shifting locomotive

from The Collaborative International Dictionary of English v.0.48

Shifting \Shift"ing\, a.
   1. Changing in place, position, or direction; varying;
      variable; fickle; as, shifting winds; shifting opinions or
      principles.
      [1913 Webster]

   2. Adapted or used for shifting anything.
      [1913 Webster]

   {Shifting backstays} (Naut.), temporary stays that have to be
      let go whenever the vessel tacks or jibes.

   {Shifting ballast}, ballast which may be moved from one side
      of a vessel to another as safety requires.

   {Shifting center}. See {Metacenter}.

   {Shifting locomotive}. See {Switching engine}, under
      {Switch}.
      [1913 Webster]