I'm thinking of rigging up a 10mm to 12mm thick line that I could in an emergency run across the beam of my inverted hull if ever the near unthinable happened and 'le Sel' capsized. She has, like most TS a high level of initial stability, but would not self-right once over. Clinging to that shiny, slippery hull would be impossible. I've run all the ratios like the AVS through the online calculator & it ain't pretty. Typical I suspect of most TS. Has anyone else given thought to this?? By the way ... I was reading the wrap up on the 1998 Sydney to Hobart & the findings were that which yachts survived & which didn't was completely random & had nothing to do with design, AVS or anything like that. Now that is terrifying. Best, Ged
That's one reason I got a Jordan Series Drogue. It is one of the devices best known for working to prevent capsize of small boats in heavy weather. :D My boat would turn turtle and stay there, being an 18' wide trimaran... so prevention is my only option. Self-righting isn't even a remote possibility.
Quote from: AdriftAtSea on April 02, 2007, 08:27:38 AM
That's one reason I got a Jordan Series Drogue. It is one of the devices best known for working to prevent capsize of small boats in heavy weather.
how much commision do they pay?
Quote from: Ged on April 02, 2007, 07:55:40 AM
By the way ... I was reading the wrap up on the 1998 Sydney to Hobart & the findings were that which yachts survived & which didn't was completely random & had nothing to do with design, AVS or anything like that. Now that is terrifying. Best, Ged
Perhaps it all came down to being under the wrong wave peak at the wrong time.
Quote from: Ol' Coot on April 02, 2007, 09:10:46 AM
Quote from: AdriftAtSea on April 02, 2007, 08:27:38 AM
That's one reason I got a Jordan Series Drogue. It is one of the devices best known for working to prevent capsize of small boats in heavy weather.
how much commision do they pay?
Don't need to pay me a commission.. :D I've had a few long conversations with Don Jordan regarding the beastie... and I'm a believer...
I plan on trying out the JSD later this season, just to get a feel for how it works on my boat. It was designed for smaller boats to help them survive conditons like that found in the Fastnet '79 storm. According to RW testimonials and the USCG testing, it does what he said it would. It is probably more effective on a multihull, which has the main problem of surfing and then pitchpoling.
Ged -
Hobie cats use a big thick bungee for that righting-line purpose. Being bungee, it retracts up out of the water when not in use, but when/if the boat flips, you can pull it out and around far enough to use it for righting the boat. It has a large diameter which is comfortable on the hands.
While this isn't the particular line I was thinking of, it might work well for you (from eBay):
http://tinyurl.com/246dyq
I think one of the problems with having a line under the boat is the drag it will cause as well as the growth that will happen on it. A piece of flat webbing, with a bit of bungie type cord on each end to keep it snug might make more sense, since it could lie fairly flat against the hull. Kind of like a jackline for the underside of the boat. I know that some of the bigger cats and tris have something like this. Some of the bigger multihulls also have a hatch through the bottom of the boat for just such a situation.
Wouldn't it better to NOT CAPSIZE?? :o :o ;D
Ged, any idea of the Capsize Screening Ratio for the TS16? I looked at the Sail Calculator Page (http://www.image-ination.com/sailcalc.html) and did not see it listed.
My 18 ft trailerable has a pretty poor CSR (2.81), but I've never worried about capsizing her, even in some failry trying conditions for an 18 foot boat. She's a centerboarder with round bilges and quite beamy for her length, but there IS some reserve stability (which you said your boat does not have).
I guess what I am saying is similar to what you often hear about getting BACK aboard after COB - "don't fall off the boat." Easy to say, plan for the worst and all that, but it seems to me maybe a bit like fixing a problem you can avoid other ways.
In case you haven't seen it yet, you might want to check out this discussion (http://forums.boatdesign.net/showthread.php?t=4431) about the TS16 seaworthiness (same boat, right?).
I agree, that preventing capsize, MOB or other such problems is a much better idea... but you can't always prevent it...
On a multihull, the trick is to reef early and for the gusts, where on a monohull, you generally will reef for the general wind strengths, and let the boat handle the gusts.
Wind-induced capsize on a cruising multihull is pretty rare, and generally it is caused by human error... not reducing sail in time, or ignoring the warning signs.
On my boat, the primary warning sign is the leeward ama will start to submerge its aft end.. that's a warning that you're overpowered and should be reefing.
Wave induced capsize is harder to control. In storm conditions, I plan on using a drogue. In conditions less than that, the boat seems to be just fine, provided you've reefed it down properly. I still need to get more time in on the boat in different conditions to be sure of how she will handle them.
I was not going to literally run a line under the hull as a permanent feature. The line would be set up and then run over the top of the inverted hull if the worst should ever happen. Of course it's best to sail well within limits, however, I have been caught out a few times with nowhere to hide and have had to make do. And Captain, the numbers I got for the TS Hartley are: AVS - 111.76 (+140 is ideal). Screening stability - 236.73. Stability - 3.12 (greater than 2 is risky) and displacement to hull lenght ratio is 80.33 (light displacement cruiser). Yes, I was aware of the center plate & capsize issue. I'm going to build in a cleat to lock it into position. Thanks for the web site ... I hadn't seen that particular one before. Best, Ged
Ged-
Ah... that makes sense. I hate to think what the capsize stability number for my boat is...
Quote from: Ged on April 03, 2007, 06:51:54 AM
the numbers I got for the TS Hartley are: AVS - 111.76 (+140 is ideal).
Using this site (http://www.sailingusa.info/cal__avs.htm) to calculate AVS for my boat (and note that there are different formulae used to compute this value), I got 116.5. Now, given that you mentioned 140+ is ideal, that seems a bit low.
BUT....
1. Computed AVS numbers with simplistic formulae are well known to be inaccurate, and known to generally be LOW. That is, the formula used tend to underestimate the AVS. The best bet is to actually measure the AVS, but short of that, the original designer of the boat may have a truer number available.
2. Here's an very similar discussion (http://www.boatdesign.net/forums/showthread.php?t=13569&page=6) to the one we are having. They do discuss AVS and other screening numbers (such as downflooding angle :o ). Another discussion (http://www.bymnews.com/VBulletin/archive/index.php?t-222.html) focuses on the way these numbers, taken alone, don't ALWAYS tell the whole picture of sailing performance, comfort and seaworthiness - as well as how crew comfort (to prevent fatigue) may be more important than some of these design numbers. It's a good discussion, in my opinion. Note how one guy in the second link claims his 'favorite' boats have AVS's in the 110 range!! Interesting, to say the least.
My favorite quote from the second link:
Quote
Boats are a reflection, not of statistics but, of the way those stats are blended.
Too bad the same guy said he'd prefer a 50+ footer to cross an ocean. ::)
3. Most of the time, various design numbers are useful only for comparing boats of similar size, shape and style. For example, it would be instructive to compare your TS16 to my Skipper's Mate, or perhaps either to the Montgomery 17. But the numbers on their own don't really tell a whole lot.
On the subject of 'getting caught out,' I'm not sure what you would consider getting caught out with nowhere to hide. I offer only for comparision that my 18 footer has handled 32 kt winds and 5-6 ft seas without "feeling" either unstable or unduly (for her size) uncomfortable. As is commonly stated, the CREW is the most important factor aboard in rough conditions. Most boats can handle far more than we can.
One final note: You mentioned the Sydney-Hobart race and how boats lost varied in design. Two comments. First, ONE of the causes of that was it was a RACE. Perhaps many crews pushed beyond when they should have slowed down and adopted storm tactics. Second, I believe ALL of the boats lost were lying ahull or running off at the time. Perhaps the cause of the stat you mentioned was a combination of (a) waiting too long to adopt 'survival' tactics and (b) not choosing the best, though highly touted, storm tactic.
So, do you plan on being out, or even getting caught out, in hurricane conditions in your TS16? ;D
Fair Winds.
QuoteMost boats can handle far more than we can.
Very, very true. IIRC, there was a small (34' or so) catamaran that was abandoned off of the coast of Mexico last year. It was sighted six months later, floating and being used by a colony of seagulls as a nesting site. I don't know what finally happened to it, but six months afloat with no human intervention says something about the toughness of boats...
In the picture, I thought I saw a mono-hull. In seas that you would capsize in (from my understanding) you would roll enough to right the boat.
There is 2 things that would stop this. 1 The boat is full of water and sunk.
2 The sails are still up.
If the boat is not full of water and the boat is still turtle, you could rig something to the end of the mast to float it up.
A supply of very tough lawn plastic bags would be of use.
A Cat is a different story.
No experience, Just a thought.
Lynx-
The OP did post a photo of his boat, which is a monohull. I have a trimaran. Capsize is a very serious concern of mine needless to say.
I agree. I have read a little about this regarding the cats. I am sure you have more knowledge. A thing nice about the cats is that when the turn over it usually does not sink like a monohull.
Knolwdge is KING here. Good luck.
James
I've been planning to do more extensive safety exercises this Spring and MOB is at the top of the list.
In looking over some of the material posted I'm confused about whether it is better to approached upwind or downwind of the victim. If the boat is upwind then there is calmer waters in the lee of the boat, but you run the risk of the boat drifting over the victim. If you're downwind of the victim then there's the risk of waves slamming the victim into the side of the boat.
Which do you prefer?
Oded
Oded-
Unfortunately, there isn't a single answer to whether the upwind side or downwind side is better for the approach to the MOB in the water. It depends on the wind, sea state, type of boat, and a few other factors.
For instance, my boat tends to drift fairly fast due to the design of it—in fact, without the centerboard down, the front end gets blown around like a kite... I would prefer to approach from the downwind side. Another reason I prefer this, is that my boat tends to move with the motion of the waves, rather than resist them, since it has no heavy keel holding it down, so the likelihood of them being slammed into the boat is a bit lower IMHO. She also has relatively little freeboard, which means that someone on the ama, hooked into the jacklines on the main deck, has a relatively safe chance of getting the MOB back aboard.
Personally, I would prefer to use the LifeSling I have mounted in the cockpit, rather than try a more traditional MOB recovery. The LifeSling allows me to get the person in the water close to the boat in a controlled manner, and choose how I am going to bring them aboard. In reading many stories about MOB situations, the LifeSling seems to have been critical in many of the successful MOB recoveries.
I haven't had much practice with the LifeSling, and hope to do a practice sesssion with it this summer at some point. I'd like to try it with an actual MOB, under controlled circumstances... but don't know if that's going to happen.
PS. Can one of the mods move my reply and Oded's post to the MOB thread please...
I do not know if the "Life Sling" would work on my boat. It just may tip the mast too much.
I have seen a wide and long webbing that can be tied to the sanctions and put overboard. The person then gets inside the you pull it up. This is called a B.O.B. Sling
http://www.creativemarine.com/newprodct/ors/ORS.htm
Any thoughts?
Lynx-
The LifeSling is mainly designed to get the MOB back to the boat. The BOB Sling doesn't do that. While a LifeSling can also be used to hoist a person aboard, that isn't its primary purpose. I also, don't see how/why it would tip your boat too much, unless you were using it to do a MOB recovery and hoisting the person into the boat with the boom swung all the way out to the side—which is not an ideal use of it.
The BOB Sling is a parbuckle type recover device, similar to using a jib to do the recovery, and it's major advantage is that it can hoist a person out of the water horizontally, which is important in cases of hypothermic MOBs.
However, I don't see it being worth $700. You can get construction site webbing for far less than that and it serves much the same purpose. If you use a boom vang to keep the boom fairly close to the boat, using the LifeSling wouldn't tip the boat any more than using the BOB Sling IMHO.
The LifeSling is a much better piece of MOB recovery equipment IMHO, as it makes it far easier to get the MOB to the boat, if the MOB is at all mobile. It also can be used to hoist the MOB, but you need to have a tackle or halyard setup to do that with. BTW, from what I've seen and read, the four-to-one tackle that LifeSling sells for use in MOB hoisting is really insufficient to the task. A six-to-one tackle is really much more appropriate, especially in the case of smaller crew lifting larger MOBs.
AdriftAtSea - I did not think about the life sling to get the person to the boat. IT is good for that.
I have a Portland Pudgy dinghy that weighs 128 pounds. I put it on deck for storage, at the dock. I tried to do this from the dock and the boat healed over to much to do it. I was able to do it next to the mast though. I do not think that the boat will heel over to much if the person stays close to the boat. If the person wouls swing out, It would be a problem. I will aslo have to beef up the boat to be able to handle the weight on the boom.
I do agree that you need a 6:1 tackle. The 4:1 that I am using to hoist the dinghy is hard to do and I am 6'4" and strong.
I do suggest that you try any system out before needed with all crew before setting out.
I don't know about the price of the BOB sling. I should make one up for an emergancy somehow.
QuoteI do suggest that you try any system out before needed with all crew before setting out.
Amen to that... Any system that hasn't been tried and tested is often worthless when push comes to shove.
Yes ... the AVS ratios are more of a curiousity than anything - especially for a smallish TS like mine. I knew the numbers would not be ideal for the sort of work I do, but there is something sweet about pulling into an anchorage and being surrounded by oceaning going yachts! I guess my philosophy is that I like to play out that tension between boat and weather. Often I cannot just simply sail home as the weather may have turned & I have to wait out until things calm down. I really believe that you can get a big boat cruising experience on a small trailable yacht if it is properly set up. You mention 32 knots & your 18 footer. I've never actually had all my canvas up in anything like that. I think it's more the angle that you sail in that type of weather that will determine your survival odds. I think the Hartley would just handle the wind OK - it's the quartering of the waves that would cause grief. 32 knots here would generate huge breaking swells. I've noticed my TS 16 handles large quartering seas on a beat, however, running in that sort of wind could be interesting. Do you have tactics for running or broad reaching in big wind and waves on a small trailer yacht??
And by the way .. the 1998 S to H was pure horror. I've just finished re-reading "Fatal Storm" - the account of the race. The findings show that a number of the yachts because of their AVS numbers etc. should not have been in the race in the first place and there were issues with life rafts etc. However, as far as who got clobbered and who did not, it was just chance, fate, luck. The rouge killer waves all came out of no where and always from a different direction to the prevailing sea condition. Some of the maxi yachts were at the front of the storm and managed to outrun it, however, if they'd have been caught in it they too would have been toast. "Fatal Storm" is a great read. Best, Ged
Not to be a stuck record, but the book, A Speck on the Sea describes several small boat skippers in the 1800s using a line under their boat to help right it after a capsize. None of the lines were rigged full time, the skippers dove under their boats to rig the line after the capsize.
Ged-
Fastnet, Force 10, is also a fascinating read. Both books have a lot to say about heavy weather sailing, and provide cautionary tales about weather planning. Both also give strength to the idea that sailboats, especially smaller ones should not be sailing on a fixed schedule. Races, due to their very nature, are fixed schedules of the worst sort, especially since many who do race are pushing their boats closer to the limits than is generally prudent.
I have one of the sailing computer games. Set it up for a small fin keel boat with the bad weather of the gulf stream and then TRIED to sail into the wind. OOH MY!!! This was worth the $ 30 for the game. I latter had to sail into some small seas and used some of the stuff that I learned.
It was a good learning experience to wreck a boat on a computer than mine at sea.
Some of the newer computer simulations are really quite good. ;)