There are ongoing changes in the handling, storage, and distribution of materials that could dramatically affect the design of walls and access points of a warehouse. Examples include the use of the just-in-time approach for handling materials, and the use of large lorries.
The influence of just-in-time
As discussed in other articles, just-in-time is an approach to product generation and distribution that seeks to adapt and adjust as far as possible to actual market demand at any time. In doing so, it aims to manufacture or store exactly the quantity of items demanded by the consumer, no more and no less. This leads to greater competitiveness, commercial capacity, and profitability.
Just-in-time (JIT) is increasingly used in large production plants. The most immediate consequence of this is that manufacturers require a constant supply of materials from warehouses or external production plants. This, in turn, leads to the need for these supply points to use JIT policies as well, and to supply components and raw materials at the rate demanded by assembly lines or supply the market with the products it demands.
To be able to offer this service, distribution centres must be very well-run warehouses capable of receiving and dispatching huge quantities of goods in very short periods of time. Therefore, it is important for these warehouses to have large access areas, equipped to provide the necessary speed and accuracy, as well as high-capacity entrances and exits in which automated loading and unloading systems can be used.
The second most important factor in the design and development of the access points in a warehouse is the increasingly common use of large lorries. The use of these vehicles is increasing as a result of the need to reduce transport costs, since the return on each trip is greater.
The size and weight of transport vehicles is determined by regulations in force in each country, which generally establish a total maximum length for road trains (18 m), articulated lorries (16.5 m), and semi-trailers (13.6 m). The maximum weight per axle cannot exceed 14 tonnes (single axle) or 18 tonnes (tandem axle), with a total maximum weight per vehicle of 40 tonnes.
However, many European Union countries have road trains longer than 18 m and the disappearance of borders within the EU and increasingly common use of intermodal traffic, which combines railways with roads, mean that this trend is gradually spreading to other countries, including Spain.
It is increasingly common to see 48- and even 53-ft long containers (14.6 m and 16.15 m, respectively) in ports around Europe. For transport inland, these require the use of longer semitrailers than those allowed under the directives. Furthermore, it is increasingly common for “swap bodies” to be delivered using intermodal transport. These have a minimum weight of 37 tonnes and often reach 45 tonnes. Thus, their land transport also exceeds the limitations stipulated in the directives, which set a limit of 40 tonnes per vehicle.
Long vehicles create serious problems when designing maneuvering areas for vehicles. Therefore, this issue must be addressed in advance and provision made for sufficiently large areas for this purpose.
It is not merely the length of the vehicle that is limited: their height is also limited to a maximum of 4 metres. The manufacturers of these vehicles have designed models known as “high cube”, which have larger trailers. To offer this greater capacity without exceeding the maximum height, the floor has been lowered.
In terms of the design of the warehouse, this lower floor must be taken into account because it means that there will be lorries with different floor heights that must be unloaded and loaded in the docks.