Excavators or Hydraulic Excavators are large pieces of construction equipment used for the digging of trenches, holes, and foundations. These machines consist of a boom, dipper, bucket, and a cab on a rotating platform known as a "house". The house sits atop an undercarriage that is track driven with rollers. All movement and functions of a hydraulic excavators are accomplished through the use of hydraulic fluid, with hydraulic cylinders and motors. These machines are also refereed to as diggers, mechanical shovels, or 360 degree excavators. Excavators come in a variety of different sizes, from mini or compact to massive machines weighing in at 1000+ tons.