Off-road Towing and Camper Trailers

4x4- Africa - camper-trailer-towingOur aspiring off-road driver Bud, had been considering investing in some type of off-road camper trailer or off-road caravan to make camping easier during his planned off-road trip through Southern Africa, however, he has never towed anything bigger than the supermarket-bought utility trailer he uses to occasionally cart some garden refuse to the local dump.

Although Bud had been doing some research on the more than 50 makes of off-road camper trailers and off-road caravans offered for sale in South Africa and if truth were told, he had no idea what made a good, proper off-road trailer and what did not, nor did he have the vaguest notion of how to tow it in off-road conditions. It was therefore a good thing he had decided to attend the lecture day at the club, since the next lecture was about off-road trailers and how to tow them. During the lunch break, Bud had been looking at some of the off-road camper trailers on display and he looked forward to learning more about them.

“OK, so, since all the camper trailers and caravans here are for display purposes only, we cannot do some of the things you need to know about off-road towing today, but much of it cannot be taught anyway: there are too many variables involved such as the towing capacities of various 4WD vehicles, trailer designs and weights, combined vehicle and trailer weights, types of terrain, and others. However, most of you have 4WD vehicles that could easily tow just about anything so much of what you will learn today will apply to most applications and conditions. So, first things first:”

Do I need an off-road camper trailer or caravan?

do-you-need-a-camper-trailerThis depends on what you want as much as your expectations of the destination you have in mind. Much of the allure of off-road driving lies in experiencing the bush in its natural state, but if you feel more comfortable in the bush with a roof of some kind over your head, by all means, get a camper trailer or an off-road caravan, but bear in mind that towing a trailer or caravan can place severe limits on the routes and obstacles you can negotiate, which means that some of the best destinations will not be accessible to you.”

“On the other hand, with the correct vehicle/off-road trailer combination, some advance planning, and the willingness to get stuck more often, you can still get to most of the places you could even if you were not towing something. So, let us look at some of the things you must look out for in off-road camper trailers and off-road caravans:

Off-road Camper Trailers

4x4-camper-trailer“Off-road camper trailers are not created equal: you will have noticed that some have frames that are made with angle-iron. This is a bad sign since angle iron just cannot cope with the loads, stresses, and strains of serious off-road driving. What you want is a frame built with heavy gauge square or rectangular section steel, which must be supported by a suspension that uses shackles on both ends of the leaf springs. This is to prevent the frame from jumping out of its retaining bracket should you hit an obstacle that causes the trailer to bounce, on the one hand, and to reduce vibration on the other, since the frame is positively connected to the suspension, which is not the case with slipper springs.”

• Shock Absorbers:

“You will also have noticed that some off-road camper trailers are not fitted with shock absorbers. This is another bad sign because there are many situations where you will have to run the trailer with reduced tyre pressures. Doing this means that the tyre sidewalls, instead of shock absorbers have to absorb and control the up and down motions of the trailer since the leaf springs are generally too stiff to do this. Excessive flexing of the sidewalls will cause your tyres to overheat, which is almost guaranteed to cause explosive tyre blowouts, which in accordance with the laws of off-road driving, will more often than not happen where it is the most difficult to repair the resulting damage to the trailer axle and/or brakes.

• Brakes:

“In most parts of the world, trailers above 750 kg are legally required to have brakes; however, in the off-road context it is a good idea to have brakes fitted to any off-road trailer, irrespective of its weight. Say for instance, you are descending a steep hill with a slippery surface: with reduced traction, regardless of whether you are using some kind of electronic driving aid or not, it might be difficult enough maintaining control of a heavy 4×4. Adding the weight, and thus the pushing force of an unbraked trailer to the mix might just be enough to cause you lose all the traction you may have had. Now, if your off-road camper trailer had working brakes, and if your 4×4 were fitted with a brake control system that applies a braking force to the trailer only, you could use the stabilising drag from the trailer to help you maintain control.”

“However, having brakes on your off-road trailer does not just help you going down a steep incline, it could prevent you jack-knifing even on even a level dirt road if you had to use the brakes in an emergency situation. Much of Southern Africa or the rest of Africa, for that matter, is over-run by either wild animals, cattle, or other livestock, and if you suddenly encountered a herd of cattle, goats, or elephants on the road, you might have severe difficulty maintaining control trying to stop in time. In that situation, you are in trouble regardless of how much your off-road trailer weighs, so avoid situations like that, and get a trailer with brakes.”

• Tow Hitch:

“Nonetheless, all other things being equal, your tow bar and hitch is probably more equal than anything else. The old-style ball hitch is just not good enough for serious off-road conditions. Many an off-road trailer has become unhitched because of hitches that cannot cope with the severe loads that serious off-road conditions place on them.”

“A sudden shock can cause the clamping mechanism on a tow ball to snap open, or break the ball off the neck. Even worse, a sudden shock can break the tow bar, because the hitch has no provision for vibration damping or shock absorption. Many off-road hitches use urethane, or some other material to dampen vibration or absorb shocks, so you will do well to insist on having such a hitch fitted to your off-road camper trailer or caravan.”

Purpose made off-road tow hitches come in many different designs and forms, but one thing they all have in common is their strength; they maintain a positive connection between the towing vehicle and the trailer at any degree of articulation. Nevertheless, bear in mind that tow hitches are designed to carry a specific, legal weight on the hitch itself. This is mostly under a 100 kg with the trailer loaded, so measure this weight with a bathroom scale under the jockey wheel when it is empty. This will give you a very good idea of how to pack your stuff to remain under this weight when the trailer is loaded.”

• Tyres and Rims:

“Tyres must be the same size as those on the towing vehicle, because you might need to fit one of your 4WD’s spares to the trailer. No matter how many spare wheels you carry, you can always run out, especially in Africa, where if you cannot repair a tyre anymore, you can more often than not find new ones. For this reason you must also ensure that the PCD, or Pitch Circle Diameter on the trailer axle is the same as that on your vehicle, but not only that, also make sure that the rim offset is the same on the trailer wheels as on the towing vehicle. This will ensure that if you interchange wheels, the track width on the trailer is the same as on the towing vehicle, something you will be glad of when you have to haul a heavy off-road camper trailer through thick mud. In mud especially, you want the trailer wheels to follow exactly in the track left by the towing vehicle to reduce rolling resistance as much as you can.”

“But speaking of mud- Africa has a lot of it, so mud tyres on your off-road trailer are often the best compromise between tyres for different conditions. For instance, if you have sand tyres, or even all terrain tyres and you encounter mud, especially the black stuff we have here in the mud pit, the tyres will not be able to clear themselves of the mud in the tread grooves, which could increase their weight and rolling resistance to the point where not even traction control could get you through the obstacle.”

“However, trailer axles usually use PCD’s that differ from those found on motor vehicles, so you may have to have the off-road trailer wheel hubs modified by an engineering shop to match the PCD on your 4×4. It could be expensive but if you compare the cost to the possibility that you may not have a serviceable spare wheel in the middle of say, Somalia, you will be glad you spent the money to have interchangeable wheels.”

• Ground Clearance:

“OK, so you might think that the manufacturers of off-road trailer and caravans would make them so that they always match the ground clearance of at least most 4×4’s, but sadly, this is not always the case. Even at the average tow hitch height of around 450 mm, you may find that the jockey wheel, even at its highest position, has much less ground clearance than the lowest points of either the trailer and/or towing vehicle.”

“So, watch out for this when you go shopping for an off-road camper trailer or caravan. Also, remember to check that the levelling jacks are also above the lowest point on the vehicle and trailer when they are fully retracted. Another thing to look out for is protection on the water tank(s) and associated piping, brake cables, or wiring and actuators on electrically operated brakes.”

“Some manufacturers place the water tanks directly above the axle, where they are vulnerable to damage by flying stones. Similarly, check that all brake components are protected against flying stones and snagging by rocks and/or tree stumps and branches that may be lying hidden in tall grass.”

Off-road caravans

“These are the important points to remember when you get an off-road trailer; the other stuff like the internal arrangement of whatever you are paying for is a personal choice, however, off-road caravans are a little different. Although much of what goes for off-road trailers as far as construction is concerned, goes for off-road caravans as well, there are two very important differences:

• Weight and Available Power:

“It is important to remember that a loaded off-road caravan can weigh up to as much as twice what an off-road camper trailer weighs; up to around 1400 kg or even more in some cases, which means that a 4WD that can comfortably tow a trailer, might not be able to tow an off-road caravan when the going gets really difficult.”

“Do not place too much faith in the rated towing capacity of your 4WD: many modern 4WD vehicles are rated to tow up to 1800 kg, but this is on paved roads. No 4×4 manufacturer goes to the trouble of taking a fully laden off-road caravan on a Cape to Cairo off-road test to see how well their 4WD can cope with the weight and associated stresses and strains. Whatever testing is done is done under controlled conditions and never under the worst off-road conditions that Africa can offer.”

“Off-road caravan manufacturers on the other hand, routinely test their products to destruction, but that is to test the caravan, not the 4WD. So, to be safe, make sure that your 4×4 develops torque in the 400 Nm range, which incidentally seems to be the industry standard for new 4×4’s. However, some older 4WD’S do not operate in this torque range, especially petrol powered models, so have your 4WD checked on a dynanometer, and if it does not deliver torque in the 400 to 420 Nm range, do not use it to tow an off-road caravan if the terrain is going to be particularly tough or challenging. Of course, there are many places to visit in South Africa, or even much of Southern Africa, where not having axle-bending torque is not an issue, but my advice would be to avoid any destination that is far off the beaten track- terrain that is not properly mapped and/or unfamiliar. You may just run into hills you do not have the torque to climb, in which case you could very well end up with a ruined off-road caravan and 4WD.”

• Overall Size:

“Regardless of what anyone says, size does matter, especially when it comes to off-road caravans. Although they are generally smaller than on-road caravans are, they are a whole lot bigger than off-road camping trailers, which means they are a whole lot heavier as well.”

“However, there is not much I can tell you about them except to say that they can be twice as difficult to tow in difficult off-road conditions as well. Therefore, if you are planning to get an off-road caravan, you have to know exactly where you are going every time you take it off-road. Make sure you do proper route planning so that you can avoid steep hill climbs, narrow mountain passes, deep water crossings, and thick sand or mud.”

“Also make sure that all the camp sites on your route are accessible: you do not want steep or narrow entrances it might not be possible to get out of the next morning. Remember that you are towing something that is as long as your 4×4, so avoid difficult passages and situations where it might not be possible to turn around. If you have never pulled a caravan out of thick sand or mud backwards, do not let your first off-road excursion be the first time you do this. This is no easy matter, but we will be talking about recovery techniques in a next series of talks, so book now, but in the meantime, we can talk about some general off-road towing tips and techniques, so here goes:

• Overall weight:

“Regardless of whether you take a camping off-road trailer or an off-road camper, make sure you know what weight it is rated to carry, and never exceed this weight. So, when you start packing, collect all the stuff you plan on taking along and weight it. Then go through the pile and take out at least a third, because you do not need nearly as much stuff as you think you do. Next, put a bathroom scale under the jockey wheel while you pack the trailer with everything you cannot fit on your 4×4. The purpose of the scale is to measure the weight on the tow hitch, which is of critical importance because it has an effect on how the towing vehicle reacts to uneven terrain, but more particularly to braking and steering inputs. These weights differ but make sure you know what it should be on your particular off-road trailer, and never exceed this. You also need to fill your water tanks and jerry cans, or you will not get an accurate reading.”

“Do not forget to weigh the stuff you pack into your towing vehicle as well: when you have everything weighed and packed, add it all up to see if you are within the load range your 4WD vehicle and tyres are rated for. This all-up weight must of course include a full fuel tank, as well as full auxiliary fuel and water tanks, plus the weight of all the persons that will be travelling in the vehicle. All of this might sound like a lot of unnecessary hassle, but the fact is that an overloaded 4×4 vehicle is several times more likely to break down or overheat than one that is operated within its weight limits, so pay particular attention to your overall weight, but always try to stay under the maximum weight allowed, and with most of the weight on the towing vehicle, instead of stuffed in the trailer or caravan, because it makes towing easier this way.”

• Tyre pressure:

“Trailer tyres do not need to be over-inflated to start a trailer bouncing all over the place when you are off-road. Running trailer tyres at their recommended pressures works well on paved roads, but things are a little different off-road. A bouncing trailer does not only cause things inside it to break, it also has a severe affect on the stability of the towing vehicle, so letting the tyres down by around 20% or so, helps to absorb much of the off-road vibrations, but remember that speed plays a crucial role on the stability of a trailer or caravan, especially if you are running on deflated tyres. So, assuming that you have a compressor to inflate your tyres, experiment with various tyre pressures until you find a pressure that works best, meaning a pressure that stops the trailer from bouncing without causing it to start swaying, or behaving in any other potentially dangerous ways.”

“There are no absolute hard and fast rules about tyre deflation, because of the many variables involved, but some deflation usually goes a long way to making off-road towing easier, especially in sand. The larger footprint of a deflated tyre makes it easier for the tyre to roll over the sand, instead of being pushed down into it. However, you will have to experiment to find the sweet spot, which is different for all 4×4 and camping trailer combinations. Much depends on the suspension set-ups of both trailer and vehicle, so experiment until you find what works for you in any given situation. Do not blindly do what you read on the internet; people who give advice and opinions on the subject of tyre deflation may have found what worked for them at a specific time, but your situation might be totally different, so do what works for you, not what you read.”

• Walk the route or obstacle:

“Always remember that with a trailer of caravan in tow, you are very likely running your 4×4 at very close to its maximum rated weight and towing capacities. This means that should you get into difficulties, your 4WD has to work so much harder to get you out of trouble. To avoid this, always investigate a difficult patch or obstacle on foot. Check for hidden obstacles like rocks, holes, and tree stumps as well as possible alternative routes through the obstacle. It may not be possible to reverse out of the bad patch should you run into an unseen obstacle, so make sure you have a safe route through the obstacle before you enter it.”

“Also remember that water crossings while towing is even more dangerous than with a 4WD vehicle alone. In deep or fast running water, the current has a much bigger contact area to act on, which means that you could be swept away in a current that would perhaps not have swept away a 4WD vehicle on its own.”

• Walk the route backwards:

“While you are checking a possible route on foot, do not forget to check the whole area for hidden obstacles, since you may have to do some reversing to get through the bad patch. You may be so intent on the obstacle that you might forget to check the area you need to reverse into, so check behind you before you get hung up on a rock or have your water tanks ruptured on a tree stump you did not know was there.”

• Investigate all wet spots on the ground:

“When you are near water, always stop and investigate soggy or damp spots. Many rivers in South Africa in particular, are banked by extensive clay deposits, which can swallow a parked 4×4 overnight. Do not worry about looking silly jumping up and down on soggy ground; any “bounce” you feel is a bad sign because the underlying ground is water logged, so rather just move on and find a drier campsite.”

• Driving in rain:

“Do not drive in rain unless you are on a firm surface: however, the problem with firm surfaces is the fact that some soil types turn to mud much sooner than others. While some soils, like the black stuff we have in here in the mud pit can take a while to turn to mud, it takes very little rain to turn the surface into an extremely slippery mess.”

“This is where an electronic brake control system can help you though; by adjusting the “gain” function on it, you can apply a slight braking force to the trailer only. This will force it back into line if it starts slipping and swaying behind you, but be careful you do not apply too much brake pressure that could cause you to lose momentum, especially on black mud.”

“Other things you could do in the rain are to use your diff locks, but only on the rear axle. A locked front differential makes it impossible to steer, which is the last thing you want in mud. Using the traction control might also be good idea, but you must weigh its benefits against the fact that some wheel spin is sometimes better to get you through mud. It all depends on the particular situation, but off-road towing always makes things more difficult, which means that if you are not 100% familiar with the handling characteristics of your 4×4, avoid sustained towing in the rain. Rather wait for the weather to clear and the ground to dry out a bit before you continue, because digging a trailer or caravan out of axle-deep mud is no joke, so do not do it unless you have to.”

• Watch your speed:

“Off-road camping trailers and caravans can very easily push the back end of towing vehicles out of line around bends and curves, which usually ends in a jack knife situation. Do not rely on your stability and traction control systems or any other electronic driving aids to prevent this kind of situation: it can happen on almost any off-road surface and at any time if you do not keep your speed in check.”

“The very real possibility of ending up in a jack knife is arguably the single best reason to fit a brake control system, because if you feel a jack knife coming on and you apply the brakes, you aggravate the situation beyond recovery. On the other hand, having an adjustable brake control system that can apply braking forces to the trailer without activating the brakes on the towing vehicle, means that you will be able to use the trailer as a kind of anchor. Braking only the trailer while counter steering is the best way to recover from a jack knife situation, but if you can apply some power at the same time, you have an even better chance of recovery. However, this may not work if you have the stability control in operation because it can cut engine power, so, unless you have advanced off-road driving skills, you will be well advised to invest in a brake control system, because it could save you from a rollover, or worse.”

“However, a possible jack knife is not the only reason to keep your speed down. Virtually the whole of Africa is over run by cattle and other livestock that is not fenced in. Killing a cow or any other domesticated animal with a 4×4 in Africa is a dangerous business: you and your 4WD may survive the accident but the local population invariably gets extremely upset at people that run over their animals. You could end up in an African jail, and have your 4WD confiscated until your appearance in a court- if you are lucky. Most often though, the local police will extract a ridiculous sum of money by way of compensation, which could leave you stranded in the middle of nowhere, so keep your speed down, and keep a sharp lookout for stray animals. If you hit one, you are in trouble, so watch out for that.”

• Learn to reverse, and watch the pinch point:

“You have to be able to reverse an off-road trailer or caravan in a straight line, however, while learning to do this, you may get confused and by turning the steering the wrong way, end up in a situation where the towing vehicle and the trailer drawbar form a right angle, which is known as the pinch point, or the nut cracker in places like Australia. On some 4WD vehicles, this is not a problem, but on others, it could result in a broken tow hitch, a crushed light plug, or a broken and/or bent tow- or draw bar. So, before you go off-road, learn to control the direction of the trailer or caravan while reversing. This exercise is included in the intermediate off-road driving course, and I would recommend that everyone here register for it; it could save you a lot of damage.”

• Do not cut corners:

“If you do not, or have not done a lot of off-road towing, it is easy to forget to allow for the length of the trailer or caravan behind you, especially in campsites that have a lot of trees. Towing a trailer or caravan sometimes more than doubles your turning circle, so if you forget you have a caravan behind you, you might just rip off the side against a tree, or worse, rip the side off someone else’s caravan.”

“So, always be aware of what is around you, keep a sharp lookout when you are towing but better still, if you have to move around in a tight spot, have an observer outside the towing vehicle to watch all your corners.”

• Take regular breaks:

“This goes for all types of driving, however, some of the silliest accidents in the bush happen because people are tired. However, if you are towing an off-road trailer or caravan while you are tired, you are inviting trouble; the combination of reduced traction, impaired concentration, and delayed reaction times is not a good one. In off-road conditions you slide further, you take longer to stop, the steering sometimes takes longer to respond, and that is in ideal conditions. If you are tired, you tend to over-react, which translates into even longer stopping distances, more acute slides, and more drastically ineffective steering inputs, and all because you did not react in time to a potentially dangerous situation.”

“There is no need to rush; take your time to get to wherever you are going, and take regular breaks while doing it. Throw out the schedule and enjoy the trip.”

Off-road towing- explained

off-road-caravan towingOnce again, Bud had the uncomfortable feeling that he was not yet qualified to undertake the extended off-road trip through Southern Africa he had been planning. Never in his wildest dreams would he have thought of any of the things the Instructor had been explaining during the lectures. He had for instance never even reversed his supermarket-bought trailer with his SUV, much less try to correct a jack knife with a fully loaded off-road camper trailer.

Nor had he known about the maximum prescribed weights that are measured on tow hitches. In addition, if truth were told, he would have thought that it would be better to place most of the weight inside the trailer, not on the towing vehicle, which is clearly the wrong way to go about distributing weight. He now fully realised that he needed all the training he could get, and with this in mind, he decided to register for the next training day, which as someone said, was a series of lectures on 4×4 recovery tips and techniques.