The wheeled excavator A 900 C ZW Litronic can be operated as a dual purpose machine either on the road or on railway tracks. The rail travel drive is mounted on either side of the undercarriage. When entering the rails, the rail travel drive lifts the tyres to rail height, whereby the inside wheels of the dual tyres ensure travel of the excavator on the tracks. As well as the standard design, a narrow track and a friction wheel design are also available.