Attempting to push the chain causes a different situation. A gentle nudge on a short
chain will generally allow for some movement along a line. However, as more force is
applied and the chain becomes longer, the chain wants to buckle in much the same way
an overloaded, un-braced column would buckle (See Figure 6-12). The same theories
that Euler applied to column buckling theory can be conceptually applied to a train
under heavy buff forces. Again, the only resistance to the buckling force becomes the
wheel/rail interface