Death of a 4 Week-Old Boat

[delmarrey]

Originally Posted by MoonlightShadow

Yup. True words. Q.E.D.

I can't say that I have never run aground. I've just been lucky as I have never done it at speed and never done any damage. There but for the grace of God...

I have run up on solid rock (submerged) doing 5 kts and I can tell you it's like a bomb going off. And the damage is time consuming to repair. Fortunately, I have a solid old boat that can handle off shore abuse, or should I say ON SHORE however you want to look at it.



But sometimes the charts or GPS doesn't have acc u right info and markers are not in place. So coastal cruising can be just as damaging as off-shore.

[Seahunter]

In the video, the sails were furled but her anchor is still locked on its rollers. Time to flake the sails, but no time to drop at least one anchor? Hmm

[sabray]

why drop the anchor if your slamming into the bottom?

[Hiracer]

Originally Posted by bastonjock

If I was in the business of selling cut away full keels or other derivations of long keels, this is the picture I would use.

You don't need a degree in stress engineering to figure why this keel came off. Sure the captain screwed up big time, but a true cruising design should be able to take a full speed slam into a sand bank. Many can and do.

Leverage (to amplify the forces) and a small foot print (to concentrate the forces) will do you in.

I have a fin keel but . . . she's long, the leading edge is sloping, she's not super high aspect, the connecting footprint is big, and the building material is strong. Would not have it any other way.

[Hiracer]

Of course, if I sold multihulls, I would use the same picture.

[bastonjock]

I sopke to a guy from the Lifeboats last year and he told me that it was not uncommon to have to tow Yachts off of the sand banks,he said that they usually keep their keels on.

We dont have rocks to contend with,its sand banks and twisty channels,it was probably the same sand banks that helped Captain Cook pollish his navigation skills and Lord Nelson Too,those guys learned their craft on the uk,s East Coast

[Seahunter]

Originally Posted by sabray

why drop the anchor if your slamming into the bottom?

I'll let the Power Squadron Boating Safety Training Manual answer this:

"If you find yourself hard aground, the best thing you can do is stay with your boat, put on your life jackets, and call for help. Do what you can to stop leaks. If the boat is in danger of sinking, or lives are at risk--call the Coast Guard on Channel 16.
Checking for leaks, damage/injuries, and setting the anchor is the first things you should do if you hit bottom. Try to place the anchor as far from the boat as you can--use your dinghy or tender if you have one.
Anchoring helps keep the boat from being driven further aground and may also provide a means of pulling you free, if you can "kedge" or pull the boat towards the anchor. Waves, the tide, and wakes from other boats may lift your boat. Once you've set the anchor, you have several options based on your situation."

[Ex-Calif]

Originally Posted by Hiracer

If I was in the business of selling cut away full keels or other derivations of long keels, this is the picture I would use.

You don't need a degree in stress engineering to figure why this keel came off. Sure the captain screwed up big time, but a true cruising design should be able to take a full speed slam into a sand bank. Many can and do.

Leverage (to amplify the forces) and a small foot print (to concentrate the forces) will do you in.

Not to armchair quarterback too much but let's look at the photo...

If the keel tore off during the actual strike with the sandbar I would expect the hull to be displaced inward at the rear a possible chunk removed at the leading edge with tearing extending from the aft edge. Clearly this keel is strongest along the longitudinal axis and is very weak laterally.

What I see is a pretty clean break except tearing extending to port (downward in the photo)

Based on this my call is that the keel failed laterally from side loading not longitudinally. This would be consistent with the keel buried in the sand and the boat receiving lateral forces from the waves. There is no way a fin keel will hold up to that for very long.

[sabray]

Originally Posted by Seahunter

I'll let the Power Squadron Boating Safety Training Manual answer this:


Checking for leaks, damage/injuries, and setting the anchor is the first things you should do if you hit bottom. Try to place the anchor as far from the boat as you can--use your dinghy or tender if you have one.
Anchoring helps keep the boat from being driven further aground and may also provide a means of pulling you free,

So What I read is its blowing f 6-7 in an area that barely has keel clearance and waves I think were suggested to be 6'. You slam into a sand bank are most likely by the conditions slamming the boat into the bottom. Not a great place to drop anchor. Unless you had some idea that you could kedge off. Ive never heard of anyone in the described situation kedging off with success. Lotta speculation which is why I wanted to hear why you would drop anchor. Were speculating. Maybe the anchor would have helped but maybe not. It sounds like the keel came off pretty soon after it hit again though speculation. Oh Boy Glad you read the book

[Stillraining]

Surprising there hasn't been more info about this coming from those on board from the media...Maybe its becoming to common and old hat already.

[Seahunter]

Originally Posted by sabray

So What I read is its blowing f 6-7 in an area that barely has keel clearance and waves I think were suggested to be 6'. You slam into a sand bank are most likely by the conditions slamming the boat into the bottom. Not a great place to drop anchor. Unless you had some idea that you could kedge off. Ive never heard of anyone in the described situation kedging off with success. Lotta speculation which is why I wanted to hear why you would drop anchor. Were speculating. Maybe the anchor would have helped but maybe not. It sounds like the keel came off pretty soon after it hit again though speculation. Oh Boy Glad you read the book

I can send you a copy if you like; in the meantime send me your itinerary so as we don't cross anchor lines.

[sabray]

no worries took the course years back and I try real hard not to anchor on a sandbar with 6'waves you can have that spot

[bewitched]

Originally Posted by David M

Building boats is the art of compromise. You can't have a fast light race boat and have it as strong as the strongest cruising boats. The best way to judge if there is a problem is to look at the number of incidents there are of problems while the boat was being used during its intended usage. Race boats are not designed to have their keels slammed against the bottom. For cruising boats its different because of nature of cruising where they are more likely to be put aground in chop or waves.

When you get outside of the intended design parameters of your vessel is when you are much more likely into trouble.

Spot on - there is no design deficiency here. Design a raceboat that will hit a sandbar at (say) 10 knots without significant damage and you're not going to win many races.

Design a cruising boat with the same keel, and your not going to sell very many.

horses for courses

[Northeaster]

Although some may say that it is not a design flaw, I would not personally want to sail a boat that had it's keel attached in such a manner. I would rather go a bit slower and be safer.

Ex-Cal - although it may have come off from lateral forces, rather than the inititial hit, you can't say that all fin keels would have immediately suffered the same fate. I am not an engineer, but common sense would say that if that keel was attached over an area twice as long, and perhaps 4 times as wide (like fin keelers who's hulls sweep down into the keel as opposed to flat bottom boats with a narrow keel bolted on), the keel certainly would have been on long enough to put out a kedge or have it towed off. The long keel would have applied more force to the attachment point as well, even laterally.
To me, if it's going to be deeper, it has to be attached over a greater length and width.

I had a 23' mid - long fin (encapuslated) keeled boat, with a wider attachment point few years ago. It broke it's mooring line in about 4' chop on a large lake. It blew into a sandy cove where it laid on it's side for an hour or so, until the keel beat an area of sand away underneath it, and it floated upright. (in about 2 ft of water)
Conditions were too bad to try towing it out, so it sat there for another day, until we walked out to it, ran a line from a halyard to heel the boat, and easily pushed it back into deep water.

The only damage was the paint removed from the bottom of the keel.
There is a definite tradeoff with different designs. I think deep, thin keels are Ok for racers (or others who know it's limits), but I would not want to be cruising on one with my family and friends.
This captain should not have run aground, but sooner or later, we all do, and I want a boat that will hold up as well as possible. This one did not!!

I have ran into a sand bar with my current 30'er (same buiilder / design as my old 23'er) at 5 kts or so. The nose dove down from the impact, and we stayed for the nbight on the sandbar, listing slightly. It was on a river, so there were no big waves pounding at us (1 - 2 ft maybe).
Next morning we freed ourselves, after a couple of hours (we were really stuck at we had tried motoring free the night before, and only dug the keel in further).
No damage! Not that this is the "best" design by any means, but don't tell me this keel will fall off as fast as the J-boat!

[conachair]

Originally Posted by bastonjock

We dont have rocks to contend with,its sand banks and twisty channels,it was probably the same sand banks that helped Captain Cook pollish his navigation skills and Lord Nelson Too,those guys learned their craft on the uk,s East Coast

Agree there, great place to start learning how to sail, turn right at north foreland and it all starts to get so much easier. I went through hook spit many times, often solo at night and never liked it. It did save some miles though, and that nice flat water inside margate sands.