CPP desapear from recreational boats Who gets the benefit of the crime ?

[gonzo]

Your thread name is a very strong statement. I did a quick search and came out with many company names that sell what you claim doesn't exist. Also, by saying "crime", imply some kind of conspiracy. Now you want me to do all the work for you and show "coherent models/prices". Come on, go shopping.

[kistinie]

You claim the product exist for the average joe leisure boat...that i described as 35feet/40 Hp sailing boat

Give one proof, just one !


as used to say my uncle André that was in the army, "trust do not exclude control"

Thanks !

[gonzo]

The average Joe has the sense to buy and outboard. You are looking for a high performance sofisticated piece of equipment. If you want it, is available. Pay up or shut up.

Originally Posted by fcfc

Technically, it does not need a clutch.
But in the context of small cruising boat, at mooring, when charging your batteries from engine alternator , do you want to turn your prop at 0 pitch ?
And in a man overboard maneuvre, the only way to stop your prop from rotating is to stop your engine. I am not sure most people would accept it.
What is acceptable in a big boat may not be acceptable in a small one.

The size of the boat has nothing to do with the sort of propulsion system one installs.
And the average boater has never seen, and will never see a "man over board" maneuvre.
For charging batt.s a main propulsiion engine is not designed!
And if you have a prop turning when mooring, be happy, that is the best you can have! No gearbox is able to respond as fast as a CPP!
So, what is proven to be the best conventional propulsion system on many thousands of ships and boats you must not fear too much!
For example: the most port control and police boats have CPP systems around the world and THEY HAVE quite often to do with "man over board" situations.
As usual: if a boater fears systems it is not related to the systems abilities, but to the boaters experience (better, the lack of). And I think you do´nt have much! Read the article below, to know what a CPP system is.

and:

Originally Posted by gonzo

Your thread name is a very strong statement. I did a quick search and came out with many company names that sell what you claim doesn't exist. Also, by saying "crime", imply some kind of conspiracy. Now you want me to do all the work for you and show "coherent models/prices". Come on, go shopping.

ten points mate!!
But take care, he will call you with bad names, like he does call me, since I refused to deliver figures on his phantasies.

Regards
Richard

[kistinie]

Originally Posted by gonzo

Pay up or shut up.

Woww !!! Keep cool nothing vital behind this !

What a technical demonstration and what a sense of a fair play discussion.
Very impressed !
So nothing new under the stars...No CPP for small power
Notice that i did not talked of price, only of power and boat size...

The last CPP i saw was on an 8.5 metre sailing boat for sale in St Maxime coupled with a lister engine...An average joe sailing boat but if i understand your position it was a kind of marine UPO unidentified propeller object ;-))

[gonzo]

kastenmarine.com
http://www.seaquipment.com
Take out your check book. There was never a lot of CPP in the recreational industry because of the cost and maintenance. At the end, it disappeared because people didn't want to pay for them. You are a good example of it, complaining but not willing to spend the money.

Originally Posted by kistinie

Woww !!! Keep cool nothing vital behind this !
What a technical demonstration and what a sense of a fair play discussion.
Very impressed !
;-))

You never had a sense for fair discussions! The only goal you have is to make your unmature dreams come true! And everyone who refuses to contribute to an issue that is non existent is called your enemy or non supportive. You are mad man!
After some 30 members have named you mad now, you should accept, you are!
Keep your mouth shut, do´nt make idiotic statements and ask others to proof them!

And to stop others from confusing the community, read this:


I. CPP RATIONALE
What Is the Advantage of Controllable Pitch?

There are real advantages provided by Controllable Pitch Propellers (CPP). This article is intended to outline several of the reasons why CPP might be favored for a motor vessel, for a sailing vessel, or for a motor sailor.

For Power Boats

Long Range Cruisers (LRC's) will necessarily carry quite a sizable fuel load, typically some 12% to 15% of the vessel's displacement. With such a highly variable load on a long range trawler yacht or other long distance power vessel, if fitted with a CPP, the pitch can be increased when the vessel is light, and decreased when loaded without having to vary the engine rpm, and will provide maximum use of the engine's power.

When running free with wind and waves 'pushing' you along, the pitch can be made greater in order to properly load the engine. Conversely when headed into the weather, the pitch can be made more fine. Much like shifting into overdrive or second gear, depending on the requirement.

While it is true that a Fixed Pitch Propeller (FPP) can be more efficient than a Controllable Pitch Propeller, it is rarely given that opportunity... The FPP can only be maximally efficient at one rpm with one horsepower input amount and one load condition: i.e. those for which it was specifically designed. At that one rpm and load, the FPP is designed to absorb all the power that the engine can produce. 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. This is so because the propeller's pitch can be adjusted as needed in order to absorb all the power that the engine is capable of producing at nearly any rpm.

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.

The Controllable Pitch arrangement will allow the engine rpm to be varied as needed for the most favorable reduction in engine vibration and noise, as well as to eliminate cavitation.

Finally, there will be no anxiety as with a Fixed Pitch Propeller over whether or not the correct pitch has been calculated for the vessel. As many boaters have discovered, predicting ideal propeller pitch is far from an exact science...! With the wrong fixed pitch propeller, efficiency will be very poor indeed.

With a Controllable Pitch Propeller, you can make pitch adjustments under-way to suit a wide variety of conditions. It is not a difficult matter to choose the appropriate pitch with a CP. One will quickly learn what works best, even without fancy instruments. Once you have sailed with CP, you will be very reluctant to go back to FP -- by comparison FP will suddenly seem rather primitive.

For Sail Boats and Motor Sailors

Should you be traveling aboard a sail boat or motor sailor, it is unquestionably the best arrangement to have a CPP for the sake of accommodating the widely varying engine power requirements, whether under sail or not; whether running free or beating; or whether simply powering.

A further benefit is that some CP units will actually permit fully feathering the blades in order to effectively eliminate prop drag while under sail alone.

Relative Efficiency

If we run at speeds other than that for which a Fixed Pitch Prop has been pitched, the propeller is not being efficient, and we are wasting fuel. It is interesting to note that here in the US where fuel is relatively inexpensive, the Fixed Pitch Propeller is the main stay. In the US, if it costs us a little more per mile to drive our vessels, we have not really taken notice.

While that has been the case for quite some time here in the US, we are seeing big changes in that situation... Now (2008) with fuel prices closing in on USD $4.00 / gallon, any extra fuel used does begin to sting...!

In Europe where fuel is several times the cost in the US, the CPP is much more common. In Scandinavian countries the CPP configuration is nearly universal, and has been so since the beginning of mechanization of their commercial fleets in the early part of the 20th century. In other words, it is extremely well proven and well supported in northern Europe, especially in Scandinavia.

Maneuvering

A CP arrangement does not require a reversing gear--only a reduction gear. Instead of changing the direction of rotation, the blades articulate clear around until they are chewing on the water in the other direction. There is no gnashing of gears, only a smooth transition from ahead to astern thrust, with any choice of the amount of thrust desired, from dead slow to full ahead or astern. It is also possible to use a higher engine rpm and shallow pitch, for example to hold station while applying full power to the hydraulics (anchor windlass, etc.).

What About Damage...?

In the Baltic and in North Sea harbors, ice is common. Still the CP prevails. CP units are designed with the blade being the weaker part. If you damage a blade, it's a simple matter to replace it, and both the shaft and pitch control mechanism are not affected. One can easily carry a spare blade. This protects the propeller hub, the shaft, the coupling, and the transmission from being damaged by a sudden stop or by striking a log or other debris.

In the event of parts being required, parts and spares can be ordered and delivered quickly worldwide. I have phoned an order for parts to Sabb of Norway for example. Parts are shipped right away by air freight and are received within a few days. That's as good as the service I get when ordering parts locally...!

In any case, this technology is nothing new, is robust and well proven... and therefore certainly nothing to be afraid of...!

II. CPP COSTS
Does a CPP Arrangement Cost More...?

To most boat owners, what matters most when considering a CPP installation, whether on a new boat or on a boat that is being re-powered, is usually purchase cost. It might at first glance seem that a Fixed Pitch installation will be less expensive to purchase. After all, isn't it simpler?

What is the real cost difference?

This question is brought up sufficiently often that I have made the following actual cost comparison. In so doing, it's possibly best to make this kind of comparison using equipment that is suited to the requirements of a specific engine. So, let's use the John Deere 6 cylinder turbo as an example: the JD 6068 TFM.

Please bear in mind that the following comparison was made at a given time, using the prevailing costs and exchange rates during early 2001.

Example CPP: Controllable Pitch Propeller Equipment

Sabb HVP 65-E as of 1999 was quoted at 60,000 Norwegian Kronor (NOK), ex works Bergen, Norway. At that time they were quoting a 20% discount for OEM direct orders. The exchange rate during April 2001 was USD $1.00 equals NOK 9.08. This translates to a cost of USD $5,286 assuming the 1999 NOK price did not change much until 2001, and assuming the same OEM direct order discount would still be available.

The completely assembled Helseth 3H-60, having a 60mm shaft, stuffing box, stern bearing, shaft tube, and 660mm diameter 3 blade CPP propeller, at that time was priced at NOK 25,000, with a 20% OEM direct order discount available. This assembly translates to a cost of USD $2,203, ex works, if making the same assumptions.

CPP Whole Shebang: USD $7,489 plus freight of around USD $350 and import brokerage of around USD $50, for a very approximate total of around USD $7,889 with shipping, but without taxes. Bear in mind that this is a 1999 price and is based on a 2001 exchange rate...!

Example FPP: Fixed Pitch Propeller Equipment

The Twin Disc MG-5050, also well suited to the output of the JD 6068 TFM, retails (in 2001) for USD $3,570. A "builder's" 10% OEM discount is sometimes available, so let's use approximately USD $3,213.

A comparable stern gear "assembly" is offered by Vetus and includes shaft, bearing, stuffing box, and shaft tube. Although that would be a fairly good "like for like" comparison, I don't have a price from Vetus for that equipment. However we can instead assemble the pieces one by one, again assuming a 60mm shaft and 3 blade 660mm prop (around 26 inches), and taking the retail prices (actual researched prices as of 2001):


* Coupling: $0.00 (usually supplied with gear)
* Shaft: Aquamet 22 approx: USD $1,500
* Machining on Shaft (Both Ends): approx: USD $500
* Prop: 26" 3 blade Ni Br Al prop (comparable to the Sabb / Helseth alloy): approx USD $1,900
* Bronze Sleeved Cutless Bearing: approx USD $200
* Stuffing Box: Varies, so assume approximately USD $400
* Bronze Stern Tube Materials: 5' x 3" OD x 0.25" wall: USD $180
* Machining on Stern Tube: Approx USD $400
* Flange Fabricated on Stern Tube: Approx USD $350


From the above, the tail shaft "assembly" amounts to a total of around USD $5,500, and the Twin Disc MG-5050 Gear comes to around USD $3,213. This gives the following total:

FPP Whole Shebang: USD $8,713 without any shipping or taxes. The FPP costs given here are using current (April 2001) quotes from suppliers and machinists in the Seattle area, and using materials of equal quality to the Sabb / Helseth system.

A Few Comments

The above cost figures have factored in the miscellaneous goodies, the machining and the fabricating required to create an "equivalent" system in terms quality, and in terms of the self enclosed type of shaft arrangement offered by Sabb / Helseth. Of course one could argue that a Manganese bronze propeller with an ordinary stainless shaft in a non-self-enclosed shaft tube will be less costly, but then we would not be comparing "like for like" in terms of quality and components.

The above cost comparison was made at a given moment in time, using prevailing exchange rates of that time (2001). Of course exchange rates have changed, but so have local costs in the US. I have been told that several of the above mentioned prices have increased over the years, however if we adjust the above figures for present day exchange rates and similarly adjust for the increased costs of a comparable FPP installation, the overall comparison will in all likelihood still show approximate parity.

Doesn't a CPP system cost more to install...?

No! It consists of a gear box and a self-enclosed shaft assembly. We encounter no end of completely unwarranted whining from boat builders who are unfamiliar with CPP equipment. Consider the following:

* Mounting the gear box is in no way different than mounting a similar FPP gear and makes use of the same SAE flywheel housing sizes, etc. Zero difference.
* Mounting the self-enclosed shaft assembly is actually easier. Why...? Because the entire shaft, shaft log, stern bearing and stuffing gland are supplied as a unit, one which is already matched to the propeller and to the shaft coupling. In other words, there is less labor involved in the installation, less coordinating of parts, and overall considerably less fooling around with it all. It is simply a matter of arranging for the shaft log to be isolated from the structure (in the case of a metal boat), or mount it directly (in the case of a GRP boat), or bore a hole for it (in the case of a wooden boat). This could not be simpler.
* Once again, the advantage goes to the CPP assembly.


III. CPP SOURCES

One should note that there are several CPP arrangements available from a variety of manufacturers.

Sabb Motor is now called Frydenb� Sabb Motor AS (name changed in 2008). Several years ago, the last remaining Sabb engines were discontinued, and replaced with a range of Lister Alpha engines having a power rating up to 50hp, and IVECO engines in larger sizes. For small boats, the Lister / Sabb / Helseth combination is an improvement over the prior Sabb engine offerings in many ways, primarily due to the Lister engines being half the weight, and also being less tall compared to the Sabb engines, making the Lister engines a much easier fit. Sabb has re-focused their business on the manufacture of CPP marine gears, available for engines of 10 hp to around 300 hp.

Up to 30 hp or so, Sabb provides the HVP-25 which makes use of a solid shaft, with a Sabb manufactured propeller and stern tube assembly. Above 30 hp, the Sabb CPP gear offerings operate a concentric shaft, and Helseth is the shaft and propeller supplier. Helseth also supplies the complete shaft / log / propeller assembly. The Helseth range includes quite large vessels, as well as high speed CPP equipment.

Hundested equipment is made in Denmark and is of extraordinary quality. The Hundested propeller assemblies make use of a concentric shaft arrangement just like the Helseth equipment, and it is therefore 100% compatible with the larger Sabb gear offerings. A Hundested installation can alternately make use of a standard reduction gear combined with a Hundested CP 'control box' in the drive line (rather than a 'servo' type of marine reduction gear). Hundested offers a variety of sizes and types of pitch control boxes: manual, electric, or hydraulic. For installations above 300 horsepower Hundested offers a CP servo pitch controlling gear from Mekanord. In still larger sizes the gear will be manufactured by Hundested.

Another excellent CP gear and propeller assembly maker from Norway whose offerings extend into somewhat larger sizes is Nogva Motorfabrikk. Nogva CP marine gears are available for installations of from 50 hp to 680 hp. Larger CP gear models also include dual hydraulic PTO, intended for heavy duty use in the North Sea fisheries. Nogva also manufactures their own line of 3-blade CP propellers, available with grease, oil or water lubricated shaft assemblies as we've described above. Yet another option available from Nogva is an in-line shaft hydraulic servo pitch control, much like the offering from Hundested. The in-line servo pitch control box allows the use of CP propeller and shaft assembly with a standard marine gear (such as Twin Disc or ZF).

West Mekan Produksjon is yet another Norwegian manufacturer specializing in propeller and shaft assemblies that are compatible with the gear offerings from Sabb and Nogva. West Mekan also makes a variety of CP servo pitch control boxes, allowing their propeller / shaft assemblies to be installed with a standard marine gear. As with Hundested, the West Mekan pitch control units are offered in mechanical, electric, or hydraulic models.

A variety of large vessel marine gear offerings are available from ZF, which offers a line of CP gears extending upwards into Mega-Yacht and even cargo vessel sizes... In fact, in the very large vessel sizes there are numerous other manufacturers of CP propellers.

Our specific challenge has been to assemble good information about CP equipment in the relatively smaller vessel sizes, accommodating up to approximately 700 horsepower.

IV. CPP CONTACT INFORMATION

Contact information for the above-mentioned manufacturers is as follows:


Nogva Motorfabrikk A.S.
N-6280 S�vik
Norway
www.nogva.no
+47 70 20 84 00
+47 70 20 84 10
firmapost@nogva.no
Mr. Kjell Norvoll


Helseth A.S.
Bakliveien 11-13
6450 Hjelset
Norway
www.helseth.no
Telephone : +47 71 20 29 00
Fax : +47 71 20 29 01
helseth@helseth.no


Hundested Propeller A.S.
Stadionvej 4
DK-3390 Hundested
DENMARK
www.hundestedpropeller.dk
Telephone +45 47 93 71 17
Fax: +45 47 93 99 02
Mogens Christensen (mogens@hundestedpropeller.dk) is helpful and very knowledgeable about CPP installations for all kinds of craft.


Frydenb� Sabb Motor AS
Post Box 7170
5020 Bergen, Norway
www.sabb.no
www.frydenbosabb.no
Phone:+47 55 34 88 00
Fax: + 47 55 34 88 01
General Inquiries: post.sabb@frydenboe.no
Tor Isdahl, Sales: tor.isdahl@frydenboe.no


West Mekan Produksjon AS
Malakoff 3
N-6770 Nordfjordeid
NORWAY
www.west-mekan.no
office@west-mekan.no
Konrad Skibenes: konrad@west-mekan.no Tel : +47 57 88 51 50. Fax : +47 57 88 51 51
Kjell Steins�ker: kjell@west-mekan.no Tel : +47 57 88 51 53

V. CPP TECHNIQUE
The "Basic Technique" Of Controllable Pitch Propellers...

Keep in mind that the technique I am about to describe is only possible to use in combination with a pyrometer in order to monitor the actual load on the engine. The reason for the pyro is that most marine engines can be overloaded and will therefore require that you monitor the exhaust temperature carefully using a pyrometer, which makes it possible to accurately gauge engine output.

At first a CP installation will seem to offer far too many choices... There are too many variables..! How can one choose the correct pitch or rpm..? After a bit of experience however, one will soon discover in a general way what works best in terms of the desired rpm and a range of pitch settings that work for the speed and weather conditions. The process is really fairly simple.

Once an operator becomes a little more familiar with their CP installation, the rpm and pitch that favors a given condition, vessel loading, or speed through the water will be virtually automatic. Prior to that, the pitch and engine loading can be roughly dialed in as follows:

* Select the pitch that seems appropriate to the requirements of the situation (by experimentation and recording or remembering the results of prior times).
* Increase the throttle to raise the engine rpm until there is no further gain in rpm.
* Allow the vessel to come to speed with the power being applied until equilibrium is reached.
* At that point, vary the throttle setting to be sure rpm is at its maximum for that pitch setting.
* Back off the throttle until you hear the engine lose a few rpm, then nudge the throttle back up to or just under maximum achievable rpm for that pitch.
* At this point, the engine is powering the propeller at its maximum ability, and no 'extra' fuel is being fed to the engine.
* Monitor the pyrometer to assure that the engine exhaust temperature does not exceed the manufacturer's recommendation.
* If the pyro reading is too high, just back off the throttle until the temperature is within tolerance.

Ideally, this will be within the preferred engine rpm range (the sweet spot) for the speed or conditions. If the pitch is too heavy for the weather conditions or the vessel load condition, there will probably be audible cavitation. Pitch should be set well clear of the cavitation range, i.e. more shallow. If the pitch is too shallow, the engine will not be loaded by the propeller and will run right up to its maximum rpm. In either case, make the requisite pitch adjustments until all is well. If conditions change (wind, weather, motor-sailing, etc.) then another series of nudges to the throttle are made to be sure you are not overloading the engine.

If the pitch is too heavy for the throttle setting (i.e. more throttle than the achievable rpm warrants) there will possibly be a darker exhaust smoke. With a pyrometer the exhaust temperature will begin to exceed the engine maker's published limits, and the throttle must be backed off.

In my own 34' schooner Emerald I installed a Sabb engine, which had an integral 2:1 gear with built-in CP control, etc. With the Sabb heavy duty slow turning motors, it is not necessary to use a pyrometer as a guide. It is sufficient to listen to both propeller and engine, and nudge the throttle until it is right. Per the Sabb manual's instructions, black exhaust smoke is an indication of excessive engine overloading.

It is far better to use the "nudge" technique described above for the throttle / rpm setting, rather than the exhaust color. This technique will quickly get you a workable preliminary throttle setting. Keep in mind though that for modern-day engines, even the "nudge" technique is not a sufficiently refined indicator for fine tuning the pitch or the throttle setting, and the pyrometer reading must be consulted.

The above-described technique is primarily used for familiarization with the CP equipment. With the pyro readings, one can gauge the load on the engine precisely. Using these techniques, and by listening to the engine and the propeller, eventually you'll know what's 'right' among the large variety of settings possible, i.e. in an intuitive way that does not rely on anything more than your senses and your common sense.

Of course all of the above is not to say that you must run the engine at its full capacity all the time...! For example, if the engine is idling you can vary the pitch as needed for the perfect salmon trolling speed... If the engine is charging a battery or running a refrigeration compressor or a water maker, you can back off the pitch some in order to allow the engine to propel the boat at maximum efficiency while still using full engine power.

VI. FINAL THOUGHTS

We have reviewed a simple cost-comparison case to illustrate the economics as well as the overall rationale that drive our recommendations in favor of a CPP installation, whether for a motor sailor or for a passagemaking power vessel. An added benefit is that the CPP system will be more efficient in use, and will be much more adaptable to variable vessel loadings, weather, maneuvering, or sail-assist situations. With these advantages the economics in favor of a CPP system become yet more compelling.

With a Fixed Pitch Propeller (FPP) system, once it is installed you will inevitably find yourself in an unknown situation in terms of whether the pitch has actually been calculated correctly for your vessel. In an alarmingly large number of cases it will not be. Therefore, in order to make a thoroughly fair cost comparison, one really should factor in the probable added costs of a second or third haulout and re-pitching ceremony...!

This would never be necessary with CPP equipment.

These thoughts are not meant to deprecate the excellent FPP equipment available. They are rather an attempt to encourage an open mind when making this choice during the course of a new vessel design, as well as to encourage the same on the part of builders who oddly are often too rigidly stuck in their ways to consider new (actually old) or unfamiliar technology...

Copyright 1998 to 2008 Michael Kasten


Regards
Richard

Originally Posted by gonzo

kastenmarine.com
http://www.seaquipment.com
Take out your check book. There was never a lot of CPP in the recreational industry because of the cost and maintenance. At the end, it disappeared because people didn't want to pay for them. You are a good example of it, complaining but not willing to spend the money.

Gonzo, there is no real difference in cost! See the article by Michael above!
And they did not disappear! The industry installs more CPP systems today on recreational craft than ever before!
Impressively you pointed towards the same designers comments while I was typing my offense.
Regards
Richard

[KnottyBuoyz]

I had thought Vetus made a CPP systems for small boats. I looked in their most recent catalog and it's not there anymore.

[kistinie]

Apex...97 post to make you share informations and give answers to a simple question.
This makes me think to amateur race engine builders hiding their small secrets on camshaft timing or head grinding when i used to race.
What a hard work...But after all only the result counts.
Thank you for this constructive position
if i could edit my N° 1 post i would add an advice to go to N°97 directly !

Now nothing is finished, the next fight, will be to find a light simple CPP that fits a 20 to 30 Kw engine and get an invoice
Do you have an idea of the lightest CPP available today or do i have to pay with the sweat of 97 more post :-)
No i'm joking, that too much unpleasant, i will keep on without your help.

[gonzo]

The cost of purchase is moderately higher. The maintenance cost is the issue. Most boaters neglect their boats, specially what they can't see (underwater ). I think the build up of marine growth will cause problems to the average owner.

[kistinie]

Neglecting maintenance is very expensive, that is true
i drive old reliable cars (40 to 50 years) with grease nipples everywhere for 20 years without significant break...but to the cost of 10 minutes grease pause every 2000Km

Prevention rather than cure

Originally Posted by kistinie

Apex...97 post to make you share informations and give answers to a simple question.

Learn to read, learn to follow advice (not only here, thats valid for all of your childish threads).
And do´nt ask the professionals to get, or provide, quotations for a unmature idea! And before your question arises: I build more yachts in one year than you probably have been aboard in your whole life. And that was told to you at least
two times in the past (not by me).
most was answered here on page one!

Originally Posted by apex1

The statement that CPP disappeared is not right. The opposite is correct! There are more CPP manufacturers today than we had in the 60´s. Most of them are mentioned above, but do´nt forget "Maxprop" and "Gori" for the low power (or sailing) range; and "Piening" and "ZF" for higher outputs.
We install mainly Hundested in our displacement boats.
The often heared statement that these systems are expensive is definetily wrong! In a fair price comparison you´ll find a CPP installation is as cheap (or expensive) as a conventional gearbox and drivetrain of the same quality. Boatbuilders often compare the cheapest available gearbox, shaft and prop with the high end Scandinavian CPP installation and find a noticeable difference then. Naturally....
Edited: I just found an old calc.(2005) and the difference was 2.300€ per drivetrain (CPP above the gearbox), but that was on a 36mtr. and each engine was about 180.000€. So I do´nt call that a difference.
The whole Scandinavian fishing fleet uses CPP only! And we all know that fishermen have no money to waste.
The main advantage of a CPP is the fact that you allways operate your Diesel on a perfect load setting, that gives the most efficient consumption and keeps your engine happy.
Fast Fred, it is not the question how often you have to go uphill in a force 10 storm. But if your yacht crosses the Atlantic at 50% power setting or just the pond from Ibiza to Mallorca at 85% makes a huge difference. And that is everyday use on larger displ. yachts.
Regards
Richard

and

Originally Posted by gonzo

The cost of purchase is moderately higher. The maintenance cost is the issue. Most boaters neglect their boats, specially what they can't see (underwater ). I think the build up of marine growth will cause problems to the average owner.

I do not see that. And that is not in line with my experience, neither for the cost of puchase, nor for maintenance.
Regards
Richard

[TollyWally]

Apex,
Thank you very much for the interesting post on the cpp units cost. In my limited experience Norwegian marine items and fishing equiptment are usually well engineered and well made. Most definietely food for thought, again thanks.

[kistinie]

you can thank.... Michael Kasten http://www.kastenmarine.com/CPprops.htm



The question was CPP for leisure boat (not billionnaire boats)
Here i will post the answers about 30Kw CPP, if i get more than one positive answer i will be lucky



Hello sir.
Sorry but we do made so small CP propellers.
Best regards / med venlig hilsen
HUNDESTED PROPELLER A/S