Q I have been carrying out a study for my company
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on the value which it might obtain from the use of containers and the most effective means of container loading. I believe there has been a variety of papers and notes prepared on this subject and I am particularly interested to know of any applying especially to container loading. Could you give me any leads on this?
AWe agree that a great deal has been written on the subject but we do not know of a comprehensive bibliography to which we can refer to. However, the Chartered Institute of Transport has prepared a number of bibliographies on various transport topics and may have one applying to the use of containers.
A book which provides quite a lot of useful information is Containerisation by G. Van Burg, published privately by Central Containers Ltd, of Wigan. This book contains quite an extensive 'bibliography covering other transport modes as well as containerization.
Another well-known work dealing with the loading of containers was prepared by Mr D. A. B. Crawford of ICI's central distribution department and called Filling and Emptying Containers. Copies of his paper have previously been circulatedat seminar's where Mr Crawford has been a speaker, including CM's 1971 Fleet Management Conference.
More recently Mr Ted Brock, transport manager of the Weldless Steel Tube Co Ltd and a member of the Freight Transport Association's technical committee, prepared some notes on securing loads in containers.
Mr Brock said that a great deal of emphasis was placed on the secure anchorage of containers on road vehicles, yet scant attention was paid to restraining the load within the container and little in the way of information was available concerning the methods which could be used except in the most general terms.
Writing in the June issue of the FTA's monthly journal Freight, Mr Brock went on to say: "On rough seas, it seems that pitching can amount to 10/20 degrees and roll to 30/40 degrees and whilst not specifically mentioned, there must also be some measure of vertical acceleration. On road vehicles acceleration, braking and cornering forces of between 0.5 and lg are to be reckoned with, while much higher g forces arise in loose shunting on railways.
"In those cases where cargoes do not occupy all the available space inside the container, problems are bound to arise in preventing movement of the contents, yet it is essential to achieve this to preVent the static load developing energy from movement generated by the external forces referred to.
"These problems reach the acute stage when stowing bundles of metal products such as steel tubes which have been oiled for protection against rust and furthermore, possess almost endless permutations as to length and width.
"Bundling into regular hexagons has much to commendit. Dimensions can be predetermined, the bundle is stable, within the strapping and usually remains so, inherent stability against rolling is 30 deg which can be doubled by the ,application of suitably angled chocks offering a face to half the length of a side.
"The use of diagonally placed dunnage about 8ft or 2.5M, in length spreads the load over approximately 3ft of the floor, thereby approximating the requirements of roughly 1 ton per foot and, if each intermediate layer of dunnage is reversed to form a cross, end and side movement is restrained by the corner pillars and sides. Dunnage trapped between bundles in this way, also provides suitable blocking points to restrain individual bundles.
"It is important to make as much use as possible of the strength offered by the corner pillars, and in erecting internal headboards in the form of cradles to secure bundles which are much shorter than the container, every effort should be made to reach these points with supporting members. To provide restraint against vertical acceleration generated from pitch and roll, strapping can be trapped underneath the bottom dunnage, faced vertically through the tiers of bundles and clipped above timbers placed on top of the load thus forming the equivalent of tie-bars."