A mobile track working machine arrangement comprises two consecutively arranged, independent track working vehicles, each track working vehicle comprising an elongated two-part machine frame, the two parts of the machine frame being linked by a pivot for pivoting of one part in relation to the other part about a horizontal axis extending perpendicularly to the track, and undercarriages supporting the machine frame on the track. A ballast excavating device is vertically adjustably mounted on the machine frame of a first track working vehicle for excavating the ballast supporting the track whereby the subgrade is exposed, and a conveyor arrangement is mounted on the machine frame of the first track working vehicle for removing the excavated ballast. A device for planing and compacting a protective layer of sand on the subgrade is mounted on the machine frame of the second track working vehicles. A track lifting device is mounted on each machine frame, each track lifting device comprising lifting rollers rollingly engaging the track rails in permanent frictional contact therewith, and a device for sweeping sand from the ties into adjacent cribs is mounted on the machine frame of at least one of the vehicles.