Abstract: A ballast cleaning machine comprises a chain for excavating the ballast and for conveying the excavated ballast to a discharge end, a screening installation arranged to receive the excavated ballast from the discharge end of the excavating and conveying chain, and to clean the received ballast by separating waste therefrom. The screening installation comprises a supporting frame and two sets of vibratory screens extending obliquely with respect to the track in the direction of elongation of the machine, the sets of screens being arranged sequentally in said direction and having a common inlet area receiving the ballast from the chain at a respective upper end of each set of screens, the two sets of screens having facing sides adjacent each other and the obliquely extending screens descending from the respective upper end whereby the screens of the two sets enclose an angle.

Abstract: In a mobile machine for tamping ballast under ties of a railroad track, which comprises a machine frame, spaced undercarriages supporting the machine frame for mobility on the railroad track in an operating direction, and a ballast tamping assembly mounted on the machine frame and comprising a vertically adjustable tamping tool carrier, a drive for vertically adjusting the tamping tool carrier, pairs of vibratory and reciprocatory tamping tools immersible in the ballast upon vertical adjustment of the tamping tool carrier, and drives for vibrating and reciprocating the tamping tools: a first device associated with the ballast tamping assembly for gripping and transversely positioning a respective one of the ties, the first device including a drive for vertically adjusting the device, and a second device operable independently of the first device for transversely displacing a respective one of the ties, the second device including a drive for vertically and transversely adjusting the second device.