Dark energy is not speeding up the expansion of the Universe

Anywhere I look, scientific articles say that.

http://news.bbc.co.uk/2/hi/science/nature/6156110.stm

Dark energy is a propelling force, not a repelling force.

As a propelling force it does not speed up the expansion of the
Universe.

The reason for the expansion is that galaxies are like trains
accelerating
on their tracks due to compression. Like a figure skater that pulls in
her
arms, the rotating galaxy gains rotational speed, and with it the
galaxy
gains momentum. If the skater that spins moves sideways as she spins
and accelerates her spin, she would not only spin faster but gain
momentum
toward her track.

Simple physics!

If all galaxies are gaining speed on their tracks, then it will appear
that
the expansion is speeding up.