Desirable and Undesirable Characteristics of Offshore Yachts

DDW

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OK, the last thing I would want...

I know that keel stepped makes sense on a racing boat as the first spreaders can be higher up but there is a reason why deck stpped is prohibited on IMOCAs...
I think the last of your worries when the mast falls is whether it started keel or deck stepped. 

One possible downside of a free standing is if it broke below the partners (or the step broke) you would open the deck like a can opener. I haven't heard of that happening to anyone but it could with an unfortunate set of circumstances. On mine I made sure the step would not fail first, and was assured by the mast engineer that it would break well above the deck, if it broke. The ultimate strength of the spar calculates to about 4x the max righting moment of the hull (on paper) and the step and partners >10x. Also the partners and step are forward of the front crash bulkhead so if that remains intact, I would not sink. 

 

Panoramix

Super Anarchist
In my earlier message, I meant keel stepped prohibited on IMOCAs...

if you get rolled and loose the mast, with a deck stepped mast, the odds of not having a hole in the roof are higher plus you can free the mast quickly to save the hull as there is no need to climb to spreader level to cut stuff. So OK, you've lost your mast but your chances of having a dry boat are higher! Obviously nothing stops you from over engineering a deck stepped mast...

 

olaf hart

Super Anarchist
I think the last of your worries when the mast falls is whether it started keel or deck stepped. 

One possible downside of a free standing is if it broke below the partners (or the step broke) you would open the deck like a can opener. I haven't heard of that happening to anyone but it could with an unfortunate set of circumstances. On mine I made sure the step would not fail first, and was assured by the mast engineer that it would break well above the deck, if it broke. The ultimate strength of the spar calculates to about 4x the max righting moment of the hull (on paper) and the step and partners >10x. Also the partners and step are forward of the front crash bulkhead so if that remains intact, I would not sink. 
In an earlier life I had a Freedom 22, with a freestanding carbon mast. The base of the mast came loose from its step once in a wind on tide situation.

Even in a small boat this was a nightmare, sold the boat the next month and moved on.

 

shaggybaxter

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ON my deck stepped mast, there was a hardpoint low on the mast and another on the deck. When I quizzed the French at commissioning what it was for, Antoine produced a short dyneema strop, it was the tether to anchor the mast base to the cabintop. 

:( . Embarrassed to admit I hadn't thought of that. 

 

MikeJohns

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Hobart
Keel stepped is the last thing you want offshore as it breaks the cardinal rule of making your best to  keep the water out in all conditions. I would make an exception for a freestanding mast as it becomes a tradeoff between robustness and an extra hole in the roof!
I prefer deck stepped for several reasons, but structurally keel stepped is better, it's a full moment connection rather than pinned at deck level. You can do this with a tabernacle, but it's both heavier and more expensive to implement.

ULDB sailboats particularly are at risk from a collapsed rig over the side in heavy weather and need to get it cleared up ASAP. Keel stepped usually retains the lower part of the mast and it can be hard to clean away the wreckage when the mast has folded over but is still attached and too high to access with nothing to haul up on.

If you look at keel steeped dismasting as a rule there's always a mast stump and often the full lower section to the fist spreaders intact. So you get to keep the boom and halyard winches etc.

You can also seal the mast internally too at assembly if required, internal seals that angle to a drain point.  These are often inserted just above deck level in hollow keel stepped masts.

But wrt sinking it's a thousand times more likely that a boat sinks from a composite spade rudder stock breaking halfway between the two bearings than through what happens to the rig after a capsize.  Just something else for you to worry about ;-)

 

DDW

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But wrt sinking it's a thousand times more likely that a boat sinks from a composite spade rudder stock breaking halfway between the two bearings than through what happens to the rig after a capsize.  Just something else for you to worry about ;-)
You're gonna have to come up with the data to support that. Although I suppose 0/0 could be said to be a thousand times. Properly engineered, a composite rudder post is unlikely to sink the boat. The calculated breaking load on mine is 4x the boat displacement at the tip, it is inside a large tube sealed from the rest of the boat, which itself is inside the aft watertight compartment. So a lot depends on the details. 

 

Jud - s/v Sputnik

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So I just put down a deposit on a boat with free standing, water tight spars. 

Not sure it puts me in the club though.



https://www.ghboats.com/our-boats/17-salish-voyager/
That’s a fun-looking little boat - I was actually looking at one of those on the Gig Harbour Boats site the other day - I’d like to have something max 17 ft that sails and rows well - to pop over to local Gulf Islands around here, pull it up on the beach in summer to camp, gear stuffed in a dry bag.  Maybe do a 7048 Race too?  More for the kid than me, but I gotta think about myself too :) But the cost is making me consider a Wayfarer dinghy instead (and the GH looks hard to sleep in).

 
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toddster

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You're gonna have to come up with the data to support that. Although I suppose 0/0 could be said to be a thousand times. Properly engineered, a composite rudder post is unlikely to sink the boat. The calculated breaking load on mine is 4x the boat displacement at the tip, it is inside a large tube sealed from the rest of the boat, which itself is inside the aft watertight compartment. So a lot depends on the details. 
That sounds good - what I don’t get about my boat (and my similar ones) is why they didn’t put a crash bulkhead forward of the rudder tube?  They put one in the bow!  I think I can add one, but it would have been a zillion times easier to put it in at the factory. 

At the last haul-out, I drilled through it to install a zirk to lube the bottom bearing and that tube is a LOT thinner that I’d hoped it was.  

 
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fufkin

Super Anarchist
There's always the old school option of having the rudder post enter the hull above the waterline. A lot of boats are/were designed for precise stern squat under motion where a portion of the rudder (and post) get used when in motion but are above the waterline when at anchor etc.

 

Jud - s/v Sputnik

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From the Pacific - there are two options - down the coast or a big loop out to polynesia and around the big stationary high and back in at Chile.  This later is quite long sea distance, but with favorable conditions and some really nice stops which most cruisers doing the pacific dont get to see. The last leg is the only potentially difficult part, several thousand miles into puerto montt in increasing difficult southern weather.  This is a passage where it is useful to be good at weather routing - We did some nice clever stuff. The down the coast run has some really nasty against the current and wind sections, and the harbours and countries are not the most hospitable.  We much preferred to do long ocean work, so we never did the down the coast and I cant speak to its details much except everyone we know who did it said 'never again'.

The advantage for the pacific entry are two fold.  One is it is downwind down the channels from there, which is a ton easier than north bound. The second is that you start at the easer end of the channels so you can get your feet wet and feel you way into the new learning experience.  When you enter from the atlantic you are thrown immediately right into the very cold deep end. 

We did two south bound trips and one northbound.  Patagonia is a bit of a shock if you think you are an expert experienced cruiser, because it really is a whole different level. It is difficult for most people to fit into their cruise plan, but I always suggest for people to try to make two trips in the chanels because the first one will be stressful as you are learning the ropes and the 2nd one you can relax a bit and enjoy the experience.
Thanks for all your thoughts on Patagonia - much appreciated, Evans!  Yeah, I’m sorta thinking that heading up to the Aleutians in the next couple years would be a sort of “prep” for down there (but mostly I just want to get up there, as it’s actually pretty close to here).
 

Re: down the S. America coast, I  think the only “down the coast” voyage I’ve ever read about is Hal Roth’s, in his “classic” Cape Horn book.  But he’s pretty breezy in his writing in general, never mentions any hardships, and doesn’t seem to make much of the fact that the Peru/Humboldt Current is against you pretty much the whole way down S. America.  Sounds unpleasant.

The account I’m currently reading is via Atlantic/Cape Town - as you say, a bit “rude” as you are sort of suddenly “there”, Le Maire being sort of the gate to the cold south  (vs. working your way down south on the Pac coast side, with favourable wind/current from Montt).

Relating cruising there to this thread, on the third approach option (via southern Polynesia, around the S Pac High, then E to Chile) —which it sounds like you did?— it’s gotta be, what 40  days?  You mentioned in a different thread that your solar panels weren’t mounted (I’m still trying to make a decision on this/sort this out) - what would you do for power generation on a long passage like that to Chile, i.e., in increasingly southern sea/rough conditions?  Since they weren’t fixed/mounted panels, you just brought them out when calm only to charge up?

 
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Autonomous

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That’s a fun-looking little boat - I was actually looking at one of those on the Gig Harbour Boats site the other day - I’d like to have something max 17 ft that sails and rows well - to pop over to local Gulf Islands around here, pull it up on the beach in summer to camp, gear stuffed in a dry bag.  Maybe do a 7048 Race too?  More for the kid than me, but I gotta think about myself too :) But the cost is making me consider a Wayfarer dinghy instead (and the GH looks hard to sleep in).
The Wayfarer is definitely proven.

https://www.yachtingworld.com/voyages/faeroes-to-norway-in-a-wayfarer-dinghy-frank-dyes-extraordinary-tale-of-sea-survival-108050

 

shaggybaxter

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it is inside a large tube sealed from the rest of the boat, which itself is inside the aft watertight compartment. So a lot depends on the details. 
This. Throw in dual rudders and I think this should be mandatory. You can't hide it/them behind the keel and the cant adds depth and width, dependent upon heel.  

Edit: for offshore that is. Bay cruising is different of course.  

 
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Fah Kiew Tu

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Tasmania, Australia
There's always the old school option of having the rudder post enter the hull above the waterline. A lot of boats are/were designed for precise stern squat under motion where a portion of the rudder (and post) get used when in motion but are above the waterline when at anchor etc.
Mine enters the hull at the DWL but extends a good 400mm above so can't flood the boat no matter what. It's grease filled as well.

FKT

 

Panoramix

Super Anarchist
I prefer deck stepped for several reasons, but structurally keel stepped is better, it's a full moment connection rather than pinned at deck level. You can do this with a tabernacle, but it's both heavier and more expensive to implement.

ULDB sailboats particularly are at risk from a collapsed rig over the side in heavy weather and need to get it cleared up ASAP. Keel stepped usually retains the lower part of the mast and it can be hard to clean away the wreckage when the mast has folded over but is still attached and too high to access with nothing to haul up on.

If you look at keel steeped dismasting as a rule there's always a mast stump and often the full lower section to the fist spreaders intact. So you get to keep the boom and halyard winches etc.

You can also seal the mast internally too at assembly if required, internal seals that angle to a drain point.  These are often inserted just above deck level in hollow keel stepped masts.

But wrt sinking it's a thousand times more likely that a boat sinks from a composite spade rudder stock breaking halfway between the two bearings than through what happens to the rig after a capsize.  Just something else for you to worry about ;-)
A moment connection isn't inherently structurally better, it just means that the Euler buckling length of your first panel is shorter (which is good and efficient!) but you can get the same effect on a deck stepped mast by lowering your first spreaders (and potentially adding an extra set at the top). Racing boats use decked stepped when allowed but that's because it gives you a bit more righting moment (structurally more efficient design) but the drawback of an extra hole in the roof is a no brainer IMO on an offshore cruising boat for the safety aspect. Plus these seals are hard to maintain, IME it is not uncommon for these to leak.

Clearing a mast that is half standing is very dangerous as it involves working at height in a chaotic environment, it takes time and meanwhile you take the risk of holing the hull with the dangling bits banging against the boat..

As for the ruder stocks, they should be behind a watertight bulkhead, I know that sadly often they aren't but this thread is titled "Desirable and Undesirable Characteristics of Offshore Yachts". Most keelboats can sink, so keeping the water out should be a top priority and if I were to sail offshore in high latitudes, I would really want as few holes as possible.

 

MikeJohns

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Hobart
You're gonna have to come up with the data to support that. Although I suppose 0/0 could be said to be a thousand times. Properly engineered, a composite rudder post is unlikely to sink the boat. The calculated breaking load on mine is 4x the boat displacement at the tip, it is inside a large tube sealed from the rest of the boat, which itself is inside the aft watertight compartment. So a lot depends on the details. 
Actually I'm not aware of any boat that's sunk from losing a keel stepped mast. But I am aware of several boats that have sunk from the loss of spade rudders.  They pull out if the stock breaks, and it sinks the boat unless it's designed to prevent this. 
 

 

Fah Kiew Tu

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Tasmania, Australia
Clearing a mast that is half standing is very dangerous as it involves working at height in a chaotic environment, it takes time and meanwhile you take the risk of holing the hull with the dangling bits banging against the boat..
Not if you have a steel boat, you don't.

You can bash on my hull all you like with an aluminium mast and all you'll do is scratch up the epoxy.

And if I really thought it was a risk clearing a broken mast stub I'd just have an 18V battery angle grinder equipped with an aluminium cutting blade. No probs mon.

But I don't care because my masts are in heavy duty welded tabernacles secured by 2 x M20 bolts each and have 8mm galvanised wire standing rigging.

FKT

 

Panoramix

Super Anarchist
ot if you have a steel boat, you don't.

You can bash on my hull all you like with an aluminium mast and all you'll do is scratch up the epoxy.

And if I really thought it was a risk clearing a broken mast stub I'd just have an 18V battery angle grinder equipped with an aluminium cutting blade. No probs mon.

But I don't care because my masts are in heavy duty welded tabernacles secured by 2 x M20 bolts each and have 8mm galvanised wire standing rigging.
Yes, nevertheless by vastly overdesigning the mast, you gave away the advantage of the moment connection in the tabernacle!

 

Fah Kiew Tu

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Tasmania, Australia
Yes, nevertheless by vastly overdesigning the mast, you gave away the advantage of the moment connection in the tabernacle!
You might have a point, *if* I designed the tabernacle.

As a matter of fact it was designed by the boat designer.

Said designer having designed *and* built more boats than you're aware of, and I venture to bet probably 100X the number you've designed and built. There have been more than 700 of a single one of his designs built. More than 200 or the design SV PANOPE and I have.

So you'll have to pardon me for not being impressed by your snarky comments.

FKT

 

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