Water is a very insidious substance, given its latent potential to become a catastrophically destructive force if not handled properly. Tanker truck drivers know this all too well (their commercial driver’s license endorsement for this application is there for good reason), but what exactly happens when a passenger car is modified into a 792-gallon (3,000-liter) tanker and then subjected to the moose test? A renowned team of Russian scientists from the world-renowned YouTube Academy of Applied What Ifs proves it.
Several decades ago, Scandinavians devised a handling test designed to test a vehicle’s ability to stay on the road and under the driver’s control while making a sudden swerve to avoid an obstacle in the road and then return to its original lane. In other words, the moose test, aptly named for the animal most likely to cause drivers to swerve at the last moment in an attempt to avoid large animals appearing on the road from the surrounding forests.
The test has long been a staple of automotive manufacturing prowess, but there are situations where automakers have to admit defeat in the face of physics. Or, more precisely, the wave of liquid. What is it? According to the Department of Motor Vehicles, it is the 'sudden movement of liquid in various directions during the maneuvering of a tanker vehicle.
If the tank is not filled to the brim, which it should never be!, the liquid inside will create waves that will flow forward, backward, left or right. This happens when starting, stopping, turning or going around curves – in other words, when the vehicle is in motion. Waves can be extremely dangerous, as the inertial force of the “water hammer” can push a vehicle through an intersection or cause it to roll over on a winding road.
At this point, I should explain water hammer: another interesting but dangerous phenomenon that occurs in any piping system where valves are used to control the flow of liquids or vapors. A water hammer is the result of a pressure surge or high-pressure shock wave that propagates through a piping system when a moving fluid is forced to change direction or stop abruptly.
Photo: YouTube/Garage 54
In other words, think about what happens when you fill a cup halfway with water and then start swirling it: the liquid gradually rises to the top, leaving the center empty. If the speed is high enough, it will overflow. The analogy applies to oil tankers: the liquid inside will move, creating tremendous shock waves that travel through—and beyond—the container.
So, a vehicle that hauls a three-cubic-meter container half-filled with water is not the ideal candidate for a moose test. Add in the fact that said car is a Soviet-era Lada, and things get very interesting. Leave it to Garage 54 to settle the debate, once and for all, with their home-built test mule. The recipe is very simple: hack a Lada sedan, remove the rear cabin, weld a 792-gallon (cylindrical) water tank in its place, and get to work.
Of course, adding a large hunk of steel to a Lada puts a serious strain on the suspension springs, so Novosibirsk mechanics and YouTubers add extra coils to keep the wheels clear of the wells. A simple 25 mph (40 km/h) braking test with an empty tank results in a stopping distance of 12 meters (39 feet). In the moose test, the bulky Lada performs well, cruising around the circuit flawlessly (at the same 25 mph speed).
Photo: YouTube/Garage 54
With a full tank, about three tons of water, the car stops in just ten meters or 33 feet. This is impossible according to any law of physics, but there is a trick. The speed reached by the overloaded Lada was only 30 km/h (18 mph). The moose test returns the same results as the first round: the heavy car manages to stay on the track, although it barely manages to pass in one piece.
The added mass of water doesn’t create huge shockwaves because it doesn’t move around inside the tank, so the car’s center of gravity is always planted between the four wheels. Things change dramatically when the Siberians remove half the liquid load and repeat the test. But before that, they test the brakes again, and guess what? The Lada stops after 25 meters (82 feet) of hard braking from 25 mph (40 km/h).
The car instantly wobbles under the constant movement of the water load. Eventually, it becomes uncontrollable for the driver, yielding to superior forces. In this case, inertia and gravity take over, flipping the car onto its roof.
Of course, this being a Garage 54 experiment, safety is a primary concern—for the channel’s viewers, not the vloggers. Vlad Barashenko, the frontman of the crazy, adventurous band of motoring heartland Asia, didn’t bother with such inconveniences as a seat belt, let alone a helmet, HANS (Head and Neck Support), or a window net. Fortunately, the bulbous cylinder behind him doubled as a roll cage, effectively preventing the Lada’s structurally weakened roof from crumpling on the man.
[YOUTUBE= https://youtu.be/orCrreHkN98]