Methods and apparatus are provided for a mounting system for attaching a container to a vehicle adapted to resist loads imparted by the container to the mounting system in sequential stages. In one exemplary mounting system a first spring is configured to elastically compress when subjected to an initiation load that exceeds a load imparted to the first spring by the container under static conditions. The first spring may have a useable load range from the initiation load to a maximum load at which the first spring is fully bottomed out. A first deformable member is disposed serially with respect to the first spring, and configured to remain substantially un-deformed until subjected to a first deformation threshold load that equals or exceeds the maximum load at which the first spring is fully bottomed out. A second deformable member may be disposed serially with respect to the first deformable member, and configured to remain substantially un-deformed until subjected to a second deformation threshold load that substantially exceeds the first deformation threshold load.