All of which leads me to my place in this tale.

A few years ago, I was engaged as the Principal Architect of one of the first cable-stay bridges to be built using carbon nanotube reinforced materials. Not the very first, of course; the construction industry is sufficiently risk-adverse that any new technology is likely to have been tried out at much smaller scales first.

But my project was to be the first where a substantial crossing was to be constructed. It was a huge opportunity for me, personally. The technology was still new, and it was exciting to be in on the ground floor of what promised to be a huge growth area leading, eventually, to the construction of bridges so large that they would be quite impossible with any other technology.

My team had spent months on the design, throwing away old ideas and outmoded design approaches and coming up with something entirely new. To one familiar with traditional bridge construction, our design would have looked impossibly flimsy, even though the support cables were bulked out with plastic shrouding - officially to protect against the weather, but in reality to provide a degree of reassurance to those trusting their lives to the crossing.

The design period was followed even more months of meticulous planning before work on the actual site could start, and yet more months when the essential but boring stuff - the foundations and the ground-works - was carried out. Once the conventional steel-reinforced towers started to grow - there were no economic benefits to using the new materials for this part of the solution - the manufacturing of the miles of support cables was ramped up. Soon, we were all set to start installing the cables.

Which is when all the problems started.

Another advantage of thinner, lighter cables is that it allows for the bridge to be put up much more quickly; for old hands in the construction industry, in particular, the rate of progress was regarded as nothing less than miraculous. All went well for a few weeks, but then progress suddenly slowed down, for reasons which could be determined from the reports produced by the project managers: the accident and injury rate had shot up, and so had the level of absenteeism.

All major construction projects pick up their own superstitions, that certain actions or places are unlucky. In an environment as complex and chaotic as a building site, accidents can and do happen, sometimes with serious - even fatal - results. But there was a strange consistency in the reports: it was considered to be unlucky to work alone near to the cables, and many of the incidents occurred near to the newly-installed cables.

At first, I regarded these as management problems, for Personnel and the Health and Safety Department. Then I started hearing reports of strange lights in the sky. They were described as glowing balls, in a variety of colours, and almost always in the vicinity of the cables themselves. So I was particularly concerned that there was some obscure technical issue and I elected to investigate myself.

It is well-known that carbon nanotubes have rather strange electrical properties. For example, they have anisotropic resistance: they are quite good conductors of electricity - nearly as good as conventional copper cables - along the axis of the tube, which is aligned with the cable for maximum strength, while they have a high resistance across the tubes. The fibres themselves are embedded in fairly soft plastic, which is itself a very good insulator.

Part 3 Part 5