Full de­tails of bridge works are re­vealed

Runcorn & Widnes Weekly News - - Front Page - BY OLIVER CLAY oliver.clay@trin­i­tymir­ror.com @Oliv­erClayRWWN

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

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