Houdini and Friends, M.J. update/upgrades
Too much work. No time to chat. Yet! And not all messages read....
As some of you who are waiting for finished work or proposals know,
we've been swamped in currcular and extra-curricular activities.
Important for some of you, the MARTHA JANE stability-reassessment and
upgrades are finished and off to publication. With this forum's
policies in mind our discussion and drawings will have to appear in
MAIB, i.e. 6-8 weeks from now.
We are offering a range of minor and mid-level additions to M.J. that
can bump her stability up into W.D.JOCHEMS territory for safety.
Several things to bear in mind:
- Until Ed Haile's dumpings and then "Landroval"'s problems, we had
not been notified of any serious stability-issues, apart from one who
was clearly 'asking for it'... We recently contacted several M.J.
owners and did not hear of such issues either. Perhaps conservative
folks?
- We don't think we ever advertised her as uncapsizable.
- It seems that most folks who flipped theirs took this for granted
and thus chose not to let us know of any such issues. On the other
hand, if there is a real problem with our designs we should be told
first, before everybody gets together swapping 'war-stories'...
- The speculations in this forum though reflected high intellectual
levels of 'ruminations' and empathy for 'dumpees'. Good to see folks
getting into gear trying to solve a problem.
- Designed well before affordable/useable computer-based calculations
were accessible, we digitized her overall configuration and ran
several scenaria of possible stability-enhancements. Some results as
the machine sees it, assuming closed hatches and sealed buoyant
spars:
- As designed she's stiffest around 20 degrees of heel and reaches
point of no-return at 60 degrees.
- A moderate upgrade will move that point to 70 degrees.
- A more serious upgrade with 500lbs steelshoe in addition to her
stock waterballast (500lbs net trailerweight gain!) results in
stiffest angle of heel bumped to 25 degrees, and positive righting
moment all the way to 140 degrees.
- As upgraded with 'all the options'including house, she'll finally
go
negative for about 20 degrees after she hits 160 degrees, and any
minor water motion will get her to come back up - if you could get
her
this far to begin with.
M.A.I.B. will show curves and numbers in greater detail.
Since, in favor of getting her upgrades squared away between other
work, we have not followed the M.J. discussion in this forum, some of
this might be obvious or 'old news'.
Depending on who is doing what with her, some have found her safe
enough for ICW adventures, while others might indeed benefit from the
upgrades, as local waters, execution of plans, impact of alterations
on overall design-integrity, helmsmanship and luck can produce
'butterflies' too early for comfort and joy sailing her.
Depending on what upgrade and relative improvement to her stability
appeals to you, you can give yourself a lot more peace of mind, than
many might have in their M.J. after this thread. By no means should
the building efforts and sailing ambitions of M.J.owners be
considered
as 'terminally' in doubt.
As some of you who are waiting for finished work or proposals know,
we've been swamped in currcular and extra-curricular activities.
Important for some of you, the MARTHA JANE stability-reassessment and
upgrades are finished and off to publication. With this forum's
policies in mind our discussion and drawings will have to appear in
MAIB, i.e. 6-8 weeks from now.
We are offering a range of minor and mid-level additions to M.J. that
can bump her stability up into W.D.JOCHEMS territory for safety.
Several things to bear in mind:
- Until Ed Haile's dumpings and then "Landroval"'s problems, we had
not been notified of any serious stability-issues, apart from one who
was clearly 'asking for it'... We recently contacted several M.J.
owners and did not hear of such issues either. Perhaps conservative
folks?
- We don't think we ever advertised her as uncapsizable.
- It seems that most folks who flipped theirs took this for granted
and thus chose not to let us know of any such issues. On the other
hand, if there is a real problem with our designs we should be told
first, before everybody gets together swapping 'war-stories'...
- The speculations in this forum though reflected high intellectual
levels of 'ruminations' and empathy for 'dumpees'. Good to see folks
getting into gear trying to solve a problem.
- Designed well before affordable/useable computer-based calculations
were accessible, we digitized her overall configuration and ran
several scenaria of possible stability-enhancements. Some results as
the machine sees it, assuming closed hatches and sealed buoyant
spars:
- As designed she's stiffest around 20 degrees of heel and reaches
point of no-return at 60 degrees.
- A moderate upgrade will move that point to 70 degrees.
- A more serious upgrade with 500lbs steelshoe in addition to her
stock waterballast (500lbs net trailerweight gain!) results in
stiffest angle of heel bumped to 25 degrees, and positive righting
moment all the way to 140 degrees.
- As upgraded with 'all the options'including house, she'll finally
go
negative for about 20 degrees after she hits 160 degrees, and any
minor water motion will get her to come back up - if you could get
her
this far to begin with.
M.A.I.B. will show curves and numbers in greater detail.
Since, in favor of getting her upgrades squared away between other
work, we have not followed the M.J. discussion in this forum, some of
this might be obvious or 'old news'.
Depending on who is doing what with her, some have found her safe
enough for ICW adventures, while others might indeed benefit from the
upgrades, as local waters, execution of plans, impact of alterations
on overall design-integrity, helmsmanship and luck can produce
'butterflies' too early for comfort and joy sailing her.
Depending on what upgrade and relative improvement to her stability
appeals to you, you can give yourself a lot more peace of mind, than
many might have in their M.J. after this thread. By no means should
the building efforts and sailing ambitions of M.J.owners be
considered
as 'terminally' in doubt.