Load Restraint Guide 2004 (Second Edition)
In the decade that followed the introduction of the Guide, there was significant progress in the understanding and application of the new performance standards. It was clear that the technical content, which was scattered throughout all sections of the Guide, was confusing many readers.
The National Road Transport Commission (NTC) in conjunction with the NSW RTA decided to call tenders for the rewrite of the Guide to incorporate new developments and to make the Guide easier to understand by non-technical readers.
Loadsafe was awarded a Contract to provide further technical content for the Guide and worked with NSW RTA mechanical engineer, Peter Goudie another SMExpert in this field, on all aspects of the revision.
It was decided to expand all technical content and separate it into a new section of the Guide for Designers and Engineers. For example, technical terms which were not familiar to many drivers (such as “g”, “µ” or “SRT”) were excluded from Part 1. The complex technical requirements of the Performance Standards were simplified for drivers in Part 1 by adding text and diagrams referring to forces directly on the load (0.8W, 0.5W and 0.2W).
The second Edition Guide was made less prescriptive and more general, following the release of numerous industry-specific, certified load restraint procedures which made some previous general information redundant and out of date.
The second Edition took into account future developments, such as load restraint curtains and innovative vehicle body structures by providing guidance in Section “I” for certification of loads restrained by side curtains, gates and headboards.
The second Edition also introduced the use lifting chain and fittings for load restraint in Australia.
Technical Issues following publication of the 2nd Edition 2004.
The Performance Standards on Page 186 have been frequently misquoted in documentation by Regulators and professional engineers. For example, this has led to load restraint containment systems being certified using friction as part of the restraint system (µ > 0), in contravention of the testing requirements (µ = 0) in Part 2 of the Guide.
Tables used 0.6 minimum friction coefficient (µ) for rubber anti-slip inter-layers. All recent Loadsafe gas pipe certifications for example, are based on actual test results of imported anti-slip mat (rated µ = 0.6 min., but testing proving µ as low as 0.47).
A range of values such as 0.3 to 0.6 should have been included in the 2nd Edition Tables to reflect the ageing of rubber, the common use of slippery re-cycled conveyor belting by industry and the lack of recognised Standards necessary for certifying anti-slip matting performance and its limited life cycle (often one-use only). The general use of rubber inter-layers should not have been inadvertently encouraged over the significantly higher reliability and robustness of friction obtained with traditional timber dunnage.