No abstract

Stand-up forklift collisions with storage racks are a known hazard in the material-handling industry. When the height of the first rack beam from the floor is close to or above the height of the forklift’s operator compartment — and is at a height that is lower than the forklift’s overhead guard — the rack beam can intrude into the forklift’s operator compartment. These collisions are typically referred to as “horizontal intrusion incidents,” also known as “underride” incidents. When the forklift is not equipped with horizontal intrusion guarding, these occurrences often lead to serious (if not fatal) injuries. This paper presents physical testing and analysis of one major forklift manufacturer’s accident database records, which show rear-mounted posts are effective guards in reducing or preventing the consequences of horizontal intrusion incidents. Further, this paper shows these rear post guards met and exceeded design requirements of the material-handling industry standards.

This paper outlines the forensic procedure and techniques used in the reconstruction and safety assessment of a fatal overhead crane accident. The decedent (a subcontractor) was working as a pipe fitter at a manufacturing plant. At the time of the accident, the decedent had climbed up onto an overhead crane rail to move existing pipework when the crane struck and killed him. This paper presents the application of various techniques/methodologies to reconstruct the complex accident, including 3D HD scanning, drone video imaging, and 3D modeling/principles of photogrammetry to understand how the incident occurred and provide visualizations of the construction project. Safety analysis was conducted by analyzing crane maintenance and operation as well as the duties/responsibilities of the different employers and comparing industrial standards and practices such as OSHA, ANSI, and safety principles.

A fatal collision involving a pedestrian struck by a public train at a rail station located in a major U.S. metropolitan city was investigated. The train was equipped with an event data recorder that recorded valuable empirical data related to the collision, such as the train speed, braking, and acceleration inputs. However, the original digital version of the data was not available to analyze, and only a single screenshot of the data in an analog graph format was available. The subject train was equipped with multiple video cameras at various vantage points that recorded video footage of the collision. Using the process of “matchmoving” — and with the assistance of three-dimensional LiDAR scanning of the station and train — video footage was analyzed to spatially determine the location of the train in three-dimensional space. The process of matchmoving is an established scientific process used to calibrate a virtual camera to “match” the movement and optic properties of the real-world camera that captured the video. Further analysis was performed to determine the train’s kinematics (such as its speed and deceleration rates) leading up to the collision. The accuracy of the matchmoving analysis was then verified with the available event data.

Unintended movement of powered industrial trucks after operators have left the operating position has led to serious — and sometimes fatal — accidents. Even though operators are trained to prevent unintended movement of powered industrial trucks, they can forget to shut off the power source or activate systems to prevent the unintended movement when leaving the truck. Operators are known to make mistakes, especially if they are working in a fast-paced environment and are required to frequently leave the trucks. Engineershave designed electrical interlocks and other systems (e.g., automatically applied parking brakes) to prevent unintended movement; however, not all powered industrial trucks are equipped with them. Furthermore, some of these systems only disconnect the power source from the truck’s drivetrain. These trucks can continue traveling due to their initial momentum or by gravity if the truck was left on a slope. The purpose of this paper is to address the design of forklift operator presence detection systems and unintended movement of unoccupied forklifts through a safety and forensic engineering analysis, highlighting a brief case study to examine the concept of use and foreseeable misuse — and to review the legal concept of strict product liability.