Summer vacations in caravans and motorhomes are just predestined to have to overcome a certain potential danger. No other season surprises nature lovers and advocates of absolute freedom more with its weather caprices. Violent thunderstorms, hail, lightning and thunder demand quite a bit of robustness from the camping soul. How high the safety in the caravan and camper can be at all, depends predominantly on the installed materials. Nevertheless: Always observe the correct behavior – it saves lives.
Who often travels knows it: The weather is unpredictable. One minute the sun is shining and the next minute dark storm clouds are gathering. When spending the night in a caravan, some uneasiness spreads and the fear of a lightning strike rises as soon as loud thunder reaches your ears. To find out if your vehicle is safe enough, you need to look at the material structure of the vehicle. Decide whether physical conditions favor your location (Faraday cage) or plastic will ruin your dream of a protected environment.
Behavior during thunderstorms in the camper or caravan!
Here are the most important rules of conduct:
- The location is crucial: avoid hills, open areas or trees
- Roll up awning
- Do not shower or wash off
- Stow towels, linen and camping utensils (chairs, table, bicycles) safely and securely
- Close roof hatches, doors and windows
- Disconnect the on-board electrical system of the camping vehicle from the power supply (do NOT let the power cable hang down!)
- Pull in the antenna mast and switch off the receiver
- Be careful with tents or awnings! Do not stay in them. They do not offer safe protection against lightning. If the robust stability is guaranteed, simply close, so that everything remains dry and if necessary less damage arises.
The fact is that the risk of being struck by lightning is far greater in a caravan or motor home than in houses. You can minimize this danger significantly with the above code of conduct. Avoid exposed places as a pitch, the edge of the forest or overhanging branches of a tree, because protruding elevations or the highest point are a preferred target and as such extremely dangerous. While maintaining the greatest possible distance from poles and masts, you should not touch the tent walls or caravan walls made of plastic during the thunderstorm.
If you are in a motorhome or caravan with a metal body in this stormy situation, you and all your fellow travelers will benefit from the Faraday cage principle. Make sure that all openings are closed, so that the voltage of a lightning can be discharged through the ground. The frightening force of nature with a discharge strong up to sometimes several hundred million volts reminds every camper to be careful. As soon as it flashes and thunders, mindfulness and the safe retreat from open areas are an important measure.
But be careful: models made of pure plastic, as is the case with GRP construction, do not offer sufficient protection against being struck. Even plastic sheeting on a filigree metal framework or a thin aluminum outer skin 0.5 millimeters thick already act like a Faraday cage.
For the physical principle to work, these and other metallic components must be conductively connected via the vehicle frame. If a gap remains, a flashover occurs and the result is damage at the interruption points. Provided the frame conducts completely, lightning can find its way directly into the ground. Ideally, it flows off via the extended crank supports or, if these were not used, via the grounded wheels.
Thus, during a violent summer thunderstorm, washing dishes and showering are taboo. If necessary, one should also not handle metal parts of the extensive interior during this time, as well as get with the head near the roof.
The safest way to survive the attack of Mother Nature is in the driver's cabin of a motorhome. This part of the vehicle usually has the highest metal content, integrated grid structures and a robust sheet metal housing is provided. In spite of all safety, you should not choose a parking space on an elevation during a thunderstorm, close all sunroofs immediately, retract antennas as far as possible and do not touch metal parts in the interior that are in contact with the bodywork.
What is a Faraday cage?
The Faraday cage is a hollow object that is made of conductive material over a closed envelope. Basically, this is the case with cars, for example. Metal is able to intercept the electric charge and move it along the casing to the ground. In other words, all the energy of a lightning strike is dissipated from the hull, through the rims of the wheels, and into the ground.
Motor homes and caravans made of plastic and with a folding or lifting roof create a gap in the system due to the roof cutout. Whereby in most cases these have metal struts incorporated in the plastic roof or a metal frame. If they are connected with the aluminum lifting linkage as well as the sheet metal roof, the Faraday cage works. Alternatively, an aluminum roof rack, which is metallically connected at its four corners to the sheet metal shell and the chassis, offers optimum protection against an unwanted lightning strike.
Different designs, from GRP roofs to aluminum constructions, guarantee a wide range of possible uses. For most models, the following applies: The right mix makes the difference! Aluminum struts are usually lighter than roof coatings made of GRP. On average, this causes an additional weight of up to 30 kilograms, but the combination offers improved protection against storms, thunderstorms and hail. Predominantly coarse surface structures of GRP roofs turn yellow after a certain time, while aluminum sidewalls can be visually polished to a smooth finish. The risk of possible leakage due to extreme precipitation is low.
If you get caught in a thunderstorm while driving a motorhome or caravan, the danger increases and you may assume the following basic rules:
- Glaring lightning causes a brief but strong glare. A little carelessness is enough to drive off the road at full speed. Therefore, it is advisable to find a parking place as soon as possible in case of thunder and lightning.
- Pay particular attention to railroad crossings, traffic lights and warning systems – they could all be down due to a spontaneous lightning strike. Keep the overview: Caution is required here.
How close is the thunderstorm?
The most important rule in dealing carefully with this force of nature is its predictability. Only about ten percent of all lightning actually strikes the earth. Normally it becomes dangerous when you approach a possible discharge to less than ten kilometers, because not only in the thunderstorm center there is the possibility of a lightning formation. So that you can better estimate and check the distances, the 30/30 rule provides you with realistic indications of how close you really are to the thunderstorm cell.
It supports the thesis of the natural visual and acoustic processes. How many seconds pass between the visual appearance of lightning and the loud rumble of thunder, mark the actual distance between you and the thunderstorm. If there's about 30 seconds between the two phenomena, you're roughly within a ten-kilometer range of each other. Now is the time to find a safe place, which ideally you should not leave until the last audible thunder.
With a few essential items on board, the Faraday cage of your camper becomes a safe place to stay during any uncomfortable thunderstorm phase.
Caravan struck by lightning
You can't outrun even the worst of storms. So the most important rule is to stay calm! Are all hatches closed, the windows tight and the doors locked?? Great, a look at your awning tells you whether it was properly and cleanly tensioned. At the latest in this moment you should stretch a storm band. For the entire electrical system, the rule is: "unplug it!"
Even with the biggest commotion – do not panic. If the caravan has been struck by lightning, do not risk anything! In case of doubt, wait for about 30 minutes after the thunderstorm. After the storm is before the cleanup. Branches, leaves, sometimes whole trees often paint a picture of devastation. Check the situation – has your motorhome or caravan been hit by heavy objects? Are the awning, the awning and canopy still in place or were they victims of wind force 10 and more??
After the initial inventory, make sure the site's utility pole is intact. Only if it is absolutely safe, you can reconnect your 230 volt cable. Avoid puddles, trees and loose dangling branches immediately after the storm. There is still a risk of already broken parts falling to the ground or larger accumulations of water under power.
If, despite all precautions, a lightning strike has put your vehicle through its paces, you are due a safety check of all systems and mounted materials. Start with the tires – they are often affected or even damaged by the force of a lightning strike.
Even a comparatively low voltage is sufficient to render tires unusable. In the case of tubeless belted tires, millimeter-sized holes appeared in the tread grooves after this attack of nature, and the wiring of the steel belt was melted. If this remains undiscovered, the subsequent water ingress will cause corrosion damage, which in the further course will lead to the detachment of the tire surface. The inglorious result: the dreaded tire blowout.
To ensure your safety, you should check your tires for punctures or other damage immediately after the storm. However, the course of lightning in itself can not be subjected to any particular rule. That is, even if it strikes, your tires are not necessarily damaged. If the concentrated energy looks for another way and is diverted directly from the vehicle floor or along the vehicle, the rubber remains completely undamaged.
How to avoid a thunderstorm? In principle not at all, but you should prepare yourself as well as possible for the impending storm.
Before leaving – things on your errand list:
- Never travel without a first aid kit
- a fire extinguisher should not be missing – fire in the caravan or motorhome is the worst case scenario
- A bright LED flashlight – in case the power is cut by the thunderstorm and you don't have to be in the dark. It is also suitable for prying open or breaking a window in case of emergency.
- Make sure you know the escape routes and always keep the emergency card with the most important data handy.
- Is the caravan or motorhome directly in the dune or on the waterfront? Note the ebb and flow of the tide, so that a rapidly rising water level does not cause any damage.