The knock-down and roll-over by boat design thread

[Captain Smollett]

I read a story on the Alberg 30 mailing list today that I considered related to Craig's Hull Form, Keel and Rudder Design thread (since it relates to hull form and keel design), but figured it might merit it's own discussion.

First, the story:

An Alberg 30 was being raced hard and essentially broached under spinnaker.  The boat was knocked down with the spreaders in the water.  The interesting bit to me was that the companionway was open and with the boat on her side, she did not take any water below.  I find this a very reassuring tidbit on information for an 'offshore boat.'

I know of another case of an Alberg 30 being completely rolled over with subsequent dismasting.  The mast snapped where the lower shrouds attached because it had lost support from those wires...the chainplate bolts had sheered.  Now, it is a known production flaw with the A-30 that undersized bolts were used on the chainplates, so one of the most important upgrades is to drill 'em out and put in larger bolts.  (Yves Gelinas had done that but not with his lowers, so he had the original 1/4" bolts there and those were the ones that failed in his dismasting).

Other than the mast being broken (perhaps preventable by the larger bolts), the boat came through the rollover fine.  She did not take excessive water and of course, self-righted immediately.  Gelinas was able to rig a jury rig and sail to land.  For those that don't know the story, he later repaired his mast with a sleeve, sailed around the Horn and completed his circumnavigation.

Okay, my point:  what stories or experiences can the sailfar crew share having to do with knockdowns and rollovers WITH YOUR BOAT model.  In these cases, what design features influenced the severity of the incident?

What improvements have you made (or are planning) to safeguard against KD and RO while "out there"?

[Delezynski]

Hi Capt.

This may not be exactly on target, but I thought I would drop it in as a data point.

From our web site position report for March 2005.....

On March 1, the San Carlos anchorage was getting very rough. It is not so much an anchorage as a small bight out of the land, an open roadstead. The weather was predicted to be blowing up to 30 knots from the northwest, with 12 + foot seas from about the same direction. Normally, we would NOT go out in that, but the anchorage was getting hard to stay in. The anchor lines were straining with a LOT of wind and the surf was starting to break further and further off shore. Read that as closer to us! There is an old adage that sailors have, "when in doubt, head out to the open sea".  The wind and sea will not hurt a well-found boat, but rocks and land surely will.

We made a course for Islas San Benitos, 15 miles west of Cedros Island. We decided this would be an interesting stop as most people traveling this coast pass it by. After about an hour, it was clear that the following LARGE waves would not let us make a safe course to San Benitos! So, we altered course for Cedros Island. There is supposed to be a lot of good places to anchor there.

I have to tell you that this passage was not one of the high points of our trip so far! The seas were over 18 foot! The wind at or above 30. I guess that at this point we have to confess that not all of our time out here is fun and games! At 0218 AM we had a rouge wave (a wave 3 to 4 times bigger than the others and coming from a far different direction) hit the starboard side just about at the cockpit! I looked down and saw Jill sitting in the cockpit foot well in what looked like a bubbling white Jacuzzi with her foul weather gear on. On a nice warm sunny day, this would be funny. But let me tell you, on a cold night, in a storm, far out at sea, this was no fun!! And certainly nothing to laugh at!  We got no sleep at all.

We did make an anchorage on Cedros Island the next morning, March 2.

-----

We took most of a knock down. The spreaders were NOT in the water, but the wave did hit the bottom of the main sail and the boom did get a dunking.

We both had our harnesses on! And that was a VERY good thing. I later found (by tracing our course on a map that showed the sea floor) that we were passing an area with a sea mount. It seems the weather and currents build in the area and we were not aware of it.

We took almost NO water below. At the most it was less than ? cup. The PortaBoat was lashed to the Stbd side of the cabin and protected the ports on that side. But I do not think they would have been a problem.

About the ONLY thing we might have changed is that we further FIRMLY believe that at night or in ANY weather we harness up!

Greg

[Bill NH]

Just a few random thoughts along these lines...

Make sure there is a way to secure the hatchboards in place.  I've added barrel bolts to the top board on all my boats.  This allows them to be secured from below for security in port, and locked in place so they don't come adrift at sea.  (If you have a design without a bridgedeck you might want to start by securing the bottom board in place semi-permanently while on passage...)

Make sure your floorboards have latches that secure them in place.  Same goes for storage compartment lids like those under settee cushions, etc.  Latches on cockpit lockers, laz hatch cover, etc are very important as we're talking water ingress here!

Batteries need to be secured with strong tiedown brackets, not just sitting on a shelf in plastic boxes held down by the old decayed poly webbing and the couple small screws that came with your battery box...)

Do not sail offshore with windsurfers, surfboards, kayaks, and other large objects lashed to the stanchions and lifelines...  its a good way to have them ripped right out of the deck.  Lashed on the cabintop is better, or best is to stuff the gear down below (I like the V-berth for my kayak when on passage - although it does stretch a fair bit into the main salon as well).

I also carry a couple of pieces of plywood under the V-berth cushions for emergency repairs.  They can be cut to board up ports or hatches, and I once even rigged a jury rudder out of a plywood square bolted through a whisker pole and lashed to a windvane frame...

In general I also have a strong bias against offset companionways for offshore sailing... downflooding after a knockdown has contributed to several major losses including the Pride of Baltimore in 1986.

[Captain Smollett]

Bill,

All good suggestions and certainly good reminders.

Do you happen to have some specific anecdotes about the Cape Dory 26 (or any other 'sailfar' boat) in knockdown/rollover situations?

What I was hoping this thread would be is a kind of 'database' of real-world experiences (ours or just ones we know about) regarding the knockdown survivability of SailFar boats.  Aside from general interest, you could think of it as a place to point when naysayers claim (solely on the basis of LOA) that these boats are not "safe" offshore.

[Delezynski]

Captain Smollet,

In regard to your request.....?(solely on the basis of LOA) that these boats are not "safe" offshore. ?  A couple of things always come to my mind.

As a smaller boat, we tend to ride the waves better. More movement, but less overhang on a wave.

Our boat has a hull thickness the same or thicker than most 40 footers. I try to explain this in terms of resistance to breaking/bending. If I take a bar of steel 1/8 inch thick, 1 inch wide and 6 inches long, try to bend it in half. Take the same metal, same thickness, same width, but make it 4 times as long and it's easy to bend in half. Same for our hull!

For Jill and I, it's easy for Jill to handle the boat by herself if something were to happen to me. And that extends to REAL life, NOT just when the weather is nice and calm, but to when it piping up strong and everything is going to poop! NO MATTER what people say, that just ain't so on a 40+foot boat. And don't get me started on electric winches making it possible. When things get real crappy, you DO NOT HAVE electric winches.

It's easier less costly to make our small boat seaworthy. A small word for a world of things that SHOULD be done to a boat before it heads off shore.

In the end I would gladly trade ?small and seaworthy? for big!

My thoughts...

Greg

[AdriftAtSea]

Knock-downs and roll-overs are effectively the same on a trimaran...since a trimaran is not self-righting.  AFAIK, none of the Telstar 28 trimarans have broached or capsized. However, multihulls are far more resistant to broaching due to the multiple hulls and extreme form stability.

A few things that you should consider when deciding whether to take a boat offshore:

Cockpit size relative to the cockpit drain size:  If you plug the cockpit drains and fill the cockpit with water then pull the cockpit drain plugs, can it drain within 30 seconds? 

Bridgedeck: Does the cockpit have a bridgedeck or sill high enough to prevent water from draining from a full cockpit into the cabin or not.  I added a bridgedeck to my boat to solve this problem.

Companionway design: Does the companionway close using dropboards?  If so, do the dropboards have some way of being locked in place? Also, does the companionway have parallel sides or does it widen towards the top?some boats have such wide companionways at the top that the strength of the dropboards are seriously compromised.   

Cockpit lockers:  Do the cockpit lockers drain into the bilge or open to the interior of the boat?  If so, can they be locked?  Also, do you have in-cockpit speakers.  In many cases flush-mounted speakers are a weak point.  Unless they are mounted into a compartment that drains overboard, they should be mounted under a removable deck plate that can be installed in case of heavy weather. A six-inch diameter opening lets a lot of water into a boat if the boat gets pooped. 

Batteries:  Are the batteries secured in battery boxes and are the battery boxes fastened securely?  When Ken Barnes was knocked down on the first leg of his aborted circumnavigation, the 14 batteries he had were not properly secured and they bounced around the cabin and broke some of the hatches from the inside. Also, battery electrolyte mixed with seawater can generate poisonous gases, so having relatively well sealed but vented battery boxes can help reduce that risk?and the electrolyte is a burn hazard.

Things on Deck:  Bill's point about not having stuff lashed to the lifelines and stanchions is a good one.  Weather cloths and dodgers should be designed so that they can be lowered or removed if necessary. Keeping the decks clear is probably better if possible, but in many cases, especially on smaller boats, this isn't a valid option.

Stowage areas:  All stowage areas should be viewed with an eye to what would happen if the boat is knocked down or rolled. Also, latches should be designed so that they are safe to use under heavy weather conditions?the finger-hole type latches are a danger.  Floorboards and stowage area lids need to have a way to be locked shut as Bill pointed out.

Anchor, anchor locker and chain pipes: Making sure that the anchor locker and the chain pipes can be locked down and sealed for heavy weather is a good idea.  The anchor and rode is an important piece of safety gear and you don't want to have the rode disappear overboard if you get knocked down or rolled.  Also, anchors should not be locked into the roller using a pin or bolt as heavy weather conditions can often bend the pin or bolt?making it very difficult or impossible to release the anchor in an emergency.   I recommend lashing the anchor in place, since lashings can be cut easily in a hurry. 

Having plywood, crash mats and wooden plugs and the screws, bolts, line to fasten them in place properly are a good idea in case the boat's hull or deck are damaged.  Underwater-setting epoxy putty is also a good item to have aboard any boat. 

A spare piece of rigging wire with the appropriate mechanical rigging terminals that is long enough to replace your longest piece of rigging is a good idea as well.  They do make a synthetic emergency shroud/stay kit that would work for most sailfar-sized boats.

[newt]

Took a knockdown with my compac 23. Boom in the water, water into the cockpit and up through a sink drain, maybe a quart of water in the cabin. Popped up quickly with no other damage.  Shrouds had to be retightened, probably due to the 60 knot winds.
Repairs since then:
Thruhull on sink drain
Sail repairs
Thinking of oversizing the rigging and plates.

[Captain Smollett]

Okay, rather than anecdotal evidence, shall we simply publish in one thread the Limit of Positive Stability (in degrees of roll) for our boats?



I've been told that the Alberg 30 has a LPS of 170*.

[evantica]

Saw on this tread " Underwater-setting epoxy putty" is what??? some fast gluing or what?

[Bubba the Pirate]

I've been told that the Alberg 30 has a LPS of 170*.

I haven't been able to find an LPS for my Cape Dory 28 on the web.  It has to be similar to the Alberg 30.  I ran the "Sail Calculator" off the Cape Dory site and compared with Alberg 30 for kicks.  All the numbers are close. 

As an aside, I once got a great deal on a boat because of a knockdown.  A guy who I bought cardboard from had his girlfriend and her two young sons aboard when knocked down.  She said "Never Again" and I got a Southern 21 for $1200.  Nice little boat but too much draft (4') for the Gulf.  I just had to agree to take him out every once in a while. 

And thanks to Adrift, I have a couple more projects before I get her in the water.  Appreciated none the less.  My early CD28 has no bridgedeck; thanks for the reminder.  I have to do something about that. 

[CharlieJ]

Underwater epoxy is a type that sets and cures while wet. Onboard Tehani I carry a type known as "Black and Yellow". Around Port Lavaca the local NAPA store carries it in 2 pint sets for 16 bucks. Two part, one black, one yellow (oddly enough). Mixed underwater, with wet hands, it becomes green when ready, then can be shoved into  a crack or hole under the boat. Good stuff-ALL the shrimpers carry it aboard.