The extra chain at the back of a tanker truck isn’t just for show—it’s a vital **safety feature**. Its purpose is to **dissipate static electricity**, which can build up as flammable liquids are transported. If this static isn’t grounded, it could spark and cause a fire or explosion.
Dragging the chain along the ground allows the static charge to safely discharge. This practice became standard after accidents in the early days of fuel transport showed the dangers of static buildup.
Though modern methods like static grounding reels and anti-static additives exist, the chain remains a **simple and reliable solution**. It’s regularly inspected to ensure safety and is still required by many transport regulations.
In short, this small chain plays a **big role** in keeping fuel transport safe.