​​​​Why do Trucks carrying Explosives have a Metal chain Touching the Ground?

 ​​​​Why do Trucks carrying Explosives have a Metal chain Touching the Ground?

The trucks carrying explosives have a metal chain touching the ground ,True. This is all because of the charges produced by the friction which is generated by the tires moving. When the tires move they create certain amount of charges which are enough to blow up the explosive tank. The main motive is to do earthing so that the charges flow down in the earth and prevent the truck from getting blown up or you can also say preventing the explosives to blast.