Zara frame
The Zara frame is a constructive solution to improve the running properties of steam locomotives with leading single running axles . In principle, it is similar to the Krauss-Helmholtz steering frame . While there is a drawbar connection between the leading running axle and the first coupling axle, the Zara frame has its own frame between these two axles. This frame is based in the front part on the spring of the running axle, in the rear part on the transverse spring of the first coupled wheel set . This spring was a leaf spring that hung on the specially designed axle box of the coupled wheel set. The main frame of the Zara frame was supported at the pivot point. This caused vertical pendulums which, together with the return springs, reached the return and thereby caused a certain smoothness in the straight line.
The Zara frame was developed by Giuseppe Zara (1856–1915) and was first executed in 1904. It was also known as the Zara Krauss bogie . Zara wanted to reduce the unsprung masses and achieve smoother vehicle running with its steering frame , which was known as carrello italiano .
The Zara frame was particularly popular where express train locomotives were to be used with small turntable diameters. It was often used in numerous express train locomotives in Italy , the FS 685 serves as an example . It was also widespread in Belgium . Also known are the Russian С series and the first three-phase - electric locomotives through the Simplon tunnel .
Individual evidence
literature
- Wolfgang Messerschmidt: Locomotive technology in the picture - steam, diesel and electric locomotives . Motorbuchverlag Stuttgart, 1991 ISBN 3-613-01384-3 ; Pp. 52-53