A modular multi-engine system having a plurality of engines and a plurality of gear units each gear unit having at least one rotatable member and a drive shaft being driven by one of the plurality of engines, where at least one of the gear units is a main gear and the other peripheral gear unit(s). Each rotatable member of each gear unit engages at least one other rotatable member of an adjacent gear unit such as to ultimately transfer torque from all the engines operable in said modular multiengine system to an output drive shaft connected to said main gear unit. The rotatable member of at least one of the peripheral gear units is located at a different height than at least one other cogwheel of another gear unit. The main gear unit includes an upper rotatable member and a lower rotatable member coaxially connected.