On Nov 27, 2017, at 10:44 AM, greatketch@... [amelyachtowners] <amelyachtowners@...> wrote:

I read the test report in YM, and like most of their work, it is a useful and well thought out piece of work.  

But (you knew that was coming, right?) they use bollard pull at full throttle as the primary measure of the prop's performance. I certainly understand the appeal of the measurement.  It is easy to measure with precision.  It is repeatable. It eliminates a lot of other variables. It is easy to report and rank. It has a lot going for it.  

But... it is a not a good measure of the real world performance of the prop in use (unless you are a tugboat).  For example, slight differences in pitch can result in fairly significant difference in engine RPM at full throttle.  If the engine is running at a different RPM it is producing different horsepower, resulting numbers would be skewed quit a bit in ways that have nothing to do with the design of the prop.  Our props typical ly run at about 30% slip, this test measures the thrust at 100% slip, a very different flow regime.

I especially think that measuring "side pull" at full throttle while tied to the dock  is a very poor stand-in for prop walk, to the point of being almost worthless.  Especially when you consider that props don't really produce side thrust on their own, it is the interaction of the slip stream with the hull that makes the boat go sideways.  A prop that had low "slip" (that's good) when the boat was moving would come out much poorer in ranking on this test than a prop with higher "slip" even though it would produce less prop walk when actually moving the boat.

It's easy to throw rocks at a published test like this and really, really hard to come up with a simple measure of prop performance. It is almost as bad as testing anchors! To be fair to YM they do acknowledge the li mitations of the testing at the end of the article.

My take-home story is that all feathering and folding props have so much lower drag than a fixed prop that whatever is left is totally insignificant on a cruising boat.  On our Amels there is no reason to discriminate between them based on this measurement.

Performance under power is really, really hard to measure in a way that you can actually compare apples to apples.  The interactions between engine, transmission, mounting geometry, gear ratios, etc, etc. will totally overwhelm the differences from one prop to another. Then there is the question of what performance measure is really important. Do you care about maximum speed?  Highest speed at cruising RPM?  Match of prop power curve to engine power output?  Maneuvering?  Motorsailing?  Fuel efficiency at cruising speed?  Overall fuel efficiency?  Different boat owners come up with different things of highest value to them.

 On one boat Prop A will be best, on another it will be Prop B. Without actual, concrete testing data on your exact hull with your exact drive train, the differences reported not really useful tools to discriminate between them.

Best to select based on whatever weighted combination of cost, robustness, maintenance needs, reputation, and advertising claims that feels right to you.  Certainly, do include published testing results in your evaluation, but understand if they used your boat in the testing the rankings might be very different in ways that would be unpredictable and, almost certainly, of very minor impact on the performance of your boat in the real world.

Bill Kinney

SM160, Harmonie

Fort Lauderdale, FL

 

Hi,

Attached you'll find the measurements of my transom that I put together for my designer when I was having the new name made (which I haven't actually put on the boat yet).  I hope it helps.

Ryan

SM 233 Iteration (ex Monarae)

Boston, MA, USA

On Sat, Nov 25, 2017 at 11:08 PM, James Cromie jamescromie@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Thanks Denise.  This is really helpful!  No need for you to measure, because the dimensions of your lettering are on your photo, and I can scale the rest from there!

Thanks again. 

On Nov 25, 2017, at 10:36 PM, Denise McGovern Mcgovern.denise@... [amelyachtowners] <amelyachtowners@yahoogroups.com> wrote:

[Attachment(s) from Denise McGovern included below]

I can measure tomorrow for you.  We have a handle and davits (not permanent) that I was working around.  Can you post a photo of your stern? Maybe from the listing?

Here is my lettering order with dimensions and with them installed.   

On 28 November 2017 at 05:35 "'sailormon' kimberlite@... [amelyachtowners]" <amelyachtowners@...> wrote:

 

 

Hi,

What is this?

Fair Winds

Eric

Kimberlite Amel Super Maramu #376

 

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Monday, November 27, 2017 5:31 AM
Subject: [Amel Yacht Owners] FYI

 

 

Good Morning,

 

Please find the attached signed document for your preview.

 

Nick

 

 

On 28 November 2017 at 05:41 "Kent Robertson karkauai@... [amelyachtowners]" <amelyachtowners@...> wrote:

 

 

Does anybody know what this is?  It smells like phishing.

Kent

S/V Kristy

karkauai@...

On Nov 27, 2017, at 05:31, ngtnewington@... [amelyachtowners] <amelyachtowners@...> wrote:

 

 

Good Morning,

Please find the attached signed document for your preview.

Nick

 

<docu(1).html>

 

On 27 November 2017 at 19:34 "Kent Robertson karkauai@... [amelyachtowners]" <amelyachtowners@...> wrote:

 

 

Hi Dean.  I don't know how the 54 bow pulpit compares to the SM 2000, but on Kristy, I was able to use a steel tape starting at the exit by the starboard light and retrieving it at the bottom of the stanchion.  I attached a small line to the end of the tape and retrieved it at the stanchion without getting the steel tape out.  I then pulled a larger line through, then pulled the new cable through using some lubricant designed for pulling wires.  I felt really lucky after doing exactly what you did.

Kent

S/V Kristy

SM243

On Nov 25, 2017, at 11:40, trifin@... wrote:

 

 

When I bought my 54 in August, the bowlight was not working.  Anyway, Lopo were great and sent me a new light free of charge.  Today I have been attempting to connect the new light, which has ended in a little disaster!

It was quite a challenge to remove the old cable which runs inside the pulpit rail with a 90degree corner at the front another maybe 70 deg corner at the aft end of the rail before going into the cockpit locker.

Eventually I succeeded in pulling the old cable through with a 3mm mouse line attached, leaving the mouse line to pull the new cable through. All good so far!

I then tried to pull the new cable through and only succeeded in breaking the mouse line before getting the new cable past the first 90 deg corner.  😡  The break was at the foot of the rail, where there must be a sharp edge which cut through the mouse cord. Maybe I should have a used a wire mouse line!

So, where does this leave me ?  Is there any clever way to recover from this and get the new cable through the pulpit rail?  

Time to open that bottle of wine Wolfgang. At least it's warm in here now :-)

Cheers

Dean

SY Stella

 

 

On Sun, Nov 26, 2017 at 9:45 AM, isaac_02906@... [amelyachtowners]

wrote:

 

Hello All,

I am fairly new to the forum and very new to Amel ownership having just purchased SM #391 in FLL.  I don't have access to the boat just yet, but would like to know the depth of the port side locker so I can begin looking into a life raft replacement that will fit in that locker.

Thanks to all for this great resource!

Mark Isaac
SM #391
Ft. Lauderdale