This case study focuses on the transport needs of the Bay Area Rapid Transit system located in San Francisco, CA. Comprised of elevated heavy rail and underground subway systems, BART connects San Francisco and Oakland with both urban and suburban areas in Alameda, Contra Costa, and San Mateo counties. After discovering that current material handling equipment could not accommodate the workplace safety needs of existing staff, BART reached out to Electro Kinetic Technologies for a custom engineered material handling solution.
Throughout the vast BART system, the maintenance department routinely transports heavy materials and supplies with payloads of up to 1,000 lbs. Previously, BART utilized standard electric tugger models to transport these supplies and materials. However, the handles on standard tugger models were not adjustable enough to be safely operated by staff members below a certain height. This required a custom handle design that could lower far enough to accommodate employee height differences. Standard carts available at the time did not come with handles of this sort, which are similar to the tillers used to operate an electric tugger. BART’s unique application therefore required an entirely custom cart.
Additionally, an investigation of BART’s specific application revealed a problem with electro-static discharge (ESD) that inhibited motorized transport. The final solution would therefore have to provide a means of safely discharging or neutralizing the ESD.
Electro Kinetic Technologies custom designed a custom scissor lift cart that is robust enough to safely transport carts of materials weighing up to 1,000 lbs. The handle, or tiller, was designed with a height adjustment range of 33” to 48” off the ground. This would allow operators with a wide range of heights to comfortably operate the cart. This range of motion is wide enough to accommodate shorter employees, who had previously struggled with less adjustable handles. The cart’s platform measured 36” wide x 60” long, and was outfitted with removable sides to prevent materials from sliding off during transport. The cart also included a safety skirt to prevent access to pinch points during the operation of scissor lift.
In order to effectively maneuver such heavy loads, the cart’s handle must be structurally robust and is therefore heavy, which necessitates a mechanism to mitigate the resultant strain on the operator. To address this, the cart’s custom handle was augmented with medium-force gas shocks to assist in leveraging the weight of the handle. This design operates similarly to a pallet jack bybalancing out the weight of the handle and eliminating potential strain on the operator. If needed, stronger gas shocks can be installed at any time. Electronics and batteries located in a NEMA enclosure were also mounted on the rear of the cart to allow for easy servicing and larger capacity batteries.
To meet BART’s requirements, the top of the cart was constructed out of stainless steel. However, the nature of the application also produces excessive ESD during operation, which is then conducted across the cart through the stainless steel. To prevent the excess ESD from inhibiting convenient transport, Electro Kinetic Technologies mounted a custom-designed ESD strap on the bottom of the tugger to discharge the electricity safely by creating an electrical connection between the top and the floor.
This uniquely custom scissor lift cart met the height and safety parameters of BART employees, while also providing a more efficient means of transporting exceptionally heavy supplies and materials.
For additional information on custom engineered solutions for your material handling challenges, contact us and a team member will help answer your questions.