The proto-planetary nebula Hen 3-1475 (IRAS 17423--1755) shows a remarkable highly--collimated optical jet with a spectacular S-shaped string of shock-excited knots (Bobrowsky et al. 1995, Riera et al. 1995, Borkowski et al. 1997). Moreover, extremely high velocities have been observed in the innermost regions of its optical jet, which decreases with distance to the source. We present an analysis of the morphology, the kinematic structure and the excitation conditions in the shock-excited knots based on new long-slit spectroscopy obtained with the Intermediate Dispersion Spectrograph at the 2.5m INT (Observatorio del Roque de los Muchachos, La Palma) and high angular resolution images obtained with the HST WFPC2 with narrow filters during 1996 and 1999. The study of the kinematics and morphology of the shock--excited emission and the dust scattered emission present in the bipolar lobes reveal the complex kinematical structure of the innermost regions. The study of the structure of the intermediate knots show a complex excitation conditions, pointing to the presence of two distinct zones of excitation. The overall picture supports the description of the system as the result of time episodic ejections in a precessing binary system. Bobrowsky was supported by STScI grant GO-06364.01-94A.