Gasoline tank trucks can become charged as they travel. How can this happen and how can it be prevented?

Answer 1

The charge comes from friction with the road. Happens in cars too. Or when you walk across a carpet. Same as running a comb through your hair too.It really cant be prevented without some undesireable chemistry changes to the rubber in the tires. But it can be ( and is ) dicharged through a wire in contact with a ground.
Long ago cars had "curb feelers " whicjh were wires extending from the side of the car. Most people thought they were just to make noise when they rubbed against a curb to help you judge how close you were. But they also discharged the static electricty that had built up. Some tires made for higher gas mileage are more prone to static build up. Back in the 1980's people noticed this be getting a little shock getting out of cars.

Answer 2

Static electricity is the cause, and prevention can be as simple as installing a grounding strap, that drags on the pavement while traveling.
Years back, many cars in this country had an leather strap fastened to either the undercarriage or the bumper, and also maybe a braided copper strip that would drag on the ground when in motion. This grounded the vehicle so a discharge did not happen when any person came in contact with the vehicle.
Some trucks even used to drag chains, but not tankers as the sparks could cause problems, so leather was used, or braided copper.

Answer 3

They Collect Static electricity while moving. The Electrons and molecules rubbing with the ties against the road. The way to discharge them is to drag a chain behind the truck. This grounds the truck so the charge doesnt build to a dangerous level and then cause the fuel inside to combust.