A revision to AS4324.1 Mobile equipment for continuous handling of bulk materials – General requirements for the design of steel structures was published by Standards Australia in December 2017. The Standard applies to equipment such as excavators, stackers, reclaimers, ship loaders, and ship unloaders.
The previous, 1995 version of the Standard had a long gestation period, with work by the Standards Australia ME43 Committee commencing in 1978. As a result of several serious failures of machines in the iron ore industry in Western Australia in the 1990’s and elsewhere, much greater awareness of the risk associated with continued use of this type of equipment ensued. On one of the failures which resulted in a fatality, the WA Coroner made specific recommendations including the introduction of an Australian Standard, conducting independent design audits and maintaining of records.
AS4324.1 has been in use for over 20 years, and major machine suppliers, and design audit engineers operating in Australia are now familiar with the document. Its application in the purchase of bulk handling equipment for Australian ports and mines has resulted in robust and reliable machines which are expected to offer long-term benefits. As part of continuous improvement in the industry, the Standards’ Committee ME43 has prepared a revision to the standard to update it and clarify some areas which have caused ambiguity as listed below.
- Boom collision on non-slewing machines
- Travel device obstructed on bridge machines
- Digging cut-off settings and protection systems
- Permanent Dynamics
- Redundancy of stays, ropes, and hydraulic cylinders
- Loss of bucket wheel
- Wind loads
- Plate buckling
In addition, considerable work has been done on revising the limit states design requirements in the standard to be compatible with the loading standard AS1170.0.