  We explore the Reissner-Nordstr\"{o}m naked singularities with a charge $Q$
larger than its mass $M$ from the perspective of the particle acceleration. We
first consider a collision between two test particles following the radial
geodesics in the Reissner-Nordstr\"{o}m naked singular geometry. An initially
radially ingoing particle turns back due to the repulsive effect of gravity in
the vicinity of naked singularity. Such a particle then collides with an
another radially ingoing particle. We show that the center of mass energy of
collision taking place at $r \approx M$ is unbound, in the limit where the
charge transcends the mass by arbitrarily small amount $0<1-M/Q\ll1$.The
acceleration process we described avoids fine tuning of the parameters of the
particle geodesics for the unbound center of mass energy of collisions and the
proper time required for the process is also finite. We show that the
coordinate time required for the trans-Plankian collision to occur around one
solar mass naked singularity is around million years while it is many orders of
magnitude larger than Hubble time in the black hole case. We then study the
collision of the neutral spherically symmetric shells made up of dust
particles. In this case, it is possible to treat the situation by exactly
taking into account the gravity due to the shells using Israel`s thin shell
formalism, and thus this treatment allows us to go beyond the test particle
approximation. The center of mass energy of collision of the shells is then
calculated in a situation analogous to the test particle case and is shown to
be bounded above. However, we find thatthe energy of a collision between two of
constituent particles of the shells at the center of mass frame can exceed the
Planck energy.
