Early on in the Aqueduct construction project, Caterpillar traction trailers were used along side the mule teams. For the first few months the noisy Caterpillars appeared to provide a saving in the financial costs to the City – – compared to the cost of road-building plus the feeding and upkeep of mule teams.
However, the harsh desert environment and rough, rocky foothills of the Sierra soon took a tremendous toll on the machines. Breakdowns were a daily occurrence and repair costs became extremely expensive.
Mules, on the other hand, were strong, surefooted, and very adaptable to the severe conditions and treacherous terrain. Use of the Caterpillars was soon abandoned and the City returned to the good old reliable mule power.