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Pooley Bridge swaps a stone crossing for a bowstring arch

Words:
Eleanor Young

When Knight Architects was asked to replace a river crossing lost in Storm Desmond, winning local support was top of the design brief

The delicacy of the bridge is enabled by the single track roadway. The materials of pavement and ‘lean rail’ are chosen for human touch.
The delicacy of the bridge is enabled by the single track roadway. The materials of pavement and ‘lean rail’ are chosen for human touch. Credit: Tom McNally

Delivering flyers for the first consultation on a new bridge for the Lake District village of Pooley Bridge, Héctor Beade Pereda of Knight Architects could tell this was going to be a tricky job. The council had charged Knight with delivering a concept design for bridge and a unanimous community decision. The village lost its stone bridge to Storm Desmond in December 2015 as the rain ran off the fells, filling Ullswater and then draining through the valley and taking the bridge with it. Now the community was looking for a replacement that would match the beautiful landscape, and there was a campaign to get back a stone bridge. 

This was never an option, the heavy piers sitting in the River Eamont had exacerbated flooding in the village, as well as leading the bridge’s collapse. It was a no-no for the Environment Agency. The hastily erected temporary bridge – with the look of an army installation – didn’t have many admirers either, though villagers and visitors alike appreciated not having to drive an extra half an hour to cross the river. They were also only too aware of the disruption of having no bridge, especially in the tourist season which the town depends on. 

After discussions over the parameters – speed of construction and water flow – in consultation session one, session two was a presentation of three concept designs. Knight wanted to know what people liked or not about each. Lots of contradictory opinions meant no idea came out a clear winner. ‘We were pretty scared,’ admits Beade Pereda. ‘There was not much time between showing the designs and the end of the commission.’ Instead the firm explained the contradictions in its next consultation session, the more modern/too modern preferences and the simple is boring/simple is best dilemma. And it used the feedback to draw out positives as design principles, looking at words and phrases like open views, unobtrusive, elegant, made to withstand flooding, lightness and transparency. 

They were helped by the fact that this was to only be a single lane for traffic so the structure and impact barriers could be less weighty or clumsy than normal. The bridge design Knight presented, along with a model, was welcomed at the consultation meeting; it was a simple arch with a 40m span. It does indeed look light, more like a footbridge than a road bridge, and the spandrel columns bet­ween arch and deck give the extra suggestion of waterflow – which Knight found was very important to locals.

 

  • Steel spandrel columns give strength with lightness.
    Steel spandrel columns give strength with lightness. Credit: Tom McNally
  • Ullswater and the River Eamont calmly flowing from it through Pooley Bridge.
    Ullswater and the River Eamont calmly flowing from it through Pooley Bridge. Credit: Tom McNally
  • Credit: Tom McNally
  • Credit: Tom McNally
  • Credit: Tom McNally
  • Credit: Tom McNally
  • Credit: Tom McNally
  • Credit: Tom McNally
  • Credit: Tom McNally
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It has now been built. At the base of the wooded valley, the arching underbelly of insitu concrete sits on prefabricated stainless steel sections above the shallow Eamont. Above is the road deck, permanently in tension. On the surface it looks very simple but there is a hidden structure in the limestone-faced abutments which avoided huge foundation work on uncertain ground. Invisible extra side spans give an uplift that needed to be held at each end of the structure – and make this a bow string arch bridge, though you would never know it.

It is unusual but ‘not rocket science’ says Beade Pereda. He has been quizzed on whether in fact it is ‘dishonest’. He puts his hands up to this. But if the result is a more elegant bridge for a happy village then why should anyone complain?

Knight continued with the project throughout as concept guardian for the design and build contract. So Beade Pereda saw the outsize crane that took days (and more cranes) to erect before swinging the steels into place in just hours last summer. And while surfaces were laid the Covid swell of visitors used a temporary footbridge. 

The crossing at Pooley Bridge was just one of 450 that Cumbria Council had to repair or replace after the 2019 floods. This one, embedded in the village, had special treatment. At £7 million, Beade Pereda admits it would have been ‘possible to cross the river for less’. Using it you get a sense of the care that went into it. The delicate balustrades enable even young children to join in with pooh sticks and drop a stick through where the bridge and pavement widen over the centre of the Eamont. Perhaps the stepping over the high Trief kerb (as seen in petrol stations) is a little hard work if you are dashing to see where the river has taken the stick, but using these safety kerbs meant that other barriers weren’t needed. But it may be that many pedestrians will have their eyes down, looking out for their names in sandstone pavers, where Beade Pereda and the teams’ names are carved alongside those of members of the community and many regular visitors.


IN NUMBERS
£7m total contract cost (25% temporary works)
£13,780 per m² GIFA cost (including temporary works)
508m² area 

Credits

Architect Knight Architects
Client Cumbria County Council
Project management Mott MacDonald
Design & build contractor Eric Wright Civil Engineering
Concept design engineer Mott MacDonald
Contractor’s consultant GHD
Cat III checking Inertia Consulting
Concept design independent checking K2 Ingeniería
Environmental consultant PBA Ecology
Stainless steel fabricator WEC Group / m-tec
Reinforced concrete works Betts Construction
Strand jacks / tensioning equipment Bill Boley
Operated plant Waitings

Suppliers

Stainless steel plate supplier Outokumpu
Stone paving and granite Trief kerbs Hardscape (installation: Helder Monteiro Ltd)
Stone cladding Eden Stonework
Bearings Ekspan
Timber handrail Woodscape
Lighting LTP integration
Expansion joints Emseal
Abutment flood doors Flood Control International
Crane for bridge installation Sarens
Temporary crossing Mabey

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