A lift device includes a chassis having a first end and an opposing second end, a first actuator coupled to the first end of the chassis, a second actuator coupled to the first end of the chassis, a third actuator coupled to the opposing second end of the chassis, a fourth actuator coupled to the opposing second end of the chassis, and a control system. The control system is configured to fluidly couple at least two of the first actuator, the second actuator, the third actuator, and the fourth actuator, and fluidly decouple and actively control the at least two of the first actuator, the second actuator, the third actuator, and the fourth actuator.

The invention relates to a measuring device (13) for recording a track geometry of a track (5) immediately after a treatment of the track (5) by means of track maintenance machine (1), wherein the measuring device comprises wheel axles (16) for travelling on the track (5), connecting elements (15) for mounting to the track maintenance machine (1) and a data interface (41) for exchanging data with the track maintenance machine (1). Further, the measuring device (13) comprises an assembly frame (22) on which an inertial measuring unit (14) is arranged, wherein a front wheel axle (16) and a rear wheel axle (16) are mounted on the assembly frame (22) for rotation relative to one another about an axis of rotation (21) extending orthogonally to the wheel axles (16). Thus, an efficient check measurement of the lateral, longitudinal and vertical position of the track (5) is possible.

The invention relates to a measuring device (13) for recording a track geometry of a track (5) immediately after a treatment of the track (5) by means of track maintenance machine (1), wherein the measuring device comprises wheel axles (16) for travelling on the track (5), connecting elements (15) for mounting to the track maintenance machine (1) and a data interface (41) for exchanging data with the track maintenance machine (1). Further, the measuring device (13) comprises an assembly frame (22) on which an inertial measuring unit (14) is arranged, wherein a front wheel axle (16) and a rear wheel axle (16) are mounted on the assembly frame (22) for rotation relative to one another about an axis of rotation (21) extending orthogonally to the wheel axles (16). Thus, an efficient check measurement of the lateral, longitudinal and vertical position of the track (5) is possible.

The invention relates to a mobile device for correction of a vertical position of a pre-measured track, in particular for a track maintenance machine, including a measuring system which comprises a moving chord as reference base, and including a lifting device for lifting the track to a target level prescribed at a work location by means of the moving chord. In this, the moving chord is defined at two reference locations as to its position relative to a non-corrected area of the track, wherein the work location is arranged behind the reference locations in a working direction. In this manner, the position of the moving chord is defined unambiguously and precisely at all times.

The invention relates to a mobile device for correction of a vertical position of a pre-measured track, in particular for a track maintenance machine, including a measuring system which comprises a moving chord as reference base, and including a lifting device for lifting the track to a target level prescribed at a work location by means of the moving chord. In this, the moving chord is defined at two reference locations as to its position relative to a non-corrected area of the track, wherein the work location is arranged behind the reference locations in a working direction. In this manner, the position of the moving chord is defined unambiguously and precisely at all times.

A tamping machine for tamping a track has a lifting-lining unit, connected to lifting and lining drives, for shifting the track into a target position. A vibration generator, which can be set to vibrate, is disposed on the lifting-lining unit. It is thereby possible to tamp a track section in a first working pass and to lower it in a controlled way in an immediately following second working pass with constant impact of vertical load and vibration. Thereafter, the track can be traveled upon with normal speed entirely unhindered.

A tamping machine for tamping a track has a lifting-lining unit, connected to lifting and lining drives, for shifting the track into a target position. A vibration generator, which can be set to vibrate, is disposed on the lifting-lining unit. It is thereby possible to tamp a track section in a first working pass and to lower it in a controlled way in an immediately following second working pass with constant impact of vertical load and vibration. Thereafter, the track can be traveled upon with normal speed entirely unhindered.

A method is proposed for track position improvement by means of a track-movable track-tamping machine (6) with a three-point work measurement system having three measurement carriages (A, B, C) and a cord (9) stretched therebetween, a tamping unit (5), a lifting and straightening unit (8) for tracks and in particular an odometer. The position of the track after the correction work of the track-tamping machine (6) is recorded by means of a measurement system. In order to reduce the straightening error, it is proposed that a computer (R) calculates the difference between a predetermined desired track position (1) and an actual position recorded by the measurement system, i.e. a residual error (K.sub.h), and in that the position of the rear cord end on the rear measurement carriage (C) of the track-tamping machine (6) of the three-point work measurement system is continuously corrected in such a way that the rear cord end on the measurement carriage (C) is guided on the desired track position (1).

A method is proposed for track position improvement by means of a track-movable track-tamping machine (6) with a three-point work measurement system having three measurement carriages (A, B, C) and a cord (9) stretched therebetween, a tamping unit (5), a lifting and straightening unit (8) for tracks and in particular an odometer. The position of the track after the correction work of the track-tamping machine (6) is recorded by means of a measurement system. In order to reduce the straightening error, it is proposed that a computer (R) calculates the difference between a predetermined desired track position (1) and an actual position recorded by the measurement system, i.e. a residual error (K.sub.h), and in that the position of the rear cord end on the rear measurement carriage (C) of the track-tamping machine (6) of the three-point work measurement system is continuously corrected in such a way that the rear cord end on the measurement carriage (C) is guided on the desired track position (1).

A rail-lifting and ballast-spreading apparatus that may be employed to rehabilitate damaged tracks or aid rough in of new tracks, is described. The apparatus includes a track-lifting unit at a forward end thereof that includes an arm that is pivotable to extend forwardly and over a section of track in need of repair or ballast replenishment. Rail clamps are provided on a distal end of the arm that engage and travel along the rails as the apparatus moves forward. A conveyor provides a stream of ballast across the width of the tracks while the tracks are lifted and as the apparatus moves forward onto the now repaired tracks. A surge bin is provided to increase a rate of distribution of the ballast material by the conveyor over that available from the ballast-delivery consist.