An In-Service Survey of Heavy Vehicle Suspensions

The purpose of this paper is to discuss a survey taken by the ARRB Group of the suspension properties of 150 heavy vehicles fitted with tri-axle groups randomly selected from the Hume Highway at Marulan Checking Station. The survey was conducted in March 2006 and looked into heavy vehicle suspensions. This paper presents key results from the survey, including statistics on the age of the trailers surveyed, the type of suspension fitted to the trailers, the load on the tri-axle group of the trailers, the damping and damped frequency of the suspension fitted to the trailers, the temperatures of the shock absorber fitted to the trailer suspensions, and the static load sharing of the suspensions. Inspection of the data found very little relationship between any of the parameters. The findings of this survey add to the body of knowledge, provide information on the characteristics of this sector of the suspension population, and provide critical information for the axle mass increase debate.