Cat Bridge Deck Clearances?

[ALIAS]

Originally Posted by D&D

Great post...thanks Dave!

We'll make a quick comment on the "all lines lead..." issue and then withdraw back toward the thread topic. Ours is probably one of those "all lines lead..." vessels, but the presence of the flybridge eliminates (in our view anyway) the crowded space and flying elbows syndromes. The flybridge raises many issues of its own, of course, and there are many detractors, as well as many who love it; we (and everyone we know with a flybridge!) are firmly in the 'lovers' category.

Back to bridge deck clearance now...

Hi D&D.... just a quickie digress and on that 440 flybridge after a delivery trip of 1500k :

Great for warm weather and the tropics.
Lousy in the cold and wet, especially at night.
Great for marina parking.
Found the steps a pain especially in the cold,wet and at night.
Suggest it needs a second helm below, at the nav station would be nice.
Btw it was an owners version and the consensus was there was no need for 2 toilets and two showers on the portside as it cramped the space for showering and we were not 'big' Guys. One separate toilet and separate shower cubicle would be a better way to go IMHO. Everybody showered in the owners shower because of the extra space.
Centralizing the electric/s board at eye height would also help.
Otherwise found it a nice and comfortable boat that handled the 'rough nicely' including running over a whale.

Geez, I didn't stop at the fly bridge.

[smj]

Originally Posted by 2Hulls

Those are the "knuckles" I described earlier in this thread that are quite common to increase hull interior volume. They have to be vulnerable to slamming. Whether this is significant is another matter, the degree of which we may never know. We'd have to compare to the same hulls without the knuckles, which do not exist.



(FYI the center protrusion is a line conduit for the main halyard, topping lift, and reefing lines. After running through this conduit (and not on the deck) they re-appear in the cockpit near the electric winch. All mainsail handling is done there.)



My boat has slammed. All cats do. Once on a boisterous passage while in my bunk there was an "explosion" that rattled my brains. I sprung up, stark nekkid, and ran out into the cockpit, expecting the mast to fall any second. The crew on watch, sitting at the stdb helm (one of those "deadly" outboard helms ) reading a book with a headlamp, looked at me like I was nuts. He hadn't heard a thing. Being in the hulls of a cat going fast is like being on the inside of a drum. Whether it's slamming or wave slap, it's noisy. Slower boats suffer this less. No cats at anchor slam. If you're not going to do passage making, you don't need to worry about bridgedeck clearance. On this subject, do not ignore excessive bridgedeck length. This is easy to spot by looking for short bows.



As for crew requirements, for routine cruising, the Admiral and I do just fine. We enjoy tacking upwind. We also enjoy a comfy run under spinnaker. We are small people and we're not particularly young. Our combined weight is about 245 pounds (~111kg). Any properly equipped boat of similar size should be similar - with practice. Right size winches. We have one electric winch that handles the main. Manual primaries. With manual primaries you learn to tack efficiently. Our genny is 140%. 60m2. It's a beast if you let it get the upper hand. When we race we get at least three additional deck apes. Two in a pinch....



I'd be wary of the boats with configurations that claim, "all lines lead to the helm for easy single handing." Who really needs that? That produces a crowded space that the crew can't work in. Imagine flying elbows in a tack. Although I rarely do it, single handing any cat with an auto pilot and good hardware is doable. Most of the time on passage, all cruising boats are no-handed. The time you really need extra hands is arriving and leaving an anchorage or a dock and landing fish. We enjoy making our guests work at sailing the boat. It's not all rum and mangoes. But they enjoy it. Watching three newbies tack the boat is a real hoot. They get it right after a try with each at the three stations - helm and each primary. This would be almost impossible with one of those "all lines lead..." boats. But not all people are sailors at heart and your mileage may be different.....



2 Hulls Dave

Our old Gemini used to slam at anchor:-(

[ALIAS]

Originally Posted by smj

Our old Gemini used to slam at anchor:-(

Did you mention that to the purchaser?

ooops smj, my special kind of humor got lose again.

[smj]

Originally Posted by ALIAS

Did you mention that to the purchaser?

ooops smj, my special kind of humor got lose again.

Didn't have to, it's pretty obvious if you look at the bridge deck clearance. And there's no doubt, your special alright.

[Kashmir cat]

I think it would be interesting to compare manufacturers specified bridge clearances with real world cruising bridge clearances. I've seen partially loaded Lagoons drop 6 inches of waterline and overloaded Prout's drop less than 2.

[ALIAS]

Originally Posted by smj

Didn't have to, it's pretty obvious if you look at the bridge deck clearance.


And there's no doubt, your special alright.

Fixed!

[D&D]

Originally Posted by Kashmir cat

I think it would be interesting to compare manufacturers specified bridge clearances with real world cruising bridge clearances. I've seen partially loaded Lagoons drop 6 inches of waterline and overloaded Prout's drop less than 2.

It has to be a matter of displacement. The volume of water displaced (reflected in the lower waterline) must be equal to the weight of the added load, which leads to the conclusion that fatter hulls (like Lagoons and FP's) will sink less than thinner hulls of the same length with the same added weight.

FWIW, we cruise fairly fully loaded with negligible effect on waterline...and we find it hard to imagine our waterline dropping by 6", even from light ship to fully loaded...

[Seaslug Caravan]

Originally Posted by ALIAS

Any links please?

Google will help starting with passage times for the ARC race/rally.
Most clubs that have mixed multihull fleets will post results on their websites.

Some of the heavier, more highsided production cats should be considered motor sailors rather than windward machines. I'm sure you will work this out for yourself.

[monte]

Kashmir I think you have that a bit backwards. A wider u shape hull will drop less than a narrow v shape. I'd guess our waterline area on our lagoon 400 to be around 20m2 so adding a tonne would lower her by 5 cm (2 inches) A similar size Prout would have considerably less area at the waterline
For the OP. Thee was a similar thread where bridgedeck slamming was addressed if you search, but the consensus was as Dave said, all cats will slam occasionally and it's really not an issue for most. Something that sounds loud in the saloon or bunk goes unnoticed at the helm. For me hearing the occasional wave noise is much less disconcerting than hearing the rigging groan on most racing monos I've sailed when hit by a gust. It's just different noises you become accustomed to. Another sound heard more frequently on cats is hull slamming, when a wave on the beam hits the large vertical flat surface of the hull and it resonates like a drum. A similar wave on a mono generally finds the surface more rounded and stiffer and doesn't make as much noise. Also the mono rolls more with the motion of the ocean.
We have never experienced uncomfortable slamming on our lagoon 380, or on our lagoon 400 which have clearances around 60-65 cm but as mentioned above, there is a lot more involved than just bridgedeck clearance (hull shape, distance between hulls etc etc) both our cats have been comfortable upwind as well as downwind. The only way to test a boats performance and comfort is to sail one or speak with people who have sailed that design in enough varied conditions to comment, but even then one persons idea of slamming might be totally different to another's.
Btw the corsair looks ok but way too expensive for a 20yr old 36ft cat. Bets bet is to go take a look and sail it if you are interested. From the L440 delivery you should have a good idea of the norm.

[ALIAS]

Originally Posted by monte

Kashmir I think you have that a bit backwards. A wider u shape hull will drop less than a narrow v shape. I'd guess our waterline area on our lagoon 400 to be around 20m2 so adding a tonne would lower her by 5 cm (2 inches) A similar size Prout would have considerably less area at the waterline
For the OP. Thee was a similar thread where bridgedeck slamming was addressed if you search, but the consensus was as Dave said, all cats will slam occasionally and it's really not an issue for most. Something that sounds loud in the saloon or bunk goes unnoticed at the helm. For me hearing the occasional wave noise is much less disconcerting than hearing the rigging groan on most racing monos I've sailed when hit by a gust. It's just different noises you become accustomed to. Another sound heard more frequently on cats is hull slamming, when a wave on the beam hits the large vertical flat surface of the hull and it resonates like a drum. A similar wave on a mono generally finds the surface more rounded and stiffer and doesn't make as much noise. Also the mono rolls more with the motion of the ocean.
We have never experienced uncomfortable slamming on our lagoon 380, or on our lagoon 400 which have clearances around 60-65 cm but as mentioned above, there is a lot more involved than just bridgedeck clearance (hull shape, distance between hulls etc etc) both our cats have been comfortable upwind as well as downwind. The only way to test a boats performance and comfort is to sail one or speak with people who have sailed that design in enough varied conditions to comment, but even then one persons idea of slamming might be totally different to another's.
Btw the corsair looks ok but way too expensive for a 20yr old 36ft cat. Bets bet is to go take a look and sail it if you are interested. From the L440 delivery you should have a good idea of the norm.

Well Monte the threads now got over 4300 hits so I'm assuming there is a varied readership of interested Cat owners of various sizes and so taking your above (in bold lettering) as a stimulus to garnishee feedback from owners of specific Cats that I could be interested in...............

So................

Does anybody herein have a 2002 Leopard 42 that they can give me a run down of its capabilities and handling in both light and heavy weather both up and down wind and their experience with bridge deck clearance and slamming?

Oh and anything else that they would like to share.

Thanks.

[colemj]

Originally Posted by 2Hulls

Once on a boisterous passage while in my bunk there was an "explosion" that rattled my brains. I sprung up, stark nekkid, and ran out into the cockpit, expecting the mast to fall any second. The crew on watch, sitting at the stdb helm (one of those "deadly" outboard helms ) reading a book with a headlamp, looked at me like I was nuts. He hadn't heard a thing.



I'd be wary of the boats with configurations that claim, "all lines lead to the helm for easy single handing." Who really needs that? That produces a crowded space that the crew can't work in.

Aren't the berths over those knuckles? I was on a 401 where the berth was over the knuckle and it was really loud just in that place because of small wave slaps, but unnoticeable anywhere else. The boat itself wasn't slamming.

We have all lines led to the helm and wouldn't want it differently. One of us can do absolutely everything - raise/lower sails (including our hank-on headsail), reef, adjust the preventer, adjust the vang, adjust the sails. Tacking is no problem because we have a self-tacking jib, but even without that, I would prefer to tack with one person instead of needing a crew. On passages, operating the entire boat by one person is heaven for the other one asleep.

Mark

[2Hulls]

Hi Mark -

Originally Posted by colemj

Aren't the berths over those knuckles?

A small part, yes. But mostly beginning just outboard of them. The "explosions" I've heard are probably more slap rather than slam. Any slap along the hull would do it. More drum-like noise than thud. I have experienced just a few what I think are real slams while in the saloon sitting at the nav desk. These are real thuds and everything jumps. But these have been rare and occur when you would expect them - fast, wind abeam or forward.

We have all lines led to the helm and wouldn't want it differently. One of us can do absolutely everything - raise/lower sails (including our hank-on headsail), reef, adjust the preventer, adjust the vang, adjust the sails. Tacking is no problem because we have a self-tacking jib, but even without that, I would prefer to tack with one person instead of needing a crew. On passages, operating the entire boat by one person is heaven for the other one asleep.

You forgot to say, one of us can do absolutely everything "without getting off my ass."

Aside from the self tacker, it seems most cruising cats with bulkhead mounted helms have similar sail handling set ups you describe - "all lines lead..." So apparently many, many folks are satisfied with them or don't mind doing everything themselves. Clearly a personal choice. I've sailed many of these cats.

I, however, prefer the classic monohull style set up with the primaries on each side of the boat. This way when you do have crew, or even when just double handed like we are most of the time, two or more people can tack without getting in each other's way. And the line runs are simpler. Like you, I can do all the other things needed. I just move around a bit more - and have much more simpler and efficient line runs.

Take singlehanded tacking (with autopilot). In my case I just activate the auto tack feature at the leeward helm; as the genny luffs release the sheet (which I am right next to), stroll over to the other side of the boat and sheet it in again as the boat comes thru the wind. Fine tune the helm (which I am right next to, again) at the new leeward helm. The only thing I do different from you is walk across the back of the cockpit.

The real benefit comes when you have crew or quests who want to help sail the boat or when racing. I realize few folks with cruising cats care about racing. With the controls spread out there's plenty of room for flying elbows and multiple winches going simultaneously, steering (since you you can't use AP), plus more room for the additional crew managing the main. We use three extra crew when racing for 5 total. I can't imagine all that taking place in the very small area of a "all lines lead...." helm.

2 Hulls Dave

[colemj]

Originally Posted by 2Hulls

You forgot to say, one of us can do absolutely everything "without getting off my ass."

I sometimes stand at the helm.

I don't understand the simpler line runs. On ours, the halyards exit the mast and run straight back to the cockpit. The mainsheet and reefing lines exit the boom and runs straight back. The jibsheet simply runs straight back. The vang and preventer run straight back.

Right before the electric winch is a bank of rope clutches. I would have to actually complicate the line runs to make them run differently. I can't even picture how I would do that short of setting up cheek blocks outside the run lines and running a maze around the deck.

Other than your jib sheets, I'm pretty sure the rest of your lines are run the same way - only to a slightly different spot on your boat (the electric winch and stopper gang at the back of the cockpit).

Mark

[Zuri]

I have a web site catamaraguru.com and the rule of thumb I use there is 4% of overall length is acceptable, 5% is good and 6% is great if the design allows.


Sent from my iPhone using Cruisers Sailing Forum

[2Hulls]

Originally Posted by colemj

I sometimes stand at the helm.

You forgot the big grin.

I don't understand the simpler line runs.

First, the Manta was on my short list. Way better than charter designed boats IMHO.I have been on several but never sailed one. Perhaps you'll help me fix this sometime. But I honestly don't remember what your set up looks like. With the self tacker it's different from other cats I can remember.

I've seen tortuous line runs, just to get them to the vicinity of a bulkhead helm, which have to be asymmetrical because the helm is on one side or the other but the line functions are not - either port or starboard. The worst seem to be the traveler lines which snake across a hardtop or otherwise switchback on 40 miles of bad road thru numerous deck organizers to the bank of clutches. We call them the "piano keys".

Other than your jib sheets, I'm pretty sure the rest of your lines are run the same way - only to a slightly different spot on your boat (the electric winch and stopper gang at the back of the cockpit).

Yes, except nothing runs on top of the decks. Lines from the mast - main halyard, topping lift, all reefing lines - run straight down under the mast to a conduit under the bridgedeck and re-appear under the electric winch in the back of the cockpit to the piano keys. Line tails collect in bins along the back cross beam. Genny furling and spi guys run under the deck outboard along the toe rail. Nothing to trip over.

But you are correct. In your case, line runs are not necessarily more complicated because you don't have a port/starboard jib sheet. I don't know what you do with spi sheets/guys.

There are different ways of accomplishing the same functions. Mostly these are distinguished by personal preference and familiarity.

2 Hulls Dave