Class D was a type of electric multiple unit train used by the Berlin U-Bahn.

In 1965, the DL type was developed, which was constructed from lighter metals (also called Dora).

After the merger of BVB with BVG in January 1992, these trains continued to deploy on the U5, U6, U7, and U8 until their retirement in 1998-99.

As work vehicles they received in the course of the conversion an orange paint job, among other things, a part of the passenger window was removed.

Due to an insufficient number of trains as well as financing constraints, the BVG decided in 2016 to modernise these two units for service on the line U55 until the U5 extension opens in 2019.

These trains were equipped with electronic destination displays, and to adapt with their modern safety requirements.

Flashing lights and warning sounds have also been introduced to the trains to let passengers know whenever doors are closing or opening.