This is Trude. She's the cutting shield of the tunnel boring machine that was used to cut the new tunnel under the Elbe opened in 2002. At that time, Trude was the biggest of her kind. The name means Tief Runter Unter Die Elbe = Deep Down Under the Elbe.
Trude weighs 380 metric tons and is over 14 metres high. When I stand next to her, I always imagine that she'll start to roll from her platform at any moment.
There's more info on Trude here, in German though.