Line U6 is a line on the Vienna U-Bahn.^[1] It currently has 24 stations and runs 17.3 km from Floridsdorf to Siebenhirten. It is connected to U4 at Längenfeldgasse, U3 at Westbahnhof and U4 at Spittelau. The first section of the line opened in 1989, and was completed at its present length in 1996. It is the only metro line in the DACH countries which is not operated by third rail but by overhead wire; this is because the centre portion of the line is an elevated part of the former Vienna Stadtbahn system, which was operated by overhead wire.

Line U6
Line U6 train at Siebenhirten
Overview
Native name	U-Bahn-Linie U6
Status	Operational
Termini	Floridsdorf Siebenhirten
Connecting lines
Stations	24
Service
Type	Light Metro
System	Vienna U-Bahn
Operator(s)	Wiener Linien
Depot(s)	Michelbeuern, Rößlergasse
History
Opened	7 October 1989 (1989-10-07)
Technical
Line length	17.3 km (10.7 mi)
Track gauge	1,435 mm (4 ft 8+1⁄2 in) standard gauge
Electrification	750 V DC overhead catenary

When the line was transformed to rapid transit standards, it was considered too expensive to rebuild the elevated portion for high-floor trains and third rail, as it was done with the U4. As a result, the U6 currently uses low-floor T-Class vehicles, but the U6 is not the only rapid transit line that uses low-floor metro trains, with Line M1 of the Budapest Metro being another notable example.