I think you need to explain to Clanky that such rudder types have existed in the past..
And still some ferries use it today
Yeah, could you explain about bow rudders to me please TFM
The problem is that they are designed to work when the ship is going astern, when the ship is going ahead it only takes a little bit of play in the rudder bearing to generate quite large forces on the rudder, which in turn damages the bearing, which in turn generates larger forces, which in.....
OK, you get the idea, the bloody thing will fall off!