The gap between car and motorhome’s world is obvious, especially if we consider the safety factor: recreational vehicles’ standard equipment includes only a few devices suited to reduce risk of accidents and consequences deriving therefrom, let alone the poor attention paid to body construction and furnishing. Is there a potential for a positive change in the next future?
Words Michel Vuillermoz
In a complex microcosm such as motor vehicles’, we find dozens of keywords: performance, economy, environment protection, comfort, design, reliability, safety … Whatever is moving today, it must have these features. If a vehicle is not appealing from design point of view, for example, people won’t be attracted by and wont’ buy it. What’s true for design applies also to the rest: economic sustainability, environmental compatibility, comfort and, of course, safety. Some of these aspects are obvious and immediately catch potential buyers’ eyes, others are now taken for granted and are likely to be almost underestimated. Of these latter aspects, unfortunately, safety is of utmost importance. Over the last twenty years, also thanks to the emergence of independent supranational organizations, including EuroNCAP, on board safety concept has been completely revolutionized: today any car, whether it be a cheap citycar or a flagship one, offers modern and sophisticted standard safety equipment. ABS, EBD, Airbag, ESP, emergency brake Assist, Hill-Holder, ASR and BAS are now the standard for every car, even the cheapest. Strictly standard equipment, such as steering wheel and seats, alongside the latest generation systems (lane departure warning, anti-collision radar, tire pressure monitoring), are offered as standard on mid to high-end vehicles but are increasingly extended to entry-level versions as well. Many safety systems come standard for two reasons, i.e. legal obligation and trivial market law, respectively. Final customers rightly consider them as necessary and indispensable. Unfortunately, there is no guarantee that cutting-edge automotive technology is transferred to the chassis used for motorhome transformation. Too often, in fact, high-priced, prestigious vehicles, offer only ABS with EBD standard, while even front airbags are missing. Unquestionably, this is as objectively absurd and anachronistic situation, involving 70,000 Euro motorhomes unable to offer a standard safety equipment proposed for mid/high-end 10,000 euro cars. Yet, very often, state-of-the-art technologies are available in combination with chassis from major car manufacturers. As we can infer form the table above, many are the safety devices (active and passive) and driving aids currently available on the market, most of which regardless of the cockpit body conservation or replacement. The most sophisticated systems, based on cameras or radars, need to be placed on the chassis in a well-defined position. In any case – theoretically, at least – three out of the four construction types (overcab, low profiles and van), by fully preserving the cockpit body and being made from vehicle chassis, originally designed by car manufacturers, should not have problems featuring all listed devices. Very often, instead, motorhomes manufacturers only offer the bare minimum: ABS with EBD and Driver Airbag, then leaving it to the final customer (or the sampling dealer) to add the now indispensable ESP, DRIVER AIRBAG, ASR, Cruise Control and HDC. This is an unfortunately shortsighted policy indeed, as it does not seem to focus enough on the actual safety of those who will use the vehicle during their relax moments. Safety is never too much: this applies both to active and passive. So, where are we supposed to start planning immediate future from? And what will be the hard but fascinating challenge that recreational vehicle will face? Motorhome should increasingly become a safe, comfortable and eco-freindly “real vehicle”. These aspects can only be included in a new and globally developed project, involving a basic vehicle and a living area no longer separated during design and building stage but increasingly joined in a single, global automotive project, in the truest sense of the term. A project that optimally balances the rear overhang with the wheel base, sprung masses with axles and barycentre, and does not try to overcome the laws of physics by exploiting to their fullest chassis made for volumes and weights differing from those they actually handle. The first “must” should be a standard equipment featuring all driving assistance solutions: however, the design should simultaneously implement a technical revolution that takes into consideration the dimensional relationship between chassis and set-up, bodies’ technical design as well as assembly systems and passengers protection system in case of impact. For cars, one of the parameters most often considered in the purchase phase relates to the results obtained during various crash-tests: impact simulations proving vehicles’ impact-resistance (frontal, side…) as well as their capacity to adequately protect passengers. Obviously, motorhomes have different size and characteristics compared to cars: they are bigger, taller, and on average move more slowly. However, they move, travel and run the same risks as any other moving vehicle. Yet, in the recreational vehicles industry, impact tests are virtually unknown. Very few have been carried out and almost exclusively on high-tech vehicles, implemented with materials and building techniques very different compared to market average: let us think about the recent crash tests’ ambitious project performed by Niesmann+Bischoff for its flagship Flair or, previously, by Hymer for S-Klasse. Too little, if any, has been done for midmarket instead, which actually accounts for the largest volumes related to sales, registered vehicles and, consequently, circulating vehicles: the real challenge now is and must be carrying out a complete technical revolution aimed at these products. Now it’s time to seriously consider cockpits’ active and passive safety. They can no longer be made with the same assembly techniques (and often even with the same materials) used in the Eighties and Nineties, offering their passengers, in the event of an impact, only one component to count on: the classic, chassis-bolted seat belts “totem”. Now it is time to introduce side anti-intrusion devices, anti roll-over safety shells, which, exploiting cutting-edge materials, are able to provide an acceptable protection level for recreational vehicles’ passengers, which should be measurable and certified as the original chassis. Now it is time to begin to rethink the recreational vehicle as a whole, starting also from the interiors: in case of impact, motorhome crew risks to be seriously injured due to furniture sudden detachment and advancing. Wall cupboards doors, table tops and, in the most serious cases, very heavy furniture pieces such as refrigerator, become true loose cannons ready to sweep everything on their way. As a mere example, data from the few impact tests performed so far, show how in an extra luxury vehicle, built with no budget limits using excellent materials and assembly techniques, a frontal impact at 30 km/h would entail, inside the cabin, refrigerator detachment and 15 cm forward movement: we can easily imagine what may happen in an “ordinary” vehicle, perhaps moving at higher speed. Body and furnishing must be mutually bound by an indissoluble common thread: each one must be at each other’s service so as to realize, through a complex system of pins and joints, a cell that will not disintegrate around the vehicle chassis. There is the need to work a lot on components’ assembly systems, since we just have to look at a vehicle accident to see that the mere use of plastic screws and turtles is not enough to prevent passenger compartment’s destruction (even total) in the event of impact. Obviously, we must consider that free-flowing kinetic energy released from the impact will grow hand in hand with masses involved: let us think of wall cupboards on a vehicle ready for vacation, often completely crammed. And let us not forget that many motorhome passengers have the bad habit to keep on their vehicle items not adequately secured. Likewise, much can be done for on boards systems, in particular for the most critical and dangerous item: cooking gas bottles. The location of the space dedicated to them should be carefully designed, avoiding the most critical areas in case of collision, i.e. passenger compartment’s rear area. In the event of a violent impact, in fact, gas bottles might turn into a very serious problem. Yet, many newly designed vehicles, especially caravans, feature gas compartment installed in the left rear corner. Indeed, motorhome in its purest form, which is experiencing a large and unstoppable rise in Europe, is often chosen for its car-like, stainless steel-printed body featuring standard size, i.e. the original cab vehicle’s. Reduced rear overhang, moderate height ( 255-280 cm) and almost non-existent side overhangs are certainly appealing to those who want a car-like vehicle. A steel-sheet made body, whose insulation is almost exclusively provided by self adhesive sheaths combined with internal abs or fiberglass pre-printed coatings, featuring large portholes, is therefore on average safer in the event of impact compared to a sandwich panels body? In all likelihood, yes. For example, let us consider the most commonly used basic vehicle: Fiat Ducato, 35 light version with 403,5 cm wheel base and 2.3 Multijet II 130 hp engine: the chassis-cab, used for its transformation into a recreational vehicle (over cab, low profile) has a tare of 1655 kg. The cab version of this vehicle (used for transforming it into a motorhome), has a 300 kg lower tare, i.e. 1,355 kg. We can therefore say that Ducato cab body alone, is 300 kg. How much does the entire body of the same van version amount to? The answer is 1975 kg, or 310 kg more than the chassis only. This value is partly due (about 25 kg), to the high roof top and is justified, inevitably, by a complete body made of welded steel sheet consisting of, beside platform, side walls and roof suitably provided with collision pillars. We find four of them at horizontal level (the lower joining with the platform, the upper supporting the roof, and two in the middle), six vertically developed with three main pillars (front, central, rear fitting with the door jambs) and three in the middle (two rear, one front) and six on the roof that, by joining the vertical uprights along the two sides, constitute the roof rib. Structures that should not be changed during the vehicle transformation (e.g. during windows installation), but significatly limit the space available and allow, in general, building set-ups for two people only. Where is the solution? Perhaps in motorhome sector’s capacity to develop effective synergies with automotive market, drawing a lot from car manufacturers’ know-how through close and effective collaboration that fully embodies the vehicle conception of the future. Supplying immediately standard passive and active safety systems available and not leaving the final customer with the task of requiring indispensable devices. And starting to think, even for the body, of a supporting skeleton that makes it safe in case of impact. Getting motorhomes even closer to cars world and keep the pace with it, at least up to the next challenges concerning alternative engines and autonomous driving.
A brief introduction of cutting-edge driving assistance technologies is reported blow
ABS ►Anti-Lock Braking System – prevents the wheels from locking up while braking, thus allowing the driver to steer away from an obstacle.
EBD/EBV ►Electronic Brakeforce Distribution – electronically varies the braking pressure applied to the wheels preventing the rear wheels, which carries the less weight, from locking up and causing a skid.
ASR ►Anti-Slip-Regulation (also known as TCS/Traction Control): integrated electronic control system that prevents drive wheels from skidding when accelerating.
Brake Assistance ►Also known as BAS/Brake Assist: generates the maximum braking power available in case driver’s pressure on the brake pedal does not suffice. This system automatically provides the optimal braking power required for an effective intervention, by increasing the braking pressure as needed up to maximum braking.
Hill-Holder ►Start-up assist device: makes it easier to start up hills by preventing the vehicle from involuntarily rolling backward.
HDC ►Hill Descent Control: allows a smooth and controlled descent in rough terrain without the driver needing to touch the brake pedal. Just press a button and the vehicle will descend using ABS braking system to control each wheel speed. If the vehicle accelerates without driver input, the HDC will automatically apply brakes to slow down vehicle speed.
LDW ►Lane Departure Warning: is an active safety system suite to monitor road markings: if the vehicle is about to leave its current lane due to driver’s distraction, the device, by means of a camera detecting lane markings position, warns the driver with a sound alarm or steering wheel vibration.
Cruise Control ►Also known as Tempomat, is a device that allows speed electronic adjustment and, consequently, its maintenance with no driver’s action needed. Latest-generation systems are Adaptive: they adapt to the speed of the vehicle ahead and keep the safety distance.
HBR ►High Beam Recognition: automatic high beam adjustment system. It detects the headlamp beams of oncoming traffic or the rear lights of vehicles in front, and switches the lighting from main beam to dipped beam in order to avoid driver’s blinding. This system is controlled by a monitor camera behind the windscreen that constantly monitors the surrounding area and the traffic in front of the vehicle. In the event of changes in the lighting conditions and depending on environment and traffic conditions, high beams are switched on/off. This allows ensuring the best road lighting, which is undoubtedly a significant comfort increase, especially during long-distance travels.
TPMS ►Tire Pressure Monitoring System: monitors tire pressure, signaling any faults due to punctures or overheating resulting in increased pressure.
Anti-collision radar ►Collision Prevention Assist: system monitoring the distance from the vehicle ahead. If this is insufficient or the system detects a likely collision, it emits optical and acoustic signals and assists the driver in case of emergency braking, using Brake Assist device. Nowadays, the new technology frontier is CEBS.
CEBS ►City Emergency Braking System: automatic braking activating system (at speed between 5 and 30 km/h) using a laser sensor that detects the distance of vehicles ahead, whether or not in motion. If the distance is reduced and the system detects a collision risk, the device will automatically brake the vehicle, thus avoiding any possible collisions.
BSA ►Blind Spot Assist: recognizes the vehicles in the blind spot and helps avoiding collisions through optical and acoustic alerts. The system uses four proximity radar sensors to control the blind spot in an area of approximately 3 m behind and beside the vehicle. The Blind Spot Assist is instrumentation- activated and operates starting from 30 km/h speed.
If a vehicle is detected in the blind spot a red triangle appears in the respective rearview mirror. If the driver operates the direction indicator despite this signal, the system emits an acoustic collision signal as well.
ESP/ESC ►Electronic Stability Program, also referred to as ESC (Electronic Stability Control), DSC (Dynamic stability control): system suited for controlling vehicle stability, which intervenes in skidding event, by adjusting engine power and apply braking to individual wheels with different intensity so as to re-stabilize its trim. When it comes to commercial vehicles, we talk about adaptive ESP, where the system adapts its action vehicle’s load and barycentre.
Crosswind Assist ►Side wind assist system allows the driver, by automatic braking, to maintain the vechicle stable, even with strong wind guts.
It promptly detectes side wind gusts through adaptive ESP driving dynamics’ control system sensors. Starting from 80 km/h speed, it rectifies vehicle’s trajectory through automatic braking on wind-exposed side’s wheels. As a result, the side wind assist system prevents clumsy reactions by inexperienced driver while increasing safety feeling.