Method and railway train for draining a railway track

Train for improving the drainage of a railway track comprising a working car consisting of a frame-car with an empty frame of a length in excess of the length of one track span, said car having two trucks rolling the rear one on the new track and the front one on the old track and, ahead of said frame-car, a set of carriages provided with equipments for loading the excavation and, at the rear of said frame-car, other cars for transporting the spans, the sand and the ballast, guide rails installed on said transport cars and said frame-car, two gantries adapted to roll on said guide rails installed on said transport cars and said frame-car, said gantries supporting hoisting means for lifting a span and means for handling buckets for transporting the sand and ballast, and a rolling truck also movable on said guide rails ahead of said two gantries and from which at least one vertically adjustable excavator is suspended, said excavator covering either the full width of the excavation or only a reduced width, and being movable laterally or adapted to pivot for excavating the ballast, a swivel-mounted digging device mounted at the rear of said excavator, and comprising an endless chain associated with helical transverse fins, said digging device being provided with hydraulic cylinders for moving same in a vertical plane and in a longitudinal plane, respectively, said digging device being so designed that it can dig to a depth greater than the excavation and covers the full excavation width.