Editor’s note: Spec Master delves deeper into the specifications reported in our annual Equipment World Spec Guide. This month’s guest experts: Mike Stec, sales engineer, and Nick Tullo, product specialist, Volvo Construction Equipment.
Payload rating (metric tons, short tons or pounds)
Payload rating is the amount of material that can be carried in the truck body. This is usually one of many values customers look at when making a purchasing decision.
Payload capacity (cubic meters, or yards)
Two terms are often used when describing payload capacities; struck or heaped. Contractors usually measure this capacity by cubic yards, and all manufacturers of articulated haulers specify payload capacity by loose cubic yards, not bank cubic yards. One way to explain struck volume is the example of filling up the truck body with water until it reaches the level of the sideboards and tail chute – no more water can be added since it would spill out. Trucks are designed to hold a theoretical load with a 2:1 heap in the body, although, of course, not all material heaps this way.
Empty machine weight (pounds)
Standards define empty machine weight as the mass of the machine with an empty bed, a 165-pound operator, a full fuel tank and all other fluid compartments at the manufacturer’s specified level. This includes, and may not be limited to, a full engine crankcase, cooling and hydraulic systems, transmission, differentials and final drives. Manufacturers must specify how the machine is equipped when this measurement is taken, including any optional equipment and/or special attachments.
Gross (loaded) machine weight (pounds)
The total operating weight of the machine is gained by adding the empty machine weight to the manufacturer’s payload rating. Certain standards also require manufacturers to list weight distributions between axles.
Loading height (feet, inches) (Point A on illustration)
This is the distance between the ground and the highest point of the sides of the articulated truck body, measured when the hauler is empty. Optional side boards will increase this height. If you typically load your hauler with a wheel loader, make sure the loader’s dump clearance (or hinge pin height) is sufficient enough to clear any side boards that may be on your truck.
Dump time, full cycle (seconds)
The time it takes to lift the truck body from the frame and return it again with the engine at the manufacturer’s rated speed.
