The buried excavation machines may offer Juliette a route home, if she can drain Mechanical and restore one.
Solo identifies the buried diggers as the machines that excavated the silo. He guesses they were too heavy to remove and says the walls were poured over them; he also says the equipment below no longer works.
Juliette does not yet know the condition of the submerged machines. She hopes to restore one after draining Neighboring Silo Mechanical, making the machinery a goal of her recovery work rather than an available resource.
An untested means of excavation that Juliette hopes to recover after draining Mechanical.