Arwen's meanderings

Hi everyone and welcome to my new blog. My name is Steve and i am the lucky owner of a John Welsford designed 'navigator' named Arwen. I built her over three years with the help of my father, father-in-law and two children. She was launched in August 2007 at Queen Anne's battery marina in the barbican area of Plymouth. This blog is a record of our voyages together around SW England.
Arwen has a YouTube channel of her own. Search "plymouthwelshboy".






Sunday, 10 May 2015

Mastering the dark arts.........of sailing!

I remain, as always, slightly baffled about some elements of sailing. A eureka moment last year was when Joel, over in the USA managed to get me sailing Arwen, without holding onto the tiller. It was a matter of balancing sails by all account.

Sailing baffles me. I sort of get the principles but only just and I do mean only just!
When I let go of Arwen's rudder, she will, all being well, turn up into the wind.....luffing up I think? But I could be wrong on that......nautical terms are another thing I am not hot on either!

I know the principles of effort and resistance come into play somewhere about now. There is, I think, the centre of effort, the lift that gets generated as wind passes over the sails. I can see this marked on the sail plans for Arwen. Then there must be something to do with the sideways pressure of water against centreboard, Skeg and hull. I'm guessing that this is in opposition to the pressure on the sails. The balance between the two forces along with the drive of wind in sails moves Arwen forward?

Alter the balance of the two and that affects what the boat does when the helm is released......I think! I assume that when sail resistance and hull resistance are in line the boat sails straight when rudder is released, although I guess trim comes into play I.e which side my considerable bulk is in poor Arwen.

Now somewhere in here comes weather and/or Lee helm. I know that if sail centre of effort is either forward or behind the centre of lateral resistance then one of e helms comes into play. I think weather helm to a slight degree is better so that the boat would always luff up head to wind.....or at least I vaguely remember someone telling me this......I could be wrong. Is it if the sail's centre of effort is behind lateral resistance then weather helm happens?

Certainly, on my longer coastal voyages in the past, I have had slight weather helm, a pull towards the wind on the rudder. Arwen seems slightly faster when this occurs or maybe it's just my imagination.

It took me some time last year to achieve this balance out in the sound but I did do it. Of course, waves would make it trickier I guess. Yet this is a technique I need to master this year. Holding onto a tiller for several hours one handed whilst trying to navigate, eat, put on and off clothing can be stressful!!!

So this half term I'm off out to develop some serious skills

Sailing onto and off a beach
Mastering the use of some form of anchor buddy or pulley system
Mastering this dark art of fine balancing a boat - raising or lowering centreboard, moving my weight about - anything to learn this dark art of shifting the centre of gravity. Raising the centreboard moves CE backwards I think and this reduces weather helm. Shifting weight inboard and aft  reduces it as does easing the sails. I'm guessing that lowering centreboard, tightening sails, heeling more to leeward, sitting more to windward and forward will increase it?

I'm getting old...I find it so difficult to retain all this. I guess just going out and trying things out will help. Main aim this season? Use the engine and rudder far less. Use the sails, centreboard and trim far more!

8 comments:

Alastair said...

Let me tell you a secret, sailing is easy. For thousands of years peopled sailed without ever hearing about "centre of effort"
How to sail:
1. Accept that you can't sail within 50 degrees of the wind.
2. Point the boat in the direction you want to go.
3. Pull in the sheet(s) until you are moving.
4. You are now sailing, enjoy it.
It is possible to go faster by tweaking lots of things, but that is racing and is a different skill set entirely.

steve said...

True true
And the stopping?
:)

Nutmeg Knitting said...

use the force Luke, let go of your feelings

Paul Mullings said...

The reverse of the above!

Simeon said...

Steve -

Here's John Vigor's blog from today that is on "weather helm"

http://johnvigor.blogspot.com/2015/05/some-cures-for-griping.html

Alden Smith said...

I think you are doing well - the key is to just keep on sailing, sailing, sailing, having lots of differenct experiences in differing weather conditions and within different sailing contexts which produce knowledge.

Alastair said...

Stopping? That's where 1 above comes in handy.

steve said...

Ahh! Shucks guys......thanks for the morale boost...clearly in the post OFSTED depression dip. Normal cheerfulness will resume when finally out in Arwen
Thanks guys
Steve