Deep Water Crossing, Measures to be Taken and What Are Its Risks?

Dear off-road and nature enthusiast friends, we are together with another sharing of our Off-road Basic Technical Information article series. The information I will provide; These are concentrated, technical-based, lived experiences, and some of the details that will find a name in the off-road literature for the first time. With the hope that it will benefit the readers.

Today’s topic is “ Deep Water Crossing, Measures to be Taken and What Are Its Risks ?” :

Water crossing is an activity that offroad vehicle owners approach very eagerly. In fact, this enthusiasm sometimes even causes us to treat our off-road vehicles, which are land vehicles, as amphibious vehicles .
Guys, be very careful at the water crossings. Internet videos whet one’s appetite for water crossing. It’s okay if you know every aspect of what you’re doing. If you enter the water without knowing what you are doing, the situation can have very serious consequences.

I will talk about 5 basic problems in water passage.

1.) Engine water intake:
Although this situation is generally thought to be a problem if there is no snorkel in the vehicle, this is not the case. Do not be too comfortable just because there is a snorkel. My guess is that the failure of the engine due to water intake from offroad vehicles is much higher in vehicles with snorkels than in vehicles without snorkels. We can say that the reason for this is the confidence and imprudence given by the presence of the snorkel. Even though we have a snorkel, if we roughly list the possible problems we may experience;

– There is a risk despite the snorkel if it is not mounted by a competent person with the right equipment.

– If the new owner of a vehicle with a snorkel, which is only used as a visual accessory, is not aware of the situation, it means that there is no snorkel.

– Although it provides a healthy service at the beginning, it may have gotten water from the joints and gaskets over the years.

– During land use, snorkel holes or crevices may have been created but not noticed by events such as branch strikes.

– After many years under the sun, the plastic material of the snorkel may become brittle and lose strength due to the UV effect, and it may be broken or cracked without the need for an extra effect in offroad road conditions.

Some other risks related to water intake of the engine can be listed as follows.

– We have always expressed our concerns about the vehicle’s intake of water from the air intake. If the vehicle stalls, the engine will be able to take back water from the exhaust system.

– With the increasing velocity in the water, the height of the water will be higher than when it is stationary due to wave motion. In other words, when you say that water does not come to the air filter, unfortunately the water will come to the air filter due to the water rising with the wave movement.

– In addition, performance style open air filters that are not located in a closed enclosure may cause problems in this regard, even under lighter conditions. Air filters, which are in a closed enclosure and provide air suction by indirect means, are not affected by water splashes. However, the performance style of air filters without enclosure box, which is exposed, may be affected by the water splashed by the movement of the vehicle.

I won’t go into too much detail about the damage caused by the engine being flooded. I guess people who are experts on this subject will give information. Let me just say it would be very annoying. Let me even give an example, even outboard marine engines that fall into the sea become unusable if not handled properly. If even equipment designed for use at sea can be so negatively affected, we should definitely be more careful with the engines of land vehicles.

2.) Problems with electronic circuits, electrical installation and electrical equipment:
Especially in old generation vehicles, electronics is almost at zero level. Defender in the attached photos is a good example of this. 12 V DC will not cause much trouble in fresh water. But this is not the case for salt water. Salt water can cause problems even in older generation vehicles, as it not only corrodes the vehicle but also provides electricity transmission.

Avoid salt water if possible. Even 1 Mix.

In the new generation vehicles, if the electronic circuits are not specially insulated, it will definitely cause problems. The problem may not be limited to this. If water gets inside the vehicle, especially the amplifiers and compact subwoofers placed under the seats, and the speakers in the vehicle doors may be affected by water.

3.) Swimming problem:
It is the situation that is overlooked and creates the greatest danger in the water passage. If the crossing is in a pond, the problem is less, and if it is a stream crossing, the swimming problem can have fatal consequences. The vehicle may drift out of control or even turn upside down in the water. See. Picture 2. Convoy transit practices and the measures that can be taken are a separate issue on their own.

Especially new generation vehicles with well-insulated door seals and vehicle bases will tend to float earlier. If the part of the vehicle that we call the cabin is ~ 1.70×3.25 m in size, it makes 1.7*3.25~5.5 m2. That is, if ~35 cm of the cabin remains in the water, the buoyancy force applied by the water is 5.5*0.35~2 tons, according to the Archimedes principle. If we add the volumes of other equipment such as the tire under water to this volume, we will see that the buoyancy force is actually more than we calculated above. In other words, a 2-ton vehicle floats with 35 cm of its cabin remaining in the water. A floating vehicle cannot hold onto the road either. Do not get it wrong, this height is not the height of the water, it is the height of the part of the cabin that is in the water. Cup High vehicles may not be able to swim even in 1 m water depth. In other words, if the trophy of the vehicle is 50 cm above the ground, it is expected to continue on its way without swimming to a depth of 50+35 ~ 85 cm. It is expected, but it is not always possible for him to continue on his way even if he does not swim. Even if the buoyant force does not reach the level to clear the vehicle from the ground, it may weaken the vehicle’s handling and prevent it from moving.

The basic rule of moving in deep water is to make the vehicle sink. See picture 1.

For this, if possible, it is necessary to open the doors and allow water to enter the vehicle. If you do not get water into the vehicle, you will float. Of course, you have to be ready to face all the problems that will come with taking water by opening the doors in the vehicle in this way.

Coarse stones or rocks that are not visible under water may not be noticed during the transition, so it may be possible to damage the vehicle. There may even be pits that will swallow the vehicle.

The oil chambers of all three equipment are atmospheric, that is, they do not have fully closed air-water-tight chambers.

Sometimes water may enter these equipments due to the hydrostatic pressure of the rising water, and sometimes due to the suction effect created by the volume drop caused by the sudden cooling of the heated equipment in the water.

All have ventilation holes. If the ventilation holes are not moved as high as possible in the hood with the extension hoses and the ends of the hoses are not equipped with special equipment to prevent the ingress of water, water may enter inside. ARB differential breather kit (ARB differential breather kit) is the right equipment to use for this purpose. See. Picture 3 .

In the differential, the contact with the external environment is also tried to be limited through the axle seals. Felts, which normally would not allow water to pass through, may take in water as a result of suction resulting from sudden cooling and volume reduction if the ventilation pipes are clogged.

Sometimes klingrite cork gaskets may also be used on the covers. Since the bottom of the gasket of the cover is in contact with oil, even if it remains sealed, water may leak out because the top remains dry. Get through the water, but don’t age in the water.

Conclusion and Suggestions:
– Use your offroad vehicles with the awareness that they are not amphibious vehicles. Prefer to obtain water tools for use in water. See. Picture 4.

– If you are not 100% sure about your snorkel, do not go into the water to a depth that will require snorkeling. Safari is a good option for your snorkeling vehicle. See. Picture 5 .

– In some sources, the water height considered as a reference for safe passage is the vehicle tire height. Knowing that this is a general recommendation; It is useful to know that the water at a height of 60% of the air inlet of the air filter box from the ground in terms of taking water into the engine will be suitable for relatively safe passage of water at heights not exceeding 20 cm from the cabin floor of the vehicle, in terms of keeping the vehicle from floating and keeping it on the road. Before making the water crossing, be sure to have information about these dimensions of your vehicle. Do not enter water deeper than these limits without a snorkel.

– If the snorkel air inlet is at a height of 180 cm or even 200 cm, but the vehicle is floating at 40+35=75 cm, you may be attaching a snorkel to a vehicle that we do not want to get water into. Seeing the entire windshield in water while driving through water does not indicate that the water level is at the level of the vehicle’s roof. If the water is at the ceiling level, the vehicle will already float, where will you pass from? This is splashing water, the splashing water cannot easily enter through the air filter, which takes air indirectly under the hood.

– In order for a vehicle with a sufficiently high air filter air intake to be affected by water, where the vehicle can walk without floating, the water block rising in front of the vehicle must be at the air intake level for a long time. The conditions for this are also clear. This can happen at certain speed levels and if you are crossing a long track. If you do not have a snorkel, try to keep your speed at a level that does not raise the water as blocks in front of you, even if the water is not very high and the course allows passage at any speed. You can determine the right speed only by experience.

– If you are stranded during the water crossing, be sure to attach the strap-like equipment that needs to be attached to the vehicle in order for other vehicles to save you, before entering the water, and place them in a way to prevent entanglement. Take this precaution at both the front and back.

– In some sources, you may come across information that you cannot pass through water that you cannot pass on foot, either by car. This is a generally accepted rule, but contradictory information. How consistent is the decision of a 165 cm tall, 65 kg Jeep Wrangler Rubicon driver with 35″ tires and 4.5″ lift, and the decision of a 190 cm tall, 120 kg Lada Niva user with 27″ tires and no lift?

– When the possibility of swimming is clearly seen, especially at the crossing of the river, connect the vehicle entering the water with a long rope to other vehicles on land and start the transition accordingly.

– In order to control the tendency of the differential to absorb water from the axle seals, which will be created by the reduced interior volume due to sudden cooling, allow it to cool a little before entering the water.

– The ignition system of gasoline engines may be sensitive to water, if necessary, apply a water-repellent spray to sensitive areas before transition.

– In the research you will do on the internet, you will come across serious warnings about the radiator fan. There are warnings to remove the fan belt depending on the fan type. This is a topic that I can comment on, but that I have not experienced. The general concern is that the fan blades, which normally rotate freely in the air, can become deformed when they start to rotate in the water and can move back and forth, causing physical damage to the radiator.

It can be a problem, especially in older generation vehicles. However, I do not think that this will be a problem in more reasonable current model vehicles. Also, you can’t remove the belt or something in vehicles with electric motor fans, without belts, maybe the power plug can be removed.

– Check the crossing route visually as much as possible, if possible, also study on foot.

– Do not enter the water without cooling your discs right after a long downhill track with continuous braking. Sudden cooling may cause deformation of the discs.

– Activate all mechanical possibilities of the vehicle before the transition, do not try to do anything halfway. The generally accepted correct transition is to drive the vehicle through the water at low speed.

– After completing the water passage, or at least after your tour is completed, drain a piece of oil from the lower plug of your differential, if there is water coming out, change your differential oil immediately by cleaning it.

– Never stop the engine of your vehicle at the water crossing, if it does, start it immediately. There may be a backflow of water from the exhaust.

– Do not change gear while shifting in manual transmission vehicles.

– If your crane is not in ip68 standards, do not make long passages through water above the level where the crane is mounted.

– Do not enter deep water unless you have a vehicle that is free from electronic circuits and electronic devices.

– It may be better not to wear your seat belt, especially in deep river crossings.

– Do not go into deep water unless you have a vehicle where the engine failure caused by the water will not hurt you. Let me state my personal preference, in order not to gain unnecessary courage, I did not have a snorkel fitted to my vehicle, nor will I.

– If you do not have a vehicle that does not sink like a stone thrown into the water and takes water immediately, do not go into deep water.

– Never go into salt water. Do not go even 1 inch deep, let alone.

– Never fight in a stream. If you do not know the rules and methods or do not have enough experience, do not embark on the adventure alone, you must have someone with you who knows what to do.

– If you need to cross quickly to stay in the water, do not enter the water without a snorkel.

– Let’s try not to prefer open performance filters, which are not in a closed enclosure, on offroad vehicles. If we are going to use it absolutely, let’s be aware that these vehicles are not used on the street and let’s put the air filter in a case that physically protects it from splashing water or short-term rising water.

Shared in attachment;

Since the vehicle seen in Picture 1 is a vehicle that sinks into the water like a stone, it did not experience any problems such as swimming and not holding the road.

The object silhouetted under water in Picture 2 is a vehicle. The photo is from the archive of our dear friend Taner Eraslan. The last condition of the vehicle, which cannot be controlled due to its tendency to float at a stream crossing, is in the photo. Our friends were still in the vehicle when the photo was taken.

Picture 3 shows a ventilation kit with up to 4 connections.

Picture 4 is a good example of the right thing to do if we love water very much.

In Picture 5, we see a snorkel whose quality we can trust.

In the short pass in the photos below, the vehicle in front has a snorkel, and the shooting vehicle does not have a snorkel, but the air filter has only been able to tolerate the effect of the water rising as a wave.

Regards, Love

09/03/2020