Originally Posted by four winds
I'm sorry, but I just can't get past the idea of shunting to sail a boat.
Am I wrong, or does every change of course that brings the wing angle across the centerline of the boat require coming to a stop?
Yes. Shunting is a little slower than tacking, considerably slower than gybing. It is safer and less stressful than either as the breeze and waves build. There is never a need to back the jib
, steer in reverse or pick a calm spot to tack. There is no wild surfing down waves while you try to pull in the main, followed by it crashing across and into the shrouds when you gybe and never any need to granny gybe. But the biggest advantages are 1) you do not need to sail over canvassed so that you have enough power to tack. You put up enough sail to be comfortable, knowing that the boat will always be under full control. 2) In a man overboard
situation, you can reverse the boat in seconds, sail straight back to the MOB
and stop, all under complete control. Obviously does not work like this if he fell overboard
while sailing downwind, but getting back upwind in the proa would be a lot quicker than in a cat, especially if the cat had a spinnaker
or screecher up.
You can short tack, but once you have sailed a properly set up proa, you don't see the point. This from an observer: " I watched Rob shunt his 7.5m/25' proa upwind up the narrow (30m/100' for some of it) boat filled channel in front of his house so fast and easy I thought he must've had an electric motor
hidden in the leeward hull. I would've had a very difficult time doing it in a beach cat without stalling, hitting somebody's boat and/or breaking out a canoe paddle. With the exception of a wind
surfer, I had never seen a sailboat with a reverse gear
before. He could head
right for something, then throw it in reverse, back away and bolt off in a new direction under perfect control."
Your post #29 is mostly irrelevant. The 40F client wanted a boat with all of his requirements, not a list of boats that fit some of them. He describes the 40F as the cleverest boat design available. This may or may not be correct, but fast, light, low cost boats and happy clients are why I design boats.
Re: "He did not want the cost, weight and hassle of extras, or any sails
that could jam in extremis and require him to leave the helm
to fix them."
This refers to headsails, extras and furling
systems. He did not want to be wrestling wet sails
on the foredeck in a squall in the middle of the night. Hence rigs that lie quietly when the sheet is released, and that can be raised, reefed or lowered singlehanded regardless of wind
strength or direction.
Re: Until comparable examples are provided, the burden of supporting the claim that this design is cheaper is on the one making the claim.
A Maine Cat
30 costs $US230,000 and weighs 2 tons. The 40F weighs less than a ton and should cost between half and 2/3rds as much. The 40F has better performance numbers, more usable space and fits in a mono slip.
The Maine cat
41 weighs 5.5 tons and costs over half a million. The 50' harryproa I mentioned in post 19 cost and weighs a little more than half this. In this video
it is travelling effortlessly at wind speed. There are no videos or reports of the cat saling at windspeed under main and headsail, or any indication from the specs that it would, so the harryproa would appear to be a better performer. This boat was the first of it's kind. Later ones have better rudders, sharper bows and are far easier to build.
These comparisons are between one off builds and production boats. If the cats were one offs as well, the difference would be much larger.
If you think the video is not "apples to apples evidence that harryproas outperform catamarans with similar design goals." please explain why not.
Re "just extending the bows".
You have it the wrong way round. The majority of cat owners and designers would be happy to add "1-2 thousand dollars" to the build price
to increase their boat's length and performance by up to 25% (ie a 40'ters accommodation on 50' hulls) and pay the increased marina fees that went with it. Most of them would jump at the chance to pay more than this for smaller performance gains. Why aren't these catamarans available?
1) the resultant narrower hulls do not have enough room.
2) the extension adds enough weight that an increase in sail area is required, which requires an increase in beam, so you end up with everything getting larger.
3) the boat will look different and most owners do not like to step outside what is currently seen as normal.
1 and 2 are not a problem with extending the narrow, low lee hull of a harryproa, which is why they work so well. 3 is slowly changing in regards to harryproas.