DON'T DO THIS: It may look spectacular if you're trying to impress your mates but driving a vehicle on its rims is incredibly dangerous. Image: YouTube
Cape Town - Earlier in August, Wheels24 reported that a Californian wildfire was reportedly caused by a car driving on its rim.
The friction between the rim and the road ignited sparks, which led to a blazing fire that firefighters struggled to bring under control.
The resulting blaze destroyed many acres of forest and damaged homes.
READ: Reason for this huge wildfire? Sparking car rim...
Wheels24 reached out to Arrive Alive and IBF Investigations to find out more about the dangers of sparking rims.
Stan Bezuidenhout, forensic collision homicide reconstructionist for IBF Investigations, shares advice:
Wheels24: What are the dangers associated with driving on your car rims?
IBF: Vehicle dynamics and stability is essentially a function of road holding. Road holding, in turn, is a function of friction (the propensity for a vehicle to 'stick' to the road and not to slide). Wherever the vehicle stability is affected negatively (steel is more slippery than rubber), the risk if a loss of control is increased enormously.
Vehicle stability is also a function of suspension design and wheel (tyre) dynamics. Some of the vehicle stability is derived form the tyre (sidewall) flexibility and the suspension (keeping the tyre in contact with the road). As such, the absence of the tyre (rubber) causes a metal/road interface, which adversely affected road holding. Essentially - driving on rims can expose the driver to enormous danger of losing control. This, in turn exposes other road users to the same risk - if the driver loses control and collides with them.
W24: Regarding the Californian wildfires, can a sparking rim cause a fire?
IBF: Oh absolutely. But it gets more complicated. There are several components that can cause fire. Because there is enormously reduced friction, the wheels will “spin” on the road, and this will cause heat. If the driver wants to keep moving, they would HAVE to keep spinning. The hard-surface friction can heat the wheels to the point of ignition.
The type of wheels also affect this. If it is plain steel, the contact surface will be small, increasing thermo-dynamics and causing the wheels to heat up quickly. If the wheel is an alloy wheel, the material is softer and will cause the wheels to collapse, increasing temperature and the likelihood of fire. Where the wheels are exceeding thermal stability, molten metal (sparks) will fly off and could easily ignite other media, like grass, bush, etc.
W24: What if you drivers have no choice (i.e a blowout in an isolated area) but to drive on their car rims? What advice can you share with readers?
IBF: In extreme cases, you might be forced to. Think hijacking, where your wheels have been shot at and are flat. If you keep driving (to safety), your tyres will eventually disintegrate to the point where you will be driving on the rims. But in extreme cases this makes sense - not in general cases.
Imagine driving at night and having a flat tyre. Driving on your rim to the point that flames are coming out (or sparks) will be a bit extreme if you can find or call for help. There is also a substantial difference between driving on ONE flat tyre and driving on TWO or more. If the situation is so dire that you are on four flat tyres, more must have happened. If it is a fear for your life (real - not imagined) driving your efforts, you would surely be forgiven; desperate times, desperate measures.
Being confronted with wildfires
Capetonians will remember the huge blaze that engulfed and destroyed large parts of Table Mountain and surroundings in 2015. With summer and hotter weather on its way, drivers should be aware of the dangers associated with wildfires in SA.
Arrive Alive lists a number of safe driving recommendations in the event of a wildfire:
• Check weather conditions of designation and route when planning a trip during the fire season.
• Keep maps of your route and frequent travel destinations in your car, and know at least two ways of getting anywhere.
• Drastically reduce speed, drive carefully and be on full alert when smoke limits visibility.
• If visibility becomes very poor, don’t attempt to drive through thick smoke or flame.
• Put your headlights and hazards on so that you are as visible as possible to other road users.
• If you are caught in your vehicle during a veld fire, your vehicle will provide a good degree of protection.
• Do not leave the vehicle - people have lost their lives by exiting the vehicle, only to be trapped on foot in the open.
• Stay in the vehicle, as low down as you can get, until the fire front has passed, then exit and inspect the vehicle for damage before proceeding.
• If you are in the veld, away from your vehicle, and you see that a fire has started, move away from the fire immediately.
• Never ignore the fire, even if it seems far away - it can quickly become large and engulf you!
• If you feel threatened and you don’t think you can outrun the fire, or if you are surrounded, find a ‘safe zone’.
• A ‘safe zone’ can be an area that has already been burnt, or is completely clear of any fuel that can burn, such as a wide road or an old homestead. The clear area should be as large as possible.
Respect and awareness of emergency operations
It is important that motorists obey and pay close attention to officials attending to wildfires. The following should be kept in mind:
• Move over when you see flashing lights at the side of the road or the presence of emergency vehicles or fire engines!
• Try to stay at least 200 metres away from the emergency vehicle.
• If an emergency exists ahead, it may be dangerous to the public to drive through the area.
• People who drive into an emergency scene may collide with a fire engine, or worse, a firefighter.
• Slow down when approaching an emergency scene.
• Be patient and keep in mind that fire and emergency personnel are trying to get the fire under control.
• Detouring traffic may cause everything to slow down, but it is better getting through slowly instead of getting stuck.