Arches, Biminis, Dodgers and Stability

[pcmm]

Most dodgers aren't particularly heavily built (and for that matter I think alot of arches are under built). Biminis the same. Most Biminis are built of 1" SS tubing which with the yard of canvas they support are pretty wiggly.

Hard dodgers on the other hand if built correctly are not too heavy for their strength There are 2 schools of thought. One says that the hard dodger should be somewhat "sacrificial" it should break before damaging the cabintop. Others want bullet proof! I fall into the later camp. I have a hard top dodger made of 2 layers of 3/8 marine ply laminated into the appropriate curve. Supported by 4 legs made of 2inch sched 40 Aluminum pipe. with 1/4" plates welded to each end. I can jump on my hard top (do it) with minimal deflection (I weigh 220)

Arches I'm in the same camp. Useful but at sea I'd rather have the dinghy last upsided down on the foredeck. A dinghy full of water on the arch weighs a ton, and out at the end of the arch, that's alot of leverage on the bases. I do like them for getting the solar panels, wind gen, antennas, etc. out of the way. I'm building an arch this spring and I'm also using sched 40 Aluminum pipe. Most arches to my eye don't have enough cant inwards and end up looking really square on the sterns which just looks ugly to me.

Once I'm done all my fab, all my ALU will go off to get anodized.

[Pete7]

Originally Posted by pcmm

I do like them for getting the solar panels, wind gen, antennas, etc. out of the way. I'm building an arch this spring and I'm also using sched 40 Aluminum pipe. Most arches to my eye don't have enough cant inwards and end up looking really square on the sterns which just looks ugly to me.

Agreed, the previous solar panel was mounted on the pushpit and was hit twice in 2 years by other yachts in tight marinas, so wanted the new panel up out of the way and be able to walk underneath it to access the sugar scoop stern and dinghy.

Starting with a second hand rib A frame costing 20% of a new tailor made frame I managed to get some tilt forwards and the sides cant inwards rather than vertical or leaning back. The panel will tilt backwards too if the sun is behind us for any length of time.

Pete

[SV.Maverick]

Not all arches are created equal. I have had the arch in a box and had trouble in heavy seas with it flexing back and forth. I bit the built and had a custom made 3” arch made and I have actually tried to get it to flex in any direction and it’s just not possible

[SV.Maverick]

http://www.cruisersforum.com/forums/...1&d=1544296447

[evm1024]

Originally Posted by SV.Maverick

Not all arches are created equal. I have had the arch in a box and had trouble in heavy seas with it flexing back and forth. I bit the built and had a custom made 3” arch made and I have actually tried to get it to flex in any direction and it’s just not possible

Nice looking arch - I have been thinking of adding one to my GS50. I think I'll use yours as a template.

[SV.Maverick]

Originally Posted by evm1024

Nice looking arch - I have been thinking of adding one to my GS50. I think I'll use yours as a template.

There are a few more angles of the arch on the boats Facebook and Instagram page under SV Maverick

[Jim Cate]

Getting back to the OP's question...

Virtually everything that you add to a yacht decreases her stability to some degree. One has to decide if the minor risk increase entailed by each and every item added is worth while. A mast mounted radar decreases stability, but adds safety in other ways... how do you equate these factors? Very, very few yachts ever encounter conditions where it becomes a significant safety factor. Simply being at sea in storm conditions does not often subject a boat to a situation where a few degrees less AVS will result in a knockdown or rollover. The guys in the GGR are not typical cruisers!

So, consider that your solar arch/davit rig will benefit you the whole time you own the boat... versus the fact that damn few boats ever go more than a few hours sail away from their home base and will never see survival conditions. Yes, the boat will sail at slightly greater heel angles with more weight aloft, and there will be a loss of a bit of windward performance due to windage, but for most folks, that is a small price to pay for the gains afforded by the arch, radar, or bimini. Serious racers will have a different set of considerations, of course, but few of them sport solar arches!

Personally, I won't tolerate the rather large increment of a davit-borne dinghy, but can live with the solar arch. Each of us must make such decisions base on our own requirements and limits. There are no absolute rules!

Jim

[GrowleyMonster]

Everything is incremental. Incremental increase in convenience, safety, and comfort. Incremental decrease in stability, increase in windage, decrease in flexibility and freedom to move about the boat in unexpected ways. Casual coastal cruising demands certain little extras. Liveaboard marina life with occasional weekends on the bay or lake, still more of those certain things. Ocean passages, or anchoring down for a hard blow, still another, leaner and meaner set of things. You have to weigh the potential benefit and badifet of each item under consideration. Also a lot depends on your style of sailing. Singlehanded? Maybe that would make mast steps more attractive, even on a long crossing. Dock every night? Maybe an inflatable dink and an electric trolling motor would be better than a towed, davited, or even lashed down hard dinghy. There is a large element of just pure preference, too. For instance my recently purchased BR 44 will be fitted out for cruising. However, the benefits of a hard dodger or partly enclosed cockpit far outweigh the negatives, for me. FOR ME. MY boat, preference, and decision. I have steered an awful lot of ships and never had to get rained on or sprayed on while doing it. I have, OTOH gotten cold and wet and sunbaked while steering small boats, and I can't reconcile that with the "pleasure" part of "pleasure boating". And yes, mast steps will be part of the fitout. Hard dinghy davits are still under consideration. Still deciding. Inflatable, full hardside, or RIB dink? Also still being considered. Radar not being considered. It, and AIS, are definitely IN. More fuel tanks, yeah. Genset? Eventually. Full bar, with ice maker? Don't be silly. OF COURSE. Have slip, must have bar. Electric wing motor / shaft generator? Regretably, no. Not now, anyway. Hot tub on deck? I am tempted, but no, LOL! Ditto regular bathtub below, and sauna. I will have maybe a bit more than most well thought cruisers but that's how I roll and I don't expect anyone to follow my example, other than that nothing goes on the boat without plenty of thought beforehand, in consideration of how I sail, where I will and where I might sail, and what I need on the boat when I am not sailing. I know I can't turn Brute Force into a Swiss army knife of a boat, and still get design performance out of her, but some things I just need/want and feel are worth the performance hits.

[Cheechako]

Just dont go too far...

[dbraymer]

Picture worth 1000 words




erh a technical difficulty


first two pictures on hekowisailing dot com.


We built this dodger for the trip from California to Florida. The original plywood home depot plexiglass
prototype/will-have-to-do now replaced with starboard and lexan, with cherry for the binding frame. The also afterfit bimini on aluminum frame folds out over the bimini by about a foot.

When you stand, you look over the dodger and below the bimini. you can see water about 50 feet in front of the boat. When you sit you look thru the large center fixed glass. It would be best if the center window would allow for opening, we did not go that more complicated route.


This is the minimum windage, least weight, and reasonable water/sun protection. Hurricane Maria took the bimini frame and bashed it thru the plywood dodger, --- in the yard.

I vouch wholeheartedly for this type of arrangement. Maybe 1 percent of boats sailing about have this done well...

[nofacey]

Weither a Bimini/arch has a significant effect on stability really depends on the boat. I am 80% of the way thru a circumnavigation, and you see EVERYTHING out there.... so my opinion is that from a stability perspective, the effect on a typical cruising boat is not significant.

Windage wise - do you have (as most cruisers do nowadays) a roller furling foresail? It is truly amazing how much windage that creates up forward! I have roller furling on both foresails (cutter rig) and that far outweighs everything on the stern.

[DeValency]

Dodgers are essential. Biminies are important with both very sunny areas and to protect from the elements. Their relative weight is marginal with the boat’s overall weight and other devices on board.

Arches and davits is a different story as they normally carry some heavier stuff. A 36’ cruiser with light displacement may not like these that much. The heavier and beamier the boat is the better she can handle the extra structure and weight, but at any case you want to minimize it to the most critical devices.
In a longer passage making I would lower the dinghy RIB (after of course removing the outboard) from the davits (or crane) and secure it on the sugar scoop transom - much less movements and fatigue on the deck mounted davits as well as lowering the center of gravity as possible.

[wingssail]

Originally Posted by budvar

I have a 25' sloop for now, but of course see myself in 3-5 yrs in some tropical paradise in a 36 ft cutter, living the dream.

Watching the u-tubers and reading cruiser's stories, I see some amazing and beautiful/functional arches/shade biminis and hard dodgers built. The arches hold the usual items, but can also include solar panels, OB motors, dinghies and the like.

My question, does this become a stability issue once you are at sea? Especially in severe conditions. Can sailboats safely carry arches and enclosed biminis when at sea? I know you can overdo anything. Was just wondering. Would this include hard dodgers, even mast steps as being problematic in a severe storm?

Thanks for reading thus far. Just trying to gain a perspective on how to configure my dream boat and keep the designer's original stability in mind.

The answer depends on your priorities and where and when you sail (if you sail).

Weight aloft definitely affects stability, and not in a good way, but it probably won't make you tip over.

However, the arch and all the stuff people put on it also presents a lot of windage, which greatly affects sailing performance, and it is weight in the ends of the boat (bad), which affects how well the boat handles waves (pitching) and also greatly affects sailing performance.

A dingy and motor hinging 10 feet off the water on davits in the back of the boat is not good seamanship and is dangerous in a heavy blow.

Biminis are lighter and can have less negative effects however on a modern boat with a wide stern they represent a lot of area of canvas and when heeled over, or rolling, it is a huge wind catcher, and often not strong enough to hold the wind it catches.

A dodger is essential, and is also generally light and in a better location than the stern mounted arch.

On the other hand an arch is a convenient place to stick the stuff you can't put anywhere else.

What is your preference? Convenience for putting stuff or sailing performance?

I have no arch and I rig a temporary awning in place of a bimini. We strike it in heavy weather and usually at night. I keep my solar panels on the stern railings. I deflate my dingy and stow it below. My dodger is weather tight but foldable and I like to fold it down in nice weather and feel the wind in my face. All in all we have chosen to emphasize sailing over motoring and dockside convenience. Other boaters obviously have different priorities.

But I will say that when I meet the most experienced offshore sailors they almost always have the same preferences: Clear decks, no on-deck stowage (no jerry cans or kayaks), no arch, no davits, solar panels down low, and an easily removable bimini.

Here is an example: Three years ago we made a crossing to Baja from Puerto Vallarta. It was a boisterous upwind crossing with winds of around 20 knots true. We arrived in Los Muertos anchorage after 3 days windblown, covered in salt, and tired, but we were exhilarated by the great sailing. Within 30 minutes three other boats also sailed into the anchorage and dropped hooks. They too were wind blown and covered in salt, but also so very much exhilarated by the passage they had just completed, under sail, not motoring. We all hailed each other and were ready to go ashore for a beer. But nobody had a dingy inflated and ready to launch! Everyone's dingy was stowed for heavy weather. There was not an arch in the group. Nor a line of jerry cans. For each of us, sailing was better when we knew we were stripped for action.

Don't do this.

[Don C L]

More an issue of windage than weight. I have a removable solar panel.. the large fixed ones, up high, say "rudder" and "drag" to me in higher winds. I WISH I had a dodger and sea hood... hoping Santa comes through for me on that one... but the house is high enough that I can duck and hide from most spray usually. MY boat came with a very strong arch, to mount the mainsheet up higher, which I really like for all kinds of things, and by itself, with out panels or other goodies permanently affixed, save the spare VHF antenna, has proven itself very handy for a myriad reasons and tasks.

[Don C L]

Originally Posted by wingssail

For each of us, sailing was better when we knew we were stripped for action.

Don't do this.

Agreed! And quite a bit safer too. If the dinghy, or anything, comes loose in its davit on a boisterous day all sorts of calamity can ensue.