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Even casual observers of the specialist press or those who search the Internet
for certain terms will soon notice that the hitherto perfect world of "proclamations"
with respect to cargo securing in road transport has been becoming rather untidy over the past few years.
So what happened? Europe is coming together.
The volume of freight transported by road, rail and water has continued to
increase, and the understandable calls for harmonized rules, not only in
respect of cargo securing, have been heard.
A standard intended to ensure a uniform
level of safety across the whole of Europe was drafted, and EN 12195-1, which
has already been revised several times, has met with a varied response from
practitioners. Those interests that have influenced the development of the standard
are, understandably, many and varied, even going as far as referencing the
regulations of the IMO, which, being an organization within the UNO, is truly
not responsible for road traffic in Europe.
The most recent version of the draft
standard represents the compromise negotiated in September 2008, which in turn
corresponds to a great extent to VDI Guideline 2700, Part 2 of November 2002,
but which ignores "findings" from the intervening years. From a
German perspective, these include the k factor that applies with tie-down
lashings tensioned on one side only, the treatment of coefficients of friction
and the "rolling" factor; and, from the perspective of some other
European representatives, the forward g force to be assumed for calculating
adequate cargo securing measures.
This is lamented by critics who are
justifiably concerned that a decline in safety may result and correctly insist
that the laws of physics have not changed and that the (German) regulations
that had applied previously must continue to apply.
It is undeniable that the laws of physics
have not changed, but exactly how much physics has been used in the extremely
simplified models used for calculation in the field of cargo securing to date?
The models should be easy to comprehend and use. What compromises have been
made? Could it be that the intuitive objections of practitioners to a
nonsensically high number of tie-down lashings proposed under certain
circumstances may well sometimes be justified because the high number is the
result of shortcomings in the model used for calculation? This would not be the
fault of the laws of physics.
In the context of the upcoming revision
of their Cargo Securing Manual as published in 1997, the German Insurers'
Association (GDV) therefore decided to investigate the underlying physical
principles used in the current regulations for calculating adequate cargo
securing measures. It is easy to derive these principles from the models used
for calculation, but it is not easy to draw such conclusions about the
reasoning behind the simplifications and assumptions that have been made.
Taking a further step backwards and closely examining what really happens to a
cargo assembly when a truck undergoes full braking or changes lane quickly thus
seemed unavoidable.
The findings were not surprising, namely
that the simplifications applied in the models hitherto used for calculation
deviate unacceptably from reality, erring sometimes on the side of caution and
sometimes on the side of danger. Irrespective of the need to present simple
rules for adequate cargo securing in the upcoming Cargo Securing Manual, it was
therefore necessary to examine closely all the factors that have an impact on
securing performance.
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