Category Archives: Heritage

Environmentally friendly concrete – the Roman or French model?

As was widely reported in July, a research team led by Paulo Monteiro (professor of civil and environmental engineering) of the US Department of Energy’s Lawrence Berkeley National Laboratory and the University of California, Berkeley, had been analyzing samples from a 2,000-year-old Roman concrete breakwater to determine why Roman seawater concrete is so durable, how its manufacture was more environmentally sound, and how to adapt those characteristics to modern concrete production.

“It’s not that modern concrete isn’t good. It’s so good we use 19 billion tons of it a year,” Monteiro said in a 2013 news release. “The problem is that manufacturing Portland cement accounts for seven percent of the carbon dioxide that industry puts into the air.”

Analysis of samples provided by team member Marie Jackson pinpointed why the best Roman concrete found in 2,000-year-old Roman piers, massive breakwaters, Trajans Markets (below) and the Pantheon in Rome, was superior to most modern concrete in durability.

Phys.org™ a leading web-based science, research and technology news service, updated this news in a July article. Ms Jackson and her colleagues found that seawater filtering through the concrete leads to the growth of interlocking minerals that lend the concrete added cohesion: when seawater percolated through the concrete in breakwaters and in piers, it dissolved components of the volcanic ash and allowed new minerals to grow from the highly alkaline leached fluids.

Marie Jackson says that the mineral intergrowths between the aggregate and the mortar prevent cracks from lengthening, while the surfaces of nonreactive aggregates in Portland cement only help cracks propagate farther. The results are published in American Mineralogist.

As ‘tufo’ volcanic rocks (tuff), common in and around Rome, are not found in many parts of the world, the team is experimenting with substitutions. A more immediate innovation, we suggest, would be further use of the ancient and durable French hemcrete (isochanvre) in Europe; more on this in the next post

 

 

 

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Fair Isle’s community group gains support for extending its renewable energy supply

Fair Isle was bought by the National Trust for Scotland in 1954 from George Waterston, the founder of the bird observatory. It is 24 miles south of Shetland, surrounded by rich fishing waters. Most of the islanders live in the crofts on the southern half of the island (below).

Fair Isle’s fifty-five residents hope to develop the three-mile long island’s infrastructure to sustain and attract more people to live here in the most remote place in the British Isles, inhabited since the Bronze Age. Its distinctive knitwear has a worldwide reputation – see: https://www.pinterest.co.uk/explore/fair-isle-knitting-patterns/

As powerful winds mean that Fair Isle is often plunged into darkness, with blackouts usually striking at the most inopportune moments, a community group, the Fair Isle Electricity Company, is leading plans to install three 60kW wind turbines, a 50kW solar array and battery storage. This scheme will bring round-the-clock electricity to the island and help to bolster its dwindling population.

Existing wind-power will be extended to the north of the three-mile-long island, enabling grid connections to the water treatment works, the airstrip, North Haven harbour and the Fair Isle Bird Observatory, after securing £2.6 million in funding.

  • Earlier this year the company was awarded capital funding of more than £1 million through the Low Carbon Infrastructure Transition Programme (LCITP).
  • Highlands and Islands Enterprise (HIE) agreed to contribute £250,000 to the renewable energy project
  • There was a lottery grant of £600,000.
  • The scheme has received £250,000 from Shetland Islands Council
  • and £245,000 from the National Trust for Scotland (which owns Fair Isle).
  • Scottish Water gave £208,000.
  • The island’s bird observatory donated £100,000.
  • The Fair Isle Electricity Company is contributing £20,000.

The island houses a series of high-technology relay stations (left)  carrying vital TV, radio, telephone and military communication links between Shetland, Orkney and the Scottish mainland.

A Fair Isle resident, David Wheeler, a former meteorologist who worked on the introduction of the original wind power system, said continuity of supply would transform domestic life on Fair Isle. “It’s the little changes to our lives that will make a difference, like the television no longer cutting off when the snooker is on or the washing machine shutting down in the middle of the cycle with the clothes still inside. They’re small issues but they do matter.”

Robert Mitchell, director of the Fair Isle Electricity Company, said the project would bring new employment opportunities to the island and sustain existing jobs. “Having a constant electricity source may help to attract more people. This ambitious project is the first step in ensuring that the community of Fair Isle continues to thrive.”

Sources include:

https://www.thetimes.co.uk/edition/scotland/mood-is-electric-as-long-suffering-islanders-anticipate-24-hour-power-6hc52bgtl

http://www.shetnews.co.uk/news/14946-fair-isle-moves-closer-to-round-the-clock-power

http://www.shetland.org/plan/areas/fair-isle

 

 

 

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‘Daylighting’ or ‘deculverting’ of rivers in Sheffield

After blogging about Sheffield residents – and many in Mumbai – protesting against the felling of urban trees by Amey, better news comes from David Bailey (right). He draws attention to an article by David Cox, about ‘daylighting’ or ‘deculverting’ of urban rivers – the source of much of the following information.

Simon Ogden, chair of the Sheffield Waterways Strategy Group, recalls that the city’s rivers were used originally for water power, then for steelworking and waste disposal and finally built over and turned into sewers, commenting “That’s about as low as a river can get.”

Sheffield rivers, the Porter, Sheaf and Don rivers spend most of their urban life underground. The Porter flows between buildings, in culverts and below the surface in tunnels. It sometimes surfaces on its way to the Ponds area and, as it approaches Sheffield Railway Station (left), joins the River Sheaf under the station.

‘Daylighting’ rivers can be a more practical and cost-effective alternative to many of the UK’s Victorian-era culverts that are difficult to maintain. Last year, in central Sheffield, a culvert over the River Porter collapsed, causing part of a car park to completely cave in.

In a once-neglected corner of Sheffield’s cultural industries quarter, where music, film and science-based businesses flourish, there is now a green oasis – a “pocket park”- among housing blocks and a derelict industrial site A small amphitheatre slopes down to the banks of the river Porter, where wild trout spawn in spring and students from the technical college picnic and paddle.

Two years ago, the park did not exist. There was just a crumbling car park with the River Porter seen briefly before it disappeared into a culvert.

Simon Ogden describes the long-standing ambition of the WSG to reconnect the city centre with its waterways – the canal, Rivers Don Porter and Sheaf.

One proposal – called ‘Putting the Sheaf back into Sheffield’, featured on the BBC’s One Show – involves taking the roof off an underground culvert and bringing the waterway back into the open, surrounded by grass, flowers, trees. The bid for funding from the Heritage Lottery Fund was not successful but ‘pocket’ parks are being created through the council’s’ City Centre Breathing Spaces programme’, using money contributed under planning rules by developers.

Climate change has been one of the major driving factors for large-scale investment in river daylighting projects

Planners hope to utilise the passive cooling provided by rivers to help combat the urban heat island effect, and most of all, increase flood protection. Funding the ‘daylighting’ of the Porter in Matilda Street and Nursery Street has been combined with the Environment Agency Local Levy which aims to cover the cost of flood defences.

“We’ve been experiencing more flash floods in recent years,” says Ogden from Sheffield council. “So we need to keep the water in the river and make more space for it. Culverts act as a kind of choke on the river, so any blockages or sudden increased rainfall forces the water out onto the streets.” He continues:

“A culvert was removed over a stretch of the brook hidden beneath a car park, and riverbed material was redistributed and stabilised using boulders and reclaimed wood. Habitats have been created for fish with help from the Trout in the Town organisation, walls made of gritstone slowly release rainwater into the brook and the park has been designed to flood in extreme weather”.

News of a Rochdale project follows.

Cox’s article also has references to work in Auckland, to Seoul’s artificial waterway that joined up with the underground river at formed 3.6 mile-long water corridor now acts as a major flood-relief channel, transforming an area of Seoul previously renowned for crime and to Zurich, where urban river restoration has been common practice and daylighting – known as the “Bachkonzept” or the “stream concept”, is has been ‘enshrined in law’  

 

 

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‘Daylighting’ or ‘deculverting’ of the River Roch in Rochdale

Last year, Rochdale successfully restored the River Roch for the first time in 100 years by daylighting it through the main high street – see a stunning account in the Daily Mail – if only they would confine themselves to this genre.

Richard Farnell, Leader of Rochdale Borough Council, writes: Hidden underneath concrete for almost 100 years, when tram lines were extended to the town at the turn of the century, was the borough’s workhorse, a packhorse bridge and river over which scores of Rochdale folk transported wool from Yorkshire to be finished in Rochdale’s mills.

Above: the bridge believed to have been built in about 1324 when Edward II ruled England. http://www.bbc.co.uk/news/uk-england-manchester-36520198

And the river re-opening also has an even more tangible benefit. It reduced flood risk for 40 properties in our town centre; that’s 40 businesses whose livelihoods depend on being able to stay open all year round, 40 businesses who bring money into the local economy and employ local residents.

The town’s ‘old workhorse’ swung into action again on Boxing Day last year, preventing flood water reaching the Grade I listed town hall and many businesses in its vicinity when heavy rain wreaked havoc across the north of England. Over 160 businesses in the borough were affected by the floods and the shocking sight of Rochdale town centre under water will stay with me for a long time to come. For a borough which is investing heavily to build a great future after difficult times, it felt like the last thing we needed.

Penny Stevenson, a resident of Rochdale said: “Shortly after they finished opening the river up, we had another flood event – but whereas before the excess water didn’t have anywhere to go because of the culvert, this time it was able to drain away naturally, and didn’t swamp the town centre.”

 

 

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Title and contents amended

plastic-hippoTitle and contents amended to reflect readers’ preference for heritage news and the realisation that humour also acts as an antidote to gloom – first offering by the Plastic Hippo coming soon.