Boat design calculators?

There is nothing more frustrating than second guessing your choices in the middle of an extensive rebuild. Recently I found myself more at the "office" than at the boat, this lead to playing with "boat design calculators". Low and behold all my calculations kept telling me that I shouldn't be thinking of doing offshore work with my boat (A '72 tartan 30)! Ah! That was the plan from the get go! I saw the T30 as a solid built boat with a beefy rig, well balanced hull and enough room down below to be comfortable. I've only been sailing around the buoys (on another boat, haven't as much as put the t30 in the water) for a year so I'm not an ubersailor, just a guy that likes to work with his hands. Was I wrong(capsize ration of 1.9...) or am I just being paranoid.

 

I think perhaps you are being a little paranoid.
Probably someone on here has experience with these boats and will give you some really good advice.
Not having any experience with them, I will just mention that the Tartan 30 is profiled in Practical Sailor's Practical Boat Buying, Volume 1. Their assesment closely matches your own. They do mention that the companionway sill should be higher and that the sink can backfill if heeled dramatically.
My guess is that a lot of folks who have done offshore sailing would have liked to have had a boat as good as the Tartan 30.

 

A nice classic coastal cruiser-racer (and not only). Very successful. 602 of them were built.
There is a recent review at the November/December 2005 issue of Good Old Boat magazine.

Some useful info on it here:
http://cruisingresources.com/Tartan_30
http://tartan30.org/about_the_t30.htm

D/L 276 (medium weighted)
B/D 42 % (nice)
SA/D 16.9 (good power)
Comfort 23.2 ( not so bad for the size)
Capsize 1.94 (OK under 2)

Don't become paranoic about its CSF of 1.94
There are multitude of boats sailing around with higher than 2 CSFs with no problems at all. It all depends on what do you want your boat for.

Enjoy it!

Cheers.

 

Some very interesting info from fellowmember Crag Cay at these forums:

".....Your Tartan 30 is very similar to our old S&S on which I have covered tens of thousand of offshore miles. They were both children of the seventies whose fine upstanding mothers were inseminated, (probably against their will) by the sperm of the IOR devil. The rig rated well but was never designed for ease of handling or outright speed. However it's not all bad news as in the 30ft size things are still manageable and the slippery hull moves well.

But they are headsail driven. Any dreams you may have of only using non over lapping headsails in winds much less than 20kts will be frustrating at best. The most versatile headsail will be a 135 percent, fairly high clewed genoa, similar to the No2's of old. On the wind, you will be able to carry this into the 20's but will lose power much below 10 kts. We carried a 155 light No1, but frequently augmented the 135 with a bit of engine, rather than do a headsail change, unless we were certain conditions would be light for some time.

Our next smaller headsail was a full hoist 100 percent solent jib, that would take us up wind in the trades, or to snug us down a bit at night with winds in the high teens. It had a set of reef points that would quickly allow us to shorten it by about 30 percent of area in squalls. After that it was a proper storm jib. Most sailing was with the 135, and today set on a roller, I still think it would be your most useful sail. But if heading for the trades, I may well still take a full hoist 100 that also fitted the roller. However, I think I would carry more diesel than the 155.

The other bad news about the 70's IOR boats is they need spinakers to move off the wind. The mainsail again is not really big enough to give much power, and the genoas twist off and do diddly. The original racing chutes were huge, driven by the boats long J measurement. However they were what we had and with a well rehearsed system were usable singlehanded by me and the girlfriend without any trouble. However if I was putting together the ideal system I would carry a .5oz conventional spinaker and a 1.5oz cruising chute for running in heavier airs with the tack on the stem and the clew poled out, or reaching set without the pole. The 135 with its higher cut clew also poles out well, and when the self steering struggled as the boat got skittish in about 25kts of wind, a reef in the main balanced her up, which defies all logic as the 135 was already significantly bigger than the main."

Full post at: http://www.boatdesign.net/forums/showpost.php?p=110083&postcount=16

 

I know the designs he's talking about and there is one big difference; the Tartan 30 has almost a whole foot more beam and about 2 inches more water line. It's this very fact that's made me a bit edgy. Any designers want to comment?