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Discussion Starter · #1 ·
I'm a recent new owner of a Cape Dory 28. The mast has been patched at the base of the starboard spreader. I've had someone look at it who deemed it safe so I will be using it for at least a season or two, but I want to replace it before cruising. Similarly, I plan on changing the shrouds and stays before leaving local waters. I also need to repair the reinforcement for the bowsprit (and possibly change the bowsprit that is not original) at next season's haul out.

Since I plan on maintenance/replacement for all of my rigging within the coming years, I've been exploring whether I can increase the sail area of the boat for light air performance as the SA/D is only 14.52.

I've looked at the option of lengthening the bowsprit and adding a boomkin and also even the possibility of changing to a gaff rig. I assumed that putting a taller rig on the boat would involve more rigging loads and didn't want to start messing with that as the mast is cabin stepped with no compression post beneath. I've just read through "The Rigger's Apprentice" and if I'm understanding correctly the shroud loads are determined by the shroud angles and the boat's ability to stand up to the wind, which suggests that this actually might be an option.

So I was hoping to get some input into whether I'm missing something in the following scenario:

Spartan Spars offers a mast section for the Cape Dory 30 that was identical to mine except it was 41'6" in length compared to my CD28's 36'. The extra 5'5" length weighs 15.8 lbs. The bowsprit on the CD28 is 1' long with a 6 degree rise and a J of 11'6" and the CD30 had a J of 13'3". The CD30's E is 13' whereas the CD28's is 12'6". The max beam of the CD30 is 9' instead of the CD28's 8'9" but the CD28 has a higher prismatic coefficient so that the staying base up at the mast appears to be of similar width.

My plan would be to essentially transplant the CD30's rig (a cutter rig so also a bonus) onto my CD28 which would raise my SA/D to 15.83. I have yet to map out the sail plan to find out if the balance would be the same and I would look at adjusting the bowsprit length once past the concept phase and into the design phase to make sure it balances.

This would entail:

Replacing the bowsprit with one that is ~2'9" long. Bobstay would need to be stronger and I'll have to check, but the bobstay fitting may need to be changed. To keep stress down, I may need to level the bowsprit or add dolphin strikers.

Keep the club footed staysail of the CD28 (the staysail will be relatively smaller to the jib compared with the CD30).

Replace pulpit to allow access to end of bowsprit & jib.

I don't think a boomkin will be necessary. There is more than enough clearance for the extra 6" of boom length but the steeper backstay angle may require a hollow roach on the main (so maybe a boom more than 6" longer to compensate?).

Obviously replace the shrouds and stays.

I am planning to replace the 40 yr old, 375 lb Volvo MD7a before cruising with a much lighter inboard or an outboard because not all parts are available anymore and don't want it to die somewhere that replacement would be impossible/$$$, so I may have 200-300 lbs to add to the 3650 lbs of ballast but the intent of the increased SA/D is to improve light air performance, so the extra weight aloft would only be the 15.8 lbs of mast and the extra shroud/stay length once reefed so I'm not expecting to have to make the boat much stiffer.

Anything I'm missing?

Any and all responses welcome,
Thanks,
 

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While what you have written makes sense. I'm personally seeing a couple of things not being included. That is the "center of effort" of the rig, and keel among others. These need to line up, or you have too much weather/lee helm, or potentially too much SA for the Keel to counter.

I personally would talk to a person with some engineering experience to see if the above makes sense from this standpoint.

Marty
 

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Ummmmm, OK I don't know anything about that type of boat except it has been successfully built and sailed for generations around the world.



And you want to change it.





I shall go to the pub and ponder why over a beer. On second thoughts, I might chat up the bar-maid instead.
 
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Unless you are an expert on sail rig and boat design leave it alone. get a larger sail inventory including spinnaker and or a 150 or larger genny,

Engine = $$$

Mast = $$$

That kind of $$$ you are talking... for a 40 year old boat?

Blessing upon you if you have it!
 
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This I should doable but pretty ambitious and I wonder if the cost is really worth it. But offhand...

1) keeping everything else the same and increasing rig height also increases rig compression. So you may already have a problem here. Adding a compression post may be necessary no matter what you do.

2) all sail area isn't the same. Adding a larger but lower aspect headsail by increasing the bowsprit will help a little. But if you really want to increase off wind performance keep itwhere it is and add an asym spin an additional 4' out fromthe sprit. Adding a foot to your J just isn't going to matter that much.


Frankly I think you bought a slow boat and should relax and learn to enjoy the slow lane. But if you really want to spend the money then I would pull the stick and start over. Put a big carbon stick with swept back spreaders and a square headed main on, no backstay, and lots of sail area. The upside is you likely won't need a compression post, the downside is you will need to move the chain plates.
 

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I an with Stubble, putting 50k into a 20k boat that can't get out of it's own way is not worth doing. after all that work still not going to be any faster. If you did put in a carbo state of the art rig which will cost in the 60k range on a slow full keel hull then the only thing left to do would be change out the hull.
a better idea for light wind would be to forget about trying to go faster upwind in that boat, it ain't going to happen. for off the wind improve the bow sprit and get a Gennaker on a furler at least you will have some fun trying to go faster.
 

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Discussion Starter · #7 ·
Hi,

Thanks. I appreciate the feedback.

I do appreciate the option of replacing the mast with exactly what I already have, but that's not really something to ask about on a forum - I already know how to do that. And I do plan on having a professional do the actual design if I do change anything but am trying to get the concepts down before-if I progress to that stage.

I'm not interested in going fast, but I do want to reduce the number of times I am going essentially nowhere or have to turn on the engine. I didn't mention my intent was to be able to reliably sail the boat singlehandedly (though I do plan on having a crew of two) and that makes many/complicated sails less attractive.

One of the reasons that I'm looking at this option is that with the exception of the bowsprit (which will be fabricated of wood) and possibly the main sail, all of the part are standard on 30 year old boats so I'm likely to be able to find them second hand.

I'll likely put in a compression post regardless just like FeNIX has, but if the compression loads on the cabin top are much more than currently I don't like the idea.

Thanks,
 

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reliably sail the boat singlehandedly
A gaff rig requires TWO halyards and TWO booms, which DOUBLES the labor involved in raising the sail. It also doubles the hands necessary, though it is possible to hoist both halyards equally until the throat is up, but then you still have to tie off one while holding the other. Lots of fun with a large sea running, especially on a 28 foot boat.
There is very little advantage in going from a Marconi rig to a gaff rig. There are lots of reasons not to. First and foremost is a normal alloy spar won't take the loads of a gaff sail's gaff. You'd be best finding a wooden spar which requires tons more maintenance. It's also going to be a lot heavier. Then you'll have to consider fortifying your chain plates and mast step.
Anyway, there'd be lots more to consider, but I'm sure by now you get the idea. Why not just go find a Tahiti ketch if you want a gaffer?
We sail a 77 thousand pound boat through the lees of the Windward and Leeward islands frequently. Yesterday we sailed the lee of Grenada to withing 1/2 of a mile of the anchorage. One year we did over 2500 miles of interisland (NOT ocean) sailing and put less that 20 hours on the engine.
No chutes or code zeros. Didn't even get out the genoa or mizzen staysail. Sailed exclusively on Yankee, staysail, main and mizzen. Point is, light air sailing is not only a factor of sail area, but taking advantage of what wind is available. Too much sail area when sailing a lee, leaves one in a very precarious position when a gust comes howling down a valley, or a downdraft barrels off a mountain.
If your boat doesn't suit your needs then it behooves you to find one that does. No amount of money, effort or desire can make a thoroughbred out of a quarter horse. Personally, I'd rather have the quarter horse for cruising.
 

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To be fair, Capta, not everyone gets to sail in the fairly reliable 15-25 knot trades (and yes, I realize that the breeze is not quite that reliable in the lee of the islands, but like you we've managed to sail those stretches too..) You're right, of course, about the gusts and lulls there...

As to the OPs idea(s), it wouldn't make financial sense to seriously modify the boat, probably hurting resale value too. However, some out-of-the-box designs have been improved by the addition of bowprits, eg, but most of these mods are to improve issues with helm balance (thinking Catalina 30, Rawson 30 as a couple of examples).

Adding a slightly taller rig while being careful to keep the CE in the same place (if boat currently balances up nicely) seems kinda reasonable. If the mast is damaged/suspect and the standing rigging is to all be replaced, I guess now's the time. Not sure I'd consider the full 4 foot taller stick unless advised by a designer that that would work well. I suppose it also depends on the owners' intentions. If eventual ocean cruising is part of the plan, the smaller rig may not be such a disadvantage then.

When we had our Viking 28, a sweet but occasionally underpowered boat, I often fantasized about turning her into a frac, keeping the I and J dimensions but adding a taller stick... oh, and a more modern keel, - and what about that scimitar rudder..... ;).. in the end simply changed boats.
 

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We owned a CD 28 and sailed it up and down the East coast for 13 years. I read your post with great interest because the thing I disliked about the boat the most, was it's light air in-ability. The first thing I added was a symmetrical spinnaker (as Denise advised). I needed a pole, mast track, etc. but that made a big difference in the CD's sailing ability. We often used a 150 genoa deck sweeper but I don't think that improved the boats performance dramatically. In fact we ended up with a 135% genoa that was the most used sail.

I took the club boom off as that was rarely any benefit in our case. We had a working jib (100%) that we used on that boom and then without it(it worked better without we found).

The other thing we found with the boat was we had overloaded it with cruising weight. That really hurt it despite what you'll often hear. Once we weren't cruising and unloaded much of the added weight, the boats light air performance improved dramatically. In fact we phrf raced that boat a bit on a lake and it did quite well with it's handicap. The only near knockdown we ever had with the boat was in moderate air, coming out of the lee of an island, on a fast reach - with the full spinnaker flying!

It is a great boat and a much better sailer than you might think, if you keep it light, have good sails and spinnaker.We loved the boat.
 

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If I remember correctly, you bought this boat fairly late season in Collins Bay and you were thinking about keeping her at Collins Bay next season?

My marina is about 100 miles from you, but I usually spend a week or so sailing around Kingston every year. I find the winds in the area to be fairly strong. I actually find myself reefed in that area quite frequently and my SA/D is even worse than yours.

Maybe take a full season of sailing in the area before changing anything. The gusty thermals off all the granite in the area combined with the funneling effect of the land on the prevailing winds can make for some fairly spirited sailing.

Raising your centre of effort may not be what you want for local sailing conditions.
 

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I agree with most of the others.

That 41ft. mast in comparison to your 36 footer is only going to result in about 12% increase of SA, not including J/LP extension.

For me, unless youre planning on trade wind type sailing, Id keep that J as short as possible in order to 'preserve' any upwind/pointing ability. Increasing J without increasing E probably isn't going to much improve the upwind performance.

I would also suggest that for especially light winds, that as a first trial (actually recording or data plotting all the possible variables) that you'd probably would closely accomplish the same by putting on a 'racing bottom' (perfectly faired and smoothed bottom, including flush through-hull protuberances, feathering/folding prop, baby-assed smooth and slippery bottom paint (Balto-Plate, etc.)); then, new high quality sails designed and lofted .... and shape-optimized .... for the exact venue and to match your exact helmsmans ability.
That 41ft. mast in comparison to your 36 footer is only going to result in about 12% increase of SA. If you dont balance that extra 12% aloft with underwater improvements your just going to heel over more, especially when near/at 'hull speed'.

If you do elect to change the mast height, be sure to recalculate the stress applied to the chainplate systems/structure and do include any trigonometric angular changes that the 'wires' make with the mast. (If you're exactly following what the previous sentence entails, then recalculate all these loads with the boat theoretically heeled over at ≈45° and recheck, or back-calculate to insure/validate that the boat's original safety factor is 'close'. How's your 'trig' analysis for a static 'free body'?). Stumbles point abut that cross beam instead of a mast partner is a good one ... you'd need to do some physical 'load/deflection' studies to see if that athwartship cross beam can take that approx. 12-15% extra load and still be within its OEM 'factor of safety' parameter.

Very Interesting project .... good luck with it, as by your questions alone you seem to be very knowledgeable. Keep us advised.
What you propose is quite reasonable, albeit can be expensive.
 

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Discussion Starter · #13 ·
Capta: hi, my post was actually about going to a taller Bermuda to increase SA/D, sorry if that wasn't clear. Other than a short boom and headroom in the cockpit, the current boats triangles are pretty well full meaning I'd need to lengthen the plan with longer bowsprit/boomkin, go with a taller mast, or go with the gaff rig if I want to increase sail area. Or I could stay with the current plan and just accept that the boat is ~20% underpowered given what is now being recommended (for more efficient hulls it should be noted).

TomMaine: really nice to hear your experiences. I definitely intend to keep the boat as light as is reasonable - Idk if I'll have better success than those who've tried before me though. :/ I just can't see a symmetrical spinnaker making it's home on my boat. One of the asymmetric types might once I've had a chance to gain familiarity and try one solo.

Arcb: hello again! yes we're overwintering in Collin's Bay. Come spring I'm considering moving my home to Kingston but if not will likely be relocating closer to Otown along the seaway. Ivy Lea potentially as it is across from Alexandria Bay where family keep their boat. Any recommendations on desirable marinas? I've only been out for two days and had good breezes both times - I don't know the boat well enough to solo it yet and could only get out when friends were available. I definitely plan on keeping the current rig for at least a season

To all: my posts are always too long. I pared down my original post and now feel I didn't convey my intent well enough I'm looking into the potential to do this, I'm not set on it. But if I am going to do something with the rig it would make sense to plan for it given the maintenance I will be doing on it regardless over the coming years. I think the thought experiment itself would be worth it - even if in the end it recommends doing nothing different with the boat I will better appreciate why it is set up as it is. I'm really happy with this boat and just want to get the best out of it. I'm not looking to get my money back - only get a simple, reliable rig set up optimally for my eventual cruising/voyaging; that does not include exotic materials and a forecabin full of condition specific sails for this particular boat. That being said, I'd try to source parts second hand (which is really why I started to consider the option of appropriating the CD30's rig for my boat).

One thing that, given the responses, I think that I did not convey is that I'm not looking to gain extra speed - this is a slow boat and I'm content with that. I'm looking at this as an opportunity to increase light wind performance with a rig meant to be reefed sooner than the current rig, such that under average-to-heavy conditions similar sail areas and overturning moments would be present with both rigs. Gaining the flexibility of a cutter rig would be an added bonus for future cruising and singlehanding ability.

Can anybody point me to some more CD28 owners' pages who have used it for extended cruising/offshore? I'd be interested to hear what's worked for them along with TomMaine's comments. I've checked out the Cale Dory Owners Association page. The only circumnavigating CD28 that I'm aware of is FeNIX, and her rudder was completely redesigned/rebuilt into being skeg-hung as well as the rig being changed to a cutter (?double-headsail sloop).

Thanks!
 

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Definitely a lot less wind down around Ivy Lea. I've never actually been into the marina at Ivy Lea, I go to the anchorage at Mulcaster Island when I'm in that neighbourhood, it's one of my favourites in the area.

Real estate of course is at a premium in the 1000 islands/seaway with some marinas having multi year waiting lists.

The closest marina to Ottawa on the St Lawrence is Sandra S Lawn in Prescott. It's a nice facility. Deep water, pubs and restaurants, multi purpose trail, public golf course. It's nice. It's small though, maybe about a dozen sailboats.

Brockville Municipal Marina is beautiful and deep, but I think there's a multi year waiting list. I took my boat there this year for the Tallships festival and they had a slip for me, so who knows, they might be able to squeeze you in.

Gananoque Municipal Marina is nice, but it's a long drive, I kept my boat at the Yacht Club in Gan for a season and I found the drive too far, the yacht Club was expensive too, I think I paid $3300 for 6 months.

There might be more but the 3 big municipal marinas I have mentioned are my main stopping points. You are a bit more shallow than me, which is a plus, it might open up some more options.

One other good option is Cryslers Park Marina in Morisburg. They have something like 50 brand new still vacant docks or at least they did when we were down there in August. They also have a pool. The sailing in the artificial lake created by the Seaway there is really nice in my opinion, it doesn't have nearly the crowds or constant stream of tour boats you get in the islands.

I'm jealous of your club footed jib, that would be a a nice feature with all the short tacking in the islands.
 

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...That being said, I'd try to source parts second hand (which is really why I started to consider the option of appropriating the CD30's rig for my boat).....


....Gaining the flexibility of a cutter rig would be an added bonus for future cruising and singlehanding ability....

The only circumnavigating CD28 that I'm aware of is FeNIX, and her rudder was completely redesigned/rebuilt into being skeg-hung as well as the rig being changed to a cutter (?double-headsail sloop).

Thanks!

I have some questions:
How do you figure that a cutter rig is easier for singlehanding?

A true cutter rig has the mast positioned farther back than on a sloop. You alluded to a double headsail sloop, sometimes called a slutter. Have you considered how this will affect the
lee helm/weather helm balance?

Oh, also, how did the present mast end up with a patch in it?
 

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IMHO, all older designs could do with a taller stick. The problem is balancing the increased healing moment of added weight aloft and healing moment of a taller stick. Most tall stick options for boats add around 10% to the height of the mast. You are talking about adding 20% to the mast height. A drastic increase. Going with a light carbon stick might help but they aren't cheap. I'd definitely want to get a naval architect involved to figure out all the ramifications involved in such a drastic increase in mast height. Might try Robert Perry to get a professional opinion of what your thinking.

FWIW, a taller stick really adds little in additional sail area. Its real benefit is added sail area where windspeed is greater and does the most good. In light air conditions, windspeeds are near zero at the deck but may be 5mph or so 40' up. So a taller stick could really help in light air performance. Also airfoils that are longer in relation to width are more efficient. That's why sail planes have long narrow wings.

Lastly, get rid of the staysail boom. They are a total PITA that make for poor setting sails once eased and are always in the way on the foredeck. The self tacking ease is hardly an advantage on a small staysail that can be easily handed without need of a winch.

As others have said, going with a Code Zero or Asym on an extendable bowsprit will be a much easier, cheaper, and much less complicated way to improve light air performance,
 

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Discussion Starter · #17 ·
Thanks Arcb, I'll check those out.

Midwesterner:
I have no idea why the mast is patched. CD's are known to have poor backing plates and the headliner was cut to starboard to access the chain plates so I suspect that they failed and allowed the upper shroud to exert a bend at the spreader base. Though the weld was done correctly, there is a slight deflection point there that I can pull out when setting up.

And yes, you're correct, I am actually talking about a slutter rig. The mast is at 57:43 aft:forward of the mast LOA on both CD28s and CD30s, but given that both have short sprits their %LOD is less than 40 and so are technically sloops.

Slutter for singlehanding? As far as I see it:
Pros:
The staysail is self-tending so only a smaller jib to tack
The staysail can be trimmed to balance, so reduced loads on the windvane/rudder drag
As the plan is reefed the jib is struck bringing it's CE aft and lower to counter the main
In severe weather all foredeck work is inboard

Cons:
Can't point as high (the CD28s hull is outperformed by the modest aspect ratio rig though, so this might be free in this particular case)
the inner forestay makes bringing the jib across harder (less so for a yankee)
If any spinnaker is being used it must be gybed outboard (I think this would be the preferable method anyways)
More complex staying usually required

Of course a sloop with a removable inner forestay is another option and would carry Pros #3 and ~4 and only Cons #4. If you know of pros/cons that I'm missing please fill me in.

When I sat down to calculate the CE I found out that I was working on misinformation: the CD30's cutter rig is based on the same 36' mast that is currently on the CD28. Putting the slutter rig on the CD28 has the CLR and mast relatively spaced slightly more aft and results in an increase of the lead by about 5% of LWL. This might be compensated for by increasing rake and making the jib smaller, but that would defeat the intent of increasing light air performance. Maybe I should look for a mast that is only moderately increased in height (that is not standard on any Cape Dory but that is available locally second hand) and then have a naval architect build a slutter/sloop rig around it.
 

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the CD 30 MKII has a taller rig then the older CD30 by about 6'
 

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More thoughts. For long distance cruising, light winds are not all that common. If you are going the trade wind routes, you'll normally see winds force 4 or greater. The Caribbean is an example. We've only experienced prolonged light wind conditions twice in our cruises and both were in the Doldrums. We sailed through once and still made respectable time for the passage making up what we lost in light air in the heavy trades that followed. The second time, a day and a half under the iron jib got us through. In that case, no amount of light air performance would have helped as there was almost no wind and sloppy seas made it impossible to capture what little wind there was. Optimizing your boat for light air areas won't benefit you all that much in the real world of open ocean sailing.
 

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Discussion Starter · #20 ·
Nice catch on the MKII, that explains my confusion re: the tall mast section.

The MKII is a bigger version of my CD28 whereas the original CD30 is a bigger version of the CD27 (which has the same LOD as mine but is 2000lbs lighter). There's no way my boat could stand up to the MKII's rig, it being 1300lbs heavier (40% of which is ballast) and 21" beamier (compared to the original being only 500 lbs heavier and 3" wider).

Definitely some food for thought roverhi. That's the sort of information that I wouldn't have sorted out until after changing my rig/replacing it with the same mast and getting out there, so definitely very valuable recon. Thnx!
 
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