“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 operation 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.”
“Forklifts operated from a stand up position rather than a seated position offer a significant advantage to increase warehouse capacity. Stand up lift trucks can be operated in warehouse aisles as narrow as 8 feet. In contrast, traditional sit down lift trucks typically require aisles approximately 11 feet wide. This paper will detail the hazards of horizontal intrusion and lower limb injury for the operators of stand up lift trucks, review standards related to operator protection against horizontal intrusion and lower limb injury, summarize a safety engineering analysis of the stand up lift truck design including guarding to mitigate the hazards, and present three cases tried to jury verdict regarding injury accidents on stand up lift trucks.”
“There are a number of blind spots on any vehicle, primarily on both sides and to the rear. Additionally, all vehicles have blind spots to some degree when traveling in reverse; the larger the vehicle, the larger the blind spot. Large forklift trucks (FLTs) typically travel in reverse (forks trailing) often as much as half the time largely due to the obstruction of forward visibility caused by the load on the fork. Also, traveling on ramps and setting a delivered load require the FLT to travel in reverse. Frequent FLT reverse travel poses problems for the operator who, when attempting to look to his rear by turning his head and/or upper body, can suffer back and neck strain and fatigue. Traveling in the forks trailing direction creates a situation of a large blind spot behind the driver’s now rotated head and upper body. A case study is presented of an accident that involved backing up a large (52,000 pound capacity) FLT. This vehicle was equipped with mirrors, a constant- sound-level back-up beeper and a flashing beacon. Despite these safety features, the injured party failed to see the oncoming FLT, nor did the driver see him due to the blind spot. The commonly accepted back-up warning systems, which include mirrors, beacons and beepers, are shown to be often inadequate during accidents involving blind spots that occur while driving in reverse.”
“Forklift trucks (FLT’s) are the single most versatile industrial material-handling device. This versatility is created by the ability of the FLT to move loads in three dimensions, i.e., forward, laterally, and vertically. This freedom of movement is provided by the rear steer front wheel drive configuration of FLT’s permitting the FLT to move loads into tight spaces and also by the mast permitting the forks to raise and lower loads for stacking. As part of the stacking operation the masts of FLT’s have the capability of tilting fore and aft, which permits the forks to get under the load and then once placed on the forks, for the load to be raised and then cradled by the forks by tilting the mast backwards…A case study is presented of a fatality accident involving a large capacity FLT (52,000 pound capacity) carrying 11 sheets of steel which were 10′ x 20′ x 1/4″ each weighing approximately 1500 pounds. The operator of the FLT set the load at about 14″–16″ above the ground, set the spotting brake, and exited the cab to rearrange a number of wooden spacers upon which he intended to place the sheets of steel. The mast drifted, causing the forks to angle down, which in turn permitted the sheets of steel to slide off the forks (much like a deck of cards) and strike the worker (previously the operator), resulting in his death.”© (2012) ASME. This paper is posted here by permission of ASME for personal use only. Additional reproduction, redistribution, or transmission in either print or digital form is not permitted without ASME’s prior written permission.