TRAILER BUILDING MATERIALS/COMPONENTS
Reinventing the fifth wheel ENGINEERING FIRM MECHANICAL SYSTEM DYNAMICS HAS ENGINEERED, DESIGNED AND PATENTED A REVOLUTIONARY COMPENSATING FIFTH WHEEL THAT HAS THE POTENTIAL TO DRAMATICALLY REDUCE THE INCIDENCE OF ROLLOVERS IN HEAVY AND MULTI COMBINATION VEHICLES. Mechanical System Dynamics was co-
Graph shows that increasing rollover threshold from 0.35g to 0.385g provides a 10 per cent improvement in roll stability. This equates on average to about a 30 per cent reduction in single heavy-vehicle rollover accidents.
founded by Dr Hans Prem and Dr Luan Mai, both of whom gained PhDs in Mechanical Engineering in the early 1980s. Both men have an intense interest in vehicle dynamics. With Hans, it commenced with his PhD and the study of motorcycles in 1979, undertaken at the University of Melbourne, and thereafter progressed in a series of logical steps to innovative large off-highway mining trucks with gross weights approaching 500 tonnes. Meanwhile, Luan Mai was awarded a first-class honours degree in Mechanical Engineering from Monash University and the J.W. Dodds Memorial Medal and Prize for Best Graduate in 1976. In 1982 Luan gained a PhD for outstanding research in the dynamics and control of load-sensitive pumps. His interest in road tanker rollover stability subsequently led to the construction of a tilt table facility that is still in use today at Linfox’s Australian Automotive Research Centre (AARC) near Anglesea in Victoria.
and developing a radically improved
which he says directly equates to about
The outcomes and recommendations
compensating fifth wheel.
from this research led to nationwide
Simply stated, Hans believes the advanced
a 30 per cent reduction in single vehicle rollovers (see Graph).
safety improvements for articulated heavy
design of the compensating fifth wheel he
As for the impetus for embarking on
vehicles and road tankers in particular.
and Luan have developed and patented
such an ambitious project, Hans says
Which brings us to the latest efforts
has the potential to achieve up to a 10
the company was repeatedly contacted
of this ‘Dynamic Duo’ in designing
per cent improvement in roll stability
by operators seeking a superior compensating fifth wheel. “Believe it or not, the currently available compensating fifth wheel was first patented just on 60 years ago and the design has changed very little since,” he says. “We decided to study its operation to understand exactly how it works and then set about designing an alternative
Further development of the New Compensator concept will include electric actuators.
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Trailer Magazine OCTOBER 21
that would improve its operation in a number of key areas.” The main purpose of a compensating fifth
