  We present a spectroscopic catalogue of 40 luminous starburst galaxies at
z=0.7--1.7 (median z=1.3). 19 of these are submillimetre galaxies (SMGs) and 21
are submillimetre-faint radio galaxies (SFRGs). This sample helps to fill in
the redshift desert at z=1.2--1.7 in previous studies as well as probing a
lower luminosity population of galaxies. Radio fluxes are used to determine
star-formation rates for our sample which range from around 50 to 500 M$_\odot$
yr$^{-1}$ and are generally lower than those in z$\sim$2 SMGs. We identify
nebular [OII] 3727 emission in the rest-UV spectra and use the linewidths to
show that SMGs and SFRGs in our sample have larger linewidths and therefore
dynamical masses than optically selected star-forming galaxies at similar
redshifts. The linewidths are indistinguishable from those measured in the
z$\sim$2 SMG populations suggesting little evolution in the dynamical masses of
the galaxies between redshift 1--2. [NeV] and [NeIII] emission lines are
identified in a subset of the spectra indicating the presence of an active
galactic nucleus (AGN). In addition, a host of interstellar absorption lines
corresponding to transitions of MgII and FeII ions are also detected. These
features show up prominently in composite spectra and we use these composites
to demonstrate that the absorption lines are present at an average blueshift of
$-240\pm$50 kms$^{-1}$ relative to the systemic velocities of the galaxies
derived from [OII]. This indicates the presence of large-scale outflowing
interstellar gas in these systems (Abridged)
