Cool Runnings: Automated handling system makes cold-storage debut

In the high-cost world of cold storage, maximizing cube use is vital. That's why when Liberty Freezers decided to revamp the racking in its London, Ontario warehouse, they looked to a high-density mechanized solution. Richard Rix bundles up to find out how they did it. With files from Deborah Aarts.

It is one thing to see a prototype pallet-handling and retrieval system being put through its paces at the developer's facility. It is quite something else to see it at work in a real-life warehousing environment. When that environment is a freezer - and the loads are heavy food products stacked on their original shipping pallets - it becomes something very "cool".

The facility - which has long served the food industry - services all points nationally as well as the eastern US. Today, it ships into distributor facilities and distribution centres, which are essentially hubs for such companies as Loblaws, Sobeys, Metro Foods and Wal-Mart. It handles an average of 175 to 250 tractor-trailer loads a week, and activity is brisk around the 26 temperature-controlled dock doors. But until a few years ago, it was hampered by less-than-ideal operating conditions.

The facility faced three main problems. The first was space. In the freezer environment - where the power and temperature control costs push cube price to a premium - every cubic inch counts. "There's a very high price to space in a freezer, so our ability to maximize the cubic footage of our freezer is critical," says Liberty president John Diduck.

The second problem was finding a way to maintain a first-in / first-out storage system that could handle the high volume of Liberty's business. The third issue was to manage the amount of labour being used for put-away and retrieval.

To solve these problems, in 2003 the company decided to give the London site a makeover. Oakville, Ontario-based Redirack Storage Systems was recruited for the job. Soon after, the facility was fitted with coolers and the existing frozen section was expanded. The renovation also included the installation of a completely new storage system. One of Redirack's senior systems design teams, headed up by David Weatherseed, applied its technical expertise in working with Liberty Freezers to solve the company's logistical challenges and meet a tight operational deadline. And at the core of the solution was the Pallet Runner.

Brisk Business

Starting at Liberty Freezers in 2002, Diduck says he aimed to fill a niche that matched his expertise, adding that he has been "servicing it like mad" ever since. The fact that he is able to inspire, innovate and delegate has allowed the enterprise to expand quickly. There are now three other Liberty facilities: two in southern Ontario (in Newmarket and Chatham) and a brand-new one in Montreal.

Diduck attributes this success to what he calls "considerable growth" in the frozen food industry over the past ten years. Supermarkets are now filled with a greater variety of home-meal replacement and microwaveable foods, thanks to more advanced freezing techniques. Safety concerns have resulted in a higher level of confidence in frozen foods vis-à-vis fresh foods. Finally, the advent of chain restaurants has led to a standardization of products and quality control standards. "The Tim Hortons doughnut you eat in Burlington (Ontario) tastes exactly the same as the one in Vancouver. Ingredients are prepared, pre-packaged and frozen," Diduck says.

Liberty operates what Diduck calls a "boutique" third-party temperature-controlled logistics service that offers personalized service for clients. Though it flies in the face of extra earnings through growth, Diduck has decided to restrict the size of his company's facilities and client base so that no one gets neglected.

"Controlled growth is incredibly important for this business, and we will control it to ensure our clients' success," Diduck says. "If the client base grows too large and diverse, you can run into scheduling problems. In the food business, the spikes all seem to come at the same time, placing a heavy demand on logistics. So who's the priority? Who gets serviced first? By limiting the size of the operation, your priorities are very clear and very manageable. It also means grouping like clients in the same building, and not over burdening it with too many of them."

A System Built for Growth

Self-imposed limitations can be tricky. If a client's business soars, how can a warehouse keep up? The answer is to design and lay out a facility with the right mix of equipment to assure flexibility.

"We need to be very flexible in the way we operate and do everything we can to assist the customer," Diduck says. "This is as much their facility as ours, which makes a lot of sense, since we don't actually own our product. For example, we do not insist on scheduling inbound loads from the manufacturing plants, such as vegetable processors, plus we offer dedicated doors for unloading."

The facility staffs 50 employees on the warehouse floor (65 in total), operating two 12-hour shifts a day seven days a week. It is run using a highly sophisticated WMS (warehouse management system) that Liberty built itself - with a Microsoft Access reporting platform - to meet its own demands and its customers' needs.

"We developed it in-house and have pushed it well beyond the scope of many packaged systems," Diduck says. "We began with the largest platform we could find and developed on it. We built wide on a wide base, which is a different philosophy than with most systems, which seem to expand outward from a narrow base. We hired a small group of programmers and taught them our business and key metrics, such as receiving, functionality, put-away, recall, lot control, LIFO (last-in / first-out), expired date control and more."

These programmers consolidated everything into one flexible program that can generate results in Access. Special modules programmed into the system allow the company to turn around any customized work (such as tempering, which is the safe warming of frozen food into refrigerator items) in 24 hours, without having to call on specialist programmers.

Finding a Framework

For its redesign, Liberty also needed good equipment. In selecting this, Diduck drew heavily on his own experience and Redirack's expertise. The racking vendor provided the site's entire storage system, building a layout designed to maximize cube while preventing bottlenecks. Its racking includes pallet flow and push back to complement the Pallet Runner module. "I travelled extensively for two years looking at different types of systems and equipment operating in both temperature-controlled and ambient environments," Diduck explains. "I knew we needed some degree of automation for reasons of productivity and labour management, but I was also aware that we needed flexibility."

The physical space of the building factored into the decision. Receiving is on one side, order staging and shipping on the other. The sides are linked by a 15-strong lift truck fleet, with double-reach trucks from Crown and counterbalanced lift trucks from Linde, all electrically powered. There is also a selection of pallet trucks, including four "long johns", which are built to handle double loads and extra-long beer pallets.

Outbound loads are on a shipping schedule, on a carrier-by-carrier basis, all based on client instructions. "We perform a high percentage of case picks at the facility," Diduck says. "It will easily handle 65 percent order assembly because of the way that it has been set up and designed and the kind of equipment that it uses."

Much of the product handled at the warehouse requires special handling. For example, in the beer section - a big part of the cooler zone - many hefty shipments of the Labatt brand must be shipped out to the US, often on a tight deadline. This demands careful planning on Liberty's part. "It is 80 percent case-pick and is highly seasonal, and it is an area where we have opted for a basic setup, with bulk storage and some standard racking for items with sensitive packaging," Diduck explains.

"The US deals with SKUs (stock keeping units) that are up to four times larger than ours. As well, there can't be more than 45 days from manufacturer to distributor, so with transit times, we have to turn every three weeks. It's a very heavy product, with up to 3,400 pounds (1,550 kg) on some loads, which is hard on equipment and dock-plates."

To help the building smoothly accommodate conditions like this, Diduck had a choice of automation options: low-level (lift trucks, single selective racking and bulk storage), medium (a high-density system that integrates some level of automation with more basic equipment) or high (full blown automated storage / retrieval systems, black-box automated sortation and mechanized order-picking). In the end, the moderate option won out.

"We are ‘medium,' which gives the highest level of productivity with flexibility," he says. "We can react more quickly. Fully automated may be faster where consistency in volumes and pick rates is assured, but it has its limitations in peaks and valleys. At our facilities, if we are slammed with 50 rush orders, we can respond with rezoning, cross-docking and other measures."

As the Thermometer Drops ...

The frozen section is where this level of automation really gels with innovation. In this heavyweight area, loads are supported by hot-rolled structural steel Konstant racking from Redirack, which has lever-action bolt connections that help it to hold up to 22,700 kg (50,000 pounds) per level. "I am a big fan of structural [steel]," Diduck says. "It is much sturdier and thicker than conventional roll-formed."

"We handle loads upward of 3,000 pounds (1,360 kg) in the freezer so we need the extra strength, plus structural withstands virtually any contact by lift trucks. We worked with Redirack to ensure that our version has specially strengthened end-frames and half-inch (12 mm) plates for end-of-aisle protection."

The freezer space also has some pallet flow racking. This section inclines at floor level toward the order-pickers in the picking aisle. Once a pallet has been picked clean and removed, the pallet behind automatically ‘flows' forward to take its place. This eliminates empty pick faces because any vacant slot in the row is immediately visible at the rear and can be replenished from the push back racking above.

The push back racking is located on three levels above the pallet flow racking and, like pallet flow racking, is four pallet loads deep. It provides the reserve storage locations for the pallet flow. It slopes away from the picking aisle and is serviced from the rear, allowing reach trucks to be segregated from the order-pickers. "By having opposite flows in the push back and the pallet flow racking, we are able to avoid conflict between pallet put-away on one side of the racking and case picking on the other side, with virtually no loss of productive space," Diduck says.

A Real Freezer Pleaser

The star of the freezer show, however, is the Pallet Runner, which handles the main storage block. This automated system is configured for pallet flow through, to achieve FIFO for functionality. Loads are stored and retrieved for full pallet order assembly or to replenish the pick lanes.

The system hinges on automated carts that move through warehouse racking using RF technology. After a pallet load is scanned with handheld readers and deposited at the pick face, the cart will move it as far back as warranted. Redirack's Weatherseed explains the put-away process. "The pallets are stored on a rail in their position, but instead of using an L-shaped rail, we use a Z-shaped rail. The pallets sit on the top part of the Z and the cart runs on the bottom part. The wheels on the cart drive with their own PC, and the cart moves up and down hydraulically."

The Liberty set up uses two carts to guarantee that there is always one available when needed. Each cart weighs 210 kg (462 pounds), plus a 24-volt battery. Four 150 by 40 mm (5.6 by 1.6 in) wheels ensure smooth travel along the channels built into each storage lane. "We can switch back and forth with Pallet Runner, with picking and put-away on the same side or use it as a flow through system," Diduck says. "The carts operate fully independently in the storage lanes because they sense the proximity of other loads, so know when to pick up or deposit a load, and return to the module face. While they go about their business, the reach truck operator is free to drive off with a load or go pick up a new load."

While the Pallet Runner had been used in warehouses before, the Liberty application was the first in a freezer environment. Adapting the system to function in the cold required some extra effort. The installation had to be done in the frigid onsite climate; the handheld devices and related accessories had to be treated to suit the temperatures and the Pallet Runner itself had to be conditioned to perform optimally.

He did have some initial questions about its ability to perform under chilly circumstances, and he acknowledges that there was a steep learning curve, but Diduck was very pleased once the system was up and running. "The only real concern I had related to batteries in a cold environment, and it's simply not an issue. The system will easily perform for a full shift, even in a freezer. In any case, Pallet Runner will never hang up because the cart will always return to the face of the module when it detects a low energy level, for the removal and recharge."

Furthermore, Diduck says the system has fixed the problems Liberty faced before the renovation. The system operates on a principle comparable to pallet flow, but with no incline and no chance of lighter pallets getting stuck on the tracks. This allows the company to make better use of the valuable freezer cube while keeping smooth FIFO operations. And, since the Pallet Runner is powered automatically through RF, the company is able to operate a multi-deep environment without adding workers.

Diduck estimates that the system has saved him from having to add 20,000 to 25,000 sqf to the London facility, plus at least three new pieces of equipment. He will likely use the design and layout of the building for a future warehouse.

Diduck feels that construction of another Ontario facility will happen soon. He also believes there are opportunities for growth in western Canada, perhaps even the US. "The Pallet Runner certainly has application outside of London for us."

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