  We investigate a Friedmann universe filled with a tachyon scalar field, which
behaves as dustlike matter in the past, while it is able to accelerate the
expansion rate of the universe at late times. The comparison with type Ia
supernovae (SNIa) data allows for evolutions driving the universe into a Big
Brake. Some of the evolutions leading to a Big Brake exhibit a large variation
of the equation of state parameter at low redshifts which is potentially
observable with future data though hardly detectable with present SNIa data.
The soft Big Brake singularity occurs at finite values of the scale factor,
vanishing energy density and Hubble parameter, but diverging deceleration and
infinite pressure. We show that the geodesics can be continued through the Big
Brake and that our model universe will recollapse eventually in a Big Crunch.
Although the time to the Big Brake strongly depends on the present values of
the tachyonic field and of its time derivative, the time from the Big Brake to
the Big Crunch represents a kind of invariant timescale for all field
parameters allowed by SNIa.
