Boat Capsize Evidence

One source for what? You have a odd way of endearing yourself and frankly, I'm fairly sure that most have given up on you all ready. I'm about the most reasonable you'll find and am also losing a desire continue. You'll find most of use are professionals in the industry here. If you have something specific to ask, instead of the generalities you've touted, that state them, other wise enjoy your peculiar world, where all boats capsize by the transom.

 

Your quote:

"The figures clearly show (from every source BTW) this is quite incorrect"

i asked you for only one source, ANY one of your "sources" will do.



I run these seas in earnest, how am i expected to give a flip about YOUR personal perception of what YOUR others might think of me?? Seriously.

I didn't give you generalities, i gave you specifics about an unsafe hull characteristic. You have absolutely no obligation to me or anyone else to address the issues that i raised, but you should at least be big enough to overtly decline the offer-

it must be my lot in life...

every once in a while i engage a forum, searching for the answers to lifes persistant questions ) {GK}


and this time like so amny others only confirms my belief: that which looms huge in the minds of some, remains entirely unexpalinable by the english language....

You are a self-proclaimed expert---so tell me how 'water accumulating at the rtransom' should NOT be a concern to the typical small production boater from the designers perspective.

Brad

(there is nothing like the feeling of utter security on a tumultuous sea..)

 

I've never met as innately inept a person yet. You've succeeded at surprising me. Posting any sources would seem foolish now, in light of the several governmental agencies that do gather statistics on accidents, mishaps, etc. as do insurance and other private companies, but once again, I'm informing you of the obvious (well at least to everyone else it's obvious).

Brad, if a sump and well is located at the base of the transom, as it is in about 60% of small power craft, and the prerequisite pump also located there, then I can assure you there is absolutely no reason to be concerned as the pump will remove the accumulated water once it gets of sufficient volume to trip the float switch. As a mater of fact, a well designed boat will have two sets of pumps, those located at the transom and those located midship, though this does imply an entirely different hull form then is currently prevalent in production. Possibly much like the one you failed to enlighten us about or were possibly referring to initially, foolishly thinking that they all are the same shape.

I guess in your world they don't mount bilge pumps at the transom, in a small sump, but fortunately for the rest of us, they do.

 

PAR, to support Your input: there are stability requirements that are developed to compensate various effects including effect of free surface of bilge water. Say, minimum GZ should be 0.2-0.3m depending on type of craft, GM requirement for commercial vessels or offset load test for pleasure craft, etc.

There is absolutely no issue with reduction of stability due to bilge water on properly designed and operated boat. Seems we deal with another misbelief of experienced sailor - it is quite common.

 

You may think i am inept, but i actually have a self-priming bilge pump mounted on the transom

While underway in wind and rough seas, the water coming over the rail is unavailable to the 2k pump nesting up in the belly--{there to protects the many nights at anchor }

I'm on my 4th 2k pump since '91. The first one actually saw some action one day back during the splendid gale. Since then they have only pumped water out of the boat two times, both fresh water from rain i couldn't avoid--i kid you not~!

Getting back to the subject at hand--It doesn't matter how the water intrudes the hull, a good design will not allow the water itself to be the single greatest force working against maximum prolonged flotation :!:

 

I think it is very well said Alik.

Thank you for your patience, you realy try, but it seams Loveofsea has a hard time to understand.

Loveofsea, I am impressed by your NM at sea, but on other matter you seams confuse. Perhaps you insisted on a peculiar reasonement, or on a strange concept.
You have to pay more attention what PAR and other has to say, they are highly trained professional and their advise are precious. Believe me, my self I have great pleasure to learn from their post.
Anyway all that will not let impair your love of the sea, transom or not.
Keep sailing, it's safer.
Daniel

 

I'm sorry you've seemed to chew up pumps, I had my share of bad pumps too, but I think this is more a function of poor manufacturing quality then any design flaw on both the yacht designer or pump engineers.

Boarding water is a fact of life, there's no sense trying to avoid it, without forever staying ashore. I agree there are many designs that don't treat boarding water as an important an element as both you and I think it is. I do think that most designs address the issue fairly, at least within guidelines and regulations. Again the various regulations, specifications and guidelines needn't be noted (hell I don't want to look them all up, honestly), but down flooding, boarding water, leaks from various sources, etc. are all handled among the various regulations, especially in commercial vessels (I treated this thread per the regs. for pleasure craft).

In the end, I think we both are in basic agreement, though I still have faith in the pumps, while you seem to have had the "fear" put in you (I know this fear). I have several boats, about half are berthed, so faith in the pumps is mandatory. I've arrived at the marina more then once to see the boot stripe looking low, to find a leaf or gum wrapper wedging the "first" switch closed (I use a multiple switch and pump system), but then again this is why I check on the boats more then once a week. Now, this may also be a function of owning 50 year old wooden boats and their nasty habit of spitting out caulk or butt block fasteners without warning or it could be my anal nature in coveting these old beauties.

 

Loveofsea, you're the one who flat said that in the vast majority of small craft capsizes, it's water coming over the transom that does them in. I would say that if anyone needs to come up with sources, it would be you--not the people questioning you.

Why do you keep badgering Par for sources, instead? Frankly, I'd say he is a source, at least compared to you. He designs boats for a living, and I suspect he has some basic knowledge concerning what sinks them and what doesn't....

You, on the other hand, seem to have no actual facts and figures to back you up; you've offered nothing that needs to be refuted. In fact, you seem to be touting your mileage at sea as the primary source of your expertise.

I'm not impressed. I drive several hundred miles a week in my pickup, but it hardly makes me a statistical expert on the main cause of car wrecks.

 

Not so fast Troy, lets take your example and have a look. Assuming a real 700 miles per week, across 52 weeks per year, for about 36.5K in annual mileage. This places you at about 3 times the national average in miles driven. Again, assuming (gets me every time) you are paying attention during your driving, you probably see considerably more by way of car wrecks and other mishaps on the road. According to Walter P. Stapleton, head judge, 3rd Circuit Court of Appeals 1975 (the precedent usually sited for clarification of what describes an expert and don't ask me how I know) you would be an expert on car crashes in your area. Of course there's always going to be a better expert that can be called, but at the moment, you're our California car crash go to guy. Live with it

In short, I didn't list statistical information because it's very easy to find, but you do have to have an idea where to look. I made a few bland suggestions, but more specifically the USCG and several transportation agencies of the US government, as well as most insurance agencies and related industries are quite annal about keeping records on these sort of things. Stuff like over 80% of all sinkings on boats with stern drives (okay to be precise, this is claims made, as I got it from an insurance company), occur because of a bellows leak and a malfunctioning bilge pump system (imagine that) or that 90% of all boats sold in the USA in the last 5 years were powerboats. Some of this information is fun to know, like the percentage of folks that wear bathing suits, compared to fully dressed and more importantly the percentage of the scantly clad boaters that were involved in alcohol related mishaps.

My point was, with a little leg work, the regulations, trends, statistics (for nearly every imaginable thing), etc. can be dug up and examined. In fact most of it is "public record". More complex issues, such as the AYBC, ISO and other standards or industry practices are also fairly easy to obtain.

I don't know everything, unless you ask my other half whom I've convinced I am a supper human from another planet (well maybe the other planet part anyway), but I do think it's important to insure you earn your grade. It's one thing to have a question and another to profoundly state that things are thus and not have a clue about the actual facts of the situation you're proclaiming is true. I just happen to know what is the primary cause of most capsizes, at least statistically and it's nothing as was suggested, hence my dander.

 

I failed to make my point clearly enough. Boats take on water for many reasons, ruptured bellows is right up there at the top of the list. My original point was that no matter how the water enters the hull, if it rushes to the transom the bow up/transom down attitude will be the ultimate cause of of the capsizing. If that same boat had level sinking ie, 'water accumulates in the belly' the boat would sink more level, buying precious last moments for action--maybe enough to save the vessle. Regardless, boats don't usually capsize until that last cup of water comes in over the transom.


I must not have been very clear about my belly pump either. My series of new bilge pumps only pumped water a couple of times over all those years in the boat--i replace that pump(s) every few years whether it ever actually pumped water or not. When you run these seas like i do, you cannot take any chances. The only time i ever need to pump water out of the hull is when i am underway, taking spray over the rail in wind and seas then i use the self-priming pump screwed to the transom. (i assure you Sir that the good skiff does not leak! I never use the belly pump--i may only need it one more time, but i WILL need it then-- so it is always a virtually new pump... (gave my old perfectly good pumps away

Here is how i achieved 'water accumulating in the belly' I built the hull upside down in a jig holding the bulkheads only. It is easier to visualize the hull right side up. View looking at the side--Y datum plane touches the hull 1/3 bottom length aft of bow--from that point aft the hull is flat and rises up 3" from the plane/ from that point fwd the hull makes a parabolic curve up 6" from the plane--

I hear you about wooden hulls--i love the feel of a wooden hull skimming the seas. My skiff is a 19ft flatbottom with a 115HP tiller. It is like riding a dirtbike on the water!

Some day we should have a discussion about how to make flatbottom work well in seas--that's something i know!

 

There will never be much exchange of good information if the discussion gets into personality flaws before anyone ever describes their position well enough for decent argument to follow.

Here goes: I think Brad is only talking about small powerboats and probably only IO's or outboards. In that case there is some point to his argument which he should have cleared up to begin with. Of course no one hardly ever gives a decent description of their question to start with on this or any other forum.

I know of three cases locally that fit this pattern. One is a Sea OX that sunk at the dock because storm water washed in over the transom. The second is similar in that a near sinking was caused by rapid check up and considerable water entered the same way. Aid from another boat was required to prevent swamping. The third case was me in a Whaler 23 Outrage I was using as a race committee boat in very rough water. The boat was at anchor and water was dashing over the bow. We mover aft and water rapidly came in over the transom.

The common thread is all three cases was the absence of an adequate safety transom ahead of the splashwell. Boats with deep V hulls have the motor mount too low for safety without a second transom ahead of the splashwell. I wrote to Boston Whaler and they said that they had provided an optional forward transom for this boat but it was no longer available.

Big deal. Optional There were also no scuppers which they said had also been available in the past. still

Another new twin inboard boat sunk a couple years ago about a mile from me on new delivery because a water intake hose parted and the boat filled and stopped the engines. Both licensed delivery captains aboard drowned in the cold water and we will never know all the details.

Still, most serious capsizes locally occur in the waves and are because the boat flipped. This is most probably due to poor seamanship and catching a big one on the beam. Power cats are not immune as the last one was such a cat with loss of life.

Now, I happened to learn that a lot of Brad's experience is in a small flatbottom skiff with pretty big outboard that he runs for long distances offshore in California. Most of us would not consider that but he makes it work by adding a big fixed trim tab on the stern to hold the bow down so that the boat does not slam and he can run a high speed in waves(his words). Not my cup of tea but even port tackers get to tell their story.

Edited to add that Brad got his latest post in while I was typing.

 

We should probably go back and define terms, before going any farther. Loveofsea was talking about 'small craft.' If he's referring to your average ski boat, he has a point; I've seen them swamped on a dead flat lake just from cutting the engine suddenly, and having the wake roll over the stern.

But this thread was originally about a 14 meter, double decked boat with 80 passengers aboard, that capsized while making a turn at speed. Does that fit his definition of small craft, and does he think it capsized because of water coming over the transom?

And I'll stick to my original point: when a person makes a controversial statement, I'd say the onus is on him to back it up with verifiable facts and figures. It isn't everyone else's job to disprove it.

 

Fully concur!

 

Well, it is possible for reasonable folks to square away and work it through. Thanks to all for having waited it out.

Stopping hard and having a following sea blast through the well isn't a design flaw, nor is having thru hull hoses falling off, nor is placing a fair bit of weight at the aft end of the cockpit in rough conditions.

Brad, boats that have the pointy end on the front, can't sink evenly without huge internal volume decreases, used up with chambers or foam. The wedge shaped hull forms used, mean the volume is aft, which is true if empty, full of crew or water. You can add some depth to the fore foot or just aft of this, but this is extra displacement and drag for most pleasure craft design briefs.

Tom, is correct, the vast majority of capsizes are operator error, frankly they broach and get flipped in a rolling or beam sea or surf.

There may come a day when all outboards are on brackets with tall, well sealed transoms, but boneheadedness can't be engineered out of the equation. You're always going to have a butthead, that after screaming along in his new 16' flats boat at 50 knots, slams the throttle closed and wonders where all the water came from. Of course the outboard bracket also makes a 14' boat a 17' boat instantly, which can kill sales and markets. There's also practical concerns on smaller craft, like a 12' fishing skiff. How much internal volume do you surrender to the extra transom? All difficult questions . . .

 

I saw a boat stop too fast once. Many years ago at the bait barge in the outer harbor, an old ski boat with a big aft V8 pulled up. My friend worked the barge and saw the floating beer cans at 6AM and decided that they should head home, and told them so...

unfortunately there was another barge a couple humdred yards away--the driver flipped us off and gunned it to the other barge and shut her down... the height and velocity of the wave that overtook them was nothing short of slow-motion perfection. From the middle finger to a dog paddle in something less than 30 seconds..They immediately climbed out of the water and i'm sure they got a ride back to the ramp shortly after. My only regret was that we failed to formally declare a MUV.

Talk about an inherent design flaw, check this out:

http://www.youtube.com/watch?v=68AOltMu768&feature=related

That should NEVER happen, but because of the relatively rare center enging configuration, it sits good and flat while virtually swamped. Most other boats would have gone down from the transom, or so i think...