Plasser & Theurer 08-475 Unimat 4S ballast tamper working near the switch
at the new S-Bahn (urban trains) station Sindorf (on Cologne-Aachen) on 12
September 2002. In the background is the tamping device that is just lowered
into the ballast. The device on the left seems to be used to compress the
trackbed.
<p>
Digital photo by
<a href="http://www-users.rwth-aachen.de/christoph.schmitz2/index.html">Christoph
Schmitz</a>