Reply
 
Thread Tools Search this Thread Display Modes
 
Old 12-02-2019, 03:28 PM   #1
Veteran Member
 
adornato's Avatar
 
City: San Francisco
Country: USA
Vessel Name: Sarah McLean
Vessel Model: Mainship 30 Pilot
Join Date: Oct 2007
Posts: 35
sharrow propeller. a revolution?

As someone who hates prop cavitation noise, particularly on my Mainship 30 , i was interested in this post on another trawler forum

https://www.boattest.com/Sharrow-Engineering-Propeller

Not yet available but sounds like a winner.
__________________
Advertisement

adornato is offline   Reply With Quote
Old 12-02-2019, 03:52 PM   #2
Enigma
 
RT Firefly's Avatar
 
City: Slicker?
Country: Bumpkin?
Join Date: Oct 2007
Posts: 12,846
Greetings,
Mr. a. I'd heard about this prop design before BUT I have also been looking at Mainship 34's with the big (370HP) Yanmar engine, some of which have vibration problems that are seemingly unsolvable by changing props. I wonder if THIS is the solution?
__________________

__________________
RTF
RT Firefly is online now   Reply With Quote
Old 12-02-2019, 06:21 PM   #3
Guru
 
MurrayM's Avatar
 
City: Kitimat, North Coast BC
Country: Canada
Vessel Name: Badger
Vessel Model: 30' Sundowner Tug
Join Date: Jul 2012
Posts: 4,861
Impressive real world test. What's also impressive is how he visualized the prop in his head, then went about bringing it into existence.
__________________
"The most interesting path between two points is not a straight line" Murray Minchin
MurrayM is offline   Reply With Quote
Old 12-02-2019, 06:46 PM   #4
Guru
 
City: Rochester, NY
Country: USA
Vessel Name: Hour Glass
Vessel Model: Chris Craft Catalina 381
Join Date: Aug 2019
Posts: 568
I'd like to have seen them include a 4 blade in that comparison as well.
rslifkin is online now   Reply With Quote
Old 12-02-2019, 08:17 PM   #5
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 16,147
I think it could have golden speeds where it performed better. Not unlike bulbous bows.
I haven’t read the link but it looks like a prop designed to trade less blade tip losses for more surface area drag losses. Under some speed/load circumstances one could gain more on tip loss .. losses and not so much lost to prevent it from being a plus.

I suspect it will be more a benefit because of it’s strength. But repairs will probably be pricy.
__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Old 12-02-2019, 09:25 PM   #6
Art
Guru
 
Art's Avatar
 
City: SF Bay Area
Country: USA
Vessel Model: Tollycraft 34' Tri Cabin
Join Date: Feb 2011
Posts: 9,706
Quote:
Originally Posted by adornato View Post
As someone who hates prop cavitation noise, particularly on my Mainship 30 , i was interested in this post on another trawler forum

https://www.boattest.com/Sharrow-Engineering-Propeller

Not yet available but sounds like a winner.
Video is impressive! Sharrow props may be the best prop design for many many boat designs.
Art is offline   Reply With Quote
Old 12-03-2019, 12:27 AM   #7
Veteran Member
 
City: Olympia
Country: USA
Vessel Model: Kingfisher 3125GFX
Join Date: Sep 2019
Posts: 25
I have a feeling it’s going to be expensive. But if it reduces fuel consumption, extends range, reduces vibration, makes it easier to back into slips, and makes things quieter...it could be worth a higher price than existing premium props. And there may be a benefit in terms of less wear and tear due to less vibration.
Haloo is offline   Reply With Quote
Old 12-03-2019, 01:22 AM   #8
Art
Guru
 
Art's Avatar
 
City: SF Bay Area
Country: USA
Vessel Model: Tollycraft 34' Tri Cabin
Join Date: Feb 2011
Posts: 9,706
Quote:
Originally Posted by Haloo View Post
I have a feeling it’s going to be expensive. But if it reduces fuel consumption, extends range, reduces vibration, makes it easier to back into slips, and makes things quieter...it could be worth a higher price than existing premium props. And there may be a benefit in terms of less wear and tear due to less vibration.
I agree!

And, I have a couple of relatively fast boats [25 to 35 knot cruise speeds / 39 to 55 knot top ends]. So, in similarity to the video-boat... for these boats of mine the new Sharrow design props would likely work quite well.

However, I'd like to see Sharrow prop tests done with some of the primary boats on TF. Will these props make much difference in 6 to 8 knot speeds of FD 7 to 30 or 40 ton "trawlers"?

Would Sharrow prop make much difference to big, multi ton boats of SD or P hull design that occasionally or more so cruise at 16 to 24 knots... but often cruise at single digit speeds... under their hull speed?

People want to know!!
Art is offline   Reply With Quote
Old 12-03-2019, 01:32 AM   #9
Guru
 
Xsbank's Avatar
 
City: Pender Harbour, BC
Country: Canada
Vessel Name: Gwaii Haanas
Vessel Model: Custom Aluminum 52
Join Date: Sep 2013
Posts: 3,265
This is one of those game-changers, like leds and lithium batteries. Neat!
__________________
Don't believe everything that you think.
Xsbank is offline   Reply With Quote
Old 12-03-2019, 10:11 AM   #10
Guru
 
MurrayM's Avatar
 
City: Kitimat, North Coast BC
Country: Canada
Vessel Name: Badger
Vessel Model: 30' Sundowner Tug
Join Date: Jul 2012
Posts: 4,861
If these are proven to be robust long term, they should be mandatory for container ships, super tankers, etc. to reduce emissions from burning bunker fuel.
__________________
"The most interesting path between two points is not a straight line" Murray Minchin
MurrayM is offline   Reply With Quote
Old 12-03-2019, 10:18 AM   #11
Art
Guru
 
Art's Avatar
 
City: SF Bay Area
Country: USA
Vessel Model: Tollycraft 34' Tri Cabin
Join Date: Feb 2011
Posts: 9,706
Quote:
Originally Posted by MurrayM View Post
If these are proven to be robust long term, they should be mandatory for container ships, super tankers, etc. to reduce emissions from burning bunker fuel.
I appreciate your thought!
Art is offline   Reply With Quote
Old 12-03-2019, 10:25 AM   #12
Guru
 
City: Rochester, NY
Country: USA
Vessel Name: Hour Glass
Vessel Model: Chris Craft Catalina 381
Join Date: Aug 2019
Posts: 568
Quote:
Originally Posted by MurrayM View Post
If these are proven to be robust long term, they should be mandatory for container ships, super tankers, etc. to reduce emissions from burning bunker fuel.
If they give a significant efficiency gain in those applications, I'd expect companies would start moving to them for fuel / money savings, even if they're not forced. But yes, I agree, that's an industry that stands to make a big difference.
rslifkin is online now   Reply With Quote
Old 12-03-2019, 10:30 AM   #13
Guru
 
MurrayM's Avatar
 
City: Kitimat, North Coast BC
Country: Canada
Vessel Name: Badger
Vessel Model: 30' Sundowner Tug
Join Date: Jul 2012
Posts: 4,861
Quote:
Originally Posted by rslifkin View Post
If they give a significant efficiency gain in those applications, I'd expect companies would start moving to them for fuel / money savings, even if they're not forced. But yes, I agree, that's an industry that stands to make a big difference.
According to this article, 2 billion barrels of bunker fuel is burned by the global shipping industry per year. Yikes!

https://www.ft.com/content/642b6b62-...c-6eeb837566c5

Hmmmm...Financial Times link doesn't work now...
__________________
"The most interesting path between two points is not a straight line" Murray Minchin
MurrayM is offline   Reply With Quote
Old 12-03-2019, 11:40 AM   #14
Senior Member
 
City: Detroit
Country: USA
Join Date: Jun 2019
Posts: 157
I hope it has all the promise it seems to have. I would rather have not seen the test performed on the Detroit River. Current variations are everywhere. I assume it was same day, same location, same direction, but still an issue. I also would rather the prop had been made from stainless as it makes it more of an apples to apples, even though the aluminum should perform worse in most aspects. Get out your wallets boys, if this thing is what it appears to be it will likely be well worth it. Sounds like at trawler speeds and loads even more so.
moparharn is offline   Reply With Quote
Old 12-03-2019, 02:37 PM   #15
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 16,147
Art wrote;
“However, I'd like to see Sharrow prop tests done with some of the primary boats on TF. Will these props make much difference in 6 to 8 knot speeds of FD 7 to 30 or 40 ton "trawlers"?”

The biggest advantage will probably be in high load situations. Quite likely boats designed w insufficient prop clearance and props too small or repowers significantly increasing power will benefit from vastly reduced tip losses. Big outboards will fall into that category too.
__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Old 12-03-2019, 03:30 PM   #16
DDW
Guru
 
City: San Francisco
Country: USA
Join Date: Apr 2018
Posts: 951
Prior art exists:

DDW is offline   Reply With Quote
Old 12-03-2019, 03:47 PM   #17
Guru
 
Fletcher500's Avatar
 
City: So-Cal
Country: USA
Vessel Model: Helmsman 4304
Join Date: May 2016
Posts: 1,165
Agree, the results shown in the video are impressive.

I have a hard time believing that the big players with large R&D departments staffed by people who have PHD/PE after their name would not have implemented this technology earlier if it is so much better.

We may not have the full picture, but it will be interesting to see where it goes.
Fletcher500 is offline   Reply With Quote
Old 12-03-2019, 04:31 PM   #18
Guru
 
Benthic2's Avatar
 
City: Boston Area
Country: United States
Join Date: Feb 2017
Posts: 1,493
I remember 10 years or so ago, there were some tests done with flying large kites off the bow of supertankers. It looked like a cheap easy way to increase efficiency...a real no brainer...but it never really got any traction. I'm not trying to create thread drift into the merits of kites....just pointing out that the shipping industry may have inherant resistance to newer technology. Who wants to be the executive that sent a billion dollars of cargo out to sea with a new idea and had it go wrong?

I'd guess if this gets a foothold it will be in competitive fishing and ski boats first, maybe pontoons, and work its way up from there.

Guys like this:
Attached Thumbnails
Click image for larger version

Name:	bassboat.jpg
Views:	42
Size:	123.0 KB
ID:	97151  
Benthic2 is offline   Reply With Quote
Old 12-03-2019, 05:59 PM   #19
Veteran Member
 
City: Olympia
Country: USA
Vessel Model: Kingfisher 3125GFX
Join Date: Sep 2019
Posts: 25
Quote:
Originally Posted by Fletcher500 View Post
Agree, the results shown in the video are impressive.

I have a hard time believing that the big players with large R&D departments staffed by people who have PHD/PE after their name would not have implemented this technology earlier if it is so much better.

We may not have the full picture, but it will be interesting to see where it goes.
Well, it took quite a while before the aircraft industry started to curl wing tips to reduce drag.
Haloo is offline   Reply With Quote
Old 12-03-2019, 06:11 PM   #20
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 16,147
That’s true Haloo,
Radial tires didn’t take ofer overnight either.

Re aviation there is an aircraft called a “joined wing” aircraft. Uses a swept lower wing just about normal but usually w a bit more sweep. A “T” tail w an upper wing that sweeps forward to “join” with the up swept winglet or air dam ... that joins the two wings together. Probably reduces tip losses to next to nothing.
__________________

__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Reply

Tags
cavitation, propeller, sharrow

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 07:20 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012
×