Full details of bridge works are revealed
DETAILS of massive and long-term works on the Silver Jubilee Bridge between Runcorn and Widnes have been revealed.
A roads chief gave the lowdown on the crossing’s condition in response to a Freedom Of Information request from the Weekly News asking if the structure or any part of it was at risk of collapse.
Nigel Case, Halton Borough Council highways service manager for structures, replied that there is no indication of any such risk on the bridge, and provided details of past and present refurbishment programmes dating back nearly two decades.
He said a full structural assessment took place in 2001 as part of the national Bridgeguard programme, resulting in a five-year scheme in which the concrete deck slab was refurbished and the original main deck joints replaced.
A shock transmission system was also added to the bridge, designed to deal with traffic loads along the length of the highway, and access gantries were installed below the deck to enable inspection and works on the joints and the shock absorbers.
A 10-year maintenance programme then came into effect, including the renewal of the protective paint on parts of the steelwork.
It also featured the installation of a cathodic protection system, which uses a less important type of metal to guard against rust, and which was put in place on the reinforced concrete deck.
Protective wrapping was fitted to the bridge’s main span hanger cables and a principal inspection of the structure’s main bearings took place.
More recently, a five-year programme of major maintenance work funded by £3m from the Liverpool City Region began in 2016.
To date this has included: ● Two major maintenance painting schemes for below-deck steelwork ● Annual monitoring and management of the cathodic protection ● Structural repairs to main deck edge girders ● Principal inspections to suswpended spans and below-deck steelwork, an annual inspection and testing of main span hanger cables ● The refurbishment of the Runcorn approach viaduct’s reinforced concrete deck.
Residents will be well aware that the roadway on the bridge has been shut since the Mersey Gateway opened last year and works have been taking place beneath heavy scaffolding and drapes.
Mr Case said: “A major maintenance painting scheme for the steel arch superstructure commenced on site in October 2017.
“A detailed assessment of the temporary construction loading to be imparted on the structure was undertaken prior to site commencement, and this dictated the necessary phasing of the work to avoid overloading the structure.
“The arch painting work is ● ● essential to preserve the integrity of the arch steelwork and is due to be completed in early summer 2019.
“Other maintenance activities programmed during the current closure period include a trial replacement of one of the main span hanger cables, works to the access gantries on the arch superstructure, renewal of the safety system for maintenance access to the steel arch.”
Bridge collapses do happen from time to time, usually ending in tragedy for anyone caught in the disaster.
Most recently, in Genoa, Italy, 43 victims were killed when part of the Ponte Morandi bridge gave way.
The Silver Jubilee Bridge is undergoing extensive renovation work; inset, the collapsed bridge at Genoa
Above, Cllr Tom McInernyLeft, council leader Rob Polhill