Reversing rudder

Has anyone designed or met a successful reversing rudder, ie a rudder that is in the prop wash when the prop is astern?

The rudder is usually small and locked when not in use.
The problem with single central inline shaft is that the rudder will need to be offset to one side of the shaft.

It is for a Work vessel with a shalow V and bow thrusters are out.

 

Yes, they are fairly common. Two small rudders are installed forward of the prop. The prop wash makes them very effective in reverse.

 

Thanks Gonzo
Any indications as to the size?
so far I have only seen them on large tugboats here but never on smaller boats. Twin makes it a bit more complex but it makes sense

 

They are called "flanking rudders". Single flankers are also common, though twins are better if possible. They are generally sized based on entirely practical issues:

1) What will fit?
2) What can a rudderstock the same size as the main one handle?
3) How big a steering gear can I afford?

Note that control can be interesting - they can't deflect when the boat is running ahead, so the steering gear often has interlocks to prevent this.

Also, traditionally, flankers are on inland boats, and (like the mains) are steered with a tiller-like "stick", not a wheel. The flanker stick is then below the main stick, often on the same axle, so that when maneuvering, the helmsmen can turn both at once.

 

They are also mounted in small towboats (As small as 25') and in paddle wheel river boats.
Search Google images for 'flanking rudders'

 

Thanks for your help, I have the info I need.

 

The "kitchen rudder" or reversing rudder, complete with drawing was discussed somewhere here in the forum.