Figure 4. Tesla S electric car fire at a highway exit at Kent, Washington.
The car hit a
“large metallic object” that damaged one of the modules in its liquid
battery pack, which is situated on the underside of the vehicle. The Tesla battery pack is
configured as a long, flat slab on the bottom of the car, beneath the passenger
compartment and protected by reinforced metal. The case shielding the battery might not
have been strong enough to keep the impact from causing a short circuit. Initial attempts
to douse the fire were unsuccessful. The fire appeared to be extinguished, then reignited
underneath the vehicle. Firefighters had to use a jack to turn the Model S on its side, and
then cut a hole in the car to apply water to the burning battery. Possibly unknown to them
is that lithium, like sodium is highly reactive with water and air.
To ensure a comfortable safety level, engineers are obligated to:
Anticipate or predict all the failure modes that can lead to an accident, both at the
design and the operational stages.
Take into account operational experience and past human and design errors, and
incorporate them into their design in view of avoiding catastrophes.
Engineers are also bound by law and by professional ethics to adopt the concepts of
“informed consent” towards the public about the involved risks in their designs and
projects. The penalty for being uninformed about the laws pertaining to risk, or failing to
follow them, could be litigation and damages that could bankrupt the offending
individuals or their businesses.