X-ray and optical observations have shown that the supernova explosions and
stellar winds of the starburst in NGC 2146 produce an outflow of hot mater
ial along the minor axis. This outflow is expected to have a more or less c
onical shape, on either side of the galactic plane, and cone walls of coole
r material where the outflow is in shock contact with halo gas. We attempt
to determine the geometry (diameter at the base and opening angle) and the
physical parameters (velocity and density) of the material in the cone wall
s from the optical emission line and radio observations presented here, and
from published X-ray, radio, and optical observations. We compare the outf
low of NGC 2146 with the outflow of M 82.