Boat Sank due to Syphoning Effect
 

A friend of mine has a Beneteau 345 moored in Corfu, it was due to be
lifted out for the winter this morning but unfortunately he had a phone
call from the Marina to say his boat had sank! The boat was stern on to
the pontoon and it was only the ropes holding the stern end out of the
water. There are no other boats on the pontoon as they have already
been lifted out.

The boat has now been pumped out and is afloat again and on inspection
there is no obvious reason why the boat would take on so much water to
sink the boat in a 12 hour period since it was last viewed.

The evening before the boat sank a large power craft powered at speed
through the Marina and created a very large bow wave, the only
explanation as to the cause that has been offered is that the bow wave
caused the toilet to overflow and created a syphoning effect which in
turn filled the yacht with water.

Anyone heard of this before?

Boat Sank due to Syphoning Effect
 

phasmatis wrote:

The evening before the boat sank a large power craft powered at speed
through the Marina and created a very large bow wave, the only
explanation as to the cause that has been offered is that the bow wave
caused the toilet to overflow and created a syphoning effect which in
turn filled the yacht with water.
Anyone heard of this before?


Many times...but it's unlikely that the large wake had anything to do
with it. Head seacocks left open when no one is aboard are the leading
causes of boats sinking in their slips.

His toilet is below the waterline...I'd bet real money that a) he's
never installed a vented loop in the head intake...and b) he never
bothers to close the head intake (nor the discharge either) seacock when
he leaves the boat, foolishly relying on the wet/dry valve in the toilet
to prevent water from overflowing the bowl. Either the valve failed
(very common), or the toilet was left in the wet mode. It only takes a
few hours for enough water to flood the boat via the toilet to sink it.


--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/books...ku=90&cat=1304

Boat Sank due to Syphoning Effect
 

Peggie Hall wrote:
....
His toilet is below the waterline...I'd bet real money that a) he's
never installed a vented loop in the head intake...

Just curious - do most new boats come without the vented loop, or is
this caused by poor refits (or both)? Also, do the vents get clogged
or fail on their own? How often should they be cleaned out?

Thanks

Boat Sank due to Syphoning Effect
 

On Mon, 12 Dec 2005 14:57:08 GMT, Peggie Hall
wrote:


His toilet is below the waterline...I'd bet real money that a) he's
never installed a vented loop in the head intake...and b) he never
bothers to close the head intake (nor the discharge either) seacock when
he leaves the boat, foolishly relying on the wet/dry valve in the toilet
to prevent water from overflowing the bowl. Either the valve failed

I would second that. Once going below to use the toilet noticed bowl
was almost full of seawater. Toilet pump valve had failed. Lucky us,
top of the bowl was just above waterline.

We usually open the toilet intake seacock when we get to our boat and
have it open as long as we are under way. Have reconsidered that
practice since then.


Mike

Boat Sank due to Syphoning Effect
 

On Mon, 12 Dec 2005 20:49:04 +0200, Mike the Spamkiller
wrote:

We usually open the toilet intake seacock when we get to our boat and
have it open as long as we are under way. Have reconsidered that
practice since then.

==========================

You can flood via the output seacock as well if the right valves fail.

Both input and output shoud have vented loops well above the
waterline.

Boat Sank due to Syphoning Effect
 

On Mon, 12 Dec 2005 14:38:07 -0500, Wayne.B
wrote:

On Mon, 12 Dec 2005 20:49:04 +0200, Mike the Spamkiller
wrote:

We usually open the toilet intake seacock when we get to our boat and
have it open as long as we are under way. Have reconsidered that
practice since then.

==========================

You can flood via the output seacock as well if the right valves fail.

Both input and output shoud have vented loops well above the
waterline.

and better keep seacocks closed or else taking a leak get more serious
meaning ;)

Mike



----------------------------------------------
Haluatko lähettää postia? Vaihda osoitteen
eka (vai oliko se toka?) numero viisi numeroon
kahdeksan...
----------------------------------------------

Vented loops and suction (was) Boat Sank due to Syphoning Effect
 

Well, this thread has me thinking, as neither of our heads has vented loops
in the intake line, and the aft head is distinctly under the waterline (fwd
isn't except on sharp port tack).

So, if I understand vented loops properly, suction gets air, rather than
water, thus preventing siphoning. So, how do you suck in the supply water
if the supply line is vented???

L8R

Skip, scratching his head, pardon the expression (solidly asking pardon for
the other - inferred solid - expression)

--
Morgan 461 #2
SV Flying Pig KI4MPC
http://tinyurl.com/384p2 The vessel as Tehamana, as we bought her

"Twenty years from now you will be more disappointed by the things you
didn't do than by the ones you did do. So throw off the bowlines. Sail
away from the safe harbor. Catch the trade winds in your sails. Explore.
Dream. Discover." - Mark Twain

Vented loops and suction (was) Boat Sank due to SyphoningEffect
 

The vent goes between the toilet pump and the toilet bowl... not
between the inlet and the pump

bob

Skip Gundlach wrote:
Well, this thread has me thinking, as neither of our heads has vented loops
in the intake line, and the aft head is distinctly under the waterline (fwd
isn't except on sharp port tack).

So, if I understand vented loops properly, suction gets air, rather than
water, thus preventing siphoning. So, how do you suck in the supply water
if the supply line is vented???

L8R

Skip, scratching his head, pardon the expression (solidly asking pardon for
the other - inferred solid - expression)

Boat Sank due to Syphoning Effect
 

Jeff wrote:
Just curious - do most new boats come without the vented loop,

Toilet mfrs do not include vented loops because they're only needed if
the toilet is below the waterline and/or discharges below the the
waterline...so a good number would be discarded, adding needless cost to
all units. So it's up to the builder or the owner to install 'em. Some
builders do, most production builders don't.

or is
this caused by poor refits (or both)?

For production builders, it's about cost. Among owners, many don't even
know what a vented loop is, much less whether they need one...I fielded
a post on a forum recently from someone who'd just replaced his toilet
and reported how he was able to discard about 8' of intake hose because
his new toilet had only a short piece of hose connecting the pump to the
bowl instead of all that extra hose and a fitting he couldn't figure out
the need for.

Also, do the vents get clogged or
fail on their own? How often should they be cleaned out?

The vent should have an air valve in it that only allows air INTO the
line to break a siphon (which is why the intake loop has to be between
the pump and the bowl...if it's installed between the thru-hull and the
pump, it interferes with the pump's ability to prime)...and yes, the air
valves do get clogged up with salt or waste...and yes, they wear
out...requiring periodic cleaning and/or replacement.

But because the air valve in most loops is a replaceable item, often
only sold separately instead of being included with new loops, many boat
owners don't know air valves exist...and without the valve, the
waste/flush water will squirt out the hole in the top of the loop where
the air valve should go when the toilet is flushed. It never occurs to
most people that there's a part missing...instead, they put a vent line
on it...which is the WRONG thing to do because that line can only be
1/4", and so it quickly becomes clogged by waste squirting into it,
turning the vented loop into an UNvented loop that no longer can
function as a siphon break...it becomes just a high arch in the line.

Although a vented loop can break a siphon--which is always started by
PULLING liquid through a line--it cannot prevent water from being PUSHED
through a line...which can happen while underway due to the pressure of
water against the hull and any open thru-hull. It's an effect known as
"ram water"--water being rammed up a line. So a vented loop will not
prevent water from flooding and overflowing the bowl while underway,
only while the boat is at rest. So it's advisable to keep all head
seacocks closed except when actually in use while aboard AND when away
from the boat...and any tank overboard discharge thru-hull closed at ALL
times except when actually dumping the tank...'cuz if water can flood
the toilet, it can also flood the tank. If the head seacocks are in
locations that are so inaccessible as to make keeping 'em closed while
aboard except when using the toilet, install shutoff valves in 'em right
next to the toilet.

Btw...something the first poster said:

The boat has now been pumped out and is afloat again and on inspection
there is no obvious reason why the boat would take on so much water to
sink the boat in a 12 hour period since it was last viewed...the only
explanation as to the cause that has been offered is that the bow wave
caused the toilet to overflow and created a syphoning effect which in
turn filled the yacht with water.

That possible explanation makes it obvious it was noticed that the head
seacocks were open...how much MORE obvious a reason would anyone
qualified to inspect the boat need???? And if they weren't closed after
raising the boat, that boat is gonna sink again (if it hasn't already)!

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/books...ku=90&cat=1304

Vented loops and suction (was) Boat Sank due to SyphoningEffect
 

Skip Gundlach wrote:

So, if I understand vented loops properly, suction gets air, rather than
water, thus preventing siphoning. So, how do you suck in the supply water
if the supply line is vented???

Skip, have you ever bothered to the read the manual for your toilet? It
includes drawings showing the locations for both discharge and intake
vented loops.

If you don't have a manual for it, download and print one from the mfr's
website. Not only do the manuals illustrate where to put the loops, they
also include exploded diagragms of the pumps and most have
trouble-shooting guides.

That said, there are some very high end manual toilets--W-C Skipper,
Groco EB and Model K--that don't have the short piece of hose connecting
the pump to the bowl...the only place TO put a vented loop in the intake
is in the line between the thru-hull and the pump. However, the design
of these toilets also makes a vented loop in the intake unncessary.

There's no way to put one between the pump and the bowl on most electric
macerating toilets either...it has to go between the thru-hull and the
pump. Instead of just an air valve in the top of the loop, it's
necessary to intall an electric solenoid valve that's wired to the flush
button.

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/books...ku=90&cat=1304

Boat Sank due to Syphoning Effect
 

On Mon, 12 Dec 2005 20:49:04 +0200, Mike the Spamkiller
wrote:


We usually open the toilet intake seacock when we get to our boat and
have it open as long as we are under way. Have reconsidered that
practice since then.

I draw lake water to flush through a seacock topped with a T-valve.
Above the T-valve (to the toilet and just a shave below the waterline)
is the drain hose to the sink. I leave the seacock SHUT unless I or
someone aboard is using the toilet. I have the option of emptying the
sink into the lake or if there's something noxious in the sink, I can
drain it into the toilet and then to the holding tank. This year, I
vented the loop as well. Everything is double-clamped. We've had two
boats sink at dock in a club of 220 in the last five years due to this
sort of issue...and it's completely avoidable.

The only seacock open when underway is the freshwater intake for the
motor. All others are shut unless in use. All others have bungs tied
to the seacock handles.

If you think of them not as seacocks but as "large holes in the bottom
of the boat capable of letting in dozens of gallons a minute" I find
it focuses the mind wonderfully.

R.

Vented loops
 

Subject

Vented loops are provided with a vent that functions like a "mechanical
ass hole", an engineering term introduced to me many years ago.

The vent allows flow in ONE direction only, just like a MAH.

Lew

Boat Sank due to Syphoning Effect
 

phasmatis wrote:
A friend of mine has a Beneteau 345 moored in Corfu, it was due to be
lifted out for the winter this morning but unfortunately he had a phone
call from the Marina to say his boat had sank! The boat was stern on to
the pontoon and it was only the ropes holding the stern end out of the
water. There are no other boats on the pontoon as they have already
been lifted out.

The boat has now been pumped out and is afloat again and on inspection
there is no obvious reason why the boat would take on so much water to
sink the boat in a 12 hour period since it was last viewed.

The evening before the boat sank a large power craft powered at speed
through the Marina and created a very large bow wave, the only
explanation as to the cause that has been offered is that the bow wave
caused the toilet to overflow and created a syphoning effect which in
turn filled the yacht with water.

Anyone heard of this before?

Yup, my cousins bilge pump started syphoning and sank his boat.

Boat Sank due to Syphoning Effect
 

Jeff wrote:
Peggie Hall wrote:
...

His toilet is below the waterline...I'd bet real money that a) he's
never installed a vented loop in the head intake...


Just curious - do most new boats come without the vented loop, or is
this caused by poor refits (or both)? Also, do the vents get clogged or
fail on their own? How often should they be cleaned out?

Thanks
Surveyors will look for the vented loops and note if they are not there.
Insurers require them. The need annual cleaning routines.

Gaz

Boat Sank due to Syphoning Effect
 

In Gtpnf.94832$ki.57113@pd7tw2no Gary writes:

phasmatis wrote:
A friend of mine has a Beneteau 345 moored in Corfu, it was due to be
lifted out for the winter this morning but unfortunately he had a phone
call from the Marina to say his boat had sank! The boat was stern on to
the pontoon and it was only the ropes holding the stern end out of the
water. There are no other boats on the pontoon as they have already
been lifted out.

The boat has now been pumped out and is afloat again and on inspection
there is no obvious reason why the boat would take on so much water to
sink the boat in a 12 hour period since it was last viewed.

The evening before the boat sank a large power craft powered at speed
through the Marina and created a very large bow wave, the only
explanation as to the cause that has been offered is that the bow wave
caused the toilet to overflow and created a syphoning effect which in
turn filled the yacht with water.

Anyone heard of this before?

Yup, my cousins bilge pump started syphoning and sank his boat.

My neighbour in the club marina had a 30 footer, where the builder was
being smart and had joined the bilge pump and kitchen sink outlet. If
you left the kitchen sink plug on after you had pumped the bilge, you
had a perfect siphon. Of course it happened once. He was lucky that
someone noticed that hes freeboard (usually about six inches higher than
mine, was about a foot lower than mine and came to the rescue.

Another case was with the toalet pump in another boat. So if you make a
sifon, once it will work. Just wait long enough.

- Lauri Tarkkonen

Boat Sank due to Syphoning Effect
 

Gary wrote:
Yup, my cousins bilge pump started syphoning and sank his boat.

I don' TEEENK that's what happened...for a couple of reasons: bilge
pumps don't bring water INTO the boat, they remove water FROM the
boat...and the thru-hulls for bilge pumps are above the waterline. So
unless there was already enough water in the boat to put the bilge pump
thru-hull under water, there's no way that a siphon can start in a bilge
pump line.

The water that sank your cousin's boat had to be coming in somewhere
else...and either the bilge pumps clogged and failed, or they kept
pumping till they drained the batteries and died...allowing the boat to
fill up and sink. Or, the water was coming in faster than the bilge
pumps could keep up with it. Or any combination/all of the above.

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/books...ku=90&cat=1304

Boat Sank due to Syphoning Effect
 

Peggie Hall wrote:
phasmatis wrote:

The evening before the boat sank a large power craft powered at speed
through the Marina and created a very large bow wave, the only
explanation as to the cause that has been offered is that the bow wave
caused the toilet to overflow and created a syphoning effect which in
turn filled the yacht with water.
Anyone heard of this before?



Many times...but it's unlikely that the large wake had anything to do
with it. Head seacocks left open when no one is aboard are the leading
causes of boats sinking in their slips.

His toilet is below the waterline...I'd bet real money that a) he's
never installed a vented loop in the head intake...and b) he never
bothers to close the head intake (nor the discharge either) seacock when
he leaves the boat, foolishly relying on the wet/dry valve in the toilet
to prevent water from overflowing the bowl. Either the valve failed
(very common), or the toilet was left in the wet mode. It only takes a
few hours for enough water to flood the boat via the toilet to sink it.

So when I heard this last week here I realized I am one of the fools who
trusted their wet/dry valve and left the seacock open on the head
intake. I spent the last week trying to reassure myself that the wet/dry
valve has held up for a good year now (since I rebuilt the toilet!), but
I was nervous. So yesterday I finally got to the boat and closed the
seacock. Everything was dry as a bone on board. Just lucky I guess.

But my question is, I don't have a vented loop in the line, a vented
loop would be hardish to install with the layout I have. Should I put
one in or not, assuming I never again leave the seacock open?


--
Stephen

-------

For any proposition there is always some sufficiently narrow
interpretation of its terms, such that it turns out true, and
some sufficiently wide interpretation such that it turns out
false...concept stretching will refute *any* statement, and will
leave no true statement whatsoever.
-- Imre Lakatos

Boat Sank due to Syphoning Effect
 

Stephen Trapani wrote:


So when I heard this last week here I realized I am one of the fools
who trusted their wet/dry valve and left the seacock open on the head
intake.

Not only the wet/dry valve, but also the last person to use the toilet
to leave it in the dry mode.

But my question is, I don't have a vented loop in the line, a vented
loop would be hardish to install with the layout I have. Should I
put one in or not, assuming I never again leave the seacock open?

Put one in. People are fallible...if you're only just beginning to
retrain yourself to close the seacocks, you WILL come in late enough and
and tired enough to say "to hell with the rest...it'll be ok this time."

Vented loops aren't quite 100% foolproof (you DO have to maintain 'em),
but they go a long way toward saving fools from ourselves, and they do
provide an arch in the line well above the waterline that water can't
rise above unless a siphon does get started.

Btw...the loop should be at least 6-8" above the waterline at ANY angle
of heel.

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/books...ku=90&cat=1304

Boat Sank due to Syphoning Effect
 

Dave wrote:

On Tue, 13 Dec 2005 01:31:56 GMT, Gary said:


Surveyors will look for the vented loops and note if they are not there.
Insurers require them.


Not my experience.

You need to get to know a better clase of surveyors...REAL ones, not
just bozos who think that 10 years experience in doing things the wrong
way qualifies 'em call themselves a "surveyor."

Unfortunately, the same applies to insurance companies who don't know
that a boat isn't just a car or house that floats, or what a REAL
surveyor is supposed to know (and shouldn't even be IN the boat
insurance business--at least when it comes to anything bigger than a ski
boat)...so they hire the cheapest bozos and take their word for it that
the boat meets all the standards without ever bothering to find out
whether the bozo has the slightest idea WHAT standards, if any, apply.

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/books...ku=90&cat=1304

Boat Sank due to Syphoning Effect
 

Lauri Tarkkonen wrote:
My neighbour in the club marina had a 30 footer, where the builder was
being smart and had joined the bilge pump and kitchen sink outlet. If
you left the kitchen sink plug on after you had pumped the bilge, you
had a perfect siphon.

You're saying that bilge pump discharged BELOW the waterline???? What
WAS the builder thinking??? Otoh, I had a consulting job last year on a
70' trawler on which both the gray water and the black water tank vents
terminated in charcoal canisters in the engine room, right next to a
propane furnace. So anything is possible.

Of course it happened once. He was lucky that
someone noticed that hes freeboard (usually about six inches higher than
mine, was about a foot lower than mine and came to the rescue.

Another case was with the toalet pump in another boat. So if you make a
sifon, once it will work. Just wait long enough.

But you CAN'T create a siphon if you close the bloomin' seacock! No
matter how inaccessible and inconvenient that may be, it's a whole LOT
easier and more convenient than drying out your boat after it's sunk in
its slip.
--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/books...ku=90&cat=1304

Vented loops and suction (was) Boat Sank due to Syphoning Effect
 

That said, there are some very high end manual toilets--W-C Skipper, Groco
EB and Model K--that don't have the short piece of hose connecting the
pump to the bowl...the only place TO put a vented loop in the intake is in
the line between the thru-hull and the pump. However, the design of these
toilets also makes a vented loop in the intake unncessary.

Thanks Peggy, that answers the question I was going to ask. I have one of
those manual types, I can't remember which right now and I'm not at the boat
to look, but it has a spring loaded pedal that you step on to flush. When I
purchased the boat, the surveyor wrote it up as needing a vented loop and
the insurance company dutifully required it, I could see no way of
installing one so I replied back that it was not possible or needed with my
head. Also the PO had conveniently installed second shutoff right alongside
of the head that can easily be reached even when sitting on it. I use this
religiously. The insurance company (BoatUS) never replied back so I suppose
they are good with it.

John

Vented loops and suction (was) Boat Sank due to Syphoning Effect
 

"Dave" wrote in message
...
On Mon, 12 Dec 2005 15:24:19 -0500, "Skip Gundlach" skipgundlach at gmail
dotcom said:

So, if I understand vented loops properly, suction gets air, rather than
water, thus preventing siphoning. So, how do you suck in the supply water
if the supply line is vented???

Peggy has already explained that the vented loop goes between the pump and

"Already," after I'd posted my question...

the head bowl, not between the pump and the intake. On the upstroke, the
pump applies suction to draw water in through the intake, and that suction
isn't broken since there's no vent in the line it's pulling on. On the
downstroke the pump is applying pressure to push the water from the pump
to
the head bowl. That pressure closes the vent valve, since it's from inside
the line, not outside the line.

and


"Peggie Hall" wrote in message
om...
Skip, have you ever bothered to the read the manual for your toilet? It
includes drawings showing the locations for both discharge and intake
vented loops.

No, Peggie, to your question, having not had a manual (or at least, that
we've discovered, yet, having moved the entire interior contents of the boat
not less than 3 times in the course of our refit) for our Raritan PHIIs, I
didn't see anything to that effect. Or the question would not have arisen.
Despite my quest for clarity and understanding on things I've not dealt with
many times already, I do have a mechanical bent and a better than ordinary
spatial perception. Given my situation (see below), which I assumed to not
be atypical, I couldn't readily make the leap to "outflow" rather than
"inflow" in the supply line chain. On my boat, the outflow hose(s) is/are
about 6" long, going directly from the pump to the intake on the bowl, which
I assumed to be standard.

Earlier (way earlier, maybe a year, in a thread about LectraSans) I
commented about the extraordinarily long runs in the aft head. The removal
of the LS makes the exhaust run only about 15 feet, total (counting the 3'
up and down it has to go to the vented loop top). However, I infer from
what I see in the thread, now, that I'm looking at something similar for our
intake.

Our intake is on the other side of the keel from the exhaust, both of which
are in front of the head (well, technically, aft of the head, but in front
of how you'd sit, rear [pardon the expression] facing, on the stool). The
only cosmetically acceptable location for a vented loop is in the engine
room, about 4' or more from the thru hull, not counting the up-and-down to
get to the pump from under the sole and raised stool location. It would
also mean another hole in the stool deck (one to go from the pump, out and
under to the engine room, and the other, original, to go back in, to go to
the toilet supply).

From all the preceding vented loop discussion, as much rube goldberg as that
seems, it's what's needed? Or, every time the head's used, the t/h valve
gets closed? There *is* a handle'd valve on both terlets' intake hoses.
Perhaps that's what it's about? Aside from the nuisance value of that, does
that suffice?

Thanks. I'm not really dense - I just want to make sure I don't screw up,
and I've not dealt with marine sanitation all my adult life...

L8R

Skip, still ashore, but getting closer to stepping aboard and cutting the
cord as PT progresses apace


--
Morgan 461 #2
SV Flying Pig KI4MPC
http://tinyurl.com/384p2 The vessel as Tehamana, as we bought her

The Society for the Preservation of Tithesis commends your ebriated
and scrutible use of delible and defatigable, which are gainly, sipid
and couth. We are gruntled and consolate that you have the ertia and
eptitude to choose such putably pensible tithesis, which we parage.

Stamp out Sesquipedalianism

Vented loops and suction (was) Boat Sank due to SyphoningEffect
 

Skip Gundlach wrote:
On my boat, the outflow hose(s) is/are
about 6" long, going directly from the pump to the intake on the bowl, which
I assumed to be standard.

Standard as all toilets come from the factory, but not necessarily an
installation that meets safety standards.

Earlier (way earlier, maybe a year, in a thread about LectraSans) I
commented about the extraordinarily long runs in the aft head. The removal
of the LS makes the exhaust run only about 15 feet, total (counting the 3'
up and down it has to go to the vented loop top).

That's still too long...

The
only cosmetically acceptable location...

Arrrrrgggghhhhh!!!!!! The obsession with "cosmetically acceptable"
locations for safety equipment on a boat is a recent innovation that
never existed before the industry began marketing boats to people who
don't really want a BOAT, they want an RV--or worse yet, a luxury
condo--that floats. No...vented loops and seacocks are NOT "decor"
items...but before decor trumped safety, that didn't concern owners. Put
the bloomin' loop(s) where it(they) belongs--above the toilet on the
bulkhead behind it. Email me--peg(dot)hall(at)sbcglobal(dot)net--and
I'll send you or anyone else who wants one a photo of the correct
installation. If that's "cosmetically unacceptable," build a teak,
mahogany, plywood, formica--whatever you consider to BE "cosmetically
acceptable!"--box to cover it and the plumbing. Just make it removeable
so you can service the air valve in the loop and check the hose clamps etc.

As for the manual for your PH II, you can download and print one from
he http://www.raritaneng.com/tech_suppo...s_manuals.html

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/books...ku=90&cat=1304

Vented loops and suction (was) Boat Sank due to Syphoning Effect
 

Understood, but I'm not going to replace a perfectly good head with one of
lesser quality so I can put in a vented loop that is not needed with my
current system.

"Wayne.B" wrote in message
...
On Mon, 12 Dec 2005 19:32:56 -0800, "johnhh"
wrote:

The insurance company (BoatUS) never replied back so I suppose
they are good with it.

============================

Don't assume that. If your boat sinks and you make a claim, that will
be one of the first things they check. It's not a risk that you
really want to take.

Vented loops and suction (was) Boat Sank due to Syphoning Effect
 

On Tue, 13 Dec 2005 06:14:16 -0500, Harry Krause
wrote:

Peggie Hall wrote:
Skip Gundlach wrote:
On my boat, the outflow hose(s) is/are
about 6" long, going directly from the pump to the intake on the bowl, which
I assumed to be standard.

Standard as all toilets come from the factory, but not necessarily an


In case anyone is interested in what a vented loop looks like:

http://tinyurl.com/bghhg

=======================

Can you make that picture more authentic?

In real life they usually have a lot of green grunge on them.

Boat Sank due to Syphoning Effect
 

Dave wrote:
The question was not what surveyors or insurance companies should do. It's
what they do do. I think the experience I reported reflects reality.

Not among good surveyors. But unfortunately the bad ones outnumber the
good ones.


--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/books...ku=90&cat=1304

Boat Sank due to Syphoning Effect
 

Peggie,

Trying to tell people to install vented loops is like trying to get them to
close seacocks when they leave the boat for extended periods. Ain't gonna
happen.

When you tell people they should close all the through hulls prior to
leaving they say that is not what they are for, or that would take to long,
or don't you trust your hoses, or I can't get too my through hulls,,,,and
that is why most boats sink at the dock.

You should see the looks I get from the yard when I tell them the ignition
key is hanging on the closed raw water engine intake and they will need to
open the intake when getting the key to start the engine.

B

"Peggie Hall" wrote in message
...
Gary wrote:
Yup, my cousins bilge pump started syphoning and sank his boat.

I don' TEEENK that's what happened...for a couple of reasons: bilge pumps
don't bring water INTO the boat, they remove water FROM the boat...and the
thru-hulls for bilge pumps are above the waterline. So unless there was
already enough water in the boat to put the bilge pump thru-hull under
water, there's no way that a siphon can start in a bilge pump line.

The water that sank your cousin's boat had to be coming in somewhere
else...and either the bilge pumps clogged and failed, or they kept pumping
till they drained the batteries and died...allowing the boat to fill up
and sink. Or, the water was coming in faster than the bilge pumps could
keep up with it. Or any combination/all of the above.

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/books...ku=90&cat=1304

Boat Sank due to Syphoning Effect
 

Bryan wrote:
Trying to tell people to install vented loops is like trying to get them to
close seacocks when they leave the boat for extended periods. Ain't gonna
happen.


Yep. And that's why somany boats are in the shape they're in.


When you tell people they should close all the through hulls prior to
leaving they say that is not what they are for, or that would take to long,
or don't you trust your hoses, or I can't get too my through hulls,,,,and
that is why most boats sink at the dock.


Yep again. "That's not what they're for"??!? Gee what are
they for then?

"Can't get to my thru-hulls"?!?!!?!!!???!! Why did you buy a
freekin' boat with inaccessible thru-hulls?

Another common one is people who don't know where their
thru-hulls are.


You should see the looks I get from the yard when I tell them the ignition
key is hanging on the closed raw water engine intake and they will need to
open the intake when getting the key to start the engine.


Another goody is people not closing their fuel tank valves.



Gary wrote:
Yup, my cousins bilge pump started syphoning and sank his boat.

"Peggie Hall" wrote
I don' TEEENK that's what happened...for a couple of reasons: bilge pumps
don't bring water INTO the boat, they remove water FROM the boat...and the
thru-hulls for bilge pumps are above the waterline.

Umm, not all of them are.


The water that sank your cousin's boat had to be coming in somewhere
else...and either the bilge pumps clogged and failed, or they kept pumping
till they drained the batteries and died...allowing the boat to fill up
and sink. Or, the water was coming in faster than the bilge pumps could
keep up with it. Or any combination/all of the above.


Rainwater can do it. Also if shore water supply is left
hooked up, and a leak begins (or a hose blows out); that is
a very common way boats sink at the dock (accoring to
insurance). I guess leaving shore water hooked up goes on
the list with leaving thru-hulls & fuel valves open....

Fresh Breezes- Doug King

Boat Sank due to Syphoning Effect
 

Bryan wrote:

Trying to tell people to install vented loops is like trying to get them to
close seacocks when they leave the boat for extended periods. Ain't gonna
happen.

I know. Today's typical boat owner is a new breed...clueless, happy to
remain so, unwilling to learn even the most basic skills, do any manual
labor, or take any responsibility for ensuring the safety of his own
boat...if I've heard "that's why I have insurance" once, I've heard it
100 times! Perhaps if the insurance industry stopped paying claims for
preventable losses.... But that ain't gonna happen either.

Btw, Doug... Not all bilge pump thru-hulls are above the waterline???
That's nutsy design...how can a pump empty out a boat through a hole
through which water can come in faster than the pump can push it out???
Otoh, I just learned that a lot of cockpit drain through-hulls are
also below the waterline...which makes no sense to me either...sigh...




--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/books...ku=90&cat=1304

Boat Sank due to Syphoning Effect
 

Bryan wrote:
Trying to tell people to install vented loops is like trying to get
them to close seacocks when they leave the boat for extended periods.
Ain't gonna happen.


Peggie Hall wrote:
I know. Today's typical boat owner is a new breed...

I dunno if it's so much a "new" breed as the same old
dumb-ass from all ages of history, only set free in today's
consumer-driven easy-credit economy.

Would we have it be any different, truly? Then it would be
much more difficult to be above average!

... clueless, happy to
remain so, unwilling to learn even the most basic skills, do any manual
labor, or take any responsibility for ensuring the safety of his own
boat...

Careful, now you're swerving into politics!

... if I've heard "that's why I have insurance" once, I've heard it
100 times! Perhaps if the insurance industry stopped paying claims for
preventable losses.... But that ain't gonna happen either.


That's true but many insurance companies either raise rates
on "accident" prone boaters just like they do for similarly
inclined auto drivers; and also insurance companies quit
writing boat policies. A big wave occurred after Hurricane
Katrina, and boat insurance is going up.

All the above are among the reasons why I think the
recreational boating market is not going to climb up into a
seller's market any time soon, if ever. The impact of peak
oil on the macro economy and the reduced interest in outdoor
activities on the part of young people (most of whom would
be perfectly content to sit around playing video games) are
two more.

Btw, Doug... Not all bilge pump thru-hulls are above the waterline???
That's nutsy design...how can a pump empty out a boat through a hole
through which water can come in faster than the pump can push it out???
Otoh, I just learned that a lot of cockpit drain through-hulls are also
below the waterline...which makes no sense to me either...sigh...


Well, boat design & construction is a compromise. Some
compromises are better than others ;)

DSK

Boat Sank due to Syphoning Effect
 

"Peggie Hall" a
écrit dans le message de news:
.. .
Bryan wrote:

Trying to tell people to install
vented loops is like trying to get
them to close seacocks when they
leave the boat for extended periods.
Ain't gonna happen.

I know. Today's typical boat owner is
a new breed...clueless, happy to
remain so, unwilling to learn even
the most basic skills, do any manual
labor, or take any responsibility for
ensuring the safety of his own
boat...if I've heard "that's why I
have insurance" once, I've heard it
100 times! Perhaps if the insurance
industry stopped paying claims for
preventable losses.... But that
ain't gonna happen either.

Btw, Doug... Not all bilge pump
thru-hulls are above the waterline???
That's nutsy design...how can a pump
empty out a boat through a hole
through which water can come in
faster than the pump can push it
out??? Otoh, I just learned that a
lot of cockpit drain through-hulls
are also below the waterline...which
makes no sense to me
either...sigh...
snip

Hi - the pump outlet issue is one I
know first hand...
On a sail boat the bilge pump outlet is
frequently underwater when heeled,
and for well designed sailboats with
the outlets on the transom to avoid
this
issue, the wave they generate making
way can sometimes reach the outlets...
No loop, sticky valve and glug, glug,
glug... ;o)
Pierre.

Boat Sank due to Syphoning Effect
 

This thread has drifted from being informational to being judgemental.
Just bcause you know some facts doesn't mean your conclusion will
match mine.

I do know what a vented loop is - I have them. I periodically check
the vents, as well as the hoses and their (double) clamps - just like
I check pretty much every system on the boat.

However, I do not close all the seacocks when I leave the boat for a
week. Doesn't mean I'm an idiot, merely that I've evaluated the risk
and found a level I'm confortable with.


On Tue, 13 Dec 2005 14:01:34 -0500, "Bryan"
wrote:

Peggie,

Trying to tell people to install vented loops is like trying to get them to
close seacocks when they leave the boat for extended periods. Ain't gonna
happen.

Boat Sank due to Syphoning Effect
 

DSK wrote:
Bryan wrote:

Trying to tell people to install vented loops is like trying to get
them to close seacocks when they leave the boat for extended periods.
Ain't gonna happen.


Yep. And that's why somany boats are in the shape they're in.


When you tell people they should close all the through hulls prior to
leaving they say that is not what they are for, or that would take to
long, or don't you trust your hoses, or I can't get too my through
hulls,,,,and that is why most boats sink at the dock.


Yep again. "That's not what they're for"??!? Gee what are they for then?

"Can't get to my thru-hulls"?!?!!?!!!???!! Why did you buy a freekin'
boat with inaccessible thru-hulls?

Another common one is people who don't know where their thru-hulls are.


You should see the looks I get from the yard when I tell them the
ignition key is hanging on the closed raw water engine intake and they
will need to open the intake when getting the key to start the engine.


Another goody is people not closing their fuel tank valves.



Gary wrote:

Yup, my cousins bilge pump started syphoning and sank his boat.


"Peggie Hall" wrote

I don' TEEENK that's what happened...for a couple of reasons: bilge
pumps don't bring water INTO the boat, they remove water FROM the
boat...and the thru-hulls for bilge pumps are above the waterline.


Umm, not all of them are.


The water that sank your cousin's boat had to be coming in somewhere
else...and either the bilge pumps clogged and failed, or they kept
pumping till they drained the batteries and died...allowing the boat
to fill up and sink. Or, the water was coming in faster than the
bilge pumps could keep up with it. Or any combination/all of the above.


Rainwater can do it. Also if shore water supply is left hooked up, and a
leak begins (or a hose blows out); that is a very common way boats sink
at the dock (accoring to insurance). I guess leaving shore water hooked
up goes on the list with leaving thru-hulls & fuel valves open....

Fresh Breezes- Doug King

I didn't conduct an investigation. His boat sank, it had a bilge pump,
no head, and an outboard. The only thru hull was the bilge pump outlet.
It's his story. Argue about something else.

Boat Sank due to Syphoning Effect
 

Peggie Hall wrote:
Bryan wrote:

Trying to tell people to install vented loops is like trying to get
them to close seacocks when they leave the boat for extended periods.
Ain't gonna happen.


I know. Today's typical boat owner is a new breed...clueless, happy to
remain so, unwilling to learn even the most basic skills, do any manual
labor, or take any responsibility for ensuring the safety of his own
boat...if I've heard "that's why I have insurance" once, I've heard it
100 times! Perhaps if the insurance industry stopped paying claims for
preventable losses.... But that ain't gonna happen either.

Btw, Doug... Not all bilge pump thru-hulls are above the waterline???
That's nutsy design...how can a pump empty out a boat through a hole
through which water can come in faster than the pump can push it out???
Otoh, I just learned that a lot of cockpit drain through-hulls are also
below the waterline...which makes no sense to me either...sigh...

Why not? None of my boats have had cockpit drains above the waterline
(unless heeled). That is why there are valves on them.

Boat Sank due to Syphoning Effect
 

In article ,
Peggie Hall wrote:

Otoh, I just learned that a lot of cockpit drain through-hulls are
also below the waterline...which makes no sense to me either...sigh...

More than you might think: Ours are above the waterline at rest. At hull
speed, they're a foot under the stern wave. And I can't easily change
them because they're structural members.

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

Boat Sank due to Syphoning Effect
 

Jere Lull wrote:
In article ,
Peggie Hall wrote:
Otoh, I just learned that a lot of cockpit drain through-hulls are
also below the waterline...which makes no sense to me either...sigh...

More than you might think: Ours are above the waterline at rest. At hull
speed, they're a foot under the stern wave. And I can't easily change
them because they're structural members.

All my 30' yachts and under have had the cockpit drains
underwater. To have a cockpit that is designed to be within
normal proportions of height, the depth of the drain fitting
in the cockpit, with a tube clamped and led away under the
cockpit sole to it's opposite hull outlet, you're already
below water level, usually on the curve away.
Not everyone has a larger boat with high freeboard and
consequently a high cockpit sole.
The major problem is from having the corresponding valves
open when leaving the boat for any length of time, unlike
all others, which can (should) be closed.
BrianH.

Boat Sank due to Syphoning Effect
 

I started this thread so I thought it best to let you all know how it
is progressing.

The boat in question is now out of the water and the insurance assessor
has completed his survey and estimated damage in excess of 12000 euros.
After listening to the advice on this NG I was worried the insurance
company would not pay out as my friend does not have a vented loop
fitted and yes the toilet manual valve was left open by the last user.

My friend received a phone call to say the insurance company would not
pay out in respect of this claim, expecting them to quote vented
loops...etc, but no! they said they would not pay out this claim
because in the small print of the policy it apparrantly states that
'boats must be lifted out for the winter by the 3rd November'. On
checking the policy my friend was horrified to find out he was not
covered.

Anyway to cut a long story short, the greek insurance company has
agreed to pay out in 'Good Faith' after a lot of pressure from the
Marina owner, but as you can guess the first item to be purchased will
be a Vented Loop!

Thanks to all

Boat Sank due to Syphoning Effect
 

Rainwater can do it. Also if shore water supply is left hooked up, and
a leak begins (or a hose blows out); that is a very common way boats
sink at the dock (accoring to insurance).



Gary wrote:
I didn't conduct an investigation. His boat sank, it had a bilge pump,
no head, and an outboard. The only thru hull was the bilge pump outlet.
It's his story. Argue about something else.

Aw, c'mon. Anyway, it wasn't me insisting that it couldn't
be the bilge pump.

DSK

Boat Sank due to Syphoning Effect
 

phasmatis wrote:

I started this thread so I thought it best to let you all know how it
is progressing.
... and yes the toilet manual valve was left open by the last user.

You're referring to the wet/dry valve on the toilet...? It's dangerous
to rely on that valve to prevent water from entering the boat while no
one is aboard! Not only can the last user leave it open, but wet/dry
valves fail.

And vented loops aren't 100% fail-safe either. Should the air valve
become clogged and someone leave the valve in the "wet" mode, water
pushed through the line over the loop can start a siphon.

So if he has ANY sense at all, not only will he install the appropriate
vented loops, but he'll close the seacocks when leaving the boat...'cuz
should it sink again, or even suffer water damage from seacocks left
open, it's unlikely that his insurance carrier will pay the next time,
no matter how much pressure the marine owner or anyone else puts on them.
--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/books...ku=90&cat=1304

Boat Sank due to Syphoning Effect
 

In article . com,
"phasmatis" wrote:

Anyway to cut a long story short, the greek insurance company has
agreed to pay out in 'Good Faith' after a lot of pressure from the
Marina owner, but as you can guess the first item to be purchased will
be a Vented Loop!

And the second purchase would be a policy from a different company.
Sometimes folks around here can get in a Thanksgiving cruise: 4 days the
last weekend in November. I still was adding to my tan in early
November. ;-) BUT it's 20°F/-10°C right now. :(

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/