An optical spectroscopic survey of the 3CR sample of radio galaxies with
  z<0.3. I. Presentation of the data
  We present a homogeneous and 92 % complete dataset of optical nuclear spectra
for the 113 3CR radio sources with redshifts < 0.3, obtained with the
Telescopio Nazionale Galileo. For these sources we could obtain uniform and
uninterrupted coverage of the key spectroscopic optical diagnostics. The
observed sample, including powerful classical FR II radio-galaxies and FR I,
together spanning four orders of magnitude in radio-luminosity, provides a
broad representation of the spectroscopic properties of radio galaxies. In this
first paper we present an atlas of the spectra obtained, provide measurements
of the diagnostic emission line ratios, and identify active nuclei with broad
line emission. These data will be used in follow-up papers to address the
connection between the optical spectral characteristics and the multiwavelength
properties of the sample.
