Prop shroud

[bargemast]

Pusher-Tugs equipped with Fixed Kort Nozzles have 2 (sometimes even 3) rudders behind the prop, and 2 flanking rudders in front, for manoeuvring in reverse.

 

Peter.

Edited December 4, 2012 by bargemast

[Idunhoe]

That sounds like a more primitive version of a Kitchen rudder - I've seen pictures of at least one narrowboat that had one installed, along with a custom tiller arrangement where the tiller could be tilted upwards to put the rudder into reverse.

Kitchen rudder gear and the Kort system are completely different. With KR the shaft always turns in the same direction and often, but not always, at a constant speed with the amount and direction of thrust being varied but the positioning if the buckets. From experience at settings other than full ahead or full astern the steering is very heavy indeed.

The, fixed or steerable shrouded prop. In the Kort system still needs the speed and direction of turning of the prop. to be varied to achieve increase/decrease in boats speed and ahead or astern propulsion.