What is CPP system in ship?

In Controllable or Variable Pitch Propellers (CPP), the propeller blades are attached to the boss and their pitch can be altered via a hydraulic system. The blades are removable so if they incur damage, can be repaired without removal of the whole propellor.

What is the main advantage of a controllable pitch propeller CPP installation?

Wärtsilä’s Controllable Pitch Propeller (CPP) proved to be the best solution to meet these challenges. Its hydrodynamic design allows for improved propulsion efficiency, resulting in improved speed, reduced fuel consumption and better manoeuvrability.

Why ships equipped with controllable pitch propellers do not need reversible engines?

A non-reversible engine can be used for both forward and astern operation of the ship. Hence, the weight of the engine and propulsion machinery is reduced considerably when compared to what is required in propulsion systems equipped with fixed pitch propellers.

How does a CPP propeller work?

A controllable-pitch propeller is made up of a boss with separate blades mounted into it. An internal mechanism enables the blades to be moved simultaneously through an arc to change the pitch angle and therefore the pitch. The cylinder movement is transferred by a crank pin and ring to the propeller blades.

What is the pitch of a propeller?

The distance that a propeller theoretically (i.e. without slip) advances during one revolution. Each radius of the blade can have a different pitch and therefore the pitch at r/R = 0.7 is often used as a representative value (the nominal pitch).

What is the difference between a fixed and variable pitch propeller?

A variable pitch propeller is one in which the pilot is able to adjust the blade pitch during flight. However, the propeller RPM will vary, in the same fashion as a fixed pitch propeller, as a function of engine RPM or of airspeed.

What is the pitch in a propeller?

What is the difference between a controllable-pitch propeller and a constant speed propeller?

The pitch on a constant-speed propeller can change automatically. With the controllable-pitch propeller, the pilot changes the angle directly in flight. The angle will not change automatically, only when the pilot manually changes it.

What is the advantages of fixed pitch propeller?

The advantages of a fixed pitch propeller solution are that it is cost-efficient and robust. There are also many different variants of the solution. For example, it can be equipped with thick propeller blades if the vessel will operate at low speeds and in areas with floating debris.

What is the difference between a controllable pitch propeller and a constant speed propeller?

Can a CPP propeller be used on a planing vessel?

Even aboard a planing power vessel, one can use a CPP to provide fine pitch and higher rpm to get going, and increased pitch with reduced engine rpm once up to speed. If the vessel has two engines, and speed is to be low, one engine can be dropped out, and its propeller feathered to reduce the drag of the stopped propeller.

Can a FPP propeller operate at any other rpm?

At any other rpm, or any other vessel loading, the FPP cannot operate efficiently, being either over pitched or under pitched. A correctly sized Controllable Pitch Propeller on the other hand is able to be efficient over a wide rpm range, and over a wide range of vessel loading.

How does a controllable pitch propeller work?

Virtually ALL controllable pitch propellers make use of a hollow shaft that contains a concentric push rod which moves forward and aft over a certain range. Via an eccentric in the propeller hub attached to the blades and to the push rod, the pitch of the blades is accurately controlled.

What is the DP of a propeller shaft?

Design of Propeller Shaft (dp) Since the propeller shaft is subjected to both bending moment due to propeller weight and twisting moment diameter of propeller shaft dp = 25% extra then the designed by pure torsion. dp = 1.25 x 400.135 dp = 500 mm Design of Intermediate Shaft (d)