VNA systems deliver many benefits, but warehouse designers risk compromising safety and productivity if they place too much emphasis on simply achieving the narrowest aisleways, says John Maguire, managing director of Narrow Aisle Ltd .
Narrow margins deliver big returns
With the fallout from the pandemic and Brexit continuing to impact on manufacturing and retail supply chains, UK warehouse space remains in short supply. In fact, the problem has become so acute in some places that one leading industrial property consultancy has forecast that parts of Britain could completely run out of empty storage facilities within the next 12 months.
So, warehouse managers and intralogistics professionals are under huge cost pressure to utilise every square foot of space available to them in the most effective way. At many sites this means reconfiguring the layout of the existing storage system around the narrowest aisleways.
With typical VNA – very narrow aisle – applications aisle widths can be reduced to between 1600 and 1800mm, which allow e-fulfilment customer orders to be picked at ground level shelves and locations. Compared to traditional ‘wide aisles’ zone picking, which usually need around 3000mm to allow two ‘low level order pickers’ to pass one another, the space saving potential of VNA systems to e-commerce companies is immediately obvious.
And, of course, better space utilisation means increased storage capacity – which, in turn, equals reduced storage costs per square foot. In some cases, it might also mean that additional storage space (if, indeed, any can be found) is not required or a costly extension to the existing warehouse (if you have room and can obtain planning permission) is avoided.
But before you begin ripping out your racking and narrowing your aisleways, be aware that VNA solutions in e-commerce applications have different requirements to traditional wide aisle zone picking systems and there a number of important factors to consider before concluding that VNA is the way ahead for your business.
For example, because older ‘guided’ VNA stacking aisles are only slightly wider than the materials handling equipment that serves them, a guidance system – wire or rail – will usually be required to ensure that lift trucks do not collide with the racking. These can be costly to install.
Another consideration is training of your forklift operators. Operating guided VNA machinery requires additional training to conventional reach or counterbalanced trucks and, at a time when qualified forklift operators are hard to find, if your lift truck drivers struggle with the demands of guided VNA materials handling equipment technology, it could be a problem.
With the type of specialist materials handling equipment often specified to operate within very narrow aisles – such as man-up Combi trucks and man-down VNA trucks – it is essential to assess the different technologies and their suitability to your operation’s unique needs before investing.
For example, because man-up Combi VNA trucks are physically big pieces of kit, storage schemes have to incorporate large transfer gangways at both ends of each aisle to allow these long trucks to switch aisles. This often means that the space savings achieved by reducing the aisle widths can be lost.
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Media contact
Rebecca Morpeth Spayne,
Editor, International Trade Magazine
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