How we will travel...
To undertake this particular journey, our, or rather, my decision, has fallen on the outfitting of a heavy vehicle. The project will be developed mainly in 2 phases, namely, the 'purchase and related modifications to the basic vehicle, and then move on to the construction of the housing module with its related outfitting. Some of the characteristics that our vehicle will have to have are as follows: the truck will have to be without electronics and therefore dating back to the 90s/early 2000s, it will have to be an ex-military truck or ex-fire truck for various reasons. The chassis configuration will be a 2 axle NOT twin, the cab will be a single cab so as not to compromise the size of the housing module, clearly 4x4 with various differential locks and manual transmission. Also, it will need for various reasons to have good ground clearance. The total registered weight will be at least 16t, maximum 18t.
Electronics ? No thanks!
The choice of a vehicle that is dated and therefore devoid of electronics certainly did not come about by accident. It becomes clear that in the event that the truck has a breakdown (and it will definitely happen), it will have to be a mechanical breakdown and therefore within my reach. By mechanical I mean that to fix the problem on the spot I will not have to use a computer but rather my own tools. There is clearly a good supply of spare parts in the inventory, chosen and researched for the trip. This will also allow us to be self-sufficient from a technical point of view thus enabling us to continue in some way.
Second, in addition to being an "easy" vehicle for myself to repair, it will also turn out to be an "easy" vehicle for any local mechanic, and this is not to be underestimated. Although, it has to be said that in the Americas, German brands are lacking in any assistance. But still, since it is a mechanical problem and not an electronic one, it will be easier to improvise a solution that can keep us going. That said, the MAN brand is at the top of my list for now for several reasons. One of them is the sharing of some mechanical and structural components with Mercedes, so in extreme cases, it will be possible to rely on another brand for a possible search for "parts," and that is no small feat!
In conclusion, I hope I have clarified the basic aspect of my choice regarding an "older" vehicle versus a more modern one. By this I in no way mean that anyone who chooses a "modern" vehicle must necessarily have made the wrong choice, we would miss it. Mine are merely considerations taken on the basis of personal experience and shared by experienced travelers.
Military? or firefighters?
Let's say that the purchase of a heavy vehicle is not an everyday occurrence, if we then add the fact that this vehicle will be converted for a very specific purpose, then it will be better to take your time and think carefully about the purchase. Having a fair amount of experience in the field, my research is focusing on vehicles from Military and Fire Department vehicles. The vehicles that are in the hands of armies around the world, offer a lot of choice and especially in good condition. I speak of armies in the plural because it will not necessarily have to be a Swiss vehicle. On this issue I have no preponderance of opinion; the nationality of the vehicle is in no way part of the criteria for choice. When I speak of choice I am referring, for example, to the length of the "wheelbase" of the vehicle, and that is the distance from the front to the rear axle. A short wheelbase has, as always, its advantages and disadvantages. The advantage is clearly greater maneuverability and remarkable off-road dowry. On the other hand, the smaller size of its chassis will provide less space to accommodate the living module later on. Again, the choices fall, as always, to the individual and are in no way dictated by strict rules. Someone may in fact give up some living space but in return will have a vehicle that is more maneuverable and agile in certain situations. The long wheelbase argument is pretty much the opposite, so we notice how the choices are really personal. My choice falls on a wheelbase of 4.5 / 5, meters between front and rear axles, so long. This will allow me to build a housing module of more than 6/6,5 meters in length, and thus also resuming the single, rather than double, cab discussion.
Fire trucks are par excellence the category where to look for a used vehicle. Their meticulous maintenance mixed with a kind of love with which they treat their vehicles, results in them being the ideal place to look for a truck. The mileage in relation to the registration date is practically zero. I have personally seen trucks with more than 30 years of honored service with as little as 30'000km! And they look like new! Impressive!!! Too bad that fire trucks for various technical reasons, are for the most part equipped with a double cab for man transport, and this unfortunately slows down the search. Still, it remains a category to keep an eye out for, as exceptions show up from time to time!
2 axles, not twinned tires
I chose a regular 2-axle 4x4 for practical issues related to travel. The first reason has to do with the total weight, so with the ceiling I have set for myself at 18t, a 2 axle will suffice, and I am more than comfortable regarding a certain reserve. By reserve I mean that when the job is done I will still have some margin should I need to modify or expand the project. In fact, I have encountered several comments from those who, because of the low total weight, had to make major modifications invariably falling into a series of give-ups that eventually blew the whole project. So, with 18t I am comfortable! Secondly, having only 2 axles there is also an economic saving in terms of maintenance....
As for wheels, I decided to have only 4 of them because of issues related to our travel style. Twin wheels are in my opinion not an optimal solution for those who, like us, prefer dirt roads and unpaved tracks. The big problem lies in their safety, in fact, having twin wheels the risk of stones and other objects getting stuck between them turns out to be a problem that can lead to some serious damage if not discovered right away. So, this is an expedient that I felt was important to consider.
Frame modifications
To later accommodate the housing module, the vehicle chassis will have to be modified and prepared accordingly. In this regard, there are various theories and variations that can be adopted according to one's needs. As I explain in a blog article, the issue of fuel autonomy is an essential point of the modifications to be made to the chassis. In fact, an additional second tank will be mounted, connected by a pumping system to the original. In this way at the time of need, it will be possible to draw diesel from the second tank and feed it into the primary. Another modification will be to build a longitudinal reinforcement under the original chassis, so as to support the stress it will be subjected to once the housing module is mounted on it. To finally accommodate the actual module, the mobile and semi-fixed airframe housings will be built and welded. This point will require quite a bit of measurement and welding work. In short, the original chassis of the vehicle will be heavily modified and adapted for the purpose. As soon as I am able to draw a diagram of the chassis and its related modifications you will find it available below. The great challenge that will arise in modifying the chassis and its respective accommodations will be to be able to keep the center of gravity of the vehicle as low as possible. In this regard, the system I have in mind will manage not only to keep it relatively low, but at the same time adopting a system of counterbalancing movements.
In short: the airframe and the truck will be uncoupled from each other, when the truck bends to one side, the airframe will tend to move to the opposite side, thus doing so will maintain a level stance regardless of the road surface.
In this image shown above, which is quite schematic, we can see the importance of moving points in action. Indeed, with a static type of attachment, the truck frame and airframe would not have the ability to move independently, invariably causing an unsafe ride and eventually a rollover. Let me preface this by saying that regardless of the anchorage chosen and designed, after a certain lateral inclination other physical factors clearly take over, from which it is not possible to escape. Thus, these mobile systems are designed for the sole purpose of facilitating driving in rough terrain with slight side slopes.
Below I have tried to draw what will be the principle of the rear movable point. It is nothing more than a coupling system via a pivot, on which the mobility of the point is based.
Height from the ground
Ground clearance is another important factor in terms of safety. The distance that separates us from the ground can in many cases be decisive in passing a variety of obstacles. Rough terrain, especially consisting of stones and shrubs, can prove to be a problem not to be underestimated. In fact, a truck that is too low will be subjected to significant risks with serious consequences. In addition, the height from the ground allows us some peace of mind when dealing with water crossings such as rivers or streams... In this regard, I have drawn a representative diagram so as not to confuse a truck with a boat!
Even the tallest truck has its limits, and contrary to what you might think, its limits are not only dictated by the height of the engine and its respective air intake, but also by other components that we easily forget about.
The components that limit the fording capacity of an off-road vehicle, are essentially: electrical parts (batteries, relays and various wiring...), air intake given by the respective filter, and last but not least, a number of small things that may later become big problems. As you can see, it would be advisable not to cross a certain line, since, submerging delicate parts such as differentials and transmissions under water could in some cases prove to be a problem. In case of uncertainty, before facing a water passage, it is good to rely on common sense and accordingly test the depth by crossing the passage on foot.
Transmissions, differentials and gearboxes, are clearly airtight, but often on the top of the "box" we find a vent. These vents can be easily modified by extending them with rubber hoses, but in case of a complete submersion, there still remains easy access for water and tiny debris. If not discovered immediately, the presence of water inside these mechanisms (gears) is clearly fatal. Should you suspect water seepage, it is imperative to proceed with the complete replacement of the respective lubricants (gear oil, differential oil) .
It should be pointed out that this type of vehicle has nothing to do with Offroad vehicles prepared and designed for this purpose. Therefore, a truck set up for traveling will not have to face an off-road competition, but rather it will have to allow for total long-term travel safety. So go ahead and leave aside expensive and sometimes purely cosmetic accessories. An Overland vehicle intended for travel will need to be able to cope with any type of terrain and consequently keep you going, but that does not mean "going for it"! Around the corner you will not find the mechanic or the tow truck.... Thus, building such a vehicle must undoubtedly make us think in terms exclusively aimed at its practicality.
Offroad vehicles are most often designed and prepared for a specific purpose, which often refers to the famous Sunday outing with friends, or perhaps for a busy weekend. But, at the end of the weekend the vehicle will surely be washed, put in the garage and calmly and warmly, you can perhaps assess any damage from the weekend. On Monday morning when you head to work and discuss the outing over coffee with company, you can calmly order your spare parts on the Internet and in a couple of days you will find them on your doorstep.
For those who will be on the other side of the world, however, things may not be so obvious. Therefore, the traveler will certainly know how to assess the situation that will suit him best, staying away from any dangers that would compromise the entire trip. In conclusion, it is good to distinguish the types and respective preparations of vehicles so that they can be used for their ultimate purpose.
Wheels and tires
The rims I have turned to are Beadlocks, specifically these rims are composed in technical terms by the inner "bell", and externally fixed by 2 rings screwed to it. The big advantage of this product is the fact that it is difficult for the tire to come off the rim. Let me explain; In the world of off-roading in general, regardless of the vehicle you own, it often happens that you have to deal with routes or even just short sections that are particularly complicated in terms of road surface. As we all know, "the trick" of literally deflating the tires can prove extremely useful to get out of certain situations or even to avoid unexpected punctures. By lowering the tire pressure, it actually translates into more friction surface on the road surface. Now, since the tire pressure is lower than what is normally prescribed by the manufacturer, its grip on the rim itself will also be lower, ending up, to use a technical term, at the risk of literally beadlocking the tire off the rim. The Beadlock system I am telling you about is expressly aimed at preventing this from happening. The outer rings have exactly the job of locking the tire in place and preventing it from slipping out.
If you are wondering whether all these arrangements are really all that necessary, the answer is of course: It depends!
Staying in Europe where the farthest population center is after at most 30 minutes by road, we might as well save ourselves a lot of talk by calling a mechanic or roadside assistance. But if, on the other hand, the trip involved long periods of 'isolation and particularly challenging roads in remote places, the story changes quite a bit!
Regarding the whole tire of the vehicle including the 2 spare wheels, I am still quite undecided on what to do. On the one hand, I would prefer to tire it exclusively for off-road use and thus with tires suitable for the purpose...
The drawback of these tires are clearly the strong noise and not least the poor availability in certain countries of the world. In addition, these tires are strongly discouraged in snowy road surfaces.
Instead, the alternative would be an On/Off tire, basically a compromise between an off-road tire and an asphalt tire. The profile would in this case be less pronounced and consequently with less Grip in difficult situations, on the other hand, however, they would be less noisy on normal roads and easier to find.
The dilemma remains!
In both cases, the only point on which I am clear is that they will have to be Tubeless tires, that is, without an inner tube. In fact, in case of a puncture, a tubeless tire will lend itself to emergency repair much more easily than a tire with an inner tube.
