SMG 50, its Like they were Reading my Mind

[beiland]

Originally Posted by Agility

I don't know the details of the other rigs but many mods have been made since the first foils were produced. The new ones are stronger, Kevlar shrouds and no flaps.

I am wondering what you mean by this statement??

I believe the mastfoil rig works specifically because of its 'flap'. I do seem to recall that the size of the flap has been experimented with.

video

discussions of flaps

[UpOnStands]

Originally Posted by admiralslater

Up on stands, that's an interesting design, but I don't see reasoning behind the curved portion and what it's purpose is.
column

Not shown but the mast is stayed for/aft
Basically the horizontal member is multipurpose replacement for the aft spreader that beiland uses for his mast-aft arrangement.
The curved piece is an attempt to reduce point loading on the mast. The curve should absorb shock loads by flexing. Well, that's the idea.

The horizontal member provides space for mast head equipment/lights and attachment points for sails.

[beiland]

Originally Posted by admiralslater

In 1972 my father Alan Slater designed and built his first catamaran . He did as much research as possible and as an engineer he was not afraid to think outside the box . This 30 foot family light cruising Cat. It features a double Bi pole rig ,he always called it A frame as the masts looked like a capital A . It had two frames both with the bases at the same place ,From the side it looked like a V. the taller frame leaned forward and the shorter leaned aft in sort of a Ketch arrangement .

The sail plan was a such,(all sails furling) forward a jib,a mizzen jib and in the middle of that V an upside down jib with a sprit to control the clue which we called the top sail.
THE advantage of the double frame was that you could get the same amount of sail up but with a lower overall height due to the topsail ,and not having masts the efficiency of the sails was increased . Windage is a valid point but for the most part the boat out performed the cruisers of the day
The masts were mild steel tubes hot dipped galvanized with hand spliced standing rigging . The tall frame was about 32 feet long .
This was our Family boat until about 1988 .

It was a dream to sail All the controls for furling where at the bottom of the V .You could go from full sail to nothing in 30 seconds ,we timed it once . She was called" Pandemonium" and to the untrained eye she looked bit like that. When I was young I took her to the Bahamas and back and the rig performed very well .
I seriously considered this rig when having our PDQ 36 built but the structure of the boat was not in the right place to accept the rig .

I would have no issues with owning a properly designed A frame rigged boat.
Hell if the Harkens did why not any one else
I have looked for her on the web but no luck . It was sold to a family in Flint Mich.If any one has news of Pandemonium let me know .last known colour was yellow.
David
PS I am not at home so I don't have pictures

VERY interesting David, does that mean you have some pics, just not with you? I would very much like to see them, or a sketch, etc.

Would it have looked something like an A-frame version of this vessel?
RunningTideYachts, Ltd. - Archives

[UpOnStands]

inverted jib?
something like this? total of 3 sails
for 50 ft cat mast head height of 15.8m above deck
2D total sail area is 124 sq m
but twisting force from front head would need serious resistance
edit: moving head of fore sail to inline with the mast drops the area to 100 sq m.

[Agility]

Originally Posted by beiland

I am wondering what you mean by this statement??

I believe the mastfoil rig works specifically because of its 'flap'. I do seem to recall that the size of the flap has been experimented with.

video

discussions of flaps

My foils do not have flaps. Think like a glider/sailplane. Flapped vs non-flapped ships. Not a huge difference but a difference.


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[SVNeko]

Originally Posted by Agility

We have a Bimini over the helm. Attachment 132352


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Yea, you can do this with the 47. No dodger though.

[Seaslug Caravan]

Originally Posted by Agility

My foils do not have flaps. Think like a glider/sailplane. Flapped vs non-flapped ships. Not a huge difference but a difference.


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Oh dear. sorry to hear that it was necessary to remove the flaps.


XXXXXXXXXX
From CWs' web page...

Why does the foil have an articulating trailing edge flap?
Because a flap adds lots of power to the foil with very little additional weight and complication. Reaching and running the flap is set at a significant angle (approx 40 degrees) to the main foil which increases the overall camber of the foil and can nearly double its power. Sailing upwind only a small amount of flap angle is used but it helps create additional lift with very little drag.

XXXXXXXXXXX

All reports were the early mastfoil equipped A47 s' were very underpowered and therefore slow.

How have you dealt with the loss of power associated with the removal of the flaps? Or are you happy to motor lots?

[UpOnStands]

Originally Posted by Seaslug Caravan

Oh dear. sorry to hear that it was necessary to remove the flaps.


XXXXXXXXXX
From CWs' web page...

Why does the foil have an articulating trailing edge flap?
Because a flap adds lots of power to the foil with very little additional weight and complication. Reaching and running the flap is set at a significant angle (approx 40 degrees) to the main foil which increases the overall camber of the foil and can nearly double its power. Sailing upwind only a small amount of flap angle is used but it helps create additional lift with very little drag.

XXXXXXXXXXX

All reports were the early mastfoil equipped A47 s' were very underpowered and therefore slow.

How have you dealt with the loss of power associated with the removal of the flaps? Or are you happy to motor lots?

You should ask Chris White whether he redesigned the mast foils to offset the removal of the flaps - seems likely that he would. Since Agility seems keen on the CW mast foil not sure why you want to claim he is getting a raw deal.

[44'cruisingcat]

Even if he does have to motor, at least he has a boat.

[tp12]

Originally Posted by Seaslug Caravan

Oh dear. sorry to hear that it was necessary to remove the flaps.


XXXXXXXXXX
From CWs' web page...

Why does the foil have an articulating trailing edge flap?
Because a flap adds lots of power to the foil with very little additional weight and complication. Reaching and running the flap is set at a significant angle (approx 40 degrees) to the main foil which increases the overall camber of the foil and can nearly double its power. Sailing upwind only a small amount of flap angle is used but it helps create additional lift with very little drag.

XXXXXXXXXXX

All reports were the early mastfoil equipped A47 s' were very underpowered and therefore slow.

How have you dealt with the loss of power associated with the removal of the flaps? Or are you happy to motor lots?

Wow. Really? Is this jealousy or some sort of mental disorder?


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[Agility]

Originally Posted by Seaslug Caravan

How have you dealt with the loss of power associated with the removal of the flaps? Or are you happy to motor lots?

We do 150 mile days on crossing on average and 200 on good days with the standard sails configuration.

Top speed was a little over 18 kts. 13 kts is about top sustainable speed is 20-25 kts.

In light winds we use a screecher. Yesterday in about 8-10kts of true wind we were doing about 6kts on average.

I've sailed from Chile to Fiji in the last 6 months and only stopped for fuel once.


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[beiland]

For a few minutes there I thought maybe I had entered the Sailing Anarchy forum.. Lets please be a little civil in our quest to find answers from those out there sailing with these new rig innovations.

My question of Agility was a quest to find out exactly what he meant by removing the 'flap' portion of the mast design that Chris White has dubbed the 'MastFoil'. As posted just previously that flap device seems to be paramount to the his new rig design....

From CWs' web page...

Why does the foil have an articulating trailing edge flap?
Because a flap adds lots of power to the foil with very little additional weight and complication. Reaching and running the flap is set at a significant angle (approx 40 degrees) to the main foil which increases the overall camber of the foil and can nearly double its power. Sailing upwind only a small amount of flap angle is used but it helps create additional lift with very little drag.

On this page there are several videos that display the 'v' shaped flap on the foil mast
https://chriswhitedesigns.smugmug.co...c-47/i-V3CHvnK

...and here the control for the flap portion
https://chriswhitedesigns.smugmug.co...c-47/i-T9hbGr2

Agility, are you saying you have removed these flap devices??

[beiland]

Found this photo today of the original MastFoil mast.



Appears to answer 2 of my questions about the size of the original foil
1) bigger than the more recent design, and
2) there are some hints as to how the foil was attached.

As found a few photos that might give someone a general idea of the size of these foils.

[UpOnStands]

Looks like the original flap design (large) would be very expensive to make and assemble. Installation would need a lot of care too.

[Agility]

Originally Posted by beiland

Agility, are you saying you have removed these flap devices??

My mastfoils were not made with flaps and in one part. I was consulted and made the decision. Can't say what others are doing. You can customize at Alwoplast as you wish.



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