Abstract: The ballast tamper comprises two tool holders articulated to a chassis and equipped with tools set in vibration and fitting one on each side of a single or double cross tie of the track. The tops of the tool holders are connected by a hydraulic gripper ram. The supply of hydraulic fluid to the ram, for at least one of its directions of travel, is provided by an external hydraulic assembly which comprises means for metering an amount of fluid let into the ram or discharged therefrom so as to cause the rod of this ram to selectively describe a limited gripper opening stroke, in the case of a single cross tie, or a full stroke, in the case of a double cross tie. A particularly quiet “hydraulic stop” effect is thus achieved.

Abstract: The ballast tamper comprises two tool holders articulated to a chassis and equipped with tools set in vibration and fitting one on each side of a single or double cross tie of the track. The tops of the tool holders are connected by a hydraulic gripper ram. The supply of hydraulic fluid to the ram, for at least one of its directions of travel, is provided by an external hydraulic assembly which comprises means for metering an amount of fluid let into the ram or discharged therefrom so as to cause the rod of this ram to selectively describe a limited gripper opening stroke, in the case of a single cross tie, or a full stroke, in the case of a double cross tie. A particularly quiet “hydraulic stop” effect is thus achieved.