As to the earlier post an S&S 34 does not actually have a great deal of righting moment, very little form stability and a high centre of gravity keel.
But of course little rig means you don't need that much.

I am not here to criticize any one boat just trying the explain what few people understand well.
Here is an example for the cruising guys and especially those who have faith in the stability of their boats.
A 7000kg 40 footer had a an AVS after inclination of 116.2 degrees.
That was with an three spreader alloy rig and plastic tuff luff (headfoil)
For an extended cruise a Profurl with an alloy furling tube was fitted.
A rough inclination afterwards indicated that the furling reduced the AVS by over 7 degrees given the height of the weight of the furler.
I always wonder if any one thinks about AVS when the davits, the solar panels, the radar tower and whatever else get fitted above the sheerline.
Nobody ever makes the keel heavier or deeper.

Perhaps this is getting a little academic. For a boat to go further than 120 degrees it will have to be in horrendous wind and sea conditions. It is heading for inverted. If you are foolish or unlucky enough to be on board you are going to be very interested if the next big sea will pop you upright. The narrow deep keel boats had a relatively small longitudinal water-plane moment of inertia and so a low meta-center, but a low CG so CG to MCH was OK. They leaned a bit and rolled a bit, but at least if they did wind up inverted they still had a small water-plane inertia and they just popped up again with the next big wave.

Not so with modern flat bottom wide transom boats. High moment of inertia and high meta-center whether upright or inverted, so they are stiff and stable whichever way up. As in Tony Bullimore's boat. If you gotta go like the clappers, that's the boat you need but if you are cruising single handed without constantly tweaking and twitching the older pre rule boats have a lot going for them.

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lydia said..
Show me a real Ct with an AVS of over 140 for an S&S 34 please.
Think you will find most are in the low 120s.
A Currawong is about 119 or a bit higher AVS, Ramona should have an IMS ct for that.

Also there two separate concepts here, righting moment and AVS.
Righting moment equal speed, hence 100 foot canters, max righting moment and minimum weight.
AVS is simply the angle where the boat no longer wants to go upright but would rather go upside down.

Also the S&S 34 is not actually an IOR boat but a CCA boat and don't have that much righting moment.
In any event when they did well it was before IOR Mark 3 (about 1972)
By 1975 it was all over for them.

My AVS is 120.5. That would be with the foil for the headsail not furler.

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PhoenixStar said..
Perhaps this is getting a little academic. For a boat to go further than 120 degrees it will have to be in horrendous wind and sea conditions. It is heading for inverted. If you are foolish or unlucky enough to be on board you are going to be very interested if the next big sea will pop you upright. The narrow deep keel boats had a relatively small longitudinal water-plane moment of inertia and so a low meta-center, but a low CG so CG to MCH was OK. They leaned a bit and rolled a bit, but at least if they did wind up inverted they still had a small water-plane inertia and they just popped up again with the next big wave.

Not so with modern flat bottom wide transom boats. High moment of inertia and high meta-center whether upright or inverted, so they are stiff and stable whichever way up. As in Tony Bullimore's boat. If you gotta go like the clappers, that's the boat you need but if you are cruising single handed without constantly tweaking and twitching the older pre rule boats have a lot going for them.

The older style yachts also depended on their cabins for self righting as well. Flush decked boats with lots of beam can spend a lot of time totally inverted.

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Ramona said..
I have a friend with a Cav 32. Just recently failed in his third attempt at Lord Howe. This is a trip that will invariably give you an arse kicking at least once. Nice accommodation and a little slower than my Currawong.

I think the Cav's reputation for speed has actually suffered from having good accommodation and a cruisey look. When the Currawongs, East Coasts, Defiances etc were all new and all sailing hard in national half ton titles, the Kiwi Cav Pretender came across the Tasman and went well, finishing about 3rd or 4th in the nationals. She had the original short NZ rig too.

The good performance of Pretender seems to have been lost when people turned towards Cavs for their accommodation. Most of the Aus boats had taller rigs than Pretender and the Kiwi boats, so they should be even quicker.

Of course, none of the halves of that generation can compete with a NS33 for speed.

LPS figures from the 1998 Hobart, as contained in Andy Dovell's report

1950-1978 "displacement" designs

Southerly (Peel 35) - 136
Maris (Tas Seabird) - 130.2
Winston Churchill - 123.6

Morning Tide S&S 34 - 132
Solandra S&S 34 - 130.3
Misty S&S 34 - 130.3
Boomaroo S&S 34 - 132.6

Not Negot. UFO 34 - 119.1
Zeus II Currawong- 120.4
Mercedes IV 42' Kaufm. - 122.2
Polaris Cole 43 - 127.9
Ruff n Tmb Cole 43 - 139
Kingurra Jbt 43 - 125.4


Later IOR mediumweights

Mirrabooka Frers 47 - 122
Bacardi Peterson 44 - 118
Renegade Holland 40M - 119.8

1970s/80s IOR lightweights

Speakeasy Farr 1104 - 117.2
Pippin Farr 37 - 115.3
HummingbirdFarr 37 - 115.4
Wild Oats Farr 43 - 115.7
Aurora Farr 40 - 115.1
Inner Circle Farr 40 - 116.3
Cyclone Frers 50 - 127.1


Cruisers

Antipodes - 119.8
Veto Cav 39 - 122.2
Blue Lady Chall 39? - 114.5


1980s non IOR "lightweights"

Forzado Farr 1020 - 117.1
New Morn. NS 38 - 116.8


IMS boats

Bin Rouge Farr 31 - 116.2
Chutzpah Hick 35 - 121.6
Assassin FarrIMS40- 122
High Flyer FarrIMS40 - 124.2
Rapscallion LyonsIMS40 119.9
OceanDesign Syd 41? - 121.6
Hawke 5 Syd 40? - 115.1
Sledgehmmr Syd 40 - 114.7
Terra Firma MBD 40 - 114.7
Sword ofOrio R/P 44 - 128.8
B 52 Syd 41 - 119
SMB Syd 40? - 119.1
97 Farr 47 - 112.8
Ausmaid Farr 47 - 135.4
Rags Farr 50xIOR- 136


So....

The S&S 34s are have a higher LPS than just about any other group of boats apart from the Maris and Southerly. They have a much higher LPS than the IMS boats apart from Ausmaid and Rags (although I cannot recall which Rags it was; I assume it was the first of the IOR 50s to have a full new IMS hull and foils underneath).

The cruisers don't have very high LPSs although there are very few of them. Some boats that cannot be characterised (mainly later mastheaders) have been ignored.

Sorry for the typos; I was having computer issues.

So here a rare pic of the boat been inclined for IMS giving rise to an AVS amongst other things.
In short you have two levers and known weights and you measure the heel as you move the weight from one extremity to the other.

PS is quite right as to cabin volume and indeed the Open 60s now require a minimum coach house volume so the boat floats on the cabin roof if inverted.
Of course the AVS quoted by Chris will be from the IMS cts and not take this into account.

Gee, I am so glad after all this discussion of racing rules and stability that Alan Wright chose not to design to a racing rule.

I think his rule was "Damned good fast comfortable yachts."

I have a copy of the January, 2012 "Boating New Zealand" magazine which on the front page refers to an article within on page 114, "36,000 miles and counting. Reefs, whales and fire... nothing can stop Kirsten J", a Lotus 9.2.

Quotes from the article:-

"She's just a boat you could take anywhere - you could go around the world on her if you wanted," 74 year old Kerry says. "She's very nice to cruise, she's competitive to race and she's part of the family."

In 1980 Kerry and Jim Lott entered the Round North Island Race a triumph that was trumped the following year when the pair won the two handed race to Suva.

The article goes on to describe how the yacht suffered a 180 knock down in 60 knots under head sail only coming out of Bulgari Passage, Noumea with the only casualty being the tin of instant coffee, in another two handed race to Suva halfway there while surfing waves in the dark struck two whales. The following night the fore stay snapped. The mast still standing they managed to rig a makeshift fore stay. They come in threes. The next night they were woken by a break water towering above them.

"Next minute we're bouncing over Solo Reef. I felt this was the end of us so sent MAYDAY and deployed EPIRB." Half an hour later they came out the other side of the reef into calm water. Finding no damage and taking the night to recover they continued to Suva and later back to Auckland without issue.

As if that was not enough in 2008 the dehumidifier caused a fire which ripped through the yacht while berthed at the marina. The insurance company said "a write off" but Kerry said NO.

Kirsten J is still sailing and I am so glad I have a Lotus 9.2.

And I'll keep sailing my humble Swanson .

Mind you, Cisco, while I like Lotuses (Loti?) there's no real indication that they have a particularly high LPS. With their quite beamy shape they could well be in the "teens". Nice boats, though.

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Chris 249 said..
LPS figures from the 1998 Hobart, as contained in Andy Dovell's report

1950-1978 "displacement" designs

Southerly (Peel 35) - 136
Maris (Tas Seabird) - 130.2
Winston Churchill - 123.6

Morning Tide S&S 34 - 132
Solandra S&S 34 - 130.3
Misty S&S 34 - 130.3
Boomaroo S&S 34 - 132.6

Not Negot. UFO 34 - 119.1
Zeus II Currawong- 120.4
Mercedes IV 42' Kaufm. - 122.2
Polaris Cole 43 - 127.9
Ruff n Tmb Cole 43 - 139
Kingurra Jbt 43 - 125.4


Later IOR mediumweights

Mirrabooka Frers 47 - 122
Bacardi Peterson 44 - 118
Renegade Holland 40M - 119.8

1970s/80s IOR lightweights

Speakeasy Farr 1104 - 117.2
Pippin Farr 37 - 115.3
HummingbirdFarr 37 - 115.4
Wild Oats Farr 43 - 115.7
Aurora Farr 40 - 115.1
Inner Circle Farr 40 - 116.3
Cyclone Frers 50 - 127.1


Cruisers

Antipodes - 119.8
Veto Cav 39 - 122.2
Blue Lady Chall 39? - 114.5


1980s non IOR "lightweights"

Forzado Farr 1020 - 117.1
New Morn. NS 38 - 116.8


IMS boats

Bin Rouge Farr 31 - 116.2
Chutzpah Hick 35 - 121.6
Assassin FarrIMS40- 122
High Flyer FarrIMS40 - 124.2
Rapscallion LyonsIMS40 119.9
OceanDesign Syd 41? - 121.6
Hawke 5 Syd 40? - 115.1
Sledgehmmr Syd 40 - 114.7
Terra Firma MBD 40 - 114.7
Sword ofOrio R/P 44 - 128.8
B 52 Syd 41 - 119
SMB Syd 40? - 119.1
97 Farr 47 - 112.8
Ausmaid Farr 47 - 135.4
Rags Farr 50xIOR- 136


So....

The S&S 34s are have a higher LPS than just about any other group of boats apart from the Maris and Southerly. They have a much higher LPS than the IMS boats apart from Ausmaid and Rags (although I cannot recall which Rags it was; I assume it was the first of the IOR 50s to have a full new IMS hull and foils underneath).

The cruisers don't have very high LPSs although there are very few of them. Some boats that cannot be characterised (mainly later mastheaders) have been ignored.

Of the S&S34s Solandra was the only one that was rolled. I have a pdf copy of the police interview with the most experienced crew member. I can't see a way to post it which is a pity as it is an interesting read.

The crew member believes the boat was inverted to 180 degrees for approx 20-30 seconds and then righted. Solandra had a deck stepped mast so there was no damage to the deck and little water entered the boat. Later advice from the then owner (I spoke to him in 2008/9 when he sent me this report) the mast apparently came down when Solandra righted rather than on the way down. This is not unusual with these style boats, Berrimilla (Brolga 33) lost her rig when she when she righted from a capsize returning from Hobart.

The S&S34 righting moment appears to be pretty good, 100% success (1 capsize, one righting :-)).

The only other S&S34 I am aware of that has capsized was a boat half way to New Zealand. The boat righted undamaged. It was abandoned but later recovered and is still I believe sailing in NZ.

Their ongoing racing success also provides assurance that they can make a reasonable passage, for their size and age. I do need to say the racing boats have usually been specially prepared at great cost, not just Azzuro but also Blondie which is a stock S&S34 Mk2 cruising boat but with top of the line sails, fittings and rigging.

Given the ocean miles S&S34s have sailed in the most difficult races and round the world ventures, probably the most of any class, it is almost impossible to imagine a more proven safe and stable yacht. An AVS of 130 degree or higher is a great confidence builder.

The point I make is that if you are considering NS33 and Cav32 yachts to sail over an ocean, the S&S34 really should be included in your search. You may want the additional volume of other boats but if you prioritise proven stability and seaworthiness you may well get yourself a good S&S. A really good one will be had for $50-55,000, either ready to go (like Morning Bird) or a $25,000 one you spend $30,000 on.

If you are considering this type of yacht and are in Sydney send me a PM and we can take MB out for a sail.

With some of the discussion here being about comparative internal volumes, after sailing on Morning Bird to Lord Howe and back with three of us on board I really have to say the S&S 34 has more than adequate room below.

Those that compete in the S to H sail with 6 crew don't they??

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cisco said..
With some of the discussion here being about comparative internal volumes, after sailing on Morning Bird to Lord Howe and back with three of us on board I really have to say the S&S 34 has more than adequate room below.

Those that compete in the S to H sail with 6 crew don't they??

You're right Cisco, internal volume is all relative. You, Havefun and I usually had one on watch and two below and it wasn't too bad. On the mooring in the lagoon being lashed with 30+ kts, it was a bit crowded but manageable.
I use to spend a week in Broken Bay with 4 onboard, two being my daughter and a friend who were then young teen girls.
Yes they do the S2H with 6 onboard, which I reckon would be a tight squeeze, but they would always have 2-3 on watch and they are racing so who cares.
But for cruising they can be easily managed by one so the normal crew is two. DrRog and I did Lord Howe two handed, as did Havefun and I, and we were fine and had plenty of room and a choice of bunks.
The other Cav and NS do have more room down below.
I have been allocated the same Lord Howe mooring this year that we had in 2015 which is easy to get to and off. If I don't get a suitable crew, I might try it single handed.

I have acquired the ORCi Certificate for Blondie, the last of the new S&S34s built in 2007/8.
There are two key features from my perspective. One is the AVS of about 130 degrees. It takes a lot to get the boat to go inverted.
Secondly but equally important for seaworthiness is the small area under the line. This shows that the S&S34 is not at all stable when inverted, the reason they right so quickly.
I am not sure how much difference there is between the new boats and the older Swarbrick ones. Blondie has features like a big anchor winch and the engine mounted under the cockpit, quite a bit higher than mine for example. She also has a lighter construction and lighter keel. It probably all balances out noting her 128.3 AVS is a couple of degrees less than the 1998 S2H S&S34s noted previously.

Don't get too carried away there MB, it also shows they are easy to put upside down!

maximum leverage at 60 deg? sort of makes the vanishing angle pointless

If you want to go fast , point high , be good down wind , win club races , have full headroom in the head shower cubicle . Go the NS 33 .

MB, I should also point out that the ORCi ct is calculated ignoring the structure above the sheer, ie flat deck no cabin area.
That is not measured for ORCi in that sense.

MB, interesting to know how those curves were obtained. The only method I would use is a dedicated surface manipulator such as Prosurf 3, then roll the shape including the cabin top through 180 degrees. That will reveal the position of the center of buoyancy as she rolls and if you have presumed CG you will get a good curve, But that would only be indicative of what would happen in flat water, not the sort of conditions that would cause an inversion, and would not take into account free water that would be present as the boat starts to fill. And that is not the method used by the rating authorities.

I like that the locally designed and built Hick 35 not only survived but won the 98 Hobart. Mid range AVS

MB, I agree with a lot of what you say but may just mention that I don't think that a 25% inversion rate proves a lot. From memory, less than 25% of boats of any type rolled in that race.

I do find it interesting that the knockdown rate in the '79 Fastnet was almost the same for the Contessa 32s (lauded after the race as seaworthy craft) and the lightweight half tonners that were abused, tested and reviled as dangerous. I'm not saying that the LPS is meaningless but some other people may make it appear to be more important than it arguably really is.

I know some of the Solandra guys and have read their statements and talked about the race with one of them. I'm still thanking my stars that I didn't take up the very attractive offer from another boat to do that race, it just looked terrifying!

LPS is voodoo physics anyway given how the boats are measured to come up with the figure.
So the boat is empty save for a few things, generally two spin poles are used as levers, with a given weight say 50kg in two 25 kg lots moved from one lever to end to the other with a manometer used to measure the change in inclination.
Freeboards are then measured to ascertain how bow down the boat is as more bow down less LPS
The IMS/ORCi computer has the hull file to the sheer.
Press enter and bingo a number comes out.

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lydia said..
LPS is voodoo physics anyway given how the boats are measured to come up with the figure.
So the boat is empty save for a few things, generally two spin poles are used as levers, with a given weight say 50kg in two 25 kg lots moved from one lever to end to the other with a manometer used to measure the change in inclination.
Freeboards are then measured to ascertain how bow down the boat is as more bow down less LPS
The IMS/ORCi computer has the hull file to the sheer.
Press enter and bingo a number comes out.

And bingo it has little to do with reality.

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Madmouse said..
I like that the locally designed and built Hick 35 not only survived but won the 98 Hobart. Mid range AVS

From memory one of the reasons she won was sail selection (I was involved in the testing at The AMC for Naiad) was that the Hick had a storm tri-sail off a Sonata 26 so it was about 2/3rds the normal size.
They flew this only with no storm headsail which allowed the to steer the boat 'around' the tri-sail rather than have the nose pushed down by the headsail, meaning they could more easily steer into each braking wave.

They also managed to skirt the worst of the weather by staying in close, I think they still had 70 knots but no where near the wave size that the guys offshore had.

The storm jib from a Young 11 was about the right size for a 45 foot IMS boat.
Interestingly, the boat would never balance with a trysail upwind and did not generate lee helm with only a storm jib on.
The point is that all boats are different.
As to AFR all the pics I have seen have the small storm jib on.

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lydia said..
The storm jib from a Young 11 was about the right size for a 45 foot IMS boat.
Interestingly, the boat would never balance with a trysail upwind and did not generate lee helm with only a storm jib on.
The point is that all boats are different.
As to AFR all the pics I have seen have the small storm jib on.

Yeah I may have got that wrong, 1999 was a long time ago!!!! But they def had a smaller storm sail than normal which helped them alot

I have never heard anyone say the storm sails are not big enough!