Warehouses today are delivering goods around the globe faster with advances in efficiency, automation, and AI-driven systems.
However, with the increasing demand for faster fulfillment, warehouse workers continue to face significant risks for injury on the job.
The numbers help to tell the story:
According to the Bureau of Labor Statistics data, warehouse workers face injury rates of 4.8 per 100 full-time workers, which is nearly double the 2.8 rate across all industries. A study of warehouse workers published in 2023 showed that 24% of warehouse workers reported low back pain, especially those performing separation tasks. Heavy machinery, fast-paced operations, and traditional storage methods create a perfect storm for slips, falls, and musculoskeletal disorders from constant lifting, bending, and reaching.
These injuries are more than statistics.
They affect employees on a personal level and disrupt operations for warehouse crews and the company.
Vertical Lift Modules (VLMs) offer a way to address these challenges, transforming dangerous manual storage tasks into safer, more efficient operations that protect your workers while boosting productivity.
In this article, we’ll explore what VLMs are and how they contribute to worker safety and ergonomics. We’ll also share some safety tips your team can utilize when working alongside a VLM.
What is a Vertical Lift Module?
A Vertical Lift Module (VLM) is an automated storage and retrieval system that brings inventory directly to your operators at an optimal ergonomic height. Instead of workers climbing ladders, bending into bins, or reaching overhead, VLMs use sophisticated storage and retrieval technology to deliver the exact tray needed right to the access opening.
Vertical Lift Modules are a proven way for warehouses to increase productivity, efficiency, and safety. Customers using the VLM Kardex Shuttle, for example, can achieve 99.9% pick accuracy, 85% floor space savings, and a 67% reduction in labor force. Delivering goods using a VLM also reduces the risk of injury.
When the item the worker needs is within the “golden zone,” or the area from the belt height to the shoulder height of the average individual, workers can grab or move items without stretching or bending.
VLMs are a fundamental part of the goods to person picking or GTP fulfillment system, where workers remain at a fulfillment station while automated machines access storage locations throughout the warehouse, bringing the goods to workers. This can be a more efficient and safer method than the “person to goods” fulfillment system, where workers go to where items are stored and retrieve them from storage.
The time savings earned by using VLMs and goods to person picking can be significant.
Warehouse pickers can walk up to 12 miles per shift searching for items stored on conventional shelving. That's essentially completing a half-marathon every day just to do their job! All that time spent walking between aisles and climbing ladders to reach high shelves? That's time not spent picking.
Vertical Lift Module (VLM) Safety Features
Adopting a VLM system in your warehouse operations can significantly reduce risk to your workers and keep operations running smoothly. But not all VLMs are created equal. Let's look at the nine safety features offered in the Vertical Lift Module Kardex Shuttle as an example of the key safety features you should look for in a VLM.
1. Personal Protection Light Curtain
Integrated light curtains are designed to detect any movement or obstruction in the access opening. If triggered, the system immediately stops tray movement to prevent injuries. This feature is especially valuable to companies that have high staff turnover or are often training new operators how to use proper procedures.
2. Automatic Shutter Doors
Moving parts within any device or machinery has the potential for injury. When the storage tray inside the VLM is moving, the shutter doors located at the back of the access opening remain closed. They will only open when the tray is securely positioned. This prevents unauthorized access and eliminates the risk of injury by preventing someone from accidentally reaching into a moving system. By making our VLMs a closed system, the Kardex Shuttle also prevent gusts of air—and potential dirt and dust—from blowing out onto the picker each time the trays change position.
3. Ergonomic Tray Delivery
Not every worker is the same height, so having a VLM system that accounts for that is key to preventing back strain or other injuries. The Kardex Shuttle Vertical Lift Module can be programmed to deliver trays at different heights based on individual operator preferences. Adjustable access points deliver items at an optimal height, reducing repetitive strain injuries from bending or reaching overhead.
4. Enclosed System Design
Within a VLM, all stored items remain fully enclosed within the unit, keeping items clean and protected from outside contaminants, while also minimizing the risk of falling objects and unauthorized access to inventory. No more worrying about items tumbling from high shelves or unauthorized personnel accessing sensitive materials.
5. Controlled Tray Extraction
Controlled tray extraction gives operators better control over how items are removed from the VLM, including the ability to control delivery speed or set trays to manual extraction mode based on your operational needs.
6. Speed control
Customized speed control provides crucial flexibility for protecting both workers and inventory. On the Kardex Shuttle VLM, this can be set for each tray, meaning you can have trays with standard items deliver at 100% speed for maximum throughput, while trays carrying sensitive goods like liquids, fragile electronics, or precision instruments can be set to 10% speed for exceptionally careful delivery.
This tray-by-tray customization prevents worker injury, damage to goods, and the spilling of your materials without slowing down your entire operation.
7. Manual extraction
When enabled, workers can manually pull the tray out onto a cart and freely move it outside the unit to another area, giving you added flexibility when working with oversized items that require additional handling space, or when operators prefer hands-on control of the retrieval process.
With the ability to set each tray set to a custom, controlled extraction method, warehouses maintain full control over exactly how items are removed, ensuring safety and efficiency for every type of inventory you handle.
8. Load Monitoring and Overload Protection
Overloading a VLM tray puts the system and its users at risk. Safe Vertical Lift Modules should have integrated sensors to monitor tray weight and system balance. When the sensors are triggered, the system won’t operate, preventing worker misuse or overloading that could lead to equipment damage or injury.
7. Emergency Stop and Lockout Features
Whatever kind of automated system you use, workers should be able to stop it quickly in case of an emergency. The Kardex Shuttle VLM has easily accessible emergency stop buttons to halt operation immediately. In addition, lockout capabilities ensure only authorized personnel can perform maintenance or inspections.
8. Fire Protection
Safety features are there to mitigate damage and injury under the worst scenarios. Kardex has partnered with Fike to provide advanced fire safety solutions specifically designed for VLM environments. Fike’s custom solution protects your inventory, and your people, by using a combination of an inert gas fire suppression system and VESDA aspirating smoke detectors.
Fike also has a dedicated technical support team available 24/7 for emergency situations.
9. Controlled Storage for Dangerous or High-Value Goods
Safety compliance and industry regulations require a high standard of security and care of dangerous or controlled substances. In some cases, high-value materials or products need added security as well. For hazardous materials, pharmaceuticals, or high-value items, the VLM provides secure, enclosed storage that reduces operator contact, keeping workers safe and your company secure.
VLM Safety Tips for Warehouse Managers
While VLM technology dramatically improves warehouse safety through design, true safety begins at the management level. Even the most advanced safety features require proper implementation and ongoing best practices to deliver their full benefits.
Here are some essential Vertical Lift Module safety tips that ensure your investment delivers maximum safety returns:
1. Conduct Regular Safety Training
Don't assume that workers who have used VLMs before are experienced with all Vertical Lift Modules. Each VLM may have unique features, depending on what materials they hold and where they are located. Ensure all operators understand how to use the VLM correctly, including emergency procedures, proper loading techniques, and tray access protocols. Then implement regular safety training to keep these procedures front of mind.
2. Maintain a Clean Access Area
Cluttered access zones can block safety sensors or create tripping hazards that defeat the system's safety benefits. Keep the area in front of the VLM clear of debris, pallets, or obstructions. Workers that fail to do so put other workers at risk.
Check out these 18 tips for practical warehouse optimization ideas.
3. Follow Load Guidelines
Maximizing space is always a priority, but overloading or uneven weight distribution can create safety hazards and system malfunctions. Always observe tray weight limits and distribute loads evenly.
4. Schedule Routine System Inspections
Scheduled maintenance keeps your system running safely and smoothly. Kardex's Life Cycle Service helps ensure your logistics and warehousing solutions operate successfully throughout their entire life cycle. Regular maintenance keeps your investment running smoothly, while our rapid support network ensures technical issues are resolved quickly before they become safety concerns. Service is what sets Kardex apart.
Did you know you can also install your VLM outside?
Real World Safety Gains With the Kardex Shuttle VLM
Christie, a leading projection system manufacturer in Kitchener, Ontario, faced mounting pressure to double their inventory capacity while maintaining 24-hour custom delivery times. By adopting the Kardex Shuttle Vertical Lift Module, Christie made its processes safer and more efficient every step of the way.
Challenge: Heavy materials = worker risk
In Christie’s manufacturing facility, workers had to manually handle 52-pound projectors stored on 200 floor carts, creating the potential for injury. Then there was the slow process of locating materials. Workers spent 15-20 minutes searching through identical-looking units to find the correct serial number, requiring four staff members for picking operations.
Solution: A VLM that could handle Christie’s needs
Christie installed two Kardex Shuttle VLMs, each equipped with automatic tray extraction and integrated crane handling. Workers now use ergonomic hoists to handle the heavy projectors, with no pushing, pulling, or lifting required. The automated system delivers the exact projector needed in under a minute.
Results: Immediate and measurable safety improvements
- Eliminated injury risk: No more manual lifting of 52-pound projectors.
- Improved ergonomics: Automatic tray extraction and crane handling removed all dangerous manual handling.
- Increased efficiency: Reduced picking time by 90% while cutting labor requirements in half.
- Space optimization: 70% floor space savings allowed Christie to expand from 6 to 9 assembly stations.
Christie now delivers custom-configured projectors within 24 hours while protecting their workers from the musculoskeletal risks that plague traditional manual storage operations.
"The Kardex Shuttles fit nicely into the lean flow in our facility,” said Philip Hibberd, Sr. Manufacturing Engineer. “From subassembly to testing to storage to configuration—we strive for a lean process, cutting wasted time and effort."
VLMs Deliver Enhanced Safety and a Competitive Advantage
VLM technology isn't just about efficiency. It's also about protecting your most valuable asset, your people.
The Kardex Shuttle VLM eliminates the primary causes of warehouse injuries: climbing, reaching overhead, lifting heavy items, and repetitive bending. By bringing goods to your workers at the optimal height, you create a safer work environment while simultaneously improving productivity and accuracy.
Ready to see how VLMs can transform your warehouse safety profile?
Let us come by your facility for a free site visit. During your on-site consultation with a Kardex Remstar warehouse automation expert, we’ll walk your floor, review your workflows, and take precise measurements of your space and inventory. After, you’ll have a clear picture of how automated storage solutions can fit into your operation and the ROI you can expect.
Contact us today to schedule your free site visit and safety assessment.
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