6 NEW CIVIL ENGINEER 26.11.09 | www.nce.co.uk NEWS

FLOODING Cumbrian bridges ripped out by torrential floods

Six bridges ANATOMY OF WEEKEND FLOODS mm collapsed 1 Warm moist air 2 Ground already 314 makes landfall over saturated from of rain fell in 24hrs on the . Deposits previous fells in Seathwaite UK record for rain rain Northside Bridge in 36 hours CUMBRIAN MOUNTAINS and 1,800 to collapsed

Keswick Derwent Water Buttermere 10mm be inspected Skiddaw Average daily rainfall for Railway station Ennerdale Cumbria in November Bassenthwaite Crummock Water Calva Bridge, Lake Water unstable and to be demolished R. Derwent Loweswater CUMBRIA FLOODS Cockermouth R. Cocker m graphic: ww 2.5 By Jessica Rowson Depth of water in Cockermouth w. & Alexandra Wynne paulw town centre during peak eston. inf o Workington Water coming down Calva Bridge Structural engineers from across 3 from the fells in the A number of bridges Derwent & Cocker Northside road bridge N 4 collapse and others the UK were being rushed to converges on become unstable 1800 H Cumbria this week as the local Cockermouth & then I R T due to shear weight Bridges being inspected S O L W A Y F highways authority battled to Workington of water & scouring in Cumbria of the foundations inspect 1,800 bridges following extreme floods. Network Rail, the Highways bridges Agency and the Royal Engi- 29 neers have been assisting with Collapsed or closed in this area inspections and an additional 65 engineers were expected to arrive in the area as NCE went to press. Scour “Capita Symonds is organising bridge checks and has redeployed Pier some staff [from around the Great force country],” said Cumbria County applied by water Area of Council highways network scour manager John Robinson. Capita Symonds has been Fast-flowing floodwater scours away working on Cumbrian highways the riverbed downstream of the for the last 10 years. bridge piers, eventually destabilising the bridge foundation “Preliminary checks assess Northside Bridge, Workington Flood water tore bridges down which bridges are affected and which ones aren’t,” said Robinson. Kenny Brooks, who has been loads from above. But the water Six bridges have already “We’ve not lost too assessing much of the damage must have caused immense hori- collapsed and many more remain much stone at the over the weekend. “They rely on zontal forces below,” he said. closed while urgent structural moment but it’s still compression and when some- Brooks confirmed that it was checks take place. thing moves, the cracking causes the sheer weight of the water as Most of the collapsed bridges going down” distress. They are strong when in well as scour which caused the were masonry arch bridges –some Andy Dean, Connect place but not adaptable to move- larger road bridges to be swept over 100 years old – in the area of ment. Modern bridges are more away. Debris in the flood waters Workington and Cockermouth. flexible. They still fail, but it’s less helped cause the collapse of the Northside Road Bridge at dramatic.” smaller pedestrian bridges. Workington was the first to be Bridge near Keswick, Camerton Local authority engineers’ body “With some of the footbridges, swept away in the early hours of Footbridge linking Great Clifton CSS’s bridges group chairman it’s the weight of the water and the Saturday 21 November resulting with Camerton and the suspen- Mike Winter who is also Dorset debris,” said Brookes. “[It seems] in the death of PC Bill Barker. sion footbridge over River Eamont County Council’s head of engi- the foundations are still in place, By the end of Saturday five more near Dalemain – had collapsed. neering agreed that the strain on but the deck has gone. Decks have bridges – Northside Footbridge in “Masonry arch bridges don’t the bridges was excessive when been pushed off the supports.” Workington, Lorton bridge near like being disturbed,” said Capita exposed to extreme flooding. Workington’s Calva Bridge Cockermouth, Newlands Beck Symonds structural engineer “Bridges are designed to take on the A596, has been severely www.nce.co.uk | 26.11.09 NEW CIVIL ENGINEER 7

Cumbrian bridges ripped out by torrential floods

Mabey in talks to supply temporary mm Warm moist air Ground already WORKINGTON 314 1 makes landfall over 2 saturated from of rain fell in 24hrs on the replacement for damaged Calva Bridge Cumbria. Deposits previous fells in Seathwaite UK record for rain rain Northside Bridge Cockermouth in 36 hours CUMBRIAN MOUNTAINS collapsed By Jo Stimpson the Royal Engineers about Calva Keswick Derwent Water Buttermere 10mm Bridge but it was decided that Skiddaw Average daily rainfall for Railway station military solutions were unneces- Ennerdale Cumbria in November sary, said a Ministry of Defence Bassenthwaite Crummock Water Calva Bridge, Temporary bridge specialist spokesman. Lake Water unstable and to be demolished Mabey is in talks with Cumbria Ministry of Defence regional R. Derwent Loweswater County Council to replace the community relations officer for Cockermouth R. Cocker m 80m long condemned Calva Cumbria and Tynedale Carol graphic: ww 2.5 Whitehaven Depth of water in Cockermouth Bridge after military solutions Bell said a small team of Territo- w.paulw town centre during peak eston. were deemed unsuitable. rial Army specialists were tasked inf o Workington The council has met with with helping assess damage to Calva bridge: Condemned structure Water coming down Calva Bridge Mabey Bridge, Mabey Hire Serv- Calva Bridge in the early hours of 3 from the fells in the A number of bridges ices and the Royal Engineers, said Sunday morning. Derwent & Cocker Northside road bridge N 4 collapse and others converges on become unstable 1800 Mabey Bridge UK director Alex are discussing,” he said. They were “asked to ascertain Maryport H Cockermouth & then I R T due to shear weight Bridges being inspected Smale. Calva Bridge is the “first one to whether a solution using mili- S O L W A Y F Workington of water & scouring in Cumbria “We are in some discussion in look at”, he said, and the council tary equipment could be used to of the foundations terms of temporary bridges for has not yet approached the span the River Derwent”, she said. Cumbria,” he said. company about any other cross- Carter said Mabey’s pre-engi- bridges Mabey Hire Services director ings. neered steel modular truss Delta 29 for bridges Chris Carter said no “We are waiting for Cumbria Bridge and heavy duty modular Collapsed or closed in this area fixed plans for Calva were in place [County Council] to assess all the design Universal bridge were most yet. “We are doing an early feasi- structures and make its decision,” likely to be used at Calva, because bility study for them but I believe said Carter. they can be built quickly and are Scour that there are other options they Council officials consulted available from stock.

Pier Great force applied by Area of Temporary railway station for Workington water scour

Fast-flowing floodwater scours away the riverbed downstream of the By Alexandra Wynne and engineering expertise that we bridge piers, eventually destabilising felt should be put at the disposal the bridge foundation of the Cumbrian authorities,” said Network Rail director opera- Network Rail was this week scram- tions and customer services Robin affected by the floods. Its condi- bling to build a new temporary Gisby. “Our people will work tion is being monitored by Balfour railway station for cut-off resi- round the clock to build a tempo- Beatty which manages that stretch dents of flood-torn Workington rary rail station to help reconnect of highway as part of the Connect in Cumbria. the town and ease people’s travel consortium. It said that it intended to problems.” “There is no doubt the integ- begin construction on Tuesday One option for Network Rail rity has been compromised,” said night and would construct a two Modular: Possible station solution could be to deploy an innovative Connect general manager Andy platform station, linked by a foot- new modular railway station it Dean. “One of the piers of the bridge, with lighting, a waiting possible sites before the operator has been investigating and testing masonry arch is sinking. room and a gravel car park. settled on an area of wasteland with Dean & Dyball Rail. “It’s moved so significantly that The operator vowed to have 800m north of the existing station, In addition, Network Rail said it’s caused structural cracking the facility built and open by the off the A596 and on the north side it was working with local operator under the arch. We’ve not lost too weekend. of the River Derwent. Northern Rail to bolster serv- much stone at the moment, but The town has been split in half Network Rail then came to an ices by adding carriages where it’s still going down.” following flood damage to the agreement to lease the site from possible. A full inspection will only footbridges and road bridges in Borough Council for The operator has also asked the be possible when water levels the area. two years. council to work the station into recede. Aerial surveys helped to identify “We have a wealth of experience local bus routes.