The South Australian Department for Transport, Energy and Infrastructure (DTEI) has announced returning to post 1999 axle mass limits for single and tandem axle pig trailers. As a result, single axle pig trailer will revert to a mass limit of 8.5 tonnes and tandem axle pig trailers will revert to 15 tonnes by 31 March 2014.
In South Australia (SA) prior to December 1999, the statutory axle mass limits for single and tandem axle pig trailers were 9.0 tonnes and 16.5 tonnes respectively.
In December 1999, nationally consistent heavy vehicle regulations were introduced and South Australia adopted the national regulations for heavy vehicle axle mass limits in the Road Traffic (Mass and Loading) Regulations. This limited the statutory axle mass limits for pig trailers to 8.5 tonnes for single axle pig trailers and 15 tonnes for tandem axle pig trailers. The tri-axle pig trailer national mass limit remained consistent with SA’s pre 1999 limit of 18 tonnes.
When the national standards were introduced in SA in 1999, the new statutory axle mass limits for pig trailers were not welcomed by the road transport industry, as they represented a reduction in payload. Industry indicated that, in their view, a reduction in mass limits without technical justification was not acceptable.
Consequently, the Department for Transport, Energy and Infrastructure (DTEI) provided a concession to allow existing pig trailers to continue to operate at the pre 1999 mass limits, and commissioned a study to examine the safety, pavement, stability and drawbar effects of allowing axle masses in excess of the nationally agreed limits for all pig trailers.
The report prepared by Australian Road Research Board (ARRB) Transport Research Ltd, and further analysis to verify some of the findings, identified a number of deficiencies in the design of single and tandem axle pig trailers. In light of these issues, DTEI is abandoning further research to identify solutions for the deficiencies on these vehicles and will begin a process of phasing out the mass concession currently available.
The research and information completed to date will be available from DTEI to interested members of the industry who may wish to progress further assessment of these vehicles through the Performance Based Standards Scheme.
To assist industry with this transition, the two Gazette Notices titled ‘Exemption for Single Axle Pig Trailers to Exceed the Maximum Mass Limit of 8.5 tonnes’ and ‘Exemption for Tandem Axle Pig Trailers to Exceed the Maximum Mass limit of 15 tonnes’ will be extended up until 31 March 2014, after which time all pig trailers revert to the post 1999 mass limit of 8.5 tonnes for single axle and 15 tonnes for tandem axle groups, respectively.