Becker Flap Rudders

For many in the maritime industry, Becker is synonymous with flap rudders. When people talk about a Becker rudder, they are often referring to the company’s classic high-lift rudder with a movable flap. The design was developed by the company’s founder, Willi Becker, in the 1950s, inspired by the flaps on aircraft wings. Since then, Becker’s flap rudder has become an international benchmark in high-performance marine rudders and remains one of the company’s best-known products.

A Becker Flap Rudder generates high lateral force across a wide range of speeds and is particularly effective in ports, river traffic, and other narrow waterways where high maneuvering precision is required. The standard design features a straight leading edge, but the rudder can also be equipped with options such as Twisted Leading Edge, Closed Linkage, King Support, a heel pin, and a rudder bulb to optimize performance and adapt the design to the individual vessel’s operational profile.

How does the flap work?

The rudder’s lateral force is generated by the distribution of pressure around the rudder profile. The movable flap affects the pressure distribution on both the suction and pressure sides, thereby providing significantly higher lift than a traditional NACA profile without a flap. Even as the rudder approachesstall, a more favorable pressure distribution is maintained compared to a conventional rudder. A rudder deflection of 45° typically results in a flap deflection of about 90°, which greatly amplifies the rudder’s hydrodynamic effect. As a result, even relatively small rudder deflections generate very large lateral forces. The high lift provides excellent maneuverability in harbors, narrow channels, and other confined waterways, while simultaneously reducing the need for towing assistance in many situations. According to Becker, maneuvering forces can increase by 10–20% compared to a corresponding rudder without a flap, while the same lift can be achieved with a smaller rudder surface area. Becker Flap Rudder is available for rudder angles of up to 65°, providing excellent performance during crab steering (sideways movement) and other advanced maneuvers.

When is a Becker Flap Rudder appropriate?

The Becker Flap Rudder is an excellent choice when high maneuverability in ports and narrow waterways is a priority without compromising course stability while underway.

Becker specifically recommends the flap rudder for:

• Container ships
• Tankers
• Ferries
• Car carriers
• Passenger ships
• Offshore vessels
• Workboats
• Fishing vessels

Options for Becker Flap Rudders

The Becker Flaproder can be equipped with several technical options that further enhance the rudder’s performance, service life, and operational reliability. Examples include Twisted Leading Edge, Closed Linkage, King Support, Rudder Bulb, and Heel Pin, with each solution designed to optimize the rudder’s characteristics for different vessel types and operating conditions.