A hand truck (also known as a wheelbarrow or barrow) is a transport vehicle propelled by human power; it is the progenitor of all vehicles. Although material handling technologies have continuously evolved, the hand truck remains in use today as an indispensable tool for conveyance. Hand trucks enjoy widespread application in both industrial production and daily life due to their low cost, simple maintenance, ease of operation, and light weight. They are capable of functioning in locations where motorized vehicles are impractical to use, and they are particularly convenient for transporting lighter loads over short distances.
Hand trucks are categorized into single-wheel, two-wheel, three-wheel, and four-wheel varieties. The single-wheel barrow is capable of traversing narrow planks, makeshift bridges, and winding footpaths; it can pivot in place, making the dumping of cargo exceptionally convenient. Commonly used two-wheel hand trucks include the hand-pushed dolly (also known as a "tiger truck") and the frame cart-both designed for transporting packaged goods-as well as the hopper cart, which is used for conveying bulk materials. Three-wheel hand trucks feature one swivel caster, while four-wheel hand trucks feature two, each capable of rotating around a vertical axis. During operation, these swivel casters automatically reorient themselves in response to changes in the vehicle's direction of travel, thereby aligning themselves in the direction that minimizes rolling resistance.
