Thread: Is that a 12' GIS I see hull down on your horizon

This is the very latest Farr designed Volvo One Design. Does that bow look familiar



Volvo Ocean Race 2014-5 65ft Farr one design announced | The Daily Sail

Well, these types of bows are currently all over the place. First time I saw them was on fast sailing multi hulls, some years back already.

But they are now used on super yachts, offshore support vessels, etc. from leisure vessels to working vessels. Often I suppose just for the looks rather than for hydrodynamic/structural/weight purposes. First time I saw one on a mono hull dinghy was on MIK's design (not saying it was not first done by others though). But anyway, I think that as a designer it is impossible not to be influenced by others and working from what is “out there” already combining different bits and pieces. When all individual bits are put together it is the final concept/design that is hopefully new and refreshing (as I feel about most of MIK’s designs).

I remember being like 18 years old (which is now 22 years ago) bending a piece of A4 to a boat shaped hull with the front bit pinched tight, thinking it would be cool if you could do the same in plywood. This exercise will give you exactly that reverse bow.

Joost

Howdy,

I'm kindof glad Rick has been busy with real life ... as you can see from the new Philippines thread I've found a place to live and this typing really is the first connection I've had with my computer through my phone. I had to swap phone companies from last time to work in the part of Malvar that I am in.

I won't be playing any videos with this connection though. But that might resolve later.

So I'm almost on normal track again now I have a real keyboard under my fingers. And survived the first night in the house without benefit of aircon. and thus found a fan can do just as well.

Lots to do here though.

The reversed bows ... they did appear first on the A-class cats I think. It makes sense there because they are very light structures and anything you can pull out is a plus.

With the 12 footer and almost any normal monohull a reversed bow does blunten up the entry of the boat in the upper bow making it less fine. So might be a bit prone to drag in waves. Frank Bethwaite once told me that the TASER with the finer upper bow from the normal raked stem as compared with the plumb stem of the NS14/Nova was a bit better in waves and NS14s have narrowed that area up in the last 30 years since the Taser was new.

I suspect that we'll all see boats in the future with reverse bows and say ... ah boat from 2010. As I think it is a trend that will fade out. But doing it in a wood boat was a little bit of fun.

For the 12 footer ... I pulled half the reverse rake out of the stem compared to the original drawing I have here.

MIK

I wish the default font for my (most?) computers didn't force me to zoom in every time someone types stem or stern. There is so little difference, at least for my very old and weak eyes. Sometimes I have to analyze the context to figure it out! )

There is a lady on the WBF who uses the name of Meli. It took me two or three years to figure out her name wasn't Mell!

You do realise you can set the default font size to whatever you like? Any browser will allow you to do this.

ETA: Aha. The stylesheets here set the font sizes in px rather than em, which is a bit of a nuisance (bad vB, naughty vB) but you can still set a minimum font size in your browser if you like, unless you're using IE (which is not the world's greatest browser, despite their hype).

Some browsers also allow you to increase the page "magnification" using the menu bar and/or a key short-cut (Ctrl_+, Ctrl_-, there are also mac equivalents). Have a browse around your menu bar. I don't know what Internet Explorer does as I won't have a bar of it (and in any case MS don't do a version for the Mac), but most of the others - Firefox, Opera, Chrome, Safari, etc. - allow this.

Ha, just saw Sumbloak's post after I'd submitted mine ;).

Yes, but you can do other tricks too. If the stylesheet set the font sizes in em, like they &$*#! well should for best accessibility (bad vB, naughty vB ) then it'd simply be a matter of setting your default font size to (for example) 20 instead of the standard 16. That would make all text 25% larger.

Since they've gone at set the sizes in px (easier for the coder, worse for some users) then you'd have to use the alternative dodge of increasing the minimum font size to whatever you can read. That should work.

So in Firefox you'd use Tools > Options > Content > Advanced > Minimum font size > pick a number that suits you. If you set it to 16, then you wont ever see any text less than 16px. The styesheet will be overridden for smaller sizes.

I'm using a brand new iMac with the optional Magic Trackpad. You can zoom in and out with two fingers, just like on the iPhone. This is a pretty good solution since 99 percent of the stuff on the screen is perfectly legible. It's the proximity of "r" and "n" in "stern" that looks just like the "m" in "stem" that throws me off.

I love the new iMac, btw. It's silent (no disc drive) and very fast and versatile.

Spent a few hours on the boat today, and managed to install the daggerboard case and seat, the chainplate mounts, the traveller mounting struts, built the rudder cassette, filleted the chines on the inside, and 'glassed them on the outside after sanding for half an eternity. Plus I glued up the mast blank and installed the cleats for the decking. I still have to coat the airtank inner sides, install the decks, coat the rest of the hull, build the boom and install the rigging. Probably another day's work like today...Having a few issues with the pictures (grandson playing with my iPhone and changed the setting where the pictures go, took a bunch, but can't find them) I'll hopefully have them up tomorrow.

Rick Landreville
Rosedale B.C. Canada.

Astounding Day Rick,

Sail is finally ordered ... waiting for an ETA.

I'm working on the rigging list. I think I can get most things from Duckworks but a few bits ... like the Dynex Dux for the stays will have to come from somewhere else.

MIK

Wow!!! Each individidual job mentioned would already take me a couple of hours to do!

Looking forward to seeing the pictures, and I hope that you are able to recover them.

Dynex Dux? Had to check that out per google as I had never heard of it before:

Dynex Dux….the greatest product ever? | Rig Pro Newport's Blog

It seems that at least this report does not like them for stays, but they are most likely talking about applications for far larger boats.

Joost

Howdy Joost,

I've done a lot of digging around and Dux has become popular for cruising boats - particularly multihulls.

The problems that they have for monohull racing boats is that they spend a lot of time setting up the rig to perfection only to have things stretch slightly and ruin the rig tune.

This is of course a bigger problem with complex rigs where one component going out will mean the whole rig has to be recalibrated.



but with Multhulls and Cruising boats where Dux has become popular the rigs are simpler.

In our case...

1/ the stays will go from the hull to the mast - no spreaders or anything. Creep is something that happens very slowly - not just in one sailing session - you take the load off the stay and the creep stops - not possible with a rigged boat on a mooring.

2/ Additionally ... each time the boat is rigged the forestay is retensioned - so the rigging length is reset again for every time the boat goes sailing. There might be some creep in the original sailing session or two - maybe considerable. But after that I can't imagine much creep in a two hour or even six hour session.

3/ Finally if there is some sailing creep ... not such a problem. With a three stay rig with no spreaders the rig just becomes looser. The only problem I can think of there is if it loosens so much the mast jumps off its pin or the sidestays allow the mast to lean so far forward it doesn't support the mast anymore and the mast falls over the bow. However ... with the NS14s there was for some time an argument between loose and tight rigs. Tight rigs won (because of the jibstay - tight is best) but the simple three stay rigs can carry loose rigging OK.

There is another point of view too. They recommend sizing for the creep. That if you size for the strength match with wire you get too much creep. But if you use a bigger size dictated by creep then a much reduced rate of creep results.

This was a great debate about the Dux Rigging from the supplier and Randy Hough - a friend - who is pretty tough in his questioning. But the supplier is able to provide real arguments that convince him. REally great questions and responses. This link is the last page which shows interest and agreement - but read the whole thread for some of the combat.
Synthetic rigging properties? - Page 3 - Boat Design Forums

The article you quoted goes on to suggest Vectran - which is highly vulnerable to UV so you need extra layers and weight to protect the Vectran. Dynex and other Spectra/Dyneema ropes are highly UV resistant. So extra cost and complication for vectran.

But obviously there is a debate.

Question for me is whether it will work on a Dinghy sized boat. The cool thing is that the builder can make their own rigging without going to a rigging shop - that is a huge advantage.

MIK

My pick is that no creep will be noticed at all. The loads here will be quite low. The mast will be stiff so the leeward stay won't be flopping around too much upwind, so don't foresee problems with the mast jumping off its pin. A few Mothies are using it and they have higher loads than our boat. Tension to a D, and you will be safe.

On the other hand, stainless steel wire is cheap, but you need special crimping tools and its nowhere near as cool.



Sent from my iPhone using Tapatalk

Thanks for your elaborate response MIK, it is appreciated.

Your answer confirms my initial thoughts that for extremely high stress applications, where even minor creep is not appreciated (monohull racing yachts with spreaders and such) there may be better options. But the application we are talking about in the way of your 12 footer is indeed very different and I also believe it should work fine.

Going to a rigging shop is expensive, so from a cost perspective Dynex Dux clearly has the advantage (base costs of Dynex Dux may be higher compared to steel wire for the materials, but it is the labour that makes the latter expensive).

Joost