Stretcher Case

I was out walking with my son recently, and I pointed out where a row of iron stumps could be seen, protruding from the limestone capping on a low wall outside a civic building. As anyone who grew up in the UK knows, our built environment bears these scars from the early 1940s, when Britain found itself under siege and struggling to re-arm against the Nazis. Park railings and the gates of historic buildings were cut down and hauled away as part of the war effort.

Workmen remove railings from a park in the early 1940s

Then and now: removal of railings from public spaces

Giving up their railings proved to have a positive effect on the morale of the nation: it offered visible proof that something was being done, and virtually everyone was happy to join in. Vast quantities of iron were collected – but the evidence for it being used is somewhat scantier. Chemically speaking, there’s nothing wrong with reclaimed cast iron: it can be melted down and made into things like bomb casings… but the historical record that includes photographs and newsreel footage of people cheerfully giving up their railings isn’t matched by anything showing said railings arriving at the foundries in places such as Port Talbot or Sheffield.

Removing the railings at Buckingham Palace

Even Buckingham Palace joined in the recycling effort…

So where did the iron go? It’s hard to be certain: a few people have suggested that the government was caught out by the sheer quantity of material collected. They couldn’t use it all, but they appreciated the morale-boosting effect of the project and allowed it to continue. Were our park railings quietly dumped at sea? Some think so. As I researched this article, each anecdote that I followed up seemed only to reference another, with no hard evidence resulting: let’s just say that the dumping hypothesis is widely believed, among those who have expressed an interest. (The aluminium pots and pans that were also collected at this time do appear to have been made into Spitfires, however.)

Did the railing recycling scheme fail because supply exceeded demand? Perhaps so, but I didn’t want to complicate the issue for my six year-old. We just looked at the row of stumps sticking up out of the wall, and imagined the railings made into tanks and bombs – just as Lord Beaverbrook, Minister for Supply, must have intended.

There is another, still more complicated twist that I won’t bother the lad with, either – and for this nugget of knowledge we must thank what must be one of London’s most ‘niche’ interest groups, the Stretcher Railing Society (“For the promotion, protection and preservation of London’s ARP Stretcher Railings”).

A civil defence organisation set up in 1937,  Air Raid Precautions (ARP) prepared for the worst. This was at a time when it was believed that the bomber would always get through. In consequence over 600,000 stretchers were manufactured, to cope with the vast number of casualties that were expected.

These weren’t very comfortable stretchers: just a tubular framework covered with a metal mesh. Their utilitarian nature was quite deliberate, though, as they would be easier to decontaminate after a gas attack.

After the war, some of those stretchers were upcycled into railings. At perhaps a dozen locations in London, new housing estates acquired railings with a distinctive ‘bulge’ at the ends of every panel: these had been the feet of the stretchers, and they’re a dead giveaway that you’re looking at no ordinary bit of fence, but a piece of our history. They’re every bit as much a sign of the war as the funny little stubs of cut-away iron that still adorn so many of our public spaces.

Upcycled stretchers, made into railings

Upcycled stretcher-railings

Very early on in this blog, I felt the need to explain why recycling doesn’t really work. We can’t afford to think of an item that we’ve finished with as a collection of chemical elements, to be reduced to their simplest state before reuse. If we do that, we waste all the effort, ingenuity and – critically – the energy that went into shaping our stuff. Because recycling is so often downcycling (reuse of the material with degradation caused by contaminants) we make life a little bit harder each time we send our materials around the loop.

McDonough and Braungart (2002) made the case for upcycling, which might be understood to mean finding new uses for unwanted items such that they don’t become waste. A key point here is that the upcycled product should have a higher value than it had at the point it ceased to be wanted by the previous owner.

If you accept that definition then most of the examples of upcycling that you will find will be art projects. Picasso’s “Bull’s Head” was an early one, made from a couple of bits of an old bicycle. It’s fun, and some will say it’s art great art (personally, I’d say it’s no Guernica, but… whatever).

Pablo Picasso, 1942: Bull’s Head

So, um… yeah. All we have to do with our waste is make it all into sculptures.

This kind of upcycling does nothing to solve the problems of our age. Paul Bonomini’s “WEEE Man” conveys a powerful message about how much e-waste we each generate, but it doesn’t offer much in the way of solutions. In fact, a cynic might say it serves to keep three tonnes of material out of the recycling loop.

WEEE man sculpture at the Eden Project

It might sound like a Glaswegian term of endearment, but the WEEE Man is actually a former exhibit at the Eden Project in Cornwall, showing the amount of waste electrical and electronic equipment an average Briton will throw away in their lifetime. (No word yet on what happens to sculptures at end-of-life…)

If we all get creative and upcycle all our waste into art, we could actually increase the demand for virgin material. How much art does a society need? Taken to the extreme, we’ll be drowning in art instead of drowning in waste. This is why the ARP stretcher railings have such an important lesson for us: they haven’t been turned into something that’s only for looking at, and unlike art installations we don’t only need one: the more you reuse, the better. Also, in their new life they’ve been in use for something like seventy years, far exceeding the useful life seen in their primary purpose.

Perhaps upcycling needs a broader interpretation of value, where it’s not about price, but utility – but if we do that, there’s really not very much upcycling going on at all.

Liter of light: a bottle, refilled with water and a little bleach, brings sunlight into a room in a shanty town.Liter of light’ – the people using old lemonade bottles to make improvised light pipes – is still looking good, though.

For introducing me to the stretcher railings, thanks to fellow bloggers Peter Watts and Diarmuid Breatnach, plus the always fascinating 99% Invisible.

Cutty Sark [photo: Krzysztof Belczyński]

A Little Less Conservation, a Little More Action…

In Greenwich, London, the Cutty Sark is a popular tourist attraction. A British merchant ship, she’s a rare survivor from a vanished, glamorous age of commerce by sail.

Exceptionally sleek and skilfully constructed, it’s a shame to have to report that this beautiful ship was just about obsolete from the outset: she was launched in November 1869… the same month that the Suez Canal was completed, changing the geography of global trade forever.

As a clipper, Cutty Sark was designed for the tea trade, then a highly competitive annual race (with cargo) from China to London. The journey involved sailing around the southern tip of Africa and steering a route that would make the most of the prevailing winds. Cutty Sark employed composite construction (wooden planking over an iron frame, all sheathed in Muntz metal) to produce an elegant, streamlined hull that made her one of the fastest ships of her time. It’s worth noting that she isn’t just a vehicle that used to be a part of the global supply network, but also a product of it: British wrought iron frames and metal sheeting, American rock elm, East India teak… all assembled on the Clyde.

Fast sailing over long distances (up to 363 nautical miles or 672 km in a day) was no longer confined to clippers, sadly. The SS Agamemnon had already been in use for three years, demonstrating the advantages of a high-pressure boiler and a compound steam engine – and when the Suez Canal opened it offered a 6,100 km shortcut that was largely unsuited to sailing vessels. The days of the tea clipper were numbered.

Richard, and some faux tea chests in the hold of the Cutty Sark

Long before the standard intermodal freight container, there were tea chests. A team of Chinese stevedores could load a ship with up to 10,000 of them in 2–3 days, and on her first return voyage, Cutty Sark brought 1,305,812 pounds (592 tonnes) of tea from Shanghai. Since there was no way to return them once empty, tea chests found all kinds of secondary uses in the UK, Australia and New Zealand, becoming storage boxes, furniture and even musical instruments.

Eight times Cutty Sark sailed in the tea season, one of a dwindling number of tea clippers. In December 1877 nobody in Shanghai was prepared to entrust their cargo of tea to a mere sailing ship (insurance premiums for steamships were a lot lower) and this marked the end of sail in the tea trade. Cutty Sark and the other clippers had to change with the times: they were modified to carry a simpler, smaller arrangement of sails that reduced crewing requirements and maintenance costs, and they carried new cargoes on new routes.

Reducing manning levels in an effort to cut costs… a reaction to hard times that shipping lines still employ today. Another tactic that we see employed almost universally today is slow steaming: reducing speed in order to save fuel. It’s a good response to industry overcapacity and the high price of fuel because reducing speed by about a third can save thousands of tonnes of fuel oil… but it’s amusing to note that this has reduced modern commerce to a speed that Cutty Sark could have bettered on a good day – without spending a penny on fuel, and without producing any emissions!

When the tea trade changed to exclude clippers, Cutty Sark began to carry wool from Australia. In the 1883–1884 season, she made a journey from Australia to London in 83 days, 25 days ahead of any other vessel. In 1885 Captain Richard Woodget managed to get the time down to 73 days. Cutty Sark dominated the wool trade for a decade… until the steamships moved in on that commodity as well. In 1895 she was sold to the Portuguese firm Joaquim Antunes Ferreira, and renamed Ferreira as a result. She traded general cargoes here and there, and by 1922 she was the last clipper still operating. A spell as a cadet training ship followed, and when she was no longer needed in that role she was installed in a purpose-built dry dock in Greenwich, becoming a museum ship in the 1950s.

After decades of sitting on her keel – an unnatural position that caused a certain amount of sagging – came an extensive conservation project, beginning in 2006. It was a textbook case of poor project management, featuring cost over-runs, poor record-keeping and questionable security arrangements… punctuated by a terrible fire in May 2007 that might have destroyed the whole ship.

Cutty Sark fire of 2007

Cutty Sark is part of the National Historic Fleet, making her equivalent to a Grade 1 Listed Building: destruction by fire is not an option. Fortunately, much of the fabric of the ship had already been taken away for conservation   [photo:]

In April 2012, Cutty Sark reopened after years of hard work. The most noticeable change is to the dry dock. In my childhood it was a simple pit where wind-blown crisp packets would tend to gather, but now it’s a glazed space, the roof appearing to be an ocean swell that the ship is riding. In the new scheme, Cutty Sark ‘sails’ some three metres above, allowing visitors a good look at her most important feature: that beautiful, streamlined hull.

Copper/zinc sheeting on the restored Cutty Sark

Visitors can now walk beneath Cutty Sark’s hull, clad in a gleaming copper/zinc alloy that’s a close match to the original Muntz metal.

The end result of Cutty Sark’s renovation is controversial. The Victorian Society described it as a misguided attempt to fit the corporate hospitality market, and Building Design magazine named it the worst new building in 2012. (The ‘anti’ camp were hoping for a restoration that would have left Cutty Sark seaworthy.) Yachting World were more appreciative, though, describing the end result as sensational.

Cutty Sark will never again be able to return to the sea, but she still formed a focus for the ceremonies that preceded the Tall Ships race of 2017. At the Sailors’ Ball on Good Friday, dancers were dressed in their best vintage sailor chic, and after champagne and fireworks on deck, I enjoyed the opportunity to explore Cutty Sark without crowds, before we went below to dance. As the band played ‘Somewhere Beyond the Sea’, I felt as if I’d become one of the denizens of Rapture, the doomed city beneath the waves in the BioShock games: even so, count me among the people who approve of the Cutty Sark in her new role. For a ship that never quite worked out as planned, she has a surprising amount to teach us.

A dance lesson, given in the space beneath Cutty Sark's Hull

Dancing the night away at the Sailors’ Ball

The Broadest Railway Gauge… Ever. Ever.

In an earlier article, I wrote about the Middlesbrough Transporter Bridge, which I found to be wonderfully quirky, with elements of boat, railway and gantry crane about it. This time, though, we look at what you’d get if you could crossbreed a seaside pier, a pleasure steamer, and a tram.

Magnus Volk had already had a success with his Electric Railway in Brighton. It opened in 1883, the third such railway or tramway in the world, the first in the UK and the oldest surviving one. In the summertime you can still go for a ride along the same seafront track, in a funny little yellow carriage.

With a successful passenger transport business in place, Volk wanted to extend the line eastwards, but found that he would need to ascend to clifftop level – a costly and difficult proposition.

So what do you do?

You build your railway in the sea, of course! (In this, Volk may have been inspired by the Pont Roulant, a ‘rolling bridge’ that ran on submerged rails, across the harbour entrance at St Malo in France. That wasn’t self-propelled, though.)

Volk had two 825 mm gauge tracks laid down on land that was exposed at low tide, running all the way to the village of Rottingdean, some 4½km away. These were no ordinary narrow gauge lines, though: they ran parallel, the whole way, and the vehicle that was designed to ride on the rails straddled both – giving it a gauge of 5.5m.

The tram itself was called ‘Pioneer’, but most people called it Daddy Long Legs – and at 7m, they certainly were long. Pioneer’s main deck was 13.7m by 6.7m, and featured a glazed cabin with leather-upholstered seating, and a second promenade deck on its roof. Because it was technically a seagoing vessel, it had to have a qualified captain at the helm, and was equipped with life preservers and a small boat on davits. (In this pre-Titanic era, it seems you weren’t obliged to have enough lifeboat space for everyone…)

Poster advertising Pioneer

A Sea Voyage, on Wheels. Six pence.

At 46 tonnes, it may have been the biggest thing that the Gloucester Railway Carriage & Wagon Company ever made. A single trolleybus-style cable stretched along the whole of Pioneer’s route, providing power at 500V (DC). Current was returned via the rails, and via the sea itself when the tide was high. (This was long before anybody ever muttered those killjoy words, “Health and Safety.”)

Equipped with a pair of 25hp (18.65kW) motors from General Electric, Pioneer was horribly underpowered, and struggled to push its way through a high tide. It wasn’t very well streamlined, but it was tremendously popular.

Volk’s sea tram, underway

They certainly don’t make ’em like they used to…

The railway opened on November 28th 1896, but there was a terrible storm a week later that caused Pioneer to slip her moorings and roll away down the track. Pioneer ended up lying on her side, badly damaged. Repairs began straight away, but it wasn’t until the following July that the line reopened. Nonetheless, 44,282 passengers were carried that year.

Presently, shifting of the stones beneath the track’s sleepers forced a closure for repairs in the middle of the tourist season. Then in 1901 the council announced construction of a beach protection barrier that would have forced Volk to divert his line in order to avoid the new obstacle. He chose to close up shop instead: the world’s only seagoing tram was moored at Ovingdean Gap until 1910, when the whole lot was cut up for scrap. Today, all that remains of the railway is some of the concrete sleepers, visible at low tide.

This 3D modelled reproduction gives some idea of the scale of the Pioneer. [Animation by Delaney Digital]

Clearly, the Brighton to Rottingdean Seashore Electric Railway never worked very well, and it didn’t bring in enough money to justify costly track alterations… but if it had somehow avoided the scrap man’s oxyacetylene torch, what a wonderful tourist attraction it would make today!

Inadvertently, in the process, those Victorian engineers built the widest railway ever. The tongue-twisting Lärchwandschrägaufzug in Austria has a broader gauge, at 8.2m, but that’s a funicular railway, and basically a repurposed goods lift that now carries tourists. If you feel that a funicular qualifies, then there’s the ship-lift at the Krasnoyarsk Dam, with a track width of 9m… but is either a ‘railway’? Hardly. Disappointingly, I can’t cite the Montech water slope either. It’s a mind-boggling contraption that uses a pair of permanently connected diesel locos on either side of a canal, working to to raise 1,500 m³ of water (and boats)… but the whole thing runs on pneumatic tyres, not rails.

So… for my money, Volk built the widest railway the world has ever seen. His 5.5m dwarfs even the Nazis’ daydream of connecting all their conquered territory with the 3m gauge Breitspurbahn – itself monstrous when compared to the 1.435 m (4 ft 8 1⁄2 in) of our standard gauge.

The idea of using water where the land doesn’t offer suitable geography has recently popped up again, with the Thames Deckway project. The proposal is for a 12km, floating toll path running from Battersea to Canary Wharf, for cyclist commuters during rush-hour and tourists at other times. Although expensive, it appears to be reasonably benign in environmental terms: one of those ideas to file under “so crazy it might just work”.

Thames Deckway concept

Thames Deckway concept [image: River Cycleway Consortium]

I’d much rather relax with a Pimm’s on the foredeck of the Brighton and Rottingdean Seashore Electric Railway, though.

Botswana’s Water Crisis

I’ve just left Botswana, a place that I visit once a year as part of our Supply Chain Masters programme. I inducted ten new students there, and kicked off their first module, on the subject of supply chain strategy.

In Botswana a topic of conversation, time and again, was the shortage of water. The people of Gaborone are waiting for the rainy season to begin, but I’m told it’s been about a decade since the rain was sufficient to really fill up the reservoir at the Gaborone Dam. My colleagues have suggested that the public hasn’t been informed as to the full extent of the problem, although research suggests that the failure of supplies is hardly a secret: there’s even a neon sign in the city that reports the current level of the reservoir. The Water Utilities Corporation (WUC) also provides regular updates as to the state of supplies via its website. It makes grim reading: the principal sources of supply for the Greater Gaborone area are well below their maximum capacity:

Dam and Water Supply Situation, September 2015
Dam and Water Supply Situation, September 2015 (information from WUC, 2015)

The situation is somewhat better elsewhere, in the north of the country, but the capital is greatly inconvenienced and some southern villages are reported to have been without water for two or three weeks at a time.

Water shortages are not new. They’ve accompanied every visit to Botswana that I have made, and an article on Mmegi Online from last year illustrates the problem:

“For the first time in its history, Gaborone Dam is dying, its once proud 141 million cubic metres of water drying up to barely four metres above silt level. Of the seven water draw-off points in the Dam, six are exposed and the last is halfway in the water.

“Once the water reaches below this last water draw-off point, Gaborone Dam will have failed, depriving the 500,000 or so residents and businesses of Greater Gaborone their primary and traditional source of water.”

– Mguni (2014)

Can a dam die? Reporter Mbongeni Mguni’s article describes the Gaborone Dam as a great beast in its death throes. It’s a colourful simile, but there’s nothing wrong with the Dam: it will still be there, ready to serve again… when the rains return. In a sense, the fault doesn’t lie with WUC and their infrastructure, but with a growing population in the area – and with all of us, for our contribution to climate change.

A bad situation is becoming worse because Gaborone depends upon South Africa for some of its water. The Molatedi Dam (in the table above) is actually in South Africa. Equally, some places in South Africa depend upon water from Botswana: national boundaries don’t always reflect the infrastructure and resourcing arrangements. Under agreements that date back to 1988, cross-border transfers of water are reduced when reserves fall below a certain level. That serves to preserve dwindling supplies, but if you happen to live on the far side of a border it exacerbates the effect of reduced rainfall.

I have personal experience of being without water, although in my case it occurred in winter: our supply froze a few days before Christmas one year, and wasn’t restored until early in the New Year. For a couple of days, we clung on: showering at the gym, cooking with bottled water, and storing dirty dishes in the dishwasher, although it couldn’t be used. I was fortunate because I could bring snow and ice indoors, and leave it to melt. (Melted snow is nasty-looking stuff and you wouldn’t want to drink it, but it’s good enough for flushing toilets.) Eventually, though, we were forced to accept defeat, and we spent Christmas with relatives. Drinking bottled water is OK, but until the mains supply fails you don’t realise how often throughout the day you depend upon water for ordinary tasks, such as for washing your hands between jobs.

Next summer, we had our water pipe replaced with a frost-proof one, buried deep – at considerable expense. I hope never to be without water again: virtually everything in the household grinds to a halt, and I can only imagine what the impact would be if one were trying to run a business.

The first time I came to Gaborone there were times of day when there was no water to be had in our hotel. These times were announced in advance, and forced us to wake up early in order to shower. (The measure didn’t seem to save water, so much as to cost us sleep.) This time, there were no such interruptions, but the water in my washbasin was distinctly brownish. There’s nothing inherently wrong with water that comes with a bit of soil in it: I recall a bath on the Isle of Arran that looked like weak tea. It still got me clean: in fact, the peat-laden water was so soft, compared to that of my London upbringing, that a moderate quantity of soap caused it to foam madly.

Gaborone water, though, was water of last resort. It smelled strongly of chlorine, so obviously the water company are doing their best to keep it wholesome. Even so, I nursed my delicate British constitution by not to drinking any, and I avoided foods such as salads that would have been washed in it. (But I’m going to start suffering from scurvy if these trips get much longer…)

Tap filling a bucket with brownish water

Water supply as seen recently in Gaborone [photo: Fahmida Miller]

This is a report without a satisfactory ending, because the story itself hasn’t yet ended. The people of Gaborone can only wait, and hope that the situation improves. WUC have to do more than merely wait and hope, reacting quickly to reports of leaks and delivering water by truck where necessary. The government of Botswana can’t just wait and hope, either: they’re engaged in large-scale, not altogether successful schemes to pipe water over longer distances, including some from neighbouring countries. There is also a long-term plan of drawing water from the Zambezi, but Botswana’s Zambezi riverfront at the ‘Four Corners of Africa’ (the border between Botswana, Namibia, Zambia and Zimbabwe) is tiny: just a point on one bank of a 2,574km river. In such a situation, how much water is it reasonable to extract from a river that others also depend upon? Perhaps the tremendous flow of the Zambezi means that dipping into this shared resource won’t cause friction? On average, 1,088m3 of water per second goes over Victoria Falls, not far downstream… but even if water is so abundant as to be considered free, such engineering projects require time. Meanwhile, Botswana’s capital must continue to function, somehow – as must the nation’s water-intensive mining activities.

In the same week, one of my lectures was on the subject of the sustainable supply chain. I explained that sustainable materials are things that grow, or are refreshed by natural processes. Water is a sustainable material, per this definition… which serves to underline the difference between ‘sustainable’ and ‘being sustained’.



Mguni, M. (2014) ‘A requiem as Gaborone Dam gives up the ghost’, Mmegi Online, October 10th. Available from: (accessed 03/10/2015)

Water Utilities Corporation, WUC (2015) ‘Dam Levels’, available from: (accessed 03/10/2015)

Running on sun… by proxy?

On several occasions, I’ve visited businesses that are known for their sustainability work, and I’ve seen that they don’t have all the ‘eco’ features that you might expect. Why don’t they have solar panels? A rainwater collection system? Light pipes? (There are quite a lot of other architectural improvements I might list.) The reason they can’t have these things is often because they’re working out of rented premises, and this means they can’t put in all the equipment that they might otherwise have done.

Some ‘eco’ businesses choose to buy their energy on a tariff that promises renewable generation, in an effort to regain some of the lost ground. That reduces the damage to their ‘green’ image a little, but… what if you could have solar panels by proxy? Who says a solar panel has to be on the roof of your building, just because you funded its installation? Energy is just a commodity, readily fed into the grid and then used wherever it’s needed. Money – the return on your solar investment – is even more readily stored and transmitted.

Understand this: the big ‘sustainability crunch’ of the early 21st century is going to be all about energy. We’re facing a crisis because a succession of UK governments have failed to face up to difficult, long-term questions. Issues such as energy security (what to do if that nice Mr Putin decides to cut gas supplies next winter) and climate change (the extent to which we can afford to disregard our Kyoto Protocol obligations) have to vie with popularity (few people vote for the party that puts a nuclear power station in their neighbourhood) and simple economics.

Renewable energy is interesting to some, although in many cases the payback period is formidable. It’ll be interesting to see if investment in renewables harms liquidity in the years to come, but even if a person or business has money to spend and is entirely happy for it to be tied up for decades, not everyone can join in the ‘dash’ for renewables.

Piggy bank, and solar panels

Solar energy: money for nothing, or the longest of long-haul investments?

Would I want to have an array of solar panels on the roof of my home in rainy Yorkshire, looking desperately out of place on a 200-year-old building? Not really – and since it doesn’t have a south-facing roof, its energy-generating potential is somewhat limited. Despite all this, the investor in me is attracted to the idea of putting my money into a renewable energy scheme.

Enter CloudSolar, slogan: “No roof? No problem.” Given the negative effect that cloud cover has upon solar generation, the name is obviously one of those immune to irony things, but the basic premise is intriguing: just because you want to buy a solar panel, why should you have to find a place for it? Instead, buy a micro-share in a solar farm and have them take care of siting and maintaining it.

Solar panels on a home

Environmentally sound. Aesthetically… not so good!

CloudSolar take a 20% cut for what they do, and they plan to send you a payment (the other 80% of the money received for the sale of ‘your’ electricity) every three months for twenty-five years.

Each panel, rated at 250 watts, is priced at US$750. (Is that good? A quick search suggests that a branded 250W panel currently goes for about £207/$325 on the Internet, but that’s for the panel itself, without the associated equipment, the installation, or the place to put it.) For those with a different amount to invest, CloudSolar offer discounts on multiple panels, and half- and quarter-sized ones are also available. A key feature of the deal is that you own the panels that you buy; if circumstances change, it seems you can claim your property back. Meanwhile, the panels are guaranteed for twenty-five years, after which they can remain in place as long as they function. That 20% fee also covers them against theft, and damage.

This could be huge. Even if people only manage to invest a small amount, a sufficient number of citizens could put a big hole in carbon emissions from electricity generation. If CloudSolar are right in their claim that over 25 years, one of their panels will deliver enough electricity to run an average household for seven months, that means you’d need 43 of the things in order to operate a carbon neutral home. (In simplistic terms, not including however many more you’d need to offset the carbon from the manufacture, installation and servicing of your share of the solar farm…) Still, it’s a start; and 43 CloudSolar panels would only cost you $32,250… which isn’t much money, compared to the price of a house nowadays. (The average UK house price is around £192,000, which is $303,000.) Best of all, they’re not just asking people to give up all that money in order to be ‘green’; they’re inviting them to make an investment that pays real dividends.

CloudSolar promotional information

CloudSolar don’t guarantee a return on investment, but their business model is refreshingly different [image: CloudSolar]

The technology is nothing new, but the business model is intriguing – and far better than those ‘plant a tree to offset your guilt’ schemes that are just about completely unregulated.

I’m not suggesting that any reader should pursue the CloudSolar option: like any major investment, you ought to speak to your financial advisor before you take the plunge. Might CloudSolar go bust? I have to wonder if they’d prove to be like every double glazing firm I’ve ever done business with; you know, the ones that close down around the time that the warranty claims begin…

Are they offering a reasonable deal? You’d have to get a professional to read the small print. The currently unspecified charges for having CloudSolar remove your panels and ship them to you might come as a nasty surprise; I really couldn’t say. Also, while you’re free to invest in an American solar farm if you want to, you might find that there are financial incentives to a home-grown solar solution: if you’re in the UK you should have a look at the Energy Saving Trust’s information.

A setback for CloudSolar came when crowdfunding service Indiegogo shut down their campaign, refunding over $440,000 to the backers. This was because the CloudSolar campaign breached Indiegogo rules by inviting backers to participate in a profit-sharing scheme… but what had originally been a successful campaign, comfortably exceeding its target, seems likely to resurface. Even if crowdfunding doesn’t offer a route to investment, it’s clear that a lot of people want what they’re offering.

Solar enthusiast homeowners who have a suitable roof might also want to investigate A Shade Greener, whose business model is to fit solar panels entirely free: this means that they benefit from the governmental feed-in tariff, not you… but when you’re in the house you get to use whatever the panels deliver for free – and the rest of the time, the surplus electricity they sell is at least preventing some greenhouse gas emissions.

So many different business models! I suspect that the price of grid electricity can only head upwards for the next couple of decades as the older nuclear and perhaps coal plants get decommissioned; running on sun (one way or another) is looking increasingly attractive, and it’s becoming easier to do, at last.

What have the Romans ever done for us?

A light honeycomb centre encased in delicious… cement

Concrete is brilliant stuff. As the Romans could have told you, it provides a great way to get just the right shape without all that expensive and highly-skilled business of messing about with bricks or blocks. That’s why concrete is humanity’s most widely-used material, by tonnage.

The trouble is… that tonnage. Actually, that’s just one of concrete’s problems. Perhaps the biggest problem with concrete is that the manufacture of cement is responsible for at least 5% (some sources say 7%) of all mankind’s CO2 emissions… but low-carbon cement isn’t the subject of today’s post.

In between all that cement, you get aggregates. Historically, that meant sand, gravel and crushed stone… but when your species is making more than two billion tonnes of concrete per year, it’s all too easy to push the price of aggregates sky-high, along with the skyscrapers. That’s why it’s a good idea to introduce a recycled aggregate; making buildings out of old buildings has got to become the norm at some point during this century. It’s already happening, but inevitably the task of crushing up whatever waste you can acquire needs energy and has its own carbon consequences.

An alternative – in fact another part of the solution – is to manufacture artificial aggregates. That’s been going on for almost a century: Lightweight Expanded Clay Aggregate (or ‘LECA’) was developed in the USA around 1917. The manufacturing process involves pellets of clay that puff up when heated, like so much breakfast cereal. The resulting balls can then go into a concrete mix in place of natural stone: it’s ‘green’ because there’s less quarrying involved, and the product is more readily transported.

I might just pause to observe that when the Romans built the concrete dome on the Pantheon (still surviving 1,900 years on, and still the world’s largest unreinforced concrete dome) they used small clay pots and pieces of pumice in the mix, in order to reduce the weight in the higher layers of the dome.

So far so good… but a 21st century take on this promises still better performance. What if, instead of relying on clay, you could use a waste material? One of the exhibitors that impressed me most at Sustainability Live was Novagg Limited, would-be makers of just such a material. They propose to supply a new kind of aggregate, using almost entirely (98%) waste diverted from landfill – and not the ‘good’ high-value waste that everybody wants, but the real junk: industrial mineral wastes from the steel, aluminium, chemical and water industries, plus mixed glass.

novagg® pellets

They might look like mouldy pumpkins, but these pellets have a lot of potential.

The company adds a secret ingredient to make up the other 2%, and uses the same rotary kiln as the LECA manufacturing process. At a temperature some 400°C lower than with LECA (another clear advantage) the “novagg®” material puffs up into vitreous spheres that I’m told are lighter, but stronger than any competitor’s product.

Cross-section of some concrete made with novagg®

Concrete made with novagg® pellets performs well in terms of both thermal and noise insulation.

“Where there’s muck there’s brass,” as we say in Yorkshire. (Or at least, we used to.) Someday, somebody is going to make a fortune from this invention, I think. Right now, though, Novagg Limited are making sample pellets by the bag-load, not commercially producing aggregates by the truck-load. If you happen to have ten million pounds kicking around, to fund the construction of a full-scale production facility for novagg® pellets, I believe the company would like to hear from you – and you might be doing the planet a favour, too.

Novagg Limited demonstrator facility

The present-day demonstrator facility

Sustainable Infrastructure… through Archaeology

As I made my way around the stands at Sustainability Live, one company stood out. At first glance, it didn’t seem like they should be there. Amid all the companies showing off valves, pumps, safety harnesses, energy-efficient lighting and so on…

Border Archaeology Ltd

From the wall of their booth, a photograph of a human skull stared out sightlessly. This grisly centrepiece was surrounded by potsherds, and images of archaeologists at work – plus a few images of excavators, theodolites and assorted paraphernalia of the trade.

Skull image, Border Archaeology

Hey… have you lost weight?

I think my face must have said it all:

Um… why?

It turns out that there’s a very good reason, and Marketing Director Rachel Cropper was patient enough to explain it to me. Imagine that you’re commencing a civil engineering project, and soon after your contractor breaks ground, you find that you’re digging up bits and pieces of our ancient history. That’s a problem, because you might wreck a priceless piece of our heritage – or turn up some human remains, halting work.

There are also more predictable occasions when you might need to call in the archaeologists as well, such as when conducting appropriate archaeological work is a condition of planning approval. A careful balance has to be struck between those who would like excavation to proceed at the speed of the archaeologist’s trowel, and those who would prefer that there’s no delay to construction work at all. Border Archaeology’s approach is to get involved early on, in order to reduce cost and time over-runs.

I’ve written before about how I feel that preserving our history is a part of sustainability. It doesn’t get as loud a voice as the efforts to “keep the lights on” or to delay the effects of climate change, and perhaps that’s only to be expected… but it is important. Future generations will not thank us if we always choose profit over heritage.

Border Archaeology brochure

Archaeologists have it in spades…

Border Archaeology particularly like working with water companies because such work is less vulnerable to the economic cycle. When a new pipeline is being laid the process might involve assessment and advice at the planning stages, monitoring the work being conducted and then stepping in to preserve any significant finds. Some pieces might be ‘rescued’ for analysis and perhaps public display, while others are documented and protected in situ, which is to say covered up again, and left alone: meeting the needs of future generations of archaeologists to have something to study, you might say.

Now, forgive my ignorance, but I’ve been watching ‘Time Team’ for decades now, and I just assumed that archaeologists either came from a university, worked for museums, or were volunteers. To me, the professional archaeologist was an entirely unknown genus – but Border Archaeology has about fifty of them on the books.

I’m told that an archaeologist will never get rich – and true enough, it seems that Indiana Jones has never been able to afford a new hat, nor Mick Aston from ‘Time Team’ a better jumper – but I’m still more than a little in awe of this, an industry that I never knew about until yesterday: protecting our past while simultaneously working with the construction industry to build our future.

Sustainability, it seems, comes in a lot of different guises.