This paper will examine the accelerations present during the operation of stand-up forklifts. Forklifts, or powered industrial trucks, are typically operated from 1 of 2 postures. Forklifts are either operated from a seated posture or a standing posture. Previous research has focused on the threshold of acceleration at which a standing forklift operator will be unable to maintain postural stability, but did not detail peak and average accelerations generated by forklifts during typical turning maneuvers. This paper will detail the accelerations generated by stand-up forklifts during typical operations from a theoretical examination of vehicle dynamics and present experimental data acquired during stand-up forklift testing. This paper will further examine performance required by consensus and industry standards, industry practice and the safety implications of stand-up forklift acceleration.
The record of serious lower leg injury associated with stand-up forklifts, reports of ejection or loss of balance from the operator and data regarding acceleration present in the operator compartment support the use of a door for stand-up forklifts.