There is an inherent beauty in machines, perhaps because they take on a life of their own, in a way that buildings never could. They are often mere tools created to overcome the challenges of the world – terrain, gravity, weather – yet we look on them to impose order on a disorderly universe.
As a child of Meccano and Lego, I was always interested in making things. Sometimes the parts came in kit form, sometimes I rummaged for scrap iron, pulley blocks, angle irons and so forth. Making a scale model of a crawler crane was one project: I had a single-cylinder Villiers engine from an old Ransomes “Typhoon” mower earmarked as a prime mover, and 56lb. lumps of pig iron set aside as a counterweight. The kinetics of craning, slewing and winching have fascinated ever since, and I guess there’s always the bonus of some entertainment when things go wrong.
Later, this childhood interest combined with the books I was reading, such as Lebbeus Woods’ “War and Architecture”, and Paul Virilio’s “Unknown Quantity”. The latter is quite unlike anything else I’ve read: Virilio explores a philosophical approach towards unpredictability and disaster. Once I’d read it through a couple of times, it clicked – here is a rational response to the seeming chaos of the world, from earthquakes and hurricanes to the smaller scale disorder and disasters of building sites.
Truckmixer in the mud
Having a project on site opens your eyes: the ground opens up while a truckmixer is reversing, the shifting sands swallow an excavator, cranes topple over and have to be rescued, lorries get stuck in muddy fields. Watching a vehicle being extracted from a morass is always interesting: when the ground doesn’t have sufficient bearing capacity, the wheels sink in, and the vehicle ends up resting on the rails of its chassis. A massive tractive effort may be required to pull it clear of the bog’s suction, perhaps using a Traxcavator or Cat D12 bulldozer if you happen to have one handy...
A perennial challenge is delivering materials to site without the need for double-handling. Ideally you want a vehicle which can drive straight off the road onto the site. Back in the early days of truckmixer, the influence of wartime ingenuity was still felt. Boughton Engineering are best known today for the big “rollatruck” skips which demolition contractors use; when full, they’re collected by an eight wheeler using a giant hydraulic hook which clasps the skip end and hauls it onto the chassis. However, they made their name during the 1940’s building all-drive lorry chassis for the Army, and in the peace which followed, they used their experience of all terrain lorries to convert standard Bedfords into 6x6 drive Boughtons with low-ratio gearboxes and diff locks. The end results were road-going lorries capable of driving through construction sites.
Scammell S24 tank tractor
On the other hand, a “normal” truck stuck in a hole can become a full-blown recovery job, perhaps requiring 50-tonne cranes and an ex-Army Scammell S24 tank tractor. The exercise begins with baulks of timber, snatch blocks, Tirfor winches, and a silent prayer to the Gods of Unconventional Lifting … Lorry rescue is a specialist business, and once freed, heavy goods vehicles are never towed on rope or chains. The two vehicles are connected by an umbilical cord in the form of an air line (since, unless there’s compressed air in the stranded vehicle’s tanks, its brakes will stay applied), but the towing lorry does the braking for both vehicles, with all the retardation transferred through a rigid steel towbar.
Laurel and Hardy made the most of getting stuck, and often ended up lying face down in the mud, with a Model T minus all its bodywork, a great cloud of black smoke, and a braying donkey looking on … I can sympathise. One day I arrived on site to discover the contractor trying to rescue a cherrypicker which was trapped in the glaur. A large crowd of workmen looked on as a JCB full-slew attempted to propel the cherrypicker out of its rut by whacking its engine pod using a two cubic metre bucket. It looked like something from Robot Wars – except there was no sign of a glamorous TV frontwoman wearing leather trousers – and although the excavator eventually won, I’m glad I didn’t have to take the cherrypicker back to the hire shop.
Channel Tunnel TBM
Tunnel Boring Machines or “TBM’s” are another good example of Homo Faber versus world. A typical shield boring machine, as built by James Howden in Glasgow, may weigh 500 tons, cost £10 million, and can drive a tunnel six metres in diameter at a speed of two revolutions per minute. The TBM is large and complex, leaving the factory on a train of oversize low-loaders, and taking months to erect in its new underground habitat. Disaster followed in the case of the Storebaelt tunnel in Denmark a few years ago. One full year after work began and with only minor progress made, water from the seabed found its way through the TBM head which had been left open by mechanics. Both 300 metre long tunnel drives were instantly flooded, and the two TBM’s seriously damaged. They needed a complete rebuild. The high stakes conform to Virilio’s risk thesis.
Ground conditions have a habit of thwarting us repeatedly. On another site I attended, a hydraulic excavator scraped away the overburden and began shifting the rock underlying it. The machine worked all morning, its boom sweeping around balletically, its counterweights sliding like part of a pinball machine. Soon, men were driving timber profiles shaped like a hangman’s gibbet into the soil. Then with a loud squeal, an NCK piledriver crawled onto the site, looking rather reptilian. It moved hard against the rock face, slewed its driving gear into position – then there was a flash of light, and a resounding CRACK! It turned out there was a high voltage cable in the path of the steel pile: it was wrapped in black tarry stuff like elephant hide, which melted in the flashover. Thankfully, the driver of the piledriver was saved by his rubber-soled boots.
An unlucky horsebox
The drowned TBM, stranded lorry and zapped piledriver prove that we’re surrounded by entropy. What we casually dismiss as Murphy’s Law is actually a sign of the fundamental lawlessness of Nature, because the universe is always trying to return to its basis state. In response, we have to improvise using machines. Yet entropic chaos has been used by artists, musicians and even architects, such as Lucien Kroll or Elemer Zalotay. It may seem perverse to consciously design something to appear random, and the result may be a little contrived, like the so-called random number generator on your calculator.
Yet there is an honesty in the approach of anyone who admits to chaos, rather than forcing order on reluctant materials and as Paul Virilio suggests, we have a morbid fascination with disaster. If we spot a lorry stuck in a bog, our sympathy for the hapless driver is mixed with a little derision, a sense of the futility of Man’s actions, and perhaps the fecklessness of building contractors.
Rescue is a practical way to deal with trucks which are stuck; Kroll’s aleatoric design method is an intellectual approach to rationalise the seeming randomness of the world and its forces, but there are countless pitfalls to consider, plus some we may not even be aware of (pace Donald Rumsfeld’s rhetoric about “known unknowns and unknown unknowns”). Instead, we can learn from another American. Hungry Joe in Joseph Heller’s novel “Catch-22” collected lists of fatal diseases and arranged them in alphabetical order, so that he could quickly put his finger on the one he most wanted to worry about.
We are in a similar fix, except that there are many more things on a building site which could go wrong...