This article examines the potential of bulk containerisation and analyses some techniques for addressing standard ISO freight containers. Standard means just that: containers that will accept any cargos that can safely stow within the specified dimensions. No top openings or similar deviations are acceptable: these complicate operational security and directly convert OPEX into CAPEX.

It is surprising that containerisation of bulk cargos has not yet significantly replaced old fashioned large scale bulk handling techniques. Freight containers are plentiful and very often anxious for backloads. A container has to move some time and at some cost. Container shipments are regular, frequent, secure and convenient. Consider that:

regularity of shipments means that consignment size can be very closely matched to supply and demand. At present most bulk cargos are delivered in enormous quantities and must be stored before dispatch and after delivery;

frequency of container consignments can reduce storage requirements in terms of size and also eliminates building cost;

security of containerised bulk offers a 2 pronged attack on convention. Spontaneous combustion is a largely unknown and unexplored subject. Containerisation confines cargo into manageable partitions. Blending of different products can be controlled more easily and accurately by identification of particular container numbers and bar-codes;

convenience of containers is exemplified by their handling standardisation. Dockside cranes, straddle carriers and skeletal trailers are already well defined. Contrast this situation with the variety, cost and complexity of alternative large scale bulk handing equipment which is infamous for dust and unreliability.

If a filling machine for loading 6m containers can extend 7m beyond the doorway then it can completely and legally fill 12m containers as well. This applies to most materials and even when some materials promise to extend beyond the doorway of a 12m box the containment membrane, dunnage, is very manageable. Unloading bulk from containers presents many options. For non-hazardous cargo in 12m boxes skid steer shovels, Bobcats, and loading ramps can suffice. A 6m box with dunnage across the doorway presents more challenge. This foregoing suggests a preference for the carriage of bulk in 12m containers. Remember that although the 12m box takes up twice the shipping space that box would have to be moved anyway; so the sooner the better.

Where the containers are dismounted from trailers then tipping the contents out represents the most viable option to date. With multiple tipping frames the discharge can be fully continuous. Using 12m containers with little or no dunnage enables cargo to be removed through the full width of the doorway. Clean up is improved to the point where liners are not necessary because the very slight residue can be handled safely in a raw box with proprietary equipment. There is no argument with cleaning tankers. If a product really needs to be loaded into a lined freight container it surely needs to be unloaded into an equally sterile plant. Cheaper alternatives to liners are readily available.

Containers are economic and flexible and deserve consideration for broader acceptance within the bulk handling community and very competent and specialised advice is available. ■