A drive system for an engine arrangement, the drive system comprising an epicyclical gear reduction mechanism having a main axis and comprising: a first main gear, a second main gear arranged to rotate about main axis in the same direction as the first main gear, a first set of planet gears with planet gears meshing with the first main gear, a second set of planet gears with planet gears meshing with the second main gear, a planet carrier, supporting planet gears of the first and second planet gears, the planet carrier being located, along the main axis, between the first main gear and the second main gear.