Talk:Variable-pitch propeller (marine)

Ship Efficiency
"Controllable pitch propellers or CPP for marine propulsion systems have been designed to give the highest propulsive efficiency for any speed, at any loading condition ... By controlling the pitch of the blades, the optimum efficiency can be obtained and fuel can be saved." This is in direct contrast to; "at full power a fixed propeller will have a slighter better efficiency then a CPP."

How is it that Controllable Pitch Propellors can be more efficient in terms of power and fuel, whilst being less efficient that fixed pitch propellors? What is the difference at "full power"? Kirby Rourke 09:17, 20 June 2006 (UTC)

A fixed pitch is "super-optimized" towards one specific condition. It is extremely good (efficient) under certain circumstances and next to useless at others, iow a shipowner can go to a propeller designhouse and tell them: "I have this hull form and I run my ship at this exact speed at these revs on the engine at this load constantly for two weeks, make me a prop for this".

A CPP on the other hand gives moderate performance on all operating conditions. It gives maximum flexibility but does not give any significant gain on any speed or load. It is half-good, half-bad all the way...

For a ship doing only one same thing all the time over and over you use a FPP, for a ship which operates under changing conditions you use a CPP... — Preceding unsigned comment added by 178.72.17.237 (talk) 21:42, 25 October 2011 (UTC)

Requested move

 * The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review. No further edits should be made to this section. 

The result of the move request was: move. --  tariq abjotu  02:46, 29 June 2013 (UTC)

Controllable pitch propeller → Variable pitch propeller – Arrivisto (talk) 19:13, 16 June 2013 (UTC)


 * Support not all VPPs are controllable, so a wider catchment topic is preferable. -- 65.94.79.6 (talk) 00:54, 18 June 2013 (UTC)
 * Support; seems reasonable to me. bobrayner (talk) 20:23, 22 June 2013 (UTC)
 * Support I think that the larger VPP scope should be built from and include content from the CPP subarticle, so I support the proposal. signed:Donan Raven (talk) 09:04, 28 June 2013 (UTC)
 * The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.