I have questions
| Flat panels, you poke a rectangular piece of ply through the hole, rotate it and let water pressure hold it in place.
How does one open the hole to a size that one can fit the patch through, while it is under water? Hand saw? Does this get complicated with kevlar?
Hand saw. There are blades that cut kevlar. As Doug and Mike say, it is a pretty rare event. Cutting the hole is not very smart. The Yachting World video way is better. Maybe with a flat piece on the inside and screw the 2 of them together. Could also make up pieces for the chine if you were that worried.
If you holed the ww hull, how many inches would one expect the hull to sink?
Not much in most cases. Depends on the thickness of foam, the weight in the hull and the distance between bulkheads/part bulkheads.
Has to be different per boat, and according to it's loading, but is this a calculation that is known?
It can be calculated, but the exact distance is not as important as whether it overflows the part bulkheads and whether the hole can be reached to fix it.
Can you step through how you would imagine a hull hole would be repaired at sea?
Shove a bundle of rags in it to stop the water sloshing around. Bail out what was in the bilges, drop the weighted string through if you didn't do so before plugging the hole, pull the patch into place. If you were well organised, the patch could have a rubber seal. Otherwise, a second piece of ply, with a seal on it placed on the inside and screw the patches together.
How likely is it that a hole breaches the hull, given the crush biws?
Not very.
| Drying out on a deep V is good on sand, but just as likely to end in damage on rocks as a flat bottom. Both need a couple of tyres or planks to sit on.
The damage, if any, would be the same for either hull shape, right?
Not really. The V is definitely stronger in terms of piercing, if it sits on the rock. Will still damage the keel though, and if it is wood, it needs repairing pretty quickly. If the rock is to one side of the V, then the holes are similar.
I imagine the lighter/longer boat would have the advantage, as less force per area?
Yes, but with only a couple of rocks supporting it, both are going to be damaged.
| The shallower the hull, the easier these are to put in place.
Why is a shallow hull easier? Shorter jack?
The planks/tyres are put in place before you dry out. On a harry, toss a loop of line over the bow, tie the line ends onto the tyre or plank and pull it under the hull.
| Peter said it all about bilges for stowage. Tanks that can't be easily drained and cleaned are useless if you are sailing off the beaten track.
Does removable tanks matter?
No, but easily cleaned does.
| On a harry (or any unstayed rig), dump the sheet, the rig weathercocks and the boat drifts. Trip the main halyard lock and the head falls to the next lock down. Unhook the luff downhaul, hook it on to the reef point and pull it down. Pull in the leech reef line. Sheet on and go.
Does one have to goto the mast to hook the luff downhaul to the reef point?
Yes, although it would be easy enough to rig it to the cockpit, either permanently (need several blocks) or temporarily.
| The sail area comparison was in response to Owly's performance comments. If he is happy with 30' cat performance, he could actually have a smaller rig on the 40' harry. Or, the hp rig could be bigger for the same safety margin and performance would go up accordingly. As would cost.
Of course, I see that now. Without regard to Owly's desires, I have considered safe speediness of a boat as a positive safety issue. Is it reasonable for me to suggest that a slow boat is less safe? Again, not much of a sailor here...
Sometimes. Slow gives more time to think and respond. Fast gives more capacity to arrive on time, escape or avoid bad weather. Ideal is a fast boat boat which can be sailed slowly. This is a major failing of tacking boats as they need to maintain speed to tack.. This often results in them being overcanvassed and difficult to handle. Harrys do it well as they do not need to maintain speed to tack.. Speed is one part of performance. The other is upwind ability. This is critical to get off a lee shore, either when the breeze blows up in an anchorage or when a storm is pushing you into trouble.
Sailing upwind in a gale is not pleasant, but is much easier if the boat can be sailed slowly, under control from a sheltered position. Getting caught head to wind in big seas due to inattention or trying to point too high to spill wind is a drama on a conventional boat/rig. The jib backs, the boat is pushed backwards and a lot of work is required to get it back under control. On a harry, you either shunt or reverse the rudders and drift back onto course.
| You are correct about rudder developments. Already seeing things that can be made simpler, particularly with the one way blades.
When you have a moment, would you explain where you are with the bidirectional blades and the one way blades?
I go one way, then the other. ;-) Undecided on which is best, there are trade offs for both. Until last week I was in favour of 2 way, then Steinar and I started brainstorming about the best way to attach them to the hull. Came up with a novel solution, I built a model, he drew the plans for it. I was ready to cut the holes in El to fit it when we had a lightbulb moment. Now one way rudders are looking good, including tillers if required.
We have used wheels in the past as 1) the loads were unknown but could be expected to be high in some situations. I am pretty sure we can now adjust the loads out of the system, although I am unsure if a single adjustment will cover all wind strengths and directions, so we will make it easy to adjust. 2) tillers are less complex, but the extensions are long, fragile and prone to poking crew in the eye. The latest ones are none of these. 3) It is possible to connect a wheel to both rudders, although more complex. The ideal steering is either or both rudders usable together, independently or with one locked, steerable from anywhere is the cockpit. Almost as big an ask as rudders which are liftable, work in both directions and kick up in a collision.
The limits on rudder aspect ratio are structural and how much draft you are happy with. There is also an issue with getting going after a shunt on a non schooner rig, when wide rudders work best and don't stall as easily. We have also been looking at rudder build methods and have simplified them a lot, making them easier to build, with easier moulds and no finishing or reinforced joins.
I am writing a piece for the web page on rudders and steering. I will post it here later this week, along with some other developments.
I imagine the one way blades give more performance per wetted area, and the Steinar's speed demon might be the impetus for its renewed development..
Sums it up pretty well.
I love how you don't get biased against ideas. Develop them all simultaneously!
yeah. A garage and garden full of "seemed like a god idea at the time"
| I am no keener on sitting in the sun or rain than you guys. But I do enjoy sailing (ie seeing the sails), sun rise, sun set and the sky at night. Any shade should be removable quickly and easily.
We had spoken on dodgers previously. I still have not seen a design that would lend itself to the modern HP cockpit.
Working on it.
| The cabin on the EX 40 is 1.5m/5' wide x 4.8m/16' long, and has direct access into the hull, which is another 750/30" wide.
That seems a big cabin.
It is, but not very high.
But I thought Owly was doing a bridge deck cat?
Maybe. I thought he was looking at a cuddy between the hulls.
Beaching in surf is an interesting subject. If the boat is shallow drafted enough, and has low frontal area, it can be anchored just beyond the surf and allowed to drift in with the anchor keeping the bow/stern pointing out. Wet on board, but relatively controlled. Alternatively, it can be sailed in just behind a wave if there is enough breeze and the rudders kick up when they hit the bottom. Once the boat is on the beach, it is far enough above the destructive part of the breaking wave to be safe, as long as it is a sandy beach. There is potentially a high tide problem but a bit of digging and/or winching against the anchor will solve it. One of my early harrys was washed up on an ocean beach in Western Australia with pretty good surf. Stayed there for 12 hours without damage.
The knife analogy is spot on.
Thanks for the analysis Bjorn and Rick. It;s cool seeing how theory and reality merge.
The Blind Date rudders were not designed by harryproa and are overdesigned and on top of that, overbuilt. They were built to overcome perceived steering and kick up problems, not strength. As far as I know, they did not break the originals, although these were the same as the Blind Date rudders which worked well, but did show some stress cracking, which was fixed. The new rudder arrangement addresses and resolves all these issues, as far as I can tell.