Reducing Overexertion Injuries and an Improved Work Process Move Rivian to Equip Metrology Cell Carts with TWERGO Swivel on Swivel Casters.

Situation.

Manufacturing facilities are challenged with keeping productivity high while minimizing employee injuries from employees moving heavy and hard-to-move carts.

While keeping employees safe is job 1, injuries related to overexertion are the leading cause and costliest, according to Liberty Mutual’s 2023 Workplace Safety Index. In 2023 alone, this type of occupational injury cost businesses $12.84 billion.

This was the situation Rivian’s Production Excellence Team faced in their Metrology Group under Josue Nunez Hernandez’s Inspection Group. One of the Metrology employees reached out to their Group Lead, Jennifer Bracken. The back pains the employee was experiencing could be exasperated by pushing and maneuvering a 1,600 Ib. cart.

This particular cart was regularly moved in and out of the Metrology Cell. This is where components and sub-assemblies undergo scanning and measurement for accuracy and tolerance control. This process involved a minimum of four movements per hour.

Upon closer inspection, it was identified that the carts failed to meet the company’s established ergonomic standards. As a result, addressing this discrepancy became imperative to ensure the team’s well-being and align with our organizational standards. A resolution was sought to bring the equipment in line with the company’s ergonomic guidelines.

Solution:

Josue and Production Excellence Leader Dirk Hardtmann turned to Caster Concepts for a much-needed and timely solution. After gathering the application requirements, Caster Concepts recommended TWERGO® Swivel on Swivel casters.

TWERGO casters move heavier loads easier by minimizing friction and eliminating scrubbing and sliding when the wheel turns. The dual swivel section offered with the Swivel-on-Swivel design also made pulling the cart straight out of the cell much easier when the wheels were at a 90-degree angle.

Testing Parameters:

Caster Concepts traveled to the Normal, IL site, where Rivian purchased a set of the recommended casters and fitted them to one cart as a proof of concept.

A battery of push-pull force tests was implemented that simulated worst-case scenarios and the practical maneuvering requirements in the daily process of the metrology cell.

The tests were measured with an IMADA, Inc. Z2S-DPU-4400 Digital Force Gauge fitted with a push and pull handle on both the existing carts and the carts featuring the new TWERGO Swivel on Swivel casters.

Results:

TWERGO Swivel-on-Swivel casters

The TWERGO Swivel on Swivel Casters reduced the push force from 76 lbs. to 37.7 lbs. This is significant, as lowering push force substantially lowers the risk of worker injury.

By reducing the push force to below 40 lbs., the cart was now safe for 92% of the workers to push without injury. At the previous push force of 76 lbs., more than 62% of the workers were at risk of developing an overexertion injury.

By recognizing the ergonomic and economic advantages of switching from low-quality casters to the new TWERGO swivel-on-swivel casters, Rivian could reduce cart push force and rolling resistance. This quickly translated into an improved work process, a better employee experience, and a world of savings.