The 3780 dwt freighter Westgard had a total power blackout after a mechanical failure while entering the Northern Lock at Brunsbuettel, Germany.   The Westgard was able to stop by an emergency anchoring, but it had already struck the staging area of the lock.   A tug assisted the Westgard into the lock and towed it to a berth in the canal harbour.  The Westgard will remain there until an investigation can be conducted.