 On top of the machine is the cobra-like heat-ray attached to a long, narrow, neck-like extension.They can be mistaken for flying-machines, but Dr. Forrester states that they are lifted by "invisible legs"; in one scene, when the first machine emerges, you can see faint traces of three energy legs beneath and three sparking traces where the three energy shafts touch the burning ground.Therefore, technically speaking, the film's war machines are indeed tripods, though they are never given that designation.