Portofino
Well-Known Member
Buttons been off more than on .Not revived anything evidence wise .
Mangusta 70 - 80ft (1996 - 2004) Advice
- Thread starter SageMaster
- Start date
Portofino
Well-Known Member
Was 3 K views this AM , shot up to 4 K in a day .
Aquaholic would be proud of those viewing figures rate of rise Mark.
When i am out on my morning ski tomorrow I will be extra vigilant forum members aren’t following me even on the slopes .
markc
Well-Known Member
billskip
Well-Known Member
Have a look on you tube for a video about the life of a Mr Fountain, I think he knew what helped boats unstick and go a bit faster.Was 3 K views this AM , shot up to 4 K in a day .
Aquaholic would be proud of those viewing figures rate of rise Mark.
When i am out on my morning ski tomorrow I will be extra vigilant forum members aren’t following me even on the slopes .
Portofino
Well-Known Member
You mixing nomenclature,
Spray rails are the title of the appendage Fwds of the disruption line .
lifting strakes are the title of the thing behind the disruption line .
Disruption line is where the hull meets the waves , so it position alters depending on trim .
Indeed some spray rails when the boats running are small , under water ( despite a bow up attitude) so cant peel off the sheet of water as it risers hence “do nothing “.He is not referring to the section of strake behind the disruptive line under water .Which is the controversial part .That’s the lifting strake .
Better you read the whole article well the para on chines , lifting strips and spray rails .
The Ride - Hunt Yachts
MapisM
Well-Known Member
Be that as it may, it seems to me that neither of us actually know what he's really referring to, and you're only clutching at straws.
Christ, you managed to make me wonder if even Ray Hunt himself knew what he was talking about...
...Assuming he was the author of that writing, which I very much doubt.
Regardless, ref. your suggestion to read the whole article (or anything else), thanks but no thanks.
I said several posts ago that I wasn't interested in arguing further, and in the meantime I just got older and even less interested.
OTOH, I didn't run out of popcorn yet, so feel free to go ahead.
Just forgive me in advance if I won't bother to reply, aware as I am that it would be pointless.
But I'm enjoying the show anyhow.
Portofino
Well-Known Member
STRAKES
Red = disruption line / area / zone .
yellow - spray rail
blue - lifting strip
pic paints a 1000 words you all remind me of .
Let’s kick off with BruceK s boat …….look MapishM the strake runs to the transom .Another one .Add Donzi and Fountain to your list of boats you claimed you never see with strakes , lifting strips now running to the transom.
Remind us did you once have a 30 ish ftr Fountain ? Which modal btw ?
A reggie fountain ^
Twin step , so two disruption lines = more hull lift+ more air entry to further reduce drag .The strake running to the stern marked in blue area lifts the stern and helps trim / running attitude and reduces drag further = sum of all the little parts = more speed .
Speed being Reggies name of the game .
Winning races is all about ( according to Reggie ) keeping the boat , as much boat as possible in the air and as little in the water .
Air is less dense than water .Too much boat in the water = more drag you loose the race .
@ Billskip - thx for the tip look up Reggie fountain .
He uses and his contemporaries strikes extended all the way to the stern ….where the submerged part , my blue area is designed to create the right amount of lift .
Red = disruption line / area / zone .
yellow - spray rail
blue - lifting strip
pic paints a 1000 words you all remind me of
.Let’s kick off with BruceK s boat …….look MapishM the strake runs to the transom .Another one .Add Donzi and Fountain to your list of boats you claimed you never see with strakes , lifting strips now running to the transom.
Remind us did you once have a 30 ish ftr Fountain ? Which modal btw ?
A reggie fountain ^
Twin step , so two disruption lines = more hull lift+ more air entry to further reduce drag .The strake running to the stern marked in blue area lifts the stern and helps trim / running attitude and reduces drag further = sum of all the little parts = more speed .
Speed being Reggies name of the game .
Winning races is all about ( according to Reggie ) keeping the boat , as much boat as possible in the air and as little in the water .
Air is less dense than water .Too much boat in the water = more drag you loose the race .
@ Billskip - thx for the tip look up Reggie fountain .
He uses and his contemporaries strikes extended all the way to the stern ….where the submerged part , my blue area is designed to create the right amount of lift .
Scolly
Well-Known Member
If facts don't change peoples minds I guess you just change the facts. Porto.... Please just shut up !!!!!STRAKES
Red = disruption line / area / zone .
yellow - spray rail
blue - lifting strip
pic paints a 1000 words you all remind me of
Let’s kick off with BruceK s boat …….look MapishM the strake runs to the transom .Another one .Add Donzi and Fountain to your list of boats you claimed you never see with strakes , lifting strips now running to the transom.
Remind us did you once have a 30 ish ftr Fountain ? Which modal btw ?
View attachment 150001
View attachment 150002
A reggie fountain ^
View attachment 150003
View attachment 150004
Twin step , so two disruption lines = more hull lift+ more air entry to further reduce drag .The strake running to the stern marked in blue area lifts the stern and helps trim / running attitude and reduces drag further = sum of all the little parts = more speed .
Speed being Reggies name of the game .
View attachment 150005
Winning races is all about ( according to Reggie ) keeping the boat , as much boat as possible in the air and as little in the water .
Air is less dense than water .Too much boat in the water = more drag you loose the race .
@ Billskip - thx for the tip look up Reggie fountain .
He uses and his contemporaries strikes extended all the way to the stern ….where the submerged part , my blue area is designed to create the right amount of lift .
Portofino
Well-Known Member
Educate us all then please tell everyone what or which part of the boat is commonly referred to as “lifting strake “
As I said earlier why do all the references I have published and indeed 100 s of others use the either the term “ lifting strip “ or “ lifting strake “ ? What are they referring to ?
Nobody has answered that ? I did politely ask that Q earlier.
Far too many uses of the terms by the great and the good in the marine world inc naval architects to be typos , material proof read , academic papers peer reviewed , websites frequently reviewed .Professional you tube vids edited post production etc .
Come on then Scolly please can you add clarity.
jfm
Well-Known Member
For every 100 uses of the terms “lifting strip/strake” there are a million uses of the much more popular term “spray rail”. It’s more popular because it’s more apt: these rails serve to deflect/peel off spray, to reduce pumping losses.
Submerged spray rails/lifting strips/whatever name you use, do not create lift, as a matter of kinda obvious basic physics.
When I say basic physics, ok I wouldn’t expect someone with a “surplus shore power” level of physics and engineering knowledge to understand it, but most others get it. Which is why this thread drift is so painful. You really are like a flat earther here Porto ??
.
Submerged spray rails/lifting strips/whatever name you use, do not create lift, as a matter of kinda obvious basic physics.
When I say basic physics, ok I wouldn’t expect someone with a “surplus shore power” level of physics and engineering knowledge to understand it, but most others get it. Which is why this thread drift is so painful. You really are like a flat earther here Porto ??
.
Chris_d
Well-Known Member
I think its called a misnomer there's 1000's of examples out there, e.g French Fries aren't french they were invented in Belgium.
Why aren't trim tabs called lifting tabs? they make the stern rise up.
Portofino
Well-Known Member
It was actually voltage .I have been plugged into 440 V or 4 something or other ….as I said only after the marina office has sent a sparky who used an adapter, assume step down transformer to plug my 220V meagre 32A in . Uneventfully .Sorry if I did not make that clear .For every 100 uses of the terms “lifting strip/strake” there are a million uses of the much more popular term “spray rail”. It’s more popular because it’s more apt: these rails serve to deflect/peel off spray, to reduce pumping losses.
Submerged spray rails/lifting strips/whatever name you use, do not create lift, as a matter of kinda obvious basic physics.
When I say basic physics, ok I wouldn’t expect someone with a “surplus shore power” level of physics and engineering knowledge to understand it, but most others get it. Which is why this thread drift is so painful. You really are like a flat earther here Porto ??
Its interesting why you on this thread backed into a corner keep dragging that up , ( is it 2, ,3 or 4 + time you keep dropping that in ? ) and hiding behind the basic , as you call it physics without outlining why or how they don’t contribute to lift .
Try us .
let’s stay on point .
If the underwater strake is flat and wide enough on a deep enough V deadrise then you will get NET lift .The value will vary depending on application of course .
That’s why the term lifting strake / strip / rail exist and so widely used in naval architecture .
Portofino
Well-Known Member
No one’s advocating they call chips Belgium fries .But I get your misnomer point .
Trim tabs alter the trim .In both directions.Well they do on my boat .Both lower the bow more and raise it .
So that’s why they aren’t called your “ lifting tabs “
So in a head sea I use them to lower the bow sos to present more of the forward sharper V to the oncoming waves.
However .
In a following big sea running fast I raise the tabs up to lift the bow / sink the stern ….altering the TRIM using the apply titled trim tabs .
The idea is is minimise the risk of broaching .Whereby running down a wave the bow naturally wants to stuff itself into the upward slope of the next wave ,This will slow the boat ,If it slows so much the following wave behind might start to catch up lift the stern and if so you can’t guarantee the hulls gonna be plonked down straight so the forces might turn it side ways .Commonly refers to as broaching .This potentially dangerous as the boat my roll over capsize in particular circumstances.
Apologies to all that know the function of trim tabs on planing boat .
Not sure if Chris d by his line of Q s new they can also be used to lower the stern / lift the bow .And why you would want that function .
Being super critical and accurate its true to say a good design planing hull running requires zero tab down they should be in a neutral position .Not permanent down all the time to get the thing to up and stay up .Or needed tabs down to get the bow down to see Fwds .
Chris there are a lot of boats you see every day running bow high …..so I fully under stand where you are coming from only using them to lower the bow , or permanently running with massive amounts of tab down .
See my post #124 page 6 for pics .Those 90 degree rotated pics of example boats i think you are referring to ?
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Elessar
Well-Known Member
Your knowledge of electrics matches that of hydrodynamics. What you just wrote is total ?
(You don’t step down from 440 to 220. 440 is made up of three phases of 220V and you simply connect one of the phases. And you don’t connect 32A either. You might draw up to 32A. And so on……)
Portofino
Well-Known Member
What difference does it make as I said they sent a sparky he fiddled around , opened the consumer up used an adapter and plugged us in .All good .I said “ assumed “ TBh not that bothered as to whys and wherefalls .
But thanks for sharing a bit of knowledge .Albeit rather rudely and impolitely .
We did use my shore power lead .The boats a 32 A .
This wasn’t the first time btw ,I have had marina sparkies come round many a time and fiddle about with the consumer box and sort out adaptors .
My knowledge of boat hulls , or any other subject matter - You are inaccurately ( for reasons you have not disclosed) extrapolating the wrong conclusions from my marina shore power experiences .
rafiki_
Well-Known Member
Porto, Albert Einstein once wrote along the lines, “Doing the same thing repeatedly and expecting a different result is the definition of madness”. Please consider and desist!
Portofino
Well-Known Member
If some one can speak “ hydrodynamics “ or / and “ physics “ , “ fluid dynamics “ or give a link to say lifting strips / strakes / rails don‘t create lift in the submerged section then the jobs done .
All will be good .
You know adding them sinks the stern …….any thing it’s getting desperate in a kinda messiah with his flowing disciples
please don’t find some one adding this to the underwater section of a 95 ft FB .
Then claiming it made no difference.
Chris_d
Well-Known Member
5 seconds googling found this:
The effect of spray rails, chine strips and V-shaped spray interceptors on the performance of low planing high-speed craft in calm water - ScienceDirect
This does mention trim, but as you told me that has nothing to do with lift
The effect of spray rails, chine strips and V-shaped spray interceptors on the performance of low planing high-speed craft in calm water - ScienceDirect
This does mention trim, but as you told me that has nothing to do with lift
billskip
Well-Known Member
Whilst I'm enjoying my popcorn, I'm getting a little confused with this "googling " thing....its been claimed that Porto should stop cutting, pasting and quoting unreliable google stuff and here you are quoting Google stuff.5 seconds googling found this:
The effect of spray rails, chine strips and V-shaped spray interceptors on the performance of low planing high-speed craft in calm water - ScienceDirect
This does mention trim, but as you told me that has nothing to do with lift
Now just so I can sit back with a new bag of popcorn, could you please explain why your Google stuff is accurate and Porto's isn't ......
Chris_d
Well-Known Member
Anyone can Google, the challenge was to find something about spray rails that doesn't mention lift but describes their purpose.