We present far-infrared and submillimetre spectra of three carbon-rich
evolved objects, AFGL 2688, AFGL 618 and NGC 7027. The spectra were obtained
with the SPIRE Fourier transform spectrometer on board the Herschel Space
Observatory, and cover wavelengths from 195-670 um, a region of the
electromagnetic spectrum hitherto difficult to study in detail. The far
infrared spectra of these objects are rich and complex, and we measure over 150
lines in each object. Lines due to 18 different species are detected. We
determine physical conditions from observations of the rotational lines of
several molecules, and present initial large velocity gradient models for AFGL
618. We detect water in AFGL 2688 for the first time, and confirm its presence
in AFGL 618 in both ortho and para forms. In addition, we report the detection
of the J=1-0 line of CH+ in NGC 7027.Comment: Accepted for A&A Herschel special issue. 4 tables, 2 figures