Gearbox, comprising: - a housing, an input shaft for receiving rotational movement, an output shaft for outputting rotational movement, at least one pair of gear elements (R1A, R1B), said pair of gear elements comprising a driver gear element (R1A) on the input shaft and a driven gear element (R1B) on the output shaft, said driver gear element (R1A) being arranged to rotate the driven gear element (R1B), the gearbox also comprising releasable locking means (DR, DR1) to lock, in a first mode of operation, the driven gear element (R1B) to the output shaft in order to rotate the output shaft to the first rotational direction, the gearbox further comprising an intermediate gear element on an additional shaft, the gearbox further comprising a further gear element on the output shaft, said intermediate gear element being arranged to be moved to a position where, when the releasable locking means is, in a second mode of operation, in a released position, the intermediate gear element is arranged to rotate the further gear element that is on the output shaft and thereby also to rotate the output shaft to a reversal rotational direction that is opposite to said first rotation direction of the output shaft, characterized in that the same driver gear element (R1A) that in the first mode of operation is for rotating the driven gear element (R1B), is, in the second mode of operation, via the intermediate gear element arranged also to rotate the further gear element that is on the output shaft and thereby also to rotate the output shaft to a reversal rotational direction that is opposite to said first rotation direction of the output shaft. - a housing, an input shaft for receiving rotational movement, an output shaft for outputting rotational movement, at least one pair of gear elements (R1A, R1B), said pair of gear elements comprising a driver gear element (R1A) on the input shaft and a driven gear element (R1B) on the output shaft, said driver gear element (R1A) being arranged to rotate the driven gear element (R1B), the gearbox also comprising releasable locking means (DR, DR1) to lock, in a first mode of operation, the driven gear element (R1B) to the output shaft in order to rotate the output shaft to the first rotational direction, the gearbox further comprising an intermediate gear element on an additional shaft, the gearbox further comprising a further gear element on the output shaft, said intermediate gear element being arranged to be moved to a position where, when the releasable locking means is, in a second mode of operation, in a released position, the intermediate gear element is arranged to rotate the further gear element that is on the output shaft and thereby also to rotate the output shaft to a reversal rotational direction that is opposite to said first rotation direction of the output shaft, characterized in that the same driver gear element (R1A) that in the first mode of operation is for rotating the driven gear element (R1B), is, in the second mode of operation, via the intermediate gear element arranged also to rotate the further gear element that is on the output shaft and thereby also to rotate the output shaft to a reversal rotational direction that is opposite to said first rotation direction of the output shaft.