The 5 ton tractor was the "workhorse" of the Line Haul Units. Combined with the M127 Stake & Platform trailer
or the M131 fuel tank trailer, the M52A2 helped the soldier in Vietnam power his tank and shoot his gun.
Using 5,000 gallon tank trailers, the truckers would become good targets for the enemy. Using the Russian
designed and built RPG-6, many drivers would be shot at hauling these fuel tanks on wheels. Their fellow
cargo drivers would name them "Zippo's"