[3] Additionally, a twin-rudder configuration and/or a bow thruster can significantly contribute to the maneuverability of even the largest ships.
Also, a pair of flat plates are typically welded to the top and bottom to prevent or minimise the end-effect on the aerofoil and maintain 'lift'.
[1] The basic principle proportions of a typical Schilling rudder layout are as follows: Or in other words, a bulbous widening for 1/5 of the total length of the rudder blade, with a streamlined narrowing for 2/5 of the length leading to a flat section lasting for around 1/5 of a cord-length, finalizing in a blunt-ended flared trailing edge for the remaining fifth.
If extreme maneuverability is not required, chord length can be reduced to a minimum of 0.55 × propeller diameter.
No information as to the layout or profile design of a twin rudder system is contained within this article.