A system for applying a force or pre-stress to a portion of a toroidal field coil may include a structure having a first arm including a first arm gap wall and a second arm including a second arm gap wall. The structure may include an arcuate space separating the first arm and the second arm. The structure may include a bean-shaped opening configured to surround the toroidal field coil.An expandable container may be positioned between the first arm gap wall and the second arm gap wall. A liquid within the expandable container may expand upon freezing.