Analyzing and measuring the vibration environment during distribution is fundamental to understanding and simulating the ability of a packaged-product system to avoid any damages from transportation hazards. During distribution, various vehicles, including forklifts, are used to perform shipping and handling tasks such as loading, unloading, and warehouse organizing processes. The aim of this paper was to provide an understanding of the average vibration levels that occur during handling so they can be used in pre-shipment testing. Various forklifts were observed, measured, and analyzed to obtain information about their average vibration levels while performing recommended tests. The measured acceleration-time data were analyzed in terms of power spectral densities (PSD) and presented with statistical data that provided an understanding of the variability of intensity. The PSD peaks were between approximately 2.5 and 5 Hz, and then they decreased to 120 Hz. The number of instances over 120 Hz was extremely low. The final recommended vibration test spectrum was determined to be in the frequency range of 1–120 Hz and the data were smoothed between six breakpoints.

Forklifts are one of the most common types of material handling equipment used in warehouses and distribution centers. Vibration generated by forklifts may have an effect on the performance of unit loads and product damage rates. Historical research projects have focused predominantly on the measurement of vibration for over-the-road transportation. Thus, there is still a lack of understanding of the level of vibration caused by forklifts. The goal of this study was to understand how the vibration that is experienced by unit loads while being transported by forklifts is affected by factors such as speed, road condition, unit load weight, type of forklift, and sensor location. For this study, power spectral density (PSD) measurements were collected using a Lansmont Saver 9X30 data logger. Vibration levels were measured for three different industrial forklifts on two different surface types. The forklifts were driven at two different speeds while carrying two different unit load weights. For all of these conditions, the vibration levels were measured at the forklift carriage, at the back of the fork tine heel, and at the fork tine tips. The results obtained show that the highest vibrational intensity occurred at 3–4 Hz, while the highest overall Grms value observed was 0.145 G²/Hz (between 1–200 Hz). An increase in the forklift speed caused an increase in vibration intensity. In contrast, an increase in the unit load weight carried by the forklift caused a decrease in vibration intensity. Among the three forklifts studied, the gas-powered forklift had the highest vibration intensity, and all forklifts, when driven on asphalt, experienced more vibration.