Not only aircraft, even vehicles can hydroplane

Hydroplaning was a term that was heard several times during the debates surrounding the first air crash in Karipur Airport in Kerala. The cause of the crash according to preliminary evidence is a layer of water on the runway which caused skidding of the plane. Not just the runway, hydroplaning can occur on roads too. Recently, it led to the death of a person in Angamaly. The motor vehicles department, through a Facebook post, has explained what is hydroplaning and the risks associated with it.

From the post:

While debates are continuing whether the Karipur tragedy was caused by hydroplaning or not, this phenomenon is a real threat to majority of motorists who are unaware of it especially during the monsoon season.

What is hydroplaning?

Though the vehicle's traction, braking and steering functions are controlled by mechanical parts, in the end it is the rolling traction or friction between the tyre and the surface that results in forward motion. For instance, it is lack of friction that prevents us from walking on a smooth floor where oil has been spilled.

When a vehicle is driven on a water-logged road, a layer of water builds between the tyre and the surface due to the tyre's pumping action. Usually, the tyre displaces the water with the help of impeller action through its grooves and restores contact with the surface. However, an increase in the peripheral speed of the tyre increases the amount of water that gets trapped between the tyre and the road under high pressure, thus reducing the time available for water displacement. This effectively shortens the area of actual ground contact since water is not compressible. Thus, the highly dangerous phenomenon called aquaplaning that separates the tyre from the road takes place.

Hydroplaning causes loss of steering, braking and power control and the person behind the wheel completely loses the control of the vehicle, leading to skidding. Speed increases the likelihood of hydroplaning. Besides, worn-out tyres will have thinner grooves that can displace water. The thread design of tyres and the weight of the vehicle too will have some bearing on aquaplaning.

What causes hydroplaning:

* The speed of the vehicle is the primary reason

* Thread design - some thread patters aid hydroplaning

*Tyre size - Wider surface will reduce chances of hydroplaning

*Air pressure - Over inflated tyres aid hydroplaning

* The thickness of the water layer

* Weight of the vehicle - The higher the weight, the lower the chances of hydroplaning

* Nature of the surface - Smoothness and presence of oil will aid chances of hydroplaning

What to do when you lose control

In case you lose control over the vehicle due to hydroplaning, the driver should take his foot off the accelerator, besides avoiding sudden braking and turning of steering.

Slowing down when roads are wet is the best way to reduce hydroplaning, especially if there are puddles or flowing water on the roads. On highways, where the speed is generally on the higher side, puddles of water on the roadside pose a higher risk. Also, replace worn-out tyres that have thinner grooves to expel water. Keep your tires properly inflated and avoid using cruise control on wet roads.