forms part of
the strategic orbital route around the town centre which is
designed to improve traffic flow around Blackburn Town Centre and
improve road safety for all road users.
The structure replaces the previous four-span
bridge which was restricted to single lane oneway traffic flow from
south to north and was assessed as sub–standard, with a maximum 17
ton vehicle weight limit.
One of the main challenges was to design a
complex and innovative structure which would meet the demands of a
busy highways network. Client specifications included the need for
a robust design which demonstrates long term stability.
The building of any structure over an
operational railway line has major safety implications and Capita
Symonds worked in partnership with Network Rail to ensure the
safety of all operational staff and the general public.
The area surrounding Wainwright Bridge forms
an integral part of the town centre transportation route and the
need to successfully divert traffic and minimise disruption was
imperative. This was overcome by extensive planning within the
early stages of the project and the development of a diversion
route which was implemented and adhered to by all contractors. The
majority of works were also undertaken during off-peak hours.
The 12m bridge project was successfully
completed by Capita Symonds, led by Technical Director Faris Samin,
which now forms a central part of Blackburn with Darwen Borough
Council’s regeneration plans.
The new bridge consists of a single span 79m
span steel bowstring arch with a steel/concrete composite deck
carrying a dual carriageway. The footways are carried on
cantilevers from the arch ties and tubular twin arches are situated
at each edge of the deck. The substructures are made of reinforced
concrete construction on piled foundations.
The new bridge creates a major new road link
from Bolton Road to Barbara Castle Way, which forms part of the
Blackburn Orbital Route – a £12m overhaul of all the major access
routes into Blackburn town centre. The final piece of the route
will be the £4m section of road linking the bridge to Montague
Street which is due to be finished 2009.
The bridge also provides a major gateway to
Blackburn Town centre, strengthening links to surrounding areas,
thereby enhancing local business opportunities and regeneration.
The structure provides access to 'Brownfield' sites in close
proximity to the bridge which have been identified for priority
redevelopment and also improves access to the rail freight
Consideration was made for long term
sustainability and management of the structure throughout the
design process and subsequently in the choice of materials. The use
of weathering steel will significantly reduce the maintenance
commitment, particularly over the railway. All closed structural
sections are fully sealed with no future maintenance required.
Cast-in corrosion & inhibitors were used in those elements
subject to the effects of maintenance gritting.