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A perfect storm | The A591's long road to recovery

A591 storm damage

Engineering know-how and cooperation have rescued the A591, a key route to the Lake District’s prosperity.

And just in time for the busy summer season: the area receives more than 40M visits per year, worth about £2.4bn to the region.

Storm “Desmond” completely disrupted the north-south tourist route running between Grasmere and Keswick back on 5 December, with 81mph gusts and 341.4mm rain falling in just a few hours.

Cumbria County Council soon closed a section of the road between St Johns in the Vale and Dunmail Raise, emergency services assisted and the Army was even called in for clearing debris.

But in the weeks after Desmond, authorities faced another storm coming from local residents and tourism operators.

For drivers, the 20-minute, 22.5km journey via Thirlmere reservoir had turned into a 58km diversion via a steep pass.

Local MP Tim Farron estimated the road closure was costing the Lake District economy up to £1M per day.

So it was with a sense of urgency that WSP Parsons Brinckerhoff highways and transportation regional director David Pluse was brought in to work with Highways England as project manager.

“I watched it [storm Desmond] on TV in the comfort of a central heated house drinking a nice cappuccino. In two weeks I was there with my thermals on.”

“This was a one-in-1,300-year storm event, so very, very severe. Generally road infrastructure projects are designed for a one-in-100-year event, in terms of intensity.”

Dunmail Raise attracted most attention, where a 100m section of road had been entirely washed away by the torrent.

The 75-year-old road was formed on a backfilled peat and silt base, created alongside the Thirlmere reservoir.

The team came up with a preliminary design for a traditional cantilevered retaining wall. But evidence produced from repeat ground investigations called for constant re-designs.

“We had to apply innovative schemes the whole time really,” says Pluse.


A591 repairs start

Repairs in early 2016 focus on a section of retaining wall.

Steel posts were eventually drilled and bolted into bedrock. These posts were supported with precast concrete panels, creating the formwork for 2,500t of concrete to be poured in as the road’s undercarriage.

Progress was slow and drilling was difficult, with the loose material locking up drill bits and teams at times hitting boulders, rather than bedrock.

And another two storm events were on their way.

“When storms Eve (to a lesser extent) and Frank (to a greater extent) came through and deposited debris that had to be cleared, the whole first month had been lost,” says Pluse.

“We could only work when it’s safe to do so, and it was unpredictable, the storms were severe, which all made it unsafe at times.”

Elsewhere on the A591, there were three bridges to repair, seven other retaining walls and 91 drains, spread across around 5km.

A total of 44,000m2 of road was to be resurfaced – equivalent to the area of six football pitches – and rock netting was fitted along a 90m stretch.

Over 100 workers from specialist contractors – the vast majority based in Cumbria – were working on the project.

With the scale, working conditions and urgency of the project, this teamwork came to the fore to get the project delivered three weeks ahead of schedule.

“But the only way it was delivered was due to collaboration by a number of individuals and organisations. We all recognised the imperative,” says Pluse.

“There was a will from everyone from day one: we had to do things well, safely, quickly, constantly informing stakeholders – many of whom had livelihoods dependant on this work – and work with our supply chain, United Utilities and the council.

“I have designed and managed motorways in Greenfield… but once you are trying to repair infrastructure in the weather – the winter months there are a severe micro climate – that’s when all your core engineering knowledge comes forward.”

Cumbria County Council leader Stewart Young says he is delighted that local residents and visitors are now be able to travel easily between the north and south of the Lake District.

“It’s important to recognise the wide range of organisations that have played a critical role in getting us to this point, not least the county council highways teams who did a phenomenal job clearing tens of thousands of tonnes of debris and carrying out technical surveys and investigatory work.”

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