In the location's words:

The former harbor tug "STIER" stands jacked up on Hans Scharoun Platz directly behind the dyke.

The STIER is a tugboat that towed and maneuvered ships in Bremen's ports. The harbor tug with Voith-Schneider propellers can be seen and walked around in the museum harbor.

One of the exhibits on display in the open-air museum of the German Maritime Museum is a "water tractor" called STIER, which was built according to a completely new concept. The aim was to create a particularly powerful, maneuverable and at the same time very safe boat that could tow and maneuver large ships that were difficult to navigate in the harbor area.
The STIER was launched in 1954 at the Jade shipyard in Wilhelmshaven, served for 24 years in the ports of Bremen for Norddeutscher Lloyd (NDL) and became the model for hundreds of similar harbor tugs worldwide. In 1978, NDL handed this ship over to the DSM.