05 February 2012

Overnight, a rather strong thunderstorm blew through our campground, bringing with it some serious wind & dangerous lightning. While the occasional rainstorm is a pleasure to experience in the Airstream, it’s easy to feel vulnerable in our conductive, aluminum cage. It can be especially scary in unfamiliar places, with no obvious alternative to just hunkering down and taking what’s coming.

Staying prepared for severe weather is always a priority for us, and so when the wind kicked up enough to rock the trailer late last night, we jumped into action, trying to mitigate the risks. Here are a few of the things we have to do when the weather turns sour:

  • The 18’ patio awning, when deployed, can easily act as a sail and strong gusts of wind have been known to tear awnings clean off a trailer and even topple a one onto its side. Rolling up the awning is always the first priority in the face of strong wind. Doing so in the cold wind & rain (and dark) (and pajamas) is not always fun.
  • We usually put away our patio furniture every night, but if not, we have to stow our camping chairs, folding table, rug, bicycles, sports equipment, and anything else we’ve left outside that might blow away.
  • We have a retractable television antenna that extends several feet above the trailer proper; it looks similar to a lightning rod. We can retract the antenna from inside the Airstream.
  • To protect all our valuable electronics, we take a few minutes to power down the computer and make sure anything vulnerable is unplugged. Most of our electronics are behind surge-protected power strips, but I still prefer to unplug the computer completely.
  • We latch all the windows and close the shades to keep the weather outside.

Just minutes after finishing the last of these chores last night, the monstrous BOOM of a nearby lightning strike rattled the Airstream. There had been a dozen impressive, echoing cracks leading up to it, but this was the closest, most immediate strike I’d ever experienced. It instantly killed power to the entire trailer and left my heart pounding and a glow in my eyes.

Here's the new $35 breaker!

Here's the new $35 breaker!

Come morning, the trailer was still without power. Three of the Airstream’s four breakers had tripped and the ground-fault isolator wouldn’t even reset. Even the 30-amp breaker on the utility post seemed to be completely toasted. I reported the issue to the office, who’d had no other reports and, honestly, seemed a bit suspicious of a lightning-related outage. Nevertheless, they immediately sent a ranger over, who verified that several of the nearby sites were without power. He replaced our post’s 30-amp breaker on the spot and eventually found a tripped main breaker somewhere upstream that restored power to the trailer. Unfortunately only half of the trailer came back online; the other half (the fun half: TV, computer, WiFi, refrigerator) had been protected by the now-broken GFCI breaker. I later replaced that breaker with one I picked up from Lowe’s (to the tune of $35) and successfully restored power to the entire trailer. In theory, I should be happy to shell out $35 for protecting our much more expensive electronics devices.

A close-up look reveals shattered rocks and shredded roots!

A close-up look reveals shattered rocks and shredded roots!

Later today we noticed a few campers and rangers standing around taking pictures of the ground near our trailer. It turned out they had found the location of the lightning strike, about a hundred feet from our bedroom. The strike appears to have hit the ground directly, bypassing all of the nearby trees, tearing through the some tree roots, splitting a large rock into pieces, and leaving an eight foot trench in the ground. I’d never seen anything quite like it before, but felt all sorts of thankful for not being the target of that strike. We chatted with a couple of our neighbors, all positioned about the same distance from the strike, and all relieved to make it out safely.

Damage from the lightning strike. Notice how close the Airstream is!

Damage from the lightning strike. Notice how close the Airstream is!

In the wake of this particular threat, and realizing I didn’t really know how serious lightning could be for an Airstream, or even how to avoid it, I’ve done a little research. In particular, I found this PDF by John McHale to be extremely helpful. The major takeaways are this:

  • Retract all trailer jacks or anything that directly connects the trailer with the ground. We almost always put our four “stabilizer jacks” down tight to the ground. These jacks keep the trailer from wobbling (or creaking) from walking or moving around inside, or even from wind on the outside. These act to make the trailer better grounded and thus, more attractive to lightning.
  • We also have a hitch jack that holds the hitch-end of the trailer off the ground when not connected to a truck. While we can’t retract this jack when unhitched, the linked paper suggests to separate the hitch jack from the ground with at least five inches of wood, or other non-conductive material. I think our red hitch jack stand fits that bill.
  • Disconnect from shore power completely. Most lightning-related damage to RVs derives from surges when lightning hits nearby transformers, and not direct strikes.
  • We’re almost equally likely to be hit within our trailer as we are outside, which is to say very unlikely. But there’s a lot of evidence that the Airstream itself, while a potentially more-attractive target for lightning, provides several protections for its inhabitants. The aluminum shell of an Airstream might act as a Faraday cage, carrying the bulk of the electrical currents on the outer surfaces, towards the ground. This skin effect is at least possible in an aluminum Airstream, where the entire outer shell is conductive; lightning striking a Fiberglass-skinned RV would likely tear straight-through, leaving just a smoking hole. One of the most dangerous places would directly outside the trailer, since the electrical current would travel around the outside of the vehicle.

The linked article has several other helpful tips, like to avoid parking near the tallest trees, or standing on the roof of your RV, or stepping off the RV to the ground. In the end, lightning is largely an indiscriminate, random phenomenon and if it aims to strike you, it will be done. The best we can do, perhaps, is take these easy precautions and just try to get some sleep.