Re: [PUP] Objectivity in boating publications
One thing that magazines like Passagemaker can do, and used to do, is
to campaign for changes that make boats inherently safer. The battery
switch gripe directed at any manufacturer who failed to do it was
beneficial to the industry. This is one example of a way that a
magazine can improve the safety of the industry.
It will be interesting to see what (if any) causes Passagemaker will
try to push going forward in the future.
I for one would like to see them push manufacturers to provide
stability data (even if its just modeled data) on any boat that claims
to be suitable for passagemaking. There are programs that can
estimate it based on detailed manufacturer inputs, and that should be
one of the basis for comparison of boats. But its data that is rarely
available for trawlers, or what data is there is presented in such a
way that its hard to compare.
A magazine editor could define the parameters that the boat
manufacturer needs to provide and do their own run on the standard
software that's available to any naval architect. If the boat builder
wasn't happy with the results, he could defend why his boat does
better than the model predicts. That would at least provide a first-
level estimate of all reviewed boats, measured with a common yardstick.
Just one suggestion.
John
On Sep 16, 2009, at 3:58 PM, David Evans wrote:
John
On Wed, Sep 16, 2009 at 7:02 AM, John Marshall
johnamar1101@gmail.com wrote:
Its been my observation that boat magazines, most recently
Passagemaker, have become less objective and critical of the boats
or equipment they review, and more likely to hide their limited
criticism between the lines or suppress it altogether to favor their
advertisers.
Further, its my opinion that Passagemaker under the previous
editorial staff (Bill Parlatore) was a bit more willing to be
critical.
Or was that just more opinionated?
Are there other magazines that do a better job?
Which also begs the question of what we can do as a group of
educated boaters to encourage magazines like Passagemaker to remain
more objective. Or should one of the purposes of PUP be to inject
the missing objectivity and criticism into our discussions?
Or am I barking up a tree that we can't possibly climb?
John Marshall
N55-20 Serendipity
Sequim Bay, WA
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Hi John,
I just wanted to comment on this...
As you may know, we build custom boats, usually from other designers
designs. Stability information is usually available from the designers, but
we normally do an inclining experiment anyway to verify the hydrostatics.
On our new design, the Pathfinder 48, we are including a full stability
booklet in the owner's manual. This isn't really a big deal because you
only need to do it once for the design, and it provides the owners with all
of the information they could ever need.
Any other Manufacturer should have this information available as it gets
generated during the design phase.....
So, I guess I'm saying - I agree with you, it should be made available!
Brian
I for one would like to see them push manufacturers to provide
stability data (even if its just modeled data) on any boat that claims
to be suitable for passagemaking. There are programs that can
estimate it based on detailed manufacturer inputs, and that should be
one of the basis for comparison of boats. But its data that is rarely
available for trawlers, or what data is there is presented in such a
way that its hard to compare.
A magazine editor could define the parameters that the boat
manufacturer needs to provide and do their own run on the standard
software that's available to any naval architect. If the boat builder
wasn't happy with the results, he could defend why his boat does
better than the model predicts. That would at least provide a first-
level estimate of all reviewed boats, measured with a common yardstick.
Just one suggestion.
John
Brian,
Your willingness to put your data out there, both modeling data and
empirical tests, is encouraging and hopefully will motivate other
manufacturers. Its crazy to me that this info is so readily available
for sailing passagemakers but as soon as we move to passagemaking
under power, then most of that data disappears, to be replaced by the
largely meaningless A/B ratio and similar.
While sailboats run their model all the way to the limit, it makes
little sense to run the model for most powerboats beyond 90 degrees of
inclination. The house is in the water then and the model changes
abruptly -- you either have windows intact and lots of buoyancy from
the house, or the windows break and you fill with water and go down
like a rock. I would like to see the model run at both light ship and
heavy ship weights.
So kudos to you and the Pathfinder 48 for putting the data out there.
John Marshall
Nordhavn 55-20 Serendipity
On Sep 17, 2009, at 7:03 AM, Brian Smyth wrote:
Hi John,
I just wanted to comment on this...
As you may know, we build custom boats, usually from other designers
designs. Stability information is usually available from the
designers, but
we normally do an inclining experiment anyway to verify the
hydrostatics.
On our new design, the Pathfinder 48, we are including a full
stability
booklet in the owner's manual. This isn't really a big deal because
you
only need to do it once for the design, and it provides the owners
with all
of the information they could ever need.
Any other Manufacturer should have this information available as it
gets
generated during the design phase.....
So, I guess I'm saying - I agree with you, it should be made
available!
Brian
I for one would like to see them push manufacturers to provide
stability data (even if its just modeled data) on any boat that claims
to be suitable for passagemaking. There are programs that can
estimate it based on detailed manufacturer inputs, and that should be
one of the basis for comparison of boats. But its data that is rarely
available for trawlers, or what data is there is presented in such a
way that its hard to compare.
A magazine editor could define the parameters that the boat
manufacturer needs to provide and do their own run on the standard
software that's available to any naval architect. If the boat builder
wasn't happy with the results, he could defend why his boat does
better than the model predicts. That would at least provide a first-
level estimate of all reviewed boats, measured with a common
yardstick.
Just one suggestion.
John
Hi John,
Thanks,
But really, it isn't that big of a deal. To me, I can't understand why
anyone wouldn't be willing to give THE OWNERS this data??? After all, when
you buy a boat, surely you have the right to know the design parameters.
The stability booklet will tell you if the vessel is stable under all
expected loading conditions, as well as damage stability and down flooding
if required. Unfortunately, there are very few stability criteria for
"yachts". The closest we have are ISO stability criteria A thru D, but
unless you really understand how these criteria are derived, it means little
to the owner. Basically the last page of the booklet is a "pass/ fail"
statement.
However, our procedure is to do a "light ship" inclining experiment, and
then, knowing the tankage, the full load condition is calculated. This
gives you your stability for all states in between also, but again it is
something that needs interpretation.
The cost of producing a stability booklet, is roughly $1500.00. A small
price to pay for piece of mind!
Hope this helps....
Brian
-----Original Message-----
From: John Marshall [mailto:johnamar1101@gmail.com]
Sent: Thursday, September 17, 2009 1:11 PM
To: Brian Smyth
Cc: 'David Evans'; 'Passage under power'
Subject: Re: [PUP] Objectivity in boating publications
Brian,
Your willingness to put your data out there, both modeling data and
empirical tests, is encouraging and hopefully will motivate other
manufacturers. Its crazy to me that this info is so readily available
for sailing passagemakers but as soon as we move to passagemaking
under power, then most of that data disappears, to be replaced by the
largely meaningless A/B ratio and similar.
While sailboats run their model all the way to the limit, it makes
little sense to run the model for most powerboats beyond 90 degrees of
inclination. The house is in the water then and the model changes
abruptly -- you either have windows intact and lots of buoyancy from
the house, or the windows break and you fill with water and go down
like a rock. I would like to see the model run at both light ship and
heavy ship weights.
So kudos to you and the Pathfinder 48 for putting the data out there.
John Marshall
Nordhavn 55-20 Serendipity
----- Original Message -----
From: "Brian Smyth" brian.smyth@ns.sympatico.ca
But really, it isn't that big of a deal. To me, I can't understand why
anyone wouldn't be willing to give THE OWNERS this data??? After all, when
you buy a boat, surely you have the right to know the design parameters.
Unfortunately, there are very few stability criteria for "yachts".
REPLY
I may have heard one explanation. While working for a large Carver
dealership I took note of the numerous hard top additions the carpenter
shop was doing on the earlier models with a canvas tops.
I learned these hard top conversions added something like 1200 - 1500
pounds at a height of 10 - 12 feet above the water line.
Having been trained about stability in the past I mentally went YIKES!
then asked if anybody had bothered to check the stability curves. This
request was met with blank starres. "stability what??"
I followed up by asking Carver directly about stability curves. I was
told this was not to be given out to customers. The boss went so far as to
tell me to shut up because raising questions about safety issues just
tended to scare the owners and especially the wives. This would hurt
sales of conversion jobs.
As a practical matter, 90% of these boats were fair weather boats or marina
queens used mostly in the inland waters of Ontario. In other words the
chances were low that these boats would actually encounter a situation
where they get into trouble in real waves.
I felt the attitude of the dealership sales people was reprehensible. Their
attitude was 'we give the customer what they ask for'.
Arild