Mammoth were tasked with modifying the standard exhaust configuration of a D65 surface drill. In a standard system the exhaust configuration houses the muffler below the canopy, this reduces the available space in the canopy making access for maintenance challenging. 

The placement also leads to excessive head under the canopy which can contribute to pre-mature wear on components like hoses. The tailpipe position was also leading to blowback from the exhaust to the cab. Due to the high operating temperatures, there had been thermal incidents that occurred at site resulting in fire suppressant systems being activated.