A device for moving at least one cutting and welding arrangement able to cut, then weld a tail of a first metal strip to a head of a second metal strip, includes at least one first carriage holding at least one welding head. The first carriage is movable over a guide path following a first course across a transverse strip region. At least one second carriage is movable separately from the first carriage and holds a cutting head. The second carriage is movable on a guide path following a second course. The welding head is used exclusively for a welding mode, the second carriage is used exclusively for a cutting mode and the two carriages have parked positions on either side of the tail and head widths of the strips. A welding method which is associated with the device is also provided.