Management Matters
Page 50
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any mixed loads—at the rear end of a container requires special care to avoid possible injuries to unloading staff at destination point. Insecure loads could easily fall on the person or persons opening the rear doors. Hence ICI's strong suggestion for the use of ropes round the last four pallet loads where lashing rings makes this possible.
The study group urged container manufacturers, through the BSI/ISO organizations, to mark container floor loading capacities clearly in both lb/sq.in. and kg/ cm2. This is an obviously sensible point that scarcely needs to be laboured. Container floors should be capable of withstanding a fork-truck wheel load of at least 60001b per wheel applied to a contact area of 22sq.in. maximum (with wheel widths of 7in. minimum and 30in. wheel centres). The use of manual or powered pallet trucks which are likely to have wheels as small as 3in. diameter and 3M. wide is not recommended for use with a load of up to 2 tons as it is highly likely that excess floor loadings would be imposed.
Another piece of highly Practical advice concerns the bridging plate area when loading a container from a loading dock. The part of the bridging plate entering the container should be 87/88in. wide and length should be such as to provide near horizontal access to the container. This is necessary to facilitate the withdrawal of forks from the last loads.
The study group noted that some containers could be as much as 36in. along the vehicle platform. (I would think that in many instances this distance could be a lot greater.) Hence the importance of an adequately strong bridging device capable of withstanding with an adequate safety margin a 3,0001b capacity fork-truck and its 1-ton load.
Tricky problem
All containerization theorists would hope that the era of internationally agreed standard sized pallets will not be too long in coming; obviously, pallet area should precisely fit the internal dimensions of containers. But, as already stressed, the marked variations in the internal measurements of containers makes this a tricky problem involving coin , promise. It is hardly surprising, therefore, that the ICI team should write: "It may be necessary to modify the existing sizes of both pallets and packages in order to obtain unit loads which will fit economically inside the container."
Containers with built-in pallet-handlink systems—such as Jolada or Rolamat—may be justified on door-to-door movements where the container is immediately returnable. The study group remind users that when pallets are stacked two high this must be done before the pallets enter the container. And proper alignment is essential or there may be insufficient room to stow a second pallet across the container width.
Stress was laid above on the need for container floors of adequate load-bearing strength. The same point arises when containers are lifted from ground to vehicle or vice versa. A hard, level, drained surface able to withstand vehicle wheel loadings when a 20 ton loaded container is involved is essential. Some form of weather protection, too, may be justified if there is any risk of product damage through damp.
Of course, there are many ways of loading goods into containers. Some cargoes may have to be hand-loaded—an expensive method, though one that does enable the fullest use of container volume. The ICI team used mobile conveyors for some goods but after testing a number of models utilizing belts, slats and rollers concluded that what was needed was a conveyor capable of reversing, advancing, retracting, elevating and slewing. "The ideal design would effect complete stowage without the need for manual positioning of the packages. It is open to considerable speculation however whether this degree of sophistication will ever be achieved at an acceptable cost."
Naturally, the study group were well aware of the existence of open top and flat deck and side-door containers—all much more easily loaded than the standard ISO end-door designs which have many virtues strengthwise and cost-wise but are not the easiest things to load economically. The loading of 40ft end-door containers may well contribute to a new form of claustrophobic disease, I fear. But adequate interior lighting and ventilation, whatever the length of the container, is necessary.
Any firm contemplating the use of containers for full load movements would be well advised to plan a loading sequence for its packages to maximize capacity loading —unless products are so heavy that maximum volume cannot be utilized; in that event, it may be possible to use half-height containers.
ICI worked out the detailed loading sequences for typical cargoes using sideshifting fork-trucks or specially fitted forktrucks with barrel clamps, and specimen loading plans are illustrated in the report. It found a number of alternative stacking methods. For example, 72 X 45 gallon drums could be got into a 20ft container when the drums were loaded on ends but when the second layer of drums was stacked horizontally only 57 drums could be loaded. When this method is used, for any reason, adequate precautions are necessary to secure the load. And it is neither safe nor reasonable to expect loaders to work with restricted head room of little more than 4ft.
Although many road haulage veterans boast of their ability to lift loads of 2cwt or even more it is interesting to note that ICI's experience suggests that there are practical difficulties in manhandling from powered conveyors sacks weighing more than 1 cwt or drums of greater weight than 60/701b. But the report concedes " . . . since the size and shape of packages will vary this is a purely arbitrary recommendation."
Not the least of the virtues of this admirably detailed report is the evaluation and cost details supplied of the many items of container-loading equipment illustrated. It is an essential report to be studied closely by all professional transport managers. If a few other major users of containers would codify and publish their experience in the thorough manner undertaken by ICI, British Industry would benefit greatly. Indeed, I suspect that road transport productivity would increase by at least one per cent if this were done.