Re: better ventilation for BW style cabins > Cartoon 40

Roger,

I did misunderstand you!
Don't most mistakes come when we think we have it right?

Anyway, there's plenty of opening front and back with the hatchboards out. Each side of my ends is about 18".

IIRC these boats float on their sides with the water about halfway up to the slot, so reduce the margin at your own risk.

How hot it feels to one inside a BW cabin is a matter of personal preference. Surely, breeze or not it's better than being exposed to glaring sun for extended periods.

Down below and with tinted lexan, I feel like I'm wearing a well found pair of giant  sunglasses.

Cheers,
Mark

On Sep 23, 2015 8:17 AM, "'Roger Padvorac'roger@...[bolger]" <bolger@yahoogroups.com> wrote:

Mark,
Thanks for your response. There has been a miscommunication here.
I was suggesting adding windows that open on the ends of the cabin, not the sides, and looking for a compromise that retained the ability to easily recover from knockdowns in moderate wave conditions. The idea being that in severe wind and wave conditions its likely to be cloudy and the windows would be closed up.
The windows would open next to the slot, so there would still be a watertight cabin space if the boat was on its side, just with less freeboard when on its side than in the stock design.
When I was wondering if 9" or 12" of solid window, on the ends of the cabin, next to the sides of the cabin, was good enough for moderate wave conditions, I was essentially wondering if 9" or 12" of freeboard when the boat is on its side, would be good enough for moderate wave conditions.
If you are wondering about what I meant in some part of the suggestions I made below, please ask questions.
May your day be filled with clarity, grace, strength, insight, balance, cooperation, listening, keeping faith, and warm laughter,
Roger
----- Original Message -----
Sent:Tuesday, September 22, 2015 7:57 PM
Subject:[bolger] Re: better ventilation for BW style cabins > Cartoon 40

Roger,

The regular BW cabin does give an incredible sense of safety, not only in a knockdown but well short of it.

Trying to imagine your open middle section, I suspect the water would pour in, not any worse than a regular boat, but much more so than with closed in high sides.

Phil drew at least one BW type boat with opening side windows, the little Supermouse shown in BWAOM.  He wrote, "The assumption is that they would be closed before the squall strikes - a fair bet, though I'm more comfortable with fixed windows," and then goes on to repeat the idea that the boats are pretty much self-ventilating. In a 15 mph breeze, I'd add.

I use my boat a little differently than most. While you might find me tucked into the turn of the bilge as expected, with plenty of ballast in a heavy bottom and a pair of big batteries, I often like sitting up on a ditty box on centerline. This gets my eyes up at slot level where it' quite a lot cooler on the face, also letting me sense the breeze direction better for steering and allow conning the boat better than through the tinted plexiglass.

Then, there's rare fun in walking toward the bow with sheet in hand and sailing standing up in perfect safety.

Mark

On Sep 22, 2015 5:19 PM, "'Roger Padvorac'roger@...[bolger]" <bolger@yahoogroups.com> wrote:

Mark,
I keep being attracted to bird-watcher style cabins because they make knockdowns so easy to recover from and because of the shelter they offer when sailing in a region known for a lot of cloudy, damp, chilly weather.
I've also wondered how hot they get when the sun finally comes out in force - they've always reminded me of a greenhouse, which is good if its 45F. Maybe a BW style boat is like winter clothing, and you don't use it in summer. However few people are able to own fleets of boats.
So I've been wondering if people have modified these boat designs for better ventilation.
A lot of regions get gusty winds on hot afternoons, so undoing the ability of the boat to recover from capsizes seems a poor choice. On a hot day it would be a dangerous temptation to have windows open on the sides, and then leave them open too long during the transition from light morning wind to gusty afternoon wind.
* * * *
Based on the pictures of capsize testing I've seen, leaving 1 foot of solid windows next to each side, in both the bow and stern ends of the cabin, seems like it would be enough to preserve the ability of the boat to recover from capsizes in most weather. In severe weather its likely it will be cloudy enough that extra ventilation won't be needed and all of the windows could stay closed.
If the rest of the window area on the ends, which is next to the slot, swings open like a shutter towards the sides of the cabin, then it would increase the amount of fresh air flowing through the cabin.
For example, if the cabin was 5 feet wide, had 1 foot of solid window left next to each side, and the windows next to the slot opened out to the sides like shutters, then you would have a 3 food wide opening allowing air to flow through the cabin. While the cabin would still be holding in some heat, it seems like this would significantly improve the situation.
This suggestion is assuming that the slot through the middle of the cabin would be completely open in the bow, top, and stern.
Maybe instead of folding the shutter windows all the way back to the solid windows, they could be latched at a 45 degree angle to solid windows so they could help funnel light breezes into the cabin.
I just grabbed the "1 foot" number as a nice round number. Maybe having 9" of solid window instead of 12" would be a better compromise between improved ventilation and retaining a reasonable amount of ability to recover from a capsize.
* * * *
Maybe in warmer areas, the slot through the cabin could just be made wider, so there was more gap on the roof for convection to carry the hot air up and out of the cabin, and more gap on the ends for air to blow through. This would be simpler than messing around with building or using the shutter windows.
* * * *
Has anybody tried something like these ideas?
May your day be filled with clarity, grace, strength, insight, balance, cooperation, listening, keeping faith, and warm laughter,
Roger
----- Original Message -----
Sent:Monday, September 21, 2015 7:31 PM
Subject:[bolger] Re: Cartoon 40

Well,  steady on course yet tacks on a dime is the grail, awright!

I think if you look at Jim Michalk's BW designs though, you'll see they all are fuller bodied than Cartoon 40.

Your mods added to the longer version, "Might just work."

OTH when it gets above 80 degrees f., my BW cabin seems frightfully hot,  whatever the theory about breeze flowing down from the sail. Someone else called their BW boat E-Z Bake.

Mark,
Thanks for your response. There has been a miscommunication here.
 
I was suggesting adding windows that open on the ends of the cabin, not the sides, and looking for a compromise that retained the ability to easily recover from knockdowns in moderate wave conditions. The idea being that in severe wind and wave conditions its likely to be cloudy and the windows would be closed up.
 
The windows would open next to the slot, so there would still be a watertight cabin space if the boat was on its side, just with less freeboard when on its side than in the stock design.
 
When I was wondering if 9" or 12" of solid window, on the ends of the cabin, next to the sides of the cabin, was good enough for moderate wave conditions, I was essentially wondering if 9" or 12" of freeboard when the boat is on its side, would be good enough for moderate wave conditions.
 
If you are wondering about what I meant in some part of the suggestions I made below, please ask questions.
 
May your day be filled with clarity, grace, strength, insight, balance, cooperation, listening, keeping faith, and warm laughter,
Roger
 
----- Original Message -----
Sent:Tuesday, September 22, 2015 7:57 PM
Subject:[bolger] Re: better ventilation for BW style cabins > Cartoon 40

Roger,

The regular BW cabin does give an incredible sense of safety, not only in a knockdown but well short of it.

Trying to imagine your open middle section, I suspect the water would pour in, not any worse than a regular boat, but much more so than with closed in high sides.

Phil drew at least one BW type boat with opening side windows, the little Supermouse shown in BWAOM.  He wrote, "The assumption is that they would be closed before the squall strikes - a fair bet, though I'm more comfortable with fixed windows," and then goes on to repeat the idea that the boats are pretty much self-ventilating. In a 15 mph breeze, I'd add.

I use my boat a little differently than most. While you might find me tucked into the turn of the bilge as expected, with plenty of ballast in a heavy bottom and a pair of big batteries, I often like sitting up on a ditty box on centerline. This gets my eyes up at slot level where it' quite a lot cooler on the face, also letting me sense the breeze direction better for steering and allow conning the boat better than through the tinted plexiglass.

Then, there's rare fun in walking toward the bow with sheet in hand and sailing standing up in perfect safety.

Mark

On Sep 22, 2015 5:19 PM, "'Roger Padvorac'roger@...[bolger]" <bolger@yahoogroups.com> wrote:
 

Mark,
I keep being attracted to bird-watcher style cabins because they make knockdowns so easy to recover from and because of the shelter they offer when sailing in a region known for a lot of cloudy, damp, chilly weather.
 
I've also wondered how hot they get when the sun finally comes out in force - they've always reminded me of a greenhouse, which is good if its 45F. Maybe a BW style boat is like winter clothing, and you don't use it in summer. However few people are able to own fleets of boats.
 
So I've been wondering if people have modified these boat designs for better ventilation.
 
A lot of regions get gusty winds on hot afternoons, so undoing the ability of the boat to recover from capsizes seems a poor choice. On a hot day it would be a dangerous temptation to have windows open on the sides, and then leave them open too long during the transition from light morning wind to gusty afternoon wind.
 
* * * *
Based on the pictures of capsize testing I've seen, leaving 1 foot of solid windows next to each side, in both the bow and stern ends of the cabin, seems like it would be enough to preserve the ability of the boat to recover from capsizes in most weather. In severe weather its likely it will be cloudy enough that extra ventilation won't be needed and all of the windows could stay closed.
 
If the rest of the window area on the ends, which is next to the slot, swings open like a shutter towards the sides of the cabin, then it would increase the amount of fresh air flowing through the cabin.
 
For example, if the cabin was 5 feet wide, had 1 foot of solid window left next to each side, and the windows next to the slot opened out to the sides like shutters, then you would have a 3 food wide opening allowing air to flow through the cabin. While the cabin would still be holding in some heat, it seems like this would significantly improve the situation.
 
This suggestion is assuming that the slot through the middle of the cabin would be completely open in the bow, top, and stern.
 
Maybe instead of folding the shutter windows all the way back to the solid windows, they could be latched at a 45 degree angle to solid windows so they could help funnel light breezes into the cabin.
 
I just grabbed the "1 foot" number as a nice round number. Maybe having 9" of solid window instead of 12" would be a better compromise between improved ventilation and retaining a reasonable amount of ability to recover from a capsize.
 
* * * *
Maybe in warmer areas, the slot through the cabin could just be made wider, so there was more gap on the roof for convection to carry the hot air up and out of the cabin, and more gap on the ends for air to blow through. This would be simpler than messing around with building or using the shutter windows.
 
* * * *
Has anybody tried something like these ideas?
 
May your day be filled with clarity, grace, strength, insight, balance, cooperation, listening, keeping faith, and warm laughter,
Roger
 
----- Original Message -----
Sent:Monday, September 21, 2015 7:31 PM
Subject:[bolger] Re: Cartoon 40

Well,  steady on course yet tacks on a dime is the grail, awright!

I think if you look at Jim Michalk's BW designs though, you'll see they all are fuller bodied than Cartoon 40.

Your mods added to the longer version, "Might just work."

OTH when it gets above 80 degrees f., my BW cabin seems frightfully hot,  whatever the theory about breeze flowing down from the sail. Someone else called their BW boat E-Z Bake.

 

Suzanne,

I’m currently building Michalak’s Robbsboat design which originally had fixed windows in front, a traditional sliding hatch and aft drop boards.  I’m modifying the design with his blessing to have Lexan “drop boards” fore and aft and a removable top.  Sounds like what you were going to do with Wandervogel.  The cabin top on this little boat is only @ 4ft long, so the whole thing as one piece will easily lift off and store in the cabin.  After reading Mark’s post, I could even tilt up the windward wide to try and direct air into the cabin in lighter winds coming from the beam.

I’ll let you all know how it works out.  We completely blew away the existing record for 90+ degree days in Portland OR this summer.

Tom


tom sorensen



On Sep 23, 2015, at 6:16 AM,philbolger@...[bolger] <bolger@yahoogroups.com> wrote:


Hello All.
     My first extended experience of sailing and living for a few days aboard a ‘Birdwatcher-style’ layout was in July ‘98 on #639 “William D. Jochems” a 25+’ trailer-schooner.
Setting:  Lake Mead, east of Las Vegas, mid-summer, air-temps per radio-broadcast National Weather Service as caught on that video about her was 122 degrees F/ 50 C !

Below with open companion-way door, closed big hatches, and fore-mast hatch open it was significantly cooler in the shade, with 85-degree water temperature no doubt cooling from below.
As the video shows, we sailed her from her ‘below’ helm which I found more comfortable than in the sun outside.

Of course, this was dry desert heat.  
Actually quite tolerable as long as you steadily drank water.
Judge Jochems had a tea-making routine with hot water, teabags, a favorite mug and all, several times every day – come desert winds or blast-furnace feel...

So would selective shading of the centerline slot on BIRDWATCHER help ?
When we had Mason Smith’s boat for a week here in Gloucester, the weather was never intolerably hot or the wind was doing well for the ventilation-effect Phil was discussing.
So I am none the wiser.

The 23’ WANDERVOGEL concept discussed in MAIB a few years back would have a companionway door aft and an opening centerline windshield forward, allowing keeping the overhead hatches closed for shading or rain.
Unfortunately while I have the shop, trailer, and to build her there still is are no plans of her.

Shading and humidity ?

Susanne
 
Sent: Tuesday, September 22, 2015 8:19 PM
Subject: Re: [bolger] better ventilation for BW style cabins > Cartoon 40
 
 

Mark,
I keep being attracted to bird-watcher style cabins because they make knockdowns so easy to recover from and because of the shelter they offer when sailing in a region known for a lot of cloudy, damp, chilly weather.
 
I've also wondered how hot they get when the sun finally comes out in force - they've always reminded me of a greenhouse, which is good if its 45F. Maybe a BW style boat is like winter clothing, and you don't use it in summer. However few people are able to own fleets of boats.
 
So I've been wondering if people have modified these boat designs for better ventilation.
 
A lot of regions get gusty winds on hot afternoons, so undoing the ability of the boat to recover from capsizes seems a poor choice. On a hot day it would be a dangerous temptation to have windows open on the sides, and then leave them open too long during the transition from light morning wind to gusty afternoon wind.
 
* * * *
Based on the pictures of capsize testing I've seen, leaving 1 foot of solid windows next to each side, in both the bow and stern ends of the cabin, seems like it would be enough to preserve the ability of the boat to recover from capsizes in most weather. In severe weather its likely it will be cloudy enough that extra ventilation won't be needed and all of the windows could stay closed.
 
If the rest of the window area on the ends, which is next to the slot, swings open like a shutter towards the sides of the cabin, then it would increase the amount of fresh air flowing through the cabin.
 
For example, if the cabin was 5 feet wide, had 1 foot of solid window left next to each side, and the windows next to the slot opened out to the sides like shutters, then you would have a 3 food wide opening allowing air to flow through the cabin. While the cabin would still be holding in some heat, it seems like this would significantly improve the situation.
 
This suggestion is assuming that the slot through the middle of the cabin would be completely open in the bow, top, and stern.
 
Maybe instead of folding the shutter windows all the way back to the solid windows, they could be latched at a 45 degree angle to solid windows so they could help funnel light breezes into the cabin.
 
I just grabbed the "1 foot" number as a nice round number. Maybe having 9" of solid window instead of 12" would be a better compromise between improved ventilation and retaining a reasonable amount of ability to recover from a capsize.
 
* * * *
Maybe in warmer areas, the slot through the cabin could just be made wider, so there was more gap on the roof for convection to carry the hot air up and out of the cabin, and more gap on the ends for air to blow through. This would be simpler than messing around with building or using the shutter windows.
 
* * * *
Has anybody tried something like these ideas?
 
May your day be filled with clarity, grace, strength, insight, balance, cooperation, listening, keeping faith, and warm laughter,
Roger
 
----- Original Message -----
Sent: Monday, September 21, 2015 7:31 PM
Subject: [bolger] Re: Cartoon 40

Well,  steady on course yet tacks on a dime is the grail, awright!

I think if you look at Jim Michalk's BW designs though, you'll see they all are fuller bodied than Cartoon 40.

Your mods added to the longer version, "Might just work."

OTH when it gets above 80 degrees f., my BW cabin seems frightfully hot,  whatever the theory about breeze flowing down from the sail. Someone else called their BW boat E-Z Bake.

 


Hello All.
     My first extended experience of sailing and living for a few days aboard a ‘Birdwatcher-style’ layout was in July ‘98 on #639 “William D. Jochems” a 25+’ trailer-schooner.
Setting:  Lake Mead, east of Las Vegas, mid-summer, air-temps per radio-broadcast National Weather Service as caught on that video about her was 122 degrees F/ 50 C !

Below with open companion-way door, closed big hatches, and fore-mast hatch open it was significantly cooler in the shade, with 85-degree water temperature no doubt cooling from below.
As the video shows, we sailed her from her ‘below’ helm which I found more comfortable than in the sun outside.

Of course, this was dry desert heat. 
Actually quite tolerable as long as you steadily drank water.
Judge Jochems had a tea-making routine with hot water, teabags, a favorite mug and all, several times every day – come desert winds or blast-furnace feel...

So would selective shading of the centerline slot on BIRDWATCHER help ?
When we had Mason Smith’s boat for a week here in Gloucester, the weather was never intolerably hot or the wind was doing well for the ventilation-effect Phil was discussing.
So I am none the wiser.

The 23’ WANDERVOGEL concept discussed in MAIB a few years back would have a companionway door aft and an opening centerline windshield forward, allowing keeping the overhead hatches closed for shading or rain.
Unfortunately while I have the shop, trailer, and to build her there still is are no plans of her.

Shading and humidity ?

Susanne
 
Sent:Tuesday, September 22, 2015 8:19 PM
Subject:Re: [bolger] better ventilation for BW style cabins > Cartoon 40
 
 

Mark,
I keep being attracted to bird-watcher style cabins because they make knockdowns so easy to recover from and because of the shelter they offer when sailing in a region known for a lot of cloudy, damp, chilly weather.
 
I've also wondered how hot they get when the sun finally comes out in force - they've always reminded me of a greenhouse, which is good if its 45F. Maybe a BW style boat is like winter clothing, and you don't use it in summer. However few people are able to own fleets of boats.
 
So I've been wondering if people have modified these boat designs for better ventilation.
 
A lot of regions get gusty winds on hot afternoons, so undoing the ability of the boat to recover from capsizes seems a poor choice. On a hot day it would be a dangerous temptation to have windows open on the sides, and then leave them open too long during the transition from light morning wind to gusty afternoon wind.
 
* * * *
Based on the pictures of capsize testing I've seen, leaving 1 foot of solid windows next to each side, in both the bow and stern ends of the cabin, seems like it would be enough to preserve the ability of the boat to recover from capsizes in most weather. In severe weather its likely it will be cloudy enough that extra ventilation won't be needed and all of the windows could stay closed.
 
If the rest of the window area on the ends, which is next to the slot, swings open like a shutter towards the sides of the cabin, then it would increase the amount of fresh air flowing through the cabin.
 
For example, if the cabin was 5 feet wide, had 1 foot of solid window left next to each side, and the windows next to the slot opened out to the sides like shutters, then you would have a 3 food wide opening allowing air to flow through the cabin. While the cabin would still be holding in some heat, it seems like this would significantly improve the situation.
 
This suggestion is assuming that the slot through the middle of the cabin would be completely open in the bow, top, and stern.
 
Maybe instead of folding the shutter windows all the way back to the solid windows, they could be latched at a 45 degree angle to solid windows so they could help funnel light breezes into the cabin.
 
I just grabbed the "1 foot" number as a nice round number. Maybe having 9" of solid window instead of 12" would be a better compromise between improved ventilation and retaining a reasonable amount of ability to recover from a capsize.
 
* * * *
Maybe in warmer areas, the slot through the cabin could just be made wider, so there was more gap on the roof for convection to carry the hot air up and out of the cabin, and more gap on the ends for air to blow through. This would be simpler than messing around with building or using the shutter windows.
 
* * * *
Has anybody tried something like these ideas?
 
May your day be filled with clarity, grace, strength, insight, balance, cooperation, listening, keeping faith, and warm laughter,
Roger
 
----- Original Message -----
Sent:Monday, September 21, 2015 7:31 PM
Subject:[bolger] Re: Cartoon 40

Well,  steady on course yet tacks on a dime is the grail, awright!

I think if you look at Jim Michalk's BW designs though, you'll see they all are fuller bodied than Cartoon 40.

Your mods added to the longer version, "Might just work."

OTH when it gets above 80 degrees f., my BW cabin seems frightfully hot,  whatever the theory about breeze flowing down from the sail. Someone else called their BW boat E-Z Bake.

 

Roger,

The regular BW cabin does give an incredible sense of safety, not only in a knockdown but well short of it.

Trying to imagine your open middle section, I suspect the water would pour in, not any worse than a regular boat, but much more so than with closed in high sides.

Phil drew at least one BW type boat with opening side windows, the little Supermouse shown in BWAOM.  He wrote, "The assumption is that they would be closed before the squall strikes - a fair bet, though I'm more comfortable with fixed windows," and then goes on to repeat the idea that the boats are pretty much self-ventilating. In a 15 mph breeze, I'd add.

I use my boat a little differently than most. While you might find me tucked into the turn of the bilge as expected, with plenty of ballast in a heavy bottom and a pair of big batteries, I often like sitting up on a ditty box on centerline. This gets my eyes up at slot level where it' quite a lot cooler on the face, also letting me sense the breeze direction better for steering and allow conning the boat better than through the tinted plexiglass.

Then, there's rare fun in walking toward the bow with sheet in hand and sailing standing up in perfect safety.

Mark

On Sep 22, 2015 5:19 PM, "'Roger Padvorac'roger@...[bolger]" <bolger@yahoogroups.com> wrote:

Mark,
I keep being attracted to bird-watcher style cabins because they make knockdowns so easy to recover from and because of the shelter they offer when sailing in a region known for a lot of cloudy, damp, chilly weather.
I've also wondered how hot they get when the sun finally comes out in force - they've always reminded me of a greenhouse, which is good if its 45F. Maybe a BW style boat is like winter clothing, and you don't use it in summer. However few people are able to own fleets of boats.
So I've been wondering if people have modified these boat designs for better ventilation.
A lot of regions get gusty winds on hot afternoons, so undoing the ability of the boat to recover from capsizes seems a poor choice. On a hot day it would be a dangerous temptation to have windows open on the sides, and then leave them open too long during the transition from light morning wind to gusty afternoon wind.
* * * *
Based on the pictures of capsize testing I've seen, leaving 1 foot of solid windows next to each side, in both the bow and stern ends of the cabin, seems like it would be enough to preserve the ability of the boat to recover from capsizes in most weather. In severe weather its likely it will be cloudy enough that extra ventilation won't be needed and all of the windows could stay closed.
If the rest of the window area on the ends, which is next to the slot, swings open like a shutter towards the sides of the cabin, then it would increase the amount of fresh air flowing through the cabin.
For example, if the cabin was 5 feet wide, had 1 foot of solid window left next to each side, and the windows next to the slot opened out to the sides like shutters, then you would have a 3 food wide opening allowing air to flow through the cabin. While the cabin would still be holding in some heat, it seems like this would significantly improve the situation.
This suggestion is assuming that the slot through the middle of the cabin would be completely open in the bow, top, and stern.
Maybe instead of folding the shutter windows all the way back to the solid windows, they could be latched at a 45 degree angle to solid windows so they could help funnel light breezes into the cabin.
I just grabbed the "1 foot" number as a nice round number. Maybe having 9" of solid window instead of 12" would be a better compromise between improved ventilation and retaining a reasonable amount of ability to recover from a capsize.
* * * *
Maybe in warmer areas, the slot through the cabin could just be made wider, so there was more gap on the roof for convection to carry the hot air up and out of the cabin, and more gap on the ends for air to blow through. This would be simpler than messing around with building or using the shutter windows.
* * * *
Has anybody tried something like these ideas?
May your day be filled with clarity, grace, strength, insight, balance, cooperation, listening, keeping faith, and warm laughter,
Roger
----- Original Message -----
Sent:Monday, September 21, 2015 7:31 PM
Subject:[bolger] Re: Cartoon 40

Well,  steady on course yet tacks on a dime is the grail, awright!

I think if you look at Jim Michalk's BW designs though, you'll see they all are fuller bodied than Cartoon 40.

Your mods added to the longer version, "Might just work."

OTH when it gets above 80 degrees f., my BW cabin seems frightfully hot,  whatever the theory about breeze flowing down from the sail. Someone else called their BW boat E-Z Bake.

Mark,
I keep being attracted to bird-watcher style cabins because they make knockdowns so easy to recover from and because of the shelter they offer when sailing in a region known for a lot of cloudy, damp, chilly weather.
 
I've also wondered how hot they get when the sun finally comes out in force - they've always reminded me of a greenhouse, which is good if its 45F. Maybe a BW style boat is like winter clothing, and you don't use it in summer. However few people are able to own fleets of boats.
 
So I've been wondering if people have modified these boat designs for better ventilation.
 
A lot of regions get gusty winds on hot afternoons, so undoing the ability of the boat to recover from capsizes seems a poor choice. On a hot day it would be a dangerous temptation to have windows open on the sides, and then leave them open too long during the transition from light morning wind to gusty afternoon wind.
 
* * * *
Based on the pictures of capsize testing I've seen, leaving 1 foot of solid windows next to each side, in both the bow and stern ends of the cabin, seems like it would be enough to preserve the ability of the boat to recover from capsizes in most weather. In severe weather its likely it will be cloudy enough that extra ventilation won't be needed and all of the windows could stay closed.
 
If the rest of the window area on the ends, which is next to the slot, swings open like a shutter towards the sides of the cabin, then it would increase the amount of fresh air flowing through the cabin.
 
For example, if the cabin was 5 feet wide, had 1 foot of solid window left next to each side, and the windows next to the slot opened out to the sides like shutters, then you would have a 3 food wide opening allowing air to flow through the cabin. While the cabin would still be holding in some heat, it seems like this would significantly improve the situation.
 
This suggestion is assuming that the slot through the middle of the cabin would be completely open in the bow, top, and stern.
 
Maybe instead of folding the shutter windows all the way back to the solid windows, they could be latched at a 45 degree angle to solid windows so they could help funnel light breezes into the cabin.
 
I just grabbed the "1 foot" number as a nice round number. Maybe having 9" of solid window instead of 12" would be a better compromise between improved ventilation and retaining a reasonable amount of ability to recover from a capsize.
 
* * * *
Maybe in warmer areas, the slot through the cabin could just be made wider, so there was more gap on the roof for convection to carry the hot air up and out of the cabin, and more gap on the ends for air to blow through. This would be simpler than messing around with building or using the shutter windows.
 
* * * *
Has anybody tried something like these ideas?
 
May your day be filled with clarity, grace, strength, insight, balance, cooperation, listening, keeping faith, and warm laughter,
Roger
 
----- Original Message -----
Sent:Monday, September 21, 2015 7:31 PM
Subject:[bolger] Re: Cartoon 40

Well,  steady on course yet tacks on a dime is the grail, awright!

I think if you look at Jim Michalk's BW designs though, you'll see they all are fuller bodied than Cartoon 40.

Your mods added to the longer version, "Might just work."

OTH when it gets above 80 degrees f., my BW cabin seems frightfully hot,  whatever the theory about breeze flowing down from the sail. Someone else called their BW boat E-Z Bake.