Lift Truck Tips: Avoiding a tight spot in narrow aisles

When it comes to storage density and cube utilization, more is good. When you look at the people to access and manage the space, the fewer the better. Narrow aisle and very narrow aisle (VNA) configurations can meet a sweet spot between the two, but such a transition is not as simple as compressing space and equipment. According to Perry Ardito, general manager of warehouse products for Mitsubishi Caterpillar Forklift America, a series of trade-offs must be carefully measured to ensure the success of a narrow or VNA storage system.

“It’s important to look at inventory, order profiles and movement and use it all to inform decisions for lift trucks, storage media, automation and whatever best suits short- and long-term goals,” Ardito says, emphasizing that the ideal narrow aisle facility is likely to include a broad mix of narrow configurations, conventional ones and more. “Data can help an operation quantify and understand the inventory to be stored, the critical dimensions, the number of pallets and the movement of product, but one size never fits all.”

SKU and labor pressures compel facilities toward the types of precision and efficiency that are baked into narrow aisle systems and the lift trucks within them. However, that specificity is also one of the biggest potential pitfalls. Narrow and VNA equipment is very specific to the size of the aisle, whether a turret truck in a 5- to 6-foot-wide VNA aisle or reach trucks in a 9- to 9.5-foot aisle.

“So if the lift truck is down for planned maintenance, there really aren’t other pieces of equipment that can work in that aisle,” Ardito says. “There is less flexibility there, not to mention the cost of a turret truck can be two or two and a half times the cost of a traditional reach truck.”

The key trade-off is the increased productivity of a turret truck, which Ardito says could be double that of a reach truck, can result in overall fewer trucks and operators. And, since the operator is only required to move forward, backward and vertically, they don’t have to turn into a location, reducing opportunities for damage to product or racking.

On the other hand, because turrets are often dedicated to putaways and picks in a specific aisle, they will not necessarily have the versatility to perform tasks elsewhere. However, Ardito has already seen creative combinations of technology that emphasize the strengths of each component. Whether segmented by SKU or by movement, there might be a mix of high-density storage, selective storage, automation or less-than-full-case picking, he says.

“I have seen turrets working in VNA alongside a multi-level pick module, incorporating multiple technologies in the same building,” Ardito says. “What’s very likely is a stronger push toward semi-automation and full automation driven by cost awareness, specifically the cost of labor.

Shuttles offer high density, so in lieu of traditional forklifts to feed high-density systems, you might incorporate automated storage and retrieval systems, and/or automated pallet movers. Everything is on the table, and more customers are open to technology and multiple ways of managing an operation.”