The ASDS (drone ships) use diesel[1] for stationkeeping but they use tugs[2] to get from the port to the landing site & back. I can't get engine details on the

The ASDS (drone ships) use diesel[1] for stationkeeping but they use tugs[2] to get from the port to the landing site & back. I can't get engine details on the tugs[3], but wikipedia says[4] tugs often have locomotive diesel engines. 1 - https://www.thrustmaster.net/out-drive-propulsion-unit/portable-dynamic-positioning-system/ https://www.thrustmaster.net/out-drive-propulsion-unit/porta... 2 - https://www.reddit.com/r/spacex/wiki/asds#wiki_ships https://www.reddit.com/r/spacex/wiki/asds#wiki_ships 3 - https://www.marinetraffic.com/en/ais/details/ships/shipid:434560/mmsi:367017460/imo:8983375/vessel:ELSBETH_III https://www.marinetraffic.com/en/ais/details/ships/shipid:43... 4 - https://en.wikipedia.org/wiki/Tugboat#Tugboat_propulsion https://en.wikipedia.org/wiki/Tugboat#Tugboat_propulsion