Knock Nevis

In terms of dead-weight and physical volume The Knock Nevis is the largest ship ever built. This supertanker has an overall length of 458.45 m (1,504 ft) and a draft of 24.6m (81ft) when fully loaded. The vessel is so large that she is unable to navigate the English Channel, the Suez Canal or the Panama canal. The hold could contain four replicas of St Paul’s cathedral simultaneously. The ship takes 5.5 miles to draw to a halt and requires a turning circle of over 2 miles.

Magdeburg Water Bridge

The Magdeburg Water Bridge (German: Wasserstraßenkreuz) is a navigable aqueduct in Germany, opened in October 2003. It connects the Elbe-Havel Canal to the Mittellandkanal, crossing over the Elbe River. It is notable for being the longest navigable aqueduct in the world, with a total length of 918 metres (3,012 ft).

The Elbe–Havel Canal and Mittelland Canal canals had previously met near Magdeburg but on opposite sides of the Elbe, which was at a significantly lower elevation than the two canals. Ships moving between the two had to make a 12-kilometre (7.5 mi) detour, descending from the Mittelland Canal through the Rothensee boat lift into the Elbe, then sailing downstream on the river, before ascending to the Elbe-Havel Canal through Niegripp lock. Low water levels in the Elbe often prevented fully laden canal barges from making this crossing, requiring time-consuming off-loading of cargo.

http://en.wikipedia.org/wiki/Magdeburg_Water_Bridge