Gambling with Thor, the god of thunder

Have you been pelted with hailstones for half the summer as well? Admittedly, there weren’t any whirlwinds in July, but plenty of storms with hailstones and floods descended on Western Europe, along with a fair portion of thunder and lightning. One local thunderstorm showed itself to be particularly conscientious and produced lightning flashes by the second. True, the damage was not excessive, but it was distressing for all that — even if was just an old TV set on its last legs.
Lightning damage in the private domain is, for the most part, merely annoying. In a process plant, on the other hand, it must not be allowed to happen under any circumstances. Here, of all places, you would think that all the technical means at our disposal would be used to avoid lightning damage. In reality, however, this is far from the case. Experts tell us that the chemical and petrochemical industries regularly suffer damage of this kind.
The reason is that plant operators have to weigh the high costs of a lightning-proof installation against a set of consequences which are hard to calculate. Provided no personal injuries or explosions take place, the single components that can be destroyed are not a decisive factor in this evaluation. They are merely small change in the game of chance against Thor, the god of thunder. It only really hurts plant operators if a lightning strike shuts down a plant for a long period, perhaps because of the failure of a key measuring device. Then we are talking about
daily costs of hundreds of thousands, or even millions!
It is precisely this problem that is now preoccupying those responsible for automation, instrumentation and control, and it will continue to do so in the future. Its roots lie in the increased use of modern bus systems. Where such systems are used, the problem can no longer be contained to a few measuring devices. Damage to one bus user can cause the whole bus to crash, forcing the entire production system to grind to a halt.
The method used to safeguard a plant’s nerve-centers — whether it be conductor shielding, intelligent routing or elaborate surge protection devices — has to be weighed up in both technical and economical terms. In this game, too, the plant operator with the better poker face can count himself lucky. Not even the current safety standards and regulations are explicit in specifying the measures required. But perhaps our article on page 30, which sets out the lightning protection measures implemented along the entire length of the transalpine crude oil pipeline, can help a little in making sure that companies don’t take too much of a gamble.