[PCW] Seaworthyness stability

[Candy & Gary]

Right on Bob, Excellent discussion.





Back to cats.  I understand that a cat (Sail?) capsized off the Oregan coast
in the last few days.

Yep.  A 45 foot South African sailing cat on the last legs of it's delivery to
a fellow in Renton Washington.  Hull, stripped of masts etc. washed up on the
beach near Lincoln City upside down.  EPIRB still locked in a cabinet inside.
Last log book entry off Cape Blanco 11 Dec. in pretty intense storm.  Three
professional delivery crew from Africa and England missing.  They apparently
left San Francisco in the face of forcasts for severe storms and none of them
had any experience with local weather and conditions.  Tragic.  Lessons
include that the inverted hull made it intact to shore.  Puzzle, there was a
length of rope TIED to one of the prop. shafts, the other end frayed.

Actually dual engine failure is more common than we
would like to think--since engines depend on both good clean fuel--and today
the electronics.

To paraphrase somebody in the real estate biz, the three most important
factors in diesel engine failures must be fuel, fuel and fuel. Coolant
failures are probably next in significance, with electric or electronic
failures a very distant place on such a list.  Each engine has it's own
independent alternator and storage battery, and if there was enough juice to
start the engine before one weighed anchor, most diesels use no other electric
power to run.  They have some current running in the guage and alarm sensors,
but few of us have automated engine shut-offs that would shut the thing down
if the little electrons went on strike. The newfangled electronic controled
engines are supposed to have a mechanical mode available, perhaps with some
small degradation in performance if the black box malfs.  In any case, the
electric parts are independent and isolated to each side.  There is an
independent cooling system for each motor as well.  Of course you can motor
into a big patch of weed or sea nettles and conceivably overheat both engines
at the same time, but any other failure on one side should leave the other
engine OK.  However, which of us has independent fuel supplies for each of our
engines?  I'll bet that if you asked the Boat Assist, the Sea Tow and the
Coast Guard they would confirm that the most common fuel problem is the
operator failed to put enough in.  Air leaking into and fuel leaking out of
the fuel plumbing is a big issue, and of course we have all heard about -- and
so many of us have real experience with crudded up fuel that many of us want
or have on board fuel polishing rigs and multiple filters.  I suggest that
what we really need is a 'day tank' for each engine, fed from the main fuel
system through filters and isolated from the other engine's tank.

If one were to have taken on bad fuel--both engines may be
effected--and if all power is lost, again both engines may be effected.  The
boat then may be allowed to be in a compormising position (beam to
seas)--before the engine problem is remedied or a sea anchor is deployed.
Also if there were flooding on one engine room--and in the PDQ (not to pick
on
one boat)--if there were severe conditons, a shaft seal failed, and the
engine
compartment filled with water, as the boat sank lower--the partial bulkhead
might allow water to enter more of the hull.    I am not saying bad design--I
am saying that under a certain set of tradgic circumstances, almost any boat
can be compromised.

Well, lemme tell ya about when I tried to sink my new PDQ 34.  On my first
trip on the Columbia River with my brand new PDQ-34 I 'T-boned' a forty foot
log with my stbd bow, which smashed a stunning hole in it.  No worries right?
There is a sealed crash chamber forward, which flooded, but that should be the
limit of the flooding.  Wrong.  The factory apparently failed to adequately
seal the bulkhead at the aft end of the bow safety chamber (they paid my
deductible, so no hard feelings), and my entire starboard hull flooded.  The
engine was almost half under water, and a little was dribbling over the
threshhold at the front of the engine chamber and onto the stateroom sole.  A
small but steady stream was squirting into the shower sump, and the sump pump
was dutifully pumping that overboard.  The stbd bilge pump plugged up with
construction debris and quit.  However because Saint Ted the designer limited
the floodable volume of the real open bilge available to my flooding waters by
sealing off large false bilges between the sole of the cabin liner and the
real bottom of the hull, rather little water was aboard. That liner also
served as a displacement hull inside the real one, adding tremendous bouyancy.
Also, the hull is Corcel foam sandwich above the waterline, and by itsself
quite bouyant. Anyway, when the bilge pump pooped out I beached the boat and
called Sea Tow for a quick patch and a tow to a local yard, who fixed it all
up better than new and gave me foam filled bows.  I feel pretty good about how
all that worked out, but I believe I'll let somebody else continue the
empirical bouyancy tests.

A PDQ 34 was lost in Katrina.  It was in a marina, and a floating casino barge
ran up over the port bow and simply crushed the whole bow.  The boat still
floated, with one side smashed open and fully flooded.  In the photos it looks
as if the stbd hull was still dry inside.  Guestimated list maybe 20 degrees.

It looks as if these power catamarans might be harder to sink than we thought.
Contrast that with the most common cruising boat ever, the monohull sailboat.
Get a sigificant hole in the hull and with often thousands of pounds of
ballast you are on a non-stop express trip to meet Mr. Davy Jones.

It is very difficult to economically design a boat which
will not fail under the right conditions.

It sounds kinda nitpicky, but for my money boat losses are very seldom due to
design faults, fairly seldom due to equipment or structural failures, rather
seldom by unpredictable natural causes (hulls crushed in mid-ocean by
whales)and by far most often due to human issues.  Failures of judgement,
failure to adequately plan, failure to get or appreciate adequate information
and mostly just plain blunders. Look at the probable causes cited for most
boat losses and you come away muttering:  "What the #$%^ were they thinking?"
Just about the time you think you have designed the idiot proof boat they come
out with a better idiot.

Even some of the CG motor lifeboats
have been lost.

A couple of years ago at LaPush on the Washington coast for example. Lost on
the rocks right at the mouth of the harbor with all hands.  I don't go into
LaPush voluntarilly.  I give the Coast Guard lots of credit though.  They are
genuine heros.  They feel duty bound to go out on a rescue that any sane
boater would faint considering.  The phrase I keep hearing is "we have to go
out, we don't have to return."  That skews the Coast Guard loss statistics
completely.  Most, perhaps nearly all their boat losses involve selfless
sacrifices in the line of duty and honor.

Gotta go

Gary