The interplanetary shocks which generate detectable low-frequency (500 km/s) coronal mass ejections (CMEs). In comparison with the set of all CMEs detected by the Solwind coronagraph the CMEs associated with IP type II events are the most massive and energetic. The majority (>50%) belong to the structural classes described by the Solwind researchers as ''curved front'' or ''halo.'' Evidence presented suggest that these are the same class viewed from a different persective. Our results are consistent with there being a close relationship between interplanetary shocks and fast CMEs. ¿ American Geophysical Union 1987