Narrow-gauge steam locomotive 0399 004 of the Austrian Federal Railways.

■ As in service in the 1990s with the Waldviertel Narrow-Gauge Railways
■ Lettering with computerised number
■ With colour-contrasting boiler rings

The narrow-gauge steam locomotive 0399 004 of the Austrian Federal Railways belonged to the tried-and-tested Class 399, whose locomotives were originally procured as Class Mh for the Lower Austrian Provincial Railways. The locomotive that later became 399.04 was built in 1906 by the Krauss locomotive works in Linz and was initially used as Mh.4. Following the electrification of the Mariazell Railway, these powerful supporting-tender locomotives found a new role on the Waldviertel narrow-gauge railways, where they became indispensable, particularly for freight traffic.
The 760 mm-gauge locomotives were characterised by four coupled driving axles, two trailing axles and a level of performance that was remarkable for narrow-gauge railways. With a top speed of 40 km/h, 399.04 proved its worth over decades on the demanding routes around Gmünd, Groß Gerungs and Heidenreichstein.
Following the introduction of computer-compatible running numbers, 399.04 was eventually designated 0399 004. It thus represents one of Austria’s most historic narrow-gauge steam locomotives, remaining closely associated with the Waldviertel narrow-gauge railways even after the end of scheduled steam operations in 1986.