Comparing azimuthing thrusters and conventional shaftlines for propulsive efficiency of pushboatbarge convoys

AuthorsJoost Schot, Erik Rotteveel
Conference/JournalMARIN Report 128
DateJan 21, 2020
Reading time3 minutes
Azimuthing thrusters can serve as an interesting alternative to conventional shaftlines. But how does this affect powering performance and efficiency?
Pushboat-barge convoys offer great flexibility for inland cargo transport, being able to transport cargo on extremely shallow rivers. However, the meandering nature of rivers requires the convoys to have optimal manoeuvrability performance. Therefore, azimuthing stern drive thrusters (ASD) can provide an interesting propulsion alternative.

ASD more efficient in deep water

For the shaftlines’ configuration, the nozzle thrust significantly decreases in the in-behind conditions compared to open water conditions. It was found that both the rudder and the propeller tunnel downstream of the propulsors have a negative effect on the thrust provided by the nozzle, leading to a reduction of the efficiency of the propulsion system.

Cut-through of flow around fixed-propeller push boat with 6 barges

azimuthing thrustersshaflinespowering perfomanceefficiency