Thursday, 3 September 2015
Conscious that this has become a little hard to find online, I thought it'd be worth posting a link to my PhD thesis, Production of Aluminium Foam using Calcium Carbonate as a Foaming Agent, from the Cambridge years, online. Because research is frankly no use unless people can access and build on it, and there's a fair bit in here about aluminium foams that's still interesting and relevant.
This was the first time that anyone had spent any real time looking into calcium carbonate as a way of making foams, and to cut a long story short it turned out to be a very cheap and cost effective way of doing it - because the gas produced was (oxidising) carbon dioxide rather than the moire widely used (reducing) hydrogen gas, it made a thin layer of alumina on the aluminium cell walls and in doing so hugely stabilised the molten foam. This transformed what had previously been a pretty unstable production process, and meant that foams could be made on a far more industrial basis, with smaller cells.
The document is a whisker under 200 pages, and if you're printing it you'll be better off doing it in colour, for the (many) diagrams to make sense. Do feel free to cite it - the British Library citation reference is linked here. I'm still always happy to answer questions on it, though I don't work in this field any more so my memory's frankly pretty rusty on the subject!
Sunday, 28 August 2011
Sunday, 3 April 2011
Friday, 2 April 2010
It's in one of Switzerland's windiest valleys - but the most famous feature of this turbine is that it's hardly ever rotating. I think I've only ever seen it in action twice. It was also taken down at various points in its lifetime - sometimes for several years; indeed on Google Maps' aerial photo (here) you can see it lying down - but now it's back up.
This old and now largely abandoned turbine is all that remains of an alternative future for Swiss energy - a future that never happened. For all of the early inventiveness (and its location right next to the motorway means it's quite widely recognised, even if a lot of people don't know that it's a wind turbine) you can't avoid the feeling that Switzerland decided early on to 'pass' on wind energy.
In the last few years a pair of more conventional wind turbines have appeared a few kilometres down the valley - though for all its green-ness, the biggest wind farm in the country still has just eight turbines.
A glance at the landscape gives some idea why - deep valleys, and huge mountains, don't really provide the ideal conditions. Unpredictable and variable wind doesn't help. And the scenery in the windy areas is mainly quite heavily protected (it's no accident that the current wind farms tend to be in industrial lowland areas).
All said, renewable energy may not be needed in Switzerland - fully 94% of its electricity is already 'low-carbon' (56% hydroelectric, the legacy of a dam-building programme in the 1950s onwards of unimaginable proportions, and most of the rest nuclear). But in a surprise move, immensely costly solar panels are currently appearing everywhere, with some cantons (regions) apparently offering generous subsidies. Hard to say where the rest of Switzerland's future electricity capacity will come from - so far, energy use is on the up, and nothing has emerged as a strong option. They've bene busy increasing the capacity of the dams (which literally, in this case, means building the existing dams a bit higher!) - and the ability of the dams to accommodate fluctuations in generation means they could have up to any amount of renewable energy. There's also a strong wariness of imported energy supplies. Could wind ever make a comeback?
Sunday, 3 May 2009
There is a small city centre - but these empty suburbs surround it in all directions and cover more than five times the total surface area of the populated town.
Some investigation later, it turns out Port Charlotte is not alone. It's much the same story at Lehigh Acres, some 150 km to the southeast -
If you follow the link, and switch to street view, every single road has been photographed by the Google Street View car - showing nothing but mile after mile of roads running through scrubland.
There's another similar one in Cape Coral (link - opens in a new window) - complete with a large complex of marinas and harbours to the north west of the city centre.
And it's not just a Florida thing - try California City, deep in the heart of the Mojave Desert, and about 150km north of Los Angeles. Again a fairly typical American suburban layout - but in the middle of the desert, and with no houses in sight.
Flick between the 'aerial' (above) and the 'map' (below) view, and it looks like a fairly major development. Note that the roads on the left half of the above image have never even been declared roads (so do not feature on the map below) - presumably at some point whoever was building the roads just stopped bothering with all the legal paperwork needed to get them officially recognised.
California Valley, which is in the middle of the desert in central California, is another are with miles of roads laid out with no settlement whatsoever beyond a few small huts (typical picture right, link to more detailed map here). Its Wikipedia article notes that fewer than 500 people live in the entire region, and warns anyone thinking of visiting the area that:
"This is a remote area and only limited services are available. As of 2005, there were no gasoline stations and no lodging open to the passing public. Rental cabins are sometimes available, and other services are advertised on the posting board at the Community Center. Travelers are advised to top off gas tanks and procure potable water and food appropriate to their travel plans in advance."
Google Street View of California Valley (link) suggests a rather spectacular landscape, but little potential for actual habitation.
Deeper still into the desert, here's another vast layout of streets stretching deep into the wilderness at Rio Rancho in New Mexico - apart from the green sections (which are reasonably densely populated), the entire area of roads in the picture below (220 square kilometres) contains a couple of dozen houses -
So what happened to these 'cities'? Who built, and who paid for, these crumbling road networks in the desert? Where were all the inhabitants going to come from, and why did they not come?
These cities were developed by real estate speculators in property booms in the 1920s and late 1960s (with a particular boom between 1969 and 1973). The business model was a simple one: buy a vast tract of rural land (preferably in the desert or somewhere out of the way, and correspondingly cheap), subdivide it into tens of thousands of small plots just big enough for a house and garden, lay out road systems (and, sometimes, rudimentary facilities), and employ salespeople to sell the plots on to aspirational Americans who want to buy their very own slice of the 'American Dream'. The marketing touted the property as having tremendous investment potential, citing authorities with quotes such as: "Ninety percent of all millionaires became so through owning real estate."
The economic case was a compelling one - as land was worth far more when subdivided into platted lots', and zoned as urban land, than when it was bought in bulk as farmland (or, more often than not, desert, marsh or scrubland) - and people in far away cities who had never been to visit the areas could (with a bit of carefully targeted advertising) be sold plots of land for far more than they were really worth.
In some cases there was a hint of a grander vision - for example in the case of California City, real estate developer and sociology professor Nat Mendelsohn purchased some 490 square kilometres of Mojave Desert land with the aim of master-planning California's next great city. He designed a model city, which he hoped would one day rival Los Angeles, around a Central Park with a 26-acre artificial lake. Growth did not happen quite as quickly as he expected, and the city ended up as a grid of crumbling paved roads, intended to lay out residential blocks.
And why did they fail? There are a variety of reasons. In California City the central area was cleared leading to huge dust storms, and in California Valley a planned irrigation scheme never materialised (leaving the city stranded in one of the most arid and inhospitable parts of the USA). Sheer oversupply was an issue in Florida. But above all, these areas were developed and sold purely speculatively as a 'dream retirement home plot ' by rather fly-by-night developers - who probably knew that the infrastructure needs of these cities (in particular the water supply) would never have been able to be met. It was only when the happy landowners arrived at their remote patch of desert that the sheer difficulty of building and servicing a house miles from anywhere, with no water, electricity, sewerage, let alone local services, sank in. These 'platted lots' (so-called because they are 'platted', or subdivided in the local land registry and assigned to individual owners) are a major drain on the resources of local government due to the huge number of roads and utility networks that have to be maintained for the tiny number of inhabitants that did actually persevere and build houses. The number of such schemes, and the impossible-to-service subdivisions they led to, subsequently led many states to introduce planning laws requiring sewer, water and power to be provided before plots could be sold.
The most celebrated example of all dead cities, though, has to be Salton City -also in California, and about 200km east of LA. As with the examples above, on on the map it looks like quite a conurbation (with 10 square miles of road network, a marina, several suburbs, a city centre park, and even an airport to the south of the area shown) -
But the aerial photo reveals a rather different scene, with the odd dilapidated house (almost all of them, on closer inspection, as well as the airport terminal, are completely derelict). These google maps images can be dragged - if you try with the one below, go south in a roughly straight line and you'll eventually see the airport.
For reasons that are anyone's guess, Google's street view cars have gone round dutifully photographing the streets of most of these 'towns' (especially the Florida ones, where every street seems to be recorded). It's a desolate scene - the image below is a typical view in Salton City (and again you can drag it around). All the streets are paved and they have the same American-style street-name signs you'd see in any city. There's also an extensive network of what look like well maintained fire hydrants for the homes that were never built.
Here's a view of Salton City's rather forlorn looking airport. It's set by a network of streets slightly separate fom the main city with themed names including 'air park circle', 'air park drive', 'skyway drive', 'skyliner court' and 'palm air court', all of which are completely empty and seem to have been designed as an airport business centre.
Salton City failed for a rather different reason: the town was initially developed in the 1950s as a resort community on the Salton Sea, an inland sea which had been accidentally created in 1905 when heavy rainfall and snow melt caused the Colorado River to swell and breach a dyke, and fill the formerly dry valley with water. It was stocked with fish and became a major tourist and retirement destination, but as with any inland sea, with water flowing in across the desert but leaving only by evaporation (think of the Dead Sea), the salinity of the already highly polluted sea rose, the fish died, and it gradually became rather a health hazard. By the time Salton City (and several other similar towns round the shore of the lake) was ready to be inhabited, it was already clear that the city was in deep trouble. Very little development took place and most of what was built - including several hotels, the airport, and the city's marina - was abandoned. Today it's a place that attracts a few loners, travellers, misfits and people who want to get away. It notably featured in the 2007 film 'Into the Wild', about the story of Christopher McCandless.
One of the worst of all developments of this kind was the 230-square-kilometre 'Golden Gate Estate South', in Florida's everglades. It was planned as a town of 400,000, but ended up as one of Florida’s most infamous real estate scams. Spurious salespeople sold 29,000 lots over the telephone to out-of-state buyers who had no idea that the land was uninhabitable marshland, and that by late June, despite 180 miles of drainage canals, they would need boats to reach their land. I quote from simplify3's notes -
"Lonely canals and little-used roads criss-cross this cypress swamp turned subdivision, which was originally platted in the early 1960s by the Gulf America Corporation. The company dug canals to drain the wetlands and carved the property into 1.25-acre lots. It then promoted Golden Gate worldwide as a vacation and retirement community. Most of the lots were sold by 1965, but unsuspecting buyers still get suckered into paying over $15,000 for a lot worth about $3,000. In 1974, when the area was less than 10 percent developed, it became apparent to county officials that the project, with limestone roads and no centralized water and sewer system, could not support the number of platted lots."
A look at the aerial photo says it all. Compare this with the level of planning that has clearly gone into Salton City - in contrast at Golden Gate the road layout is the most rudimentary possible - with long straight unpaved tracks that don't even connect to each other. There were no services or utilities of any kind, no schools or provision for any kind of employment, and little prospect of any being developed, and certainly no intention of developing a town that could actually work. The development eventually went bankrupt, but (along with several similar schemes that followed) gave rise to the expression 'I have Swampland in Florida to sell you'.
The Golden Gate estate continues to be a particular headache for all concerned - on top of all the other problems, it's in the centre of a very ecologically sensitive area (and street names like 'alligator avenue' hint at what lurks in the swamps). The cash-strapped municipality is doing its best to prevent further development and consolidate the land into the neighbouring national park - but untangling legal ownership of the thousands of plots (many of which were abandoned by their owners over a generation ago), and consolidating what development may occur, is a difficult and costly process. There is little incentive for any developer to tidy up the area (for example by adding drainage, lighting, pavements and utilities) because the land is already sold, and it is nigh-on impossible to assemble enough of the tiny lots in any area from their absentee owners to make a viable modern development - which seems to condemn these areas to sit in this strange partly-developed state for the foreseeable future.
City governments know that they will never be able to supply utilities to all these scattered lots, or maintain the roads, even if it wanted to - and across the US are gradually tightening the rules to prevent the small nuber of people who still try to develop these plots of land (sometimes insisting small plots be combined to larger and more viable ones, banning development in areas altogether in the remoter parts of these zones, or offering more suitable plots nearer the city in exchange for remote ones).
These scams still take place regularly, albeit not on such an epic scale, and the existing plots of land (in these cities and many others) continue to be bought and sold on the internet at inflated prices. Many also still cling to the notion that they might just, one day, build that dream home on that plot of land in California they inherited from their grandparents.
PS. There's a good article with more on these failed settlements, and what became of hem, in an article by Hubert Stroud - Planning of the wake of Florida Land Scams.
Saturday, 25 April 2009
Back when I lived in North Battersea, I grew a bit curious about an old (and rather run down) church, lost in a tangle of industrial units and luight warehousing in the unfashionable bit of Battersea. As a bit of out-of-place Victoriana it was a bit of an architectural curiosity, that seemed to have survived long after all its neighbours were bombed, demolished or redeveloped between the 1940s and 1980s. Caius House (variously known as Caius House, Caius Mission, Caius House Church and Caius College Mission Church) was on Holman Road in Battersea - and as of January 2009, Caius House is no more.
"The Settlements, as they are called, [are] where educated men and women, putting theory into practice, take up their abode with the poor, striving by force of example to raise the moral tone of the district in which they have settled. [...] The University of Cambridge has taken charge of the vast population on the south of the Thames, as Oxford has done in the East-end. Cambridge House and Hall is their headquarters in a district said to present the largest area of unbroken poverty in any European city; and, as in a semi-circle, South London is apportioned to various colleges; for instance, St. John's works in Walworth; Caius, in Battersea; Clare, in Rotherhithe; Corpus Christi, in Christ Church district, Camberwell; Pembroke, in Newington; and - chief of them all - Trinity, in St. George's Park, Camberwell."
There is a fairly large electrical substation to the north, and another one to the east (not pictured) opening onto Lombard Road, built in 2003-4.The building still had most of its original windows towards the end, though some of the panes seem to have fallen out over the years. The general state of repair was fairly good, given that it was in a fairly run down area, though seemed to vary between different bits of the building.
The most impressive feature of the building was a stained glass window located in the western gable on the first floor. It has been identified as a design by Sir Edward Burne-Jones by the Victoria and Albert Museum. Sir Edward Burne-Jones (1833 - 1898) was an English artist and designer closely associated with the Pre-Raphaelite Brotherhood. This window commemorates the lives of four young men who died tragically in a drowning accident in Saltdean in August 1912 while the Caius Summer Club was in session at Rottingdean near Brighton. Lady Georgiana Burne-Jones had a home in Rottingdean and, upset by the tragedy, offered to release an Edward Burne-Jones memorial window to the memory of the four boys (Edward Burne-Jones had died in 1898). It is intended that the window will be removed carefully during demolition and reinstated in the new building.
My first photo of Caius House approximately corresponds to the viewpoint from the left hand parked car in the right hand picture above. What a change...
The Punt Pool
All punt trips using St John';s college punts start (and hopefully end) here. Note the swan nest on the island in the spring (sometimes populated with rare black swans, imported from New Zealand and only usually seen in St James' park in London).
A little-known tributary of the River Cam; it is shallow and muddy. It has been known for Johnians and lost tourists to punt down here. That said, it isn't exactly one of the highlights of Cambridge.
You can't go much further than Jesus Green without permission to use the lock, as the river below is infested with boaties and houseboats. It is puntable (albeit quite deep) and a bit of an adventure.
The Wren Bridge
There's an engraving of third court, with the bridge in it, on one of the piers facing the bridge of sighs. Note the flood lines on the south side (there's also another much higher one - a couple of metres higher - of the southernmost pillar in Third court).
The punts are all named after things associated with three (french hens, toed sloth, fate, musketeers, steps to heaven...). Go right past them without looking, while drawing attention to the superior red punt you're in and loudly saying 'You'll never be at John's'.
You'll notice that the archways are visibly bent (this happened soon after it was built, though it's stayed stable ever since). Also, one of the stones is missing a slice (apparently the stone mason wasn't fully paid, so didn't complete the bridge).
Wall's Ice Cream Punt
The best view of it is from the river. Note the spikes on the turrets to stop people climbing them. The large field with cows in it was supposed to have courts built on it too, but the money ran out. Years ago there used to be sheep, but they got found in the corridors at night once too often! Their (purple) punts are mostly named after kings. If you turn right immediately after Kings bridge there's a side river that you can punt up, leading to the back of Queens. It's a bit overgrown, and not one for the learner punter.
You can moor punts here at the terrace, though best to go right under the road bridge or Scudamores will find you in the pub to complain. One of the most popular punting pubs, and actually underwater from time to time when the river is in flood.
This pub makes all its profits in the summer, by selling drinks to thousands of people on the island next to it. The island itself is generally full of tourists and cows. Fairly easy to herd the cows so that they surround groups of foreign tourists, who sometimes don't know they're vegetarian.
The less crowded of the two lakes. Take the punt up the small side river through the gardens of Darwin College to get here. Two small islands to your left are owned by Darwin College. You can punt a bit further under the small white bridge if you're determined, but it soon turns to marshland.
A classic punting pub facing the mill pit, generally less crowded than the Anchor.
The Old Mill
The old mill is now Bella Pasta restaurant, though you can still scare the people on your punt by punting into the tunnel underneath (which used to be the mill stream). If you look up inside the tunnel you can see the underneath of several glass tables inside the restaurant (no, really).
THE UPPER RIVER
This section of the river is higher up, and tends to have more students than tourists. The river is deeper and wilder.
A set of wheels where you can push the punt up the 1 metre height difference to the upper river, by-passing the weir. Punts are heavy, and some of the wheels are missing! On the way back, if you all sit in the punt as it rolls down, it will sink (and there's usually a big audience with cameras). The adjacent weir is where good swimmers can try white water punting.
After the last road bridge, the river bed is actually paved, as this section was used as a swimming pool of sorts in the 1900s. There's still a paddling pool in summer. A colony of not-too-friendly geese is often in residence here.
Two low bridges
Popular site for bridge-jumping (ie climbing up off the punt onto the bridge, over the bridge, and back onto the punt at the other side before it's gone). Warning: Only small and light people should even think of trying this, or we'll fine you £lots to repair the punt...
Also formerly a swimming area, now somewhat overgrown. Several grassy clearings make this a popular place for barbecues in the summer.
This is as close as Cambridge gets to a forest (and it's not very close). Some trees have ropes to swing on; there are a number of student residences (abnd what was an abandoned hospital) lurking among the trees.
The deep bend
You may find the river is significantly deeper than the punt pole here. It's not clear why as there's very rarely enough flow of water to deepend the river. To make it more interesting, the bank is covered with nettles too...
The nudist colony
You'll see a hedge next to the river with a sign saying Private Property. Apparently there's a nudist club behind it...
A large area of open countryside, sometimes quite crowded in the summer. If you look back, there's a good view of Cambridge. All you can see is the University Library tower and (of course) Johns' chapel.
Small village including four pubs (The Red Lion, The Blue Ball, The Green Man and The Rupert Brooke), a few houses, and a church. Of the pubs, the Red Lion is the nearest to the river and has a large garden, often full of suspiciously wet-looking students. Rupert Brooke, who lived here as a student, wrote 'The old vicarage, Grantchester', one of his most famous poems.
A long Cambridge tradition (since 1897, apparently) sees students punt here for tea on deckchairs set among the apple trees. A traditional destination after May Balls. Now expanded to include an indoor restaurant.
Named when Lord Byron (famous poet) used to swim here as a student. The weir here is as far as you can go with St John's punts - the river continues upstream for about sixteen miles to the east. If you get this far, you definitely know how to punt...
ODDS & ENDS
This is the little-known official name for a punt pole. The first record of this word was in 1440, when it was common to see barges in Norfolk pushed with similar poles. It later led to 'quanting' being known as an alternative name for punting. Each college (and a few of the commercial punt hire companies) has its own colour, in order to identify lost poles - some of the more common ones are illustrated aboveon the rigrht. Scudamores is probably the biggest of the punt hire compaies, and you'll see a lot of their poles around. There are also (rare) aluminium poles, and even carbon fibre ones - they're better but they need to be treated with respect to avoid damage, so don't tend to get hired out as much.
Punting in Oxford
Punts were originally developed for shooting wild fowl, and the punter would stand somewhere in the low bit of the punt with a big gun on the platform (which was the front of the punt). When punting became popular in Oxford & Cambridge, Oxford stubbornly kept punting in the traditional way, without using the platform, whereas people in Cambridge soon realised that it was far easier to steer by standing on the platform, using the punt in the opposite direction. Even now, if you go to Oxford, you'll see some die-hards punting at the wrong end of the punt.
A few of these were recently introduced at Oxford, on the grounds that it was easier for the tourists. Vetoed in Cambridge on the grounds that it was too tacky.