Narrowing down the options for an aisle configuration can be a harrowing experience. Is maximum space more important than maximum speed of operation? Malory Davies reports…
Making the most of the space in a warehouse is good business for any company – and critical for some. So it is not surprising that there is increasing interest in narrow aisle and balancing the demand for more efficient use of space with speed and flexibility of operation.
Frank Hasleden, logistics solutions manager at Toyota, says: “We are certainly looking at increased demands from companies for better utilisation of available warehouse space using VNA and higher density storage solutions, like the BT Radioshuttle aisle-free storage system.
“This is coupled with more requirements for simulation and throughput calculation to quantify efficiency benefits within a given material handling equipment process. In terms of flexibility and innovation, it’s fair to say that we have to be as innovative as possible with both the product technology and the service and finance packages that support it.”
Steve Richmond, director of Jungheinrich’s systems & projects division, points out that VNA technology is being adopted at many more UK warehouses and distribution centres. “Significant advantages can be gained by moving from a wide aisle to a narrow aisle storage configuration and, by making better use of an existing facility by increasing storage capacity, many organisations have realised very worthwhile financial benefits,” he says.
John Maguire, sales director at Flexi Narrow Aisle, agrees: “The lack of speculative industrial property development in recent years has resulted in an acute shortage of good quality, affordable warehouse and distribution space. So companies are looking for ways of maximising the performance efficiency of their existing property assets and increasing storage density and pallet capacity is one way of making the most of a facility and this has led many businesses to consider VNA storage systems.”
Jana Vitkova, Linde’s warehouse product manager, points out: “With the return on investment vital for warehouse operations, customers need to feel confident in the equipment that they use – which is why we have invested in our VNA offering.”
But there can be a trade-off between maximising storage space and speed of operation. At fast-moving operations where speed of pallet put-away and pick is essential, the speed at which a truck can safely operate in the aisle ways is arguably more important than the need to narrow the aisle ways, says John Maguire. “I think that this is sometimes forgotten at the warehouse planning stage. If, by shrinking the aisles, the trucks that operate within them have to travel at less than half of their top speed because clearance each side is too small, it would clearly be counter productive to any benefits the user may have derived by being able to add extra pallet positions by cutting the aisle dimensions.”
Bendi managing director Simon Brown points out that narrowing the aisles to increase storage capacity or freeing up space for more production facilities is extremely attractive, but more and more companies want the flexibility an articulated fork truck can offer.
He highlights advantages such as a reduction in the number of trucks and operators, no expensive guidance system, no super-flat floors, huge reduction in the transfer aisle, no requirement for pick and drop stations (more pallet positions) as the Bendi takes the product direct into the racks.
Richmond argues that there is a compelling commercial argument for considering automated and semi-automated technology at those facilities where manually operated VNA trucks are in use. By using an “automation option” it is straightforward to adapt production line trucks to become fully automated.
“Today we can start with a standard VNA truck with wire guidance and transponder technology and, by introducing additional sensors, automation controls and an interface to the warehouse management system, the truck becomes fully automated.
“This approach makes automation scalable. Trucks can be supplied as manual machines, upgraded to semi-automated vehicles and ultimately to fully automated systems as the client’s requirements change. However, as with any automation project, it is important to ensure that the system is planned and designed by a company experienced in automation and integration as the legislation and working practices for automated VNA trucks differ significantly from manual operations. Design, safety and system integration must be treated as an integrated project – not just a truck supply contract,” says Richmond.
Linde’s Vitkova says that the company has extended the K range (man up dual purpose order picker) modular design to the V range (man up order picker) allowing customers to create their own truck designed specifically for their application. With the VNAP software, everything from aisle widths to battery life can be discussed and amended when building a bespoke truck. VNA trucks have also been designed with the latest RFID systems, allowing mapping of a truck’s operation in the warehouse.
Vitkova points out that Linde offers the STRATOS software and consultancy service that helps customers plan and design a warehouse to ensure their operation achieves maximum efficiency. “Our bespoke damage reduction programme helps reduce costs by up to 50 per cent through process improvements and operator awareness.”
Linde has also been developing the safety features of its trucks, including automatic speed reduction, camera systems, dual-wired electronics, creep speed function, automatic shutdown during traction, steering or lift failure and additional warning devices.
Maguire says: “At Flexi we focus all our energies on making our established articulated forklift ranges more productive and more customer friendly. The Flexi articulated truck concept is now established technology – comparable, for example, with the technology behind a counterbalanced or reach truck.
“By focusing on established and successful design principles and quality we have been able to develop products that offer ever higher throughput efficiencies and safety and the lowest running costs.
“While this mature and measured attitude to product design and quality is paying off for Flexi – as our spiralling sales figures testify – some materials handling equipment manufacturers appear to be taking a different approach,” he says.
Exclusive reader survey: Making the most of the space
Almost 70 per cent of warehouse truck buyers regard maximising the use of space in the warehouse as a key consideration when selecting the aisle configuration, according to Logistics Manager’s exclusive reader survey.
The survey covering 111 truck buyers shows that flexibility is also an important factor (39.5 per cent) while speed of operation is vital for about a third.
While almost two thirds are happy with a standard aisle configuration, more than a quarter have gone for a narrow aisle arrangement – and 11.4 per cent prefer a very narrow aisle configuration.
And that is reflected in the trucks that LM readers are buying. More than 25 per cent are using specialist man-up VNA trucks, and a similar proportion are using narrow aisle reach trucks. Articulated trucks are also popular with more than 20 per cent of buyers.
Top of the list of buyer requirements is reliability – nine out of ten readers surveyed put that at the top of the list. Safety also figures strongly at 64 per cent while total cost of ownership comes third with 49 per cent. Perhaps surprisingly, low purchase price is considered important by a relatively small 19.3 per cent.
The relationship with the dealer /distributor is also an important factor for almost half the buyers in our survey.
Case study: Eddie ready for Aisle-Master
Eddie Stobart is taking delivery of 35 Aisle-Masters for its Contract Logistics and Warehousing Division.
This arm of Stobart’s operations offers over six million square feet of storage. 25 Aisle-Masters have so far been delivered to various sites, with another ten due to be operational over the next 12 months.
As Stobart’s ageing articulated trucks were coming to the end of their operational life the company decided to investigate alternative brands as it was keen to stick to the articulated system which ensures optimum pallet density in narrow aisle configurations.
Stobart operations director Graeme Undy says: “We like to forge amicable relationships with suppliers who are open to suggestions from our side. This helps to drive innovation, is ultimately beneficial for all concerned and accords with Aisle-Master’s ethos of providing customer led solutions.”
Feedback from initial trials led to certain modifications for some or all of the fleet: to the design of the overhead guard and steering column for example. The electric powered 20WHE models with 2,000kg capacity that are now working in around 70 per cent of Stobart’s warehousing network are bespoke units and some suggestions made by the Stobart team will be incorporated in the Aisle-Master design going forward. The trucks are mainly used for inside operation to place and pick pallets that have been deposited in the goods-in bay by other forklifts or power pallet trucks, but their indoor/outdoor capability means that at sites with external pallet banks they can also be used for offloading and yard work. Existing narrow aisle widths vary from 1660mm to 2400mm depending on the location and racking heights are typically from 9m to 11m.
One issue was the provision of continual battery power. The solution was to supply three batteries for each unit.