Abstract
Mining truck body (tray) manufacturers whether OEMs or 3rd party after-market have generally developed truck bodies to date with 2 major assumptions: (1) that the payload sits in the body of a truck at a 2:1 slope, effectively an angle of repose of 26.6o, and (2) the loose (broken) density of the payload in the body is 2.0 t/m3. Both assumptions are flawed, with densities for broken rock ranging from above 2.0 t/m3 in hard dense rock operations to less than 1.7 t/m3 in oil sand operations; and angles of repose from less than 25o in hard over-fragmented rock conditions to greater than 45o in oil sand winter operations. The operational impacts range from unbalanced payload distributions causing adverse motions and structural fatigue, overloaded front tires to differential rolling resistances and road deterioration by wheel set position relative to the running surface. In addition, payload achievement per haul may not be assured to the OEM truck sticker specification.
This paper and presentation will present a new body design guideline for OEMs, after-market suppliers and operational in-house consideration; suggesting a new design strategy as a function of payload density, broken rock angle of repose and a new body geometry alternative for existing rigid body hauler as a retrofit, customizable for the end user. The technical design approach and verifiable calculations will be presented, allowing the user to develop an alternative to the existing truck body designs for any operation; without the need for time consuming field visual profile analyses driving current custom body design, other than gaining a fuller understanding of the angle of repose and broken rock density distributions across a mining operation. The presentation will also suggest some simple field level approaches to gauge whether an operation has a significant issue warranting the need for body redesign.