Trig Help

[MicHughV]

Trente Pieds, step into my workshop....I use my thumb and fingers to measure stuff......... "it looks about right"....or "near enuff"....or " cut it a bit larger and trim to fit"......or " try hitting it with a hammer to make it go in"...or "it looks right, more or less".....or "bend it, see if it will break"....oh yeah....I can do stuff....

[TrentePieds]

Quote: "Trente Pieds, step into my workshop..."

Why, Thankee kind Sir :-)!

A half century ago I started a sailing club at my uni. Bought a "frozen snot" Enterprise dinghy, and got the members going on building a wooden one in my basement. In those days the Class Association still permitted "homebuilt" boats .

One of the chaps was a "mature student", a welder by trade. Nice guy, even so :-) He'd been fitting a Bruynzeel bottom panel in my absence, and I found it necessary to point out that the fit wasn't quite up to snuff. "Nah", he said, "it'll be okay. I can just fill that gap with weld"

TP

[MicHughV]

I can relate.....

I built my first boat...a steel 38' Roberts.
At the time, I had never welded in my life before, but I took lessons at a local high school.
My first welds were pathetic and I struggled until a welder came by to show me the ropes and then it was of to the races.
Fortunately, the thing about welding is that even a bad weld is incredibly strong.

Then I had to do the interior. At the time, I barely knew which end of the hammer to hold, but I learned.....most often the hard way.

Sorry about the thread drift.....just old memories coming back. Welding bruynzeel was something I never learned how to do..must be a specialized art.

[CruiseN]

I like Roberts. One of the boats I want to look at is a Roberts Offshore. You'd know about halyard weighting to heel more than I.

Regarding heel plane. Robert and I earnt a beauty of a look at plane technology.

We had heavy weather.
We were racing.
We tacked late to allow give way.
But having a deep keelson, we needed to reverse sheet eg just be slow to uncleat until bow has been Forced to yaw about. The sheet was released and we sat there for minute, beautifully riding the point in steep waves, unsure of next tacks side. Bang. Starboard hit by fellow race boat. Directly punching Robert with bow at momentum.

Fellow racing boat then rode her keelson along our gunnel making contact with our starboard shroud.
With emergency medical requirements we slowly beated to above harbours Webb, turned, got some plane balance and launched the kite to reduce medical time delay. All on starboard tack, starboard reach. We'd lost our starboard shroud.

That plane built to balance, beyond is call of wind. Eg ain't linear forces.

Old mate learnt quick. Probably sails better than I nowadays

[CruiseN]

Drifting thread too.
I loved the helm on heavy wind forecast and follow up race day.
New mainsheet hand with continual instructions," drop the traveller, she's friggen heavy and we want main power down." On that boat was our kept high gooseneck.
No time to verify crews jobs, simply holding on being told tales and demanding instructions on mainsheet hand such as heave and ease. Traveller beamed aft of all.
We were so lost when coming about, more like Watt happened we've plenty of wind and should have dragged keelson easy.
During minute was calm thought though because nothing to do until sail ready again. Noticing traveller, dropped that aye, there it was, a high powered main without thrust strength nearer keelson plus getting pounded hence forehands choice of a quicker release.

But realistically thinking.. whilst sitting beating true. Gotta save up and get me one of these for anchorage purposes. Wouldn't even need to bridle such a beautiful stall I on. Just sit peacefully until heaving yard and enjoying plane speed. A long keel race boat.

With wind apply because balance of bouyansy much slower a response.

I like your chine sir.. looks like a perfect surfing rocker.
Plane Trigonometry

[CruiseN]

Hence tackfully returning to topic..

Back before then I thought the older men were crazy saying that our multiple height gooseneck should be down in light winds and higher up in the heavy stuff such that we didn't need bother to reef.

They made sense sailing by taking time to learn leeward flow of sail. Because our mains have a fixed luff: Majority of rotation comes from force on that and forestay to a lesser extent because leading edge leads down.

It doesn't make sense to me. Simply learning leeward flow of sail too.

With regards to Trigonometry bridge clearance, luff is stick. Can take some sidewards but in my eyes beyond plane is a risk worth avoiding. I'm hoping you can low tide straight up aye.

Best luck is well prepared.
Best luck Neil.
Nathan

[StuM]

Hmmm, I'm getting the feeling that we have an auto-text generating bot with a sailing corpus subscribed to CF

[CruiseN]

Originally Posted by StuM

Hmmm, I'm getting the feeling that we have an auto-text generating bot with a sailing corpus subscribed to CF

Did you pick my wrong about forestay bro?
Up side down but fasten able.

Glad to learn 2 too.

[CruiseN]

Originally Posted by StuM

Hmmm, I'm getting the feeling that we have an auto-text generating bot with a sailing corpus subscribed to CF

Cheers too.
Trigonometry.
When in primary school I asked resident boat wright if he could arrange me a forestay as pictured. Picture from internet, unknown vessel to my eyes. Thanks though.

He laughed. Yeah I'd reduce rotational force from luff but how he supposed to secure that? How we supposed to get sheet tension? Improvement of beat but would drag early downwind.
Hence idea sucked..

Be easier to yard if a square was there.
Which is probably why square riggers were used in the early days of need over want.


All good too bro.
I like long keels also.. getting control during fast pace energy systems. Watt another story regarding Trigonometry.

Hope you're winning too. Turtles versus hares.

[CyKlop]

The short answer is 26 degrees. HOWEVER that actually won’t be enough as it leaves 0 safety factor for any rise of the Center of rotation for heeling, any waves (or wakes) you’ll encounter. If we use a 5% safety margin then we arrive at a heel angle of 36 degrees.

[Hermia II]

Please let me suggest un-stepping the mast and re-stepping it again. The yacht under a 60ft mast could be a 25 ton yacht. The force needed to cant the boat 30° would be considerable. Fiddling with forces like that while passing under a bridge at the same time trying to steer the boat exactly and saving the little x-mas tree on top of the mast seems very unsafe. What if you meet a barge coming the other way? What about current. What about swells from the express ferry.
Take the safe route and un-step your mast.

[tomtriad]

I agree with Montanan and Hermia II. remove the antenna to gain 3' of clearance and look for a low spring tide, if that measures up great. Otherwise unstep the mast. Everything else is too risky; if you try anyway make sure your insurance policy is paid up.

So much can go wrong. I had a 7' draft cutter that needed to be heeled over to clear the 6' bar going into a boatyard in St. Thomas. It took a very powerful launch (Blue Moppie) to heel the boat over and drag it through the mud. Not fun.

[merrydolphin]

Very quick easy and simple solution for this problem is just draw it out on a piece of graph paper. Set a convenient scale and you will quickly have your answer. Save it and use it again as needed. If you want, make a paper scale boat and mast. Use it over and over for different heights. One problem that I ran into was you also need to watch your horizontal clearances as you heel over. The graph solution is easily drawn in here too.
That’s how I have done it in the past.

[betwys1]

Originally Posted by Time2Go

Hi Friends,
Need a little help with Trigonometry
It's been a long time since High School
I'm trying to figure out how much heel angle I would
need to induce to get a 60 foot stick under a 54 foot bridge ?
And what width of channel would be required.
I know one has to use the Pythagorean Theory,
but to tell you the truth just looking at it on Google
made my head spin.
So Id appreciate any help from anybody good with sums
Cheers
Neil

Forget trig: use on board barrels or overboard bags.
https://www.facebook.com/watch/?v=774475666307223

https://www.youtube.com/watch?v=ZJR_9x7LXAw

[john manning]

Other factors to consider.

If your bridge clearance is a mapped value then it will be the height of the bridge above the map datum for sea level. This is usually set below lowest tide level.

Bridge clearance will vary with tide.

Combining those two your may find the actual bridge clearance is over 60ft at low tide. Remember to allow for wave height.

Trying to achieve a controlled heel angle while moving a yacht does not sound like a safe choice to me.

I would start with a dinghy passage and a laser distance measuring tool. Repeated about 10 - 15 times at low tide, this should give you a good estimate of true clearance.