  Detection of gravitational waves from the inspiral phase of binary neutron
star coalescence will allow us to measure the effects of the tidal coupling in
such systems. These effects will be measurable using 3rd generation
gravitational wave detectors, e.g. the Einstein Telescope, which will be
capable of detecting inspiralling binary neutron star systems out to redshift
z=4. Tidal effects provide additional contributions to the phase evolution of
the gravitational wave signal that break a degeneracy between the system's mass
parameters and redshift and thereby allow the simultaneous measurement of both
the effective distance and the redshift for individual sources. Using the
population of O(10^3-10^7) detectable binary neutron star systems predicted for
the Einstein Telescope the luminosity distance--redshift relation can be probed
independently of the cosmological distance ladder and independently of
electromagnetic observations. We present the results of a Fisher information
analysis applied to waveforms assuming a subset of possible neutron star
equations of state. We conclude that for our range of representative neutron
star equations of state the redshift of such systems can be determined to an
accuracy of 8-40% for z<1 and 9-65% for 1<z<4.
