Never realized this
Why Tanker Trucks Have Hanging Chains
Tanker trucks carry flammable or sensitive liquids like fuel, chemicals, and milk. To ensure safety, they’re designed with special features — one of the most important being the metal chain hanging from the back or side.
What the Chain Does
This isn’t for decoration. It’s a grounding chain, and its purpose is to prevent static electricity from building up. As the liquid sloshes inside during travel, it creates friction. This can lead to dangerous static charge. “If the cargo is flammable, a spark from that static could cause a fire or explosion.”
How It Keeps Us Safe
Dragging along the ground, the chain safely releases the charge into the earth.
This simple method became widely used after accidents caused by static sparks led to serious fires. “Agencies like the DOT now require grounding chains on trucks carrying flammable materials.”
Simple, Reliable, and Still Essential
Though there are modern options like grounding reels and anti-static additives, the basic chain remains popular.
“It works without electronics and doesn’t fail easily.” Safety inspectors check chains often, and trucks can’t operate if one is missing or damaged.
