Best surface Drive for Marine diesel?

Frosty,

What's your opinion of the Seafury drives from NZ?

http://www.seafury.com/recreational.html

A Google search came up with a number of other manufacturers, other than Arneson

http://www.powervent.com/

http://www.pulsedrive.net/

http://www.q-spd.com/benefits.htm

http://zf-marine.com/surface_drives...=f030ea8c0a9624804d9e7a6251a3667743c3&CFApp=1

http://www.godevil.com/Surface_Drive_Release.html

Then of course, I found this!

http://www.rbbi.com/links/drives/surfacedrive.htm

Pericles

 

Sometime ago there was a question about contra rotating shaft drive duo props.

http://www.duodrive.co.uk/preformance_engineering.htm seem to offer this facility.

"The Duodrive system brings significant efficiency improvements. Counter-rotating propellers eliminate waste. In this type of installation, two propellers are positioned one immediately ahead of the other on the same shaft line, but rotating in opposite directions. The rotational energy imparted to the water by the forward of the two propellers is cancelled out by the opposite rotation of the rearward propeller. The slipstream from counter-rotating propellers is almost smooth and straight, with little twist. When a single propeller accelerates water into itself from ahead and expels it astern, it generates thrust like a jet engine. Unfortunately, a significant percentage of the power delivered to the propeller also goes into twisting the water around, creating the helically-shaped propeller wake. This energy is exhausted and does nothing in providing propulsion, or drive; it is, simply, wasted. Duodrive’s concept of counter-rotating propellers aims at dramatically reducing this waster effect and is expected to be 15 to 40 per cent, dependant upon configuration, more efficient than standard, single propeller sets. This all helps to provide the necessary thrust to achieve the 30-knot holy grail that today’s market demands.

The Duodrive product is a self-contained, maintainable sealed mechanism initially intended for the marine leisure industry. It is designed to slot in between a recipient craft’s gearbox output shaft and its driveshaft through-hull gland. After substituting the recipient craft’s driveshaft with a shorter dual shaft arrangement, the Duodrive system slots into place.

Benefits resulting from the introduction of this new technology are significantly increased efficiencies through performance gains, reduced operating costs and environment improvements."

Comments please?


Pericles

 

Shall I answer the first question first, I normally prefer the 3rd question first followed by the 2nd question last or further away from the middle as possible.

I know the Seafury well I use their props, which is a diamond back. Strange really when that is a Levy patent. those props develop in my case 28% slip.

The shaft counter rotation props? Dunno!! I am concerened with surface propulsion.

By the way surface propulsion can be generated without a drive system.

When you by a conventional shaft system do you look for a manufacturer?

Just glancing through the urls I am well aware of them,--Ive never owned one --Why?

" Go devil" is a fishermans mud skipper.

If you ever try to contact these people other than Seafury and possible Pulse drive or Zf there is no reply.
DB is another one that seems to have been posted on the internet and forgotten about.

I emailed Flexitab a few days go,----zilch.

 

Mr. Frosty good luck with you approache for answeres.

 

Volare, Welcome to boatdesign.net? You have jumped in "where angels fear to tread". Therefore you have seen a bit of the seamier side of life here where a recalcitrant, called Rik seems to be in denial? I don't know any-more. I would like the information that Frosty sought from Rik - That is, What are the specifics of the steering-ram that effectively wipe off barnacle growth in vessels permanently in the water where that ram is submerged. I have only read denial & implausible refutation of the existence of any problem.???? This has been carried on over three different threads.

When someone claims "no problem" it is appropriate that that claim is supported by detail on how it is done - particularly when experience shows there is a barnacle growth problem on similar materials (stainless steel hydraulic rams permanently immersed in the ocean) elsewhere in the marine environment.

 

I heard the other day from a reliable source that the police here do not like the Arnesons. They say that they are easily recognized 20 miles away by the rooster tail. I have to admit that It catches my eye when I see one over the bay. If its got a rooster its the police.

The next time I see one in the marina im going to ask him about marine growth on the drive , I cant wait ,--watch this space.

 

Frosty, Masalai,

I have been doing my best to see things from your prospective. So far it has been tough. I think if Rik told you that the sun was coming up in the morning you would call him a liar.

Steve

 

If he said at his command - - yes........

The question still sits unanswered..... Please explain the function on the hydraulic rams, which "remove" (Rik denies they grow on the shafts) the barnacle growth when those parts are normally below the waterline on boats PERMANENTLY kept in salt (ocean as opposed to mix of brackish and or fresh, as in tidal flushing.) water - either on a swing mooring or pen in a marina or on a pick at an overnight stop.

A simple and perfectly valid question that is denied/ignored, responded with attacks or "Who Are You" questions....... Is that too difficult to answer? The invective is to be expected (from me), when a person who should know and be in a position to give reasoned and technical information refuses or otherwise does not????

I am looking for solutions to meet my own concerns as to how & what to power with when operating in remote areas of Melanesia where hull liftout facilities don't exist....

 

Mr. Masalai I read him post and I see him answer to question and he sayes they have design different. I see him answer in post and I see you no accept answer. We non see problem with anresin in Italy. Possbly diffent water.

 

I have NO problems with the drive - per se, - I don't understand his explanation on removing barnacles???? after they settle on the metal of the ram that moves inside the hydraulic cylinder. They (barnacles) are not readily removed - intoto - (every particle of calcium abrasive material or whatever it is that they use to hold fast - it is abrasive & can reduce seals/rings or other mechanisms used inside the hydraulic cylinders to get the cylinders/pistons to function without leaking the hydraulic fluids. It does happen. I have seen the leakage which usually ended up (not in surface drives but other mechanisms relating to rudder actuation) being moved to above waterlines.... Screw shafts rotate and are usually sealed elsewhere and do not have to contain high pressures in hydraulic actuation using rams.

My issue is how does one resolve those issues relating to hydraulic ram actuation which is in-&-out within a cylinder, not round & round.... Mentioning a shear ring is not enough the fine particles left are the problem over time.

 

This is unbeleivable. Mas must and I must have asked this question 10 or more times now.

I refuse to believe that the participants of this thread are really confused at the question, no one can be this dim I think your having a laugh.

Mr Volaire if you understood the answer to the question then please explain to me because I am a bit dim also, I did'nt get it.
Just to remind (again) how do Arneson drives manage to have "no" marine growth as claimed by Rik?

Geeeez I can hear you all laughing I cant believe I am falling for this, day after day.

 

I was wreck diving in Truck Lagoon a few years back. I vividly remember a Japanese aircraft that was lying inverted exposing the landing gear in about 30 feet of water. The oleo struts were still clean and shiny (oleo struts are very much like hydraulic rams) Not one barnacle. This plane had been in salt water for over 60 years.
I was a sport fishing guide in Alaska for several summers. The barnacles up there are nasty. Yet I really don't remember any significant seal problems on our Merc drives (I do admit it was a long long time ago) These boats were left in the water all season.

I am just relating my personal experiance with the question at hand. Not interjecting off topic gibberish. Like the police don't like Arnesons because of the rooster tails Jeesh

By the way, rooster tails are not exclusive. This video wes taken about 6 years ago showing my boat at cruise with fixed surface drives before the Arnesons were installed. Hellacious rooster!

http://youtube.com/watch?v=QIno_IM0Y-s

 

if there is fresh water content in this lagoon ,,you wont have barnicals,,,,just a thought.longliner

 

Mr. Frosty I see you approache non still work. Like Mr. Steve H say "interjecting off topic gibberish" I not knowe why you say when you have surface drive. It non "rooster tail"? I think you have rooster tail if you have surface drive no? Why only anresin? Why no Levi? Why no Sea Fury? Why no Zf? Why no Frosty?

 

I no speak Italian, Can't be bothered, By-by - all yours now...