Of all types of warehouses the cold store is the most costly to build, run and most affected by standards and legislation. Energy is the main running cost bugbear, typically accounting for 25% of total costs, so it makes sense to pay careful attention to the building design and the internal static and dynamic handling equipment, such as the various racking designs and forklifts, not forgetting the crucial issue of appropriate doors, which if poorly chosen can have serious energy loss and safety consequences.
Starting at ground level, floors are important for two reasons. They should be designed to minimise any temperature transfer between the building to the subsoil, otherwise it could undermine the warehouse structure and the store’s efficiency. Secondly, speciality floor coating systems are needed so that they can be installed at low temperatures in damp conditions, with a low odour to avoid food contamination. The floor surfaces should also have added hygiene protection and a high grade texture to prevent slips when surfaces are wet.
At the top level, well-chosen lighting can yield remarkable savings. Consider LED lights because these do not generate heat so less cooling is needed, and they also last the longest and give the least maintenance problems.
When connected to motionactivated lighting that ensures lights come on automatically only when required there is the potential to cut energy demand by more than 50%.
In between floor level and ceiling the potential for mistakes demands much more thought.
Over the years racking manufacturers have developed various high density forms of storage, like mobile, drive-in, pushback and satellite systems to minimise the overall building construction and running costs, but each racking design has its own limitations and there will usually be a trade-off between the need to conserve space without compromising productivity flows.
Safety is a big issue with racking designs and so the HSE recommends thorough annual racking checks and that any repairs should not be done by normal oxyacetylene or arc welding techniques. Welds could become eutectic and liable to collapse without warning. In mobile racking the welding steel becomes more of a problem because there are dynamic as well as static forces so it would be wiser to stick to bolted or boltless racking rather than welded.
If the dynamics of the cold store handling show that adjustable pallet racking (APR) is the best choice then that has consequences for the choice of forklifts. The common truck of choice for internal cold store work is the reach truck but a more spaceefficient truck would be the articulated forklift, fitted with heated cabs, like the Bendi, Flexi and Aisle Master because they can work in aisles only 1.8 mt wide compared with 2.6 mt needed by reach trucks. If there are many aisles then articulated trucks would save much space and therefore costly building and running costs.
Cold store temperatures pose special problems for forklifts, like the impact on battery capacity, which can fall by about 1% per degree below 20 deg C. The main problem, however, occurs if the trucks frequently move in and out of the cold store because metal contracts when frozen and expands when warmed up, causing problems when the moisture refreezes. If there is a build up of thick ice on the truck that could cause component damage so the advice is to keep the truck, including battery changing, within the cold store as long as possible, something that can be facilitated by using a conveyor within an airlock tunnel, with two fast-acting doors, so that pallet loads can be moved from cold to cool or ambient part of the store.
But what of the driver? It seems that many operations rely on very warmly clad drivers to keep out the cold but if they work without a heated cab then it makes it difficult to operate the truck and remain sensitive to driving and lifting feedback. So why not treat them to lovely warm cabs, which might also cut illness absenteeism?
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