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Wind indicators

Postby Lea Foster on Mon Nov 29, 2004 2:26 pm

G'day,
Looking at the Photo Gallery it seems that no one uses a masthead fly. I see Forestay, Shroud and Foredeck indicators but no masthead. Is there a reason for this aside from not having to crane your neck trying to see up the mast all the time?
Lea Foster
Northern Rivers NSW
Lea Foster
 
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Mast head Wind Indicators

Postby shane Navin on Mon Nov 29, 2004 9:09 pm

Lea,
You got it in one.
Looking up at the indicator is an absolute pain in the A**.
It is also dangerous.
Try doing that in the 100 boat fleet at the last Nationals. Especially at the Start.
A lower mounting allows you the check the wind and keep an eye out for the other 99 boats.

Shane N,
1493.
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Postby Lea Foster on Mon Nov 29, 2004 9:39 pm

Thanks Shane. The Sabre is an absolute beauty. What a joy to sail. It lets you exercise all the technique without wiping you out just trying to hold the boat up.
Lea Foster
 
Posts: 26
Joined: Wed Aug 18, 2004 4:39 pm
Location: Northern Rivers,NSW

Mast Head Wind Indicators

Postby Phillip Johnson on Mon Nov 29, 2004 9:45 pm

There are some people who still think that a mast wind indicator is useful. It is very difficult to guage downwind wind angles from shroud ribbons and impossible to know when the wind direction is significantly different at the mast to the direction at waterlevel. This becomes very important in light conditions both at sea or on lakes and rivers.

Phillip Johnson
1644
Phillip Johnson
 

Postby Lea Foster on Tue Nov 30, 2004 8:36 am

Thanks for that Phil. Things quiten down I guess, when running downwind and so there would be more time to monitor the masthead indicator. But I can also see Shanes point when going upwind and in a busy start.
Lea
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Joined: Wed Aug 18, 2004 4:39 pm
Location: Northern Rivers,NSW

I consider a mast top wind indicator to be crucial

Postby Barry Eastgate on Tue Nov 30, 2004 11:18 am

If you sail on a lake or in light conditions anywhere it is the most important indicator. I also use it for gybing angles downwind.
Wind direction in light conditions frequently is at a different angle than lower down where most shroud indicators are located...ramifications for mainsheet and twist settings.
Barry Eastgate
 

Postby fitzwarryne on Wed Dec 01, 2004 9:12 am

l fully support the view of Phillip and Barry. Even with the short mast on a Sabre, with winds under 3 knots you can get toyally different wind direction. The situation is very common on inland waters where there is a significant amount of very localised wind due the the water/land temperature differences. Often the old wind sticks to the surface with the new wind sliding over the top such that you can have a 180 degree difference in direction.

While it is difficult to set your sail for such a difference, ithe knowledge gives you time to get ready for when the new wind creeps down to blow over most of the sail. It is a very miniture version of what happens to winds at the edge of a front, or when the sea breeze kakes over from the previous land breeze. The change happens at an angle not straight vertically due to surface drag.

If you sail in these conditions a mast wind indicator is essential ,but it must be ulrasensitive with minimum friction not a typical cheap flag which needs 5 knots to get a reaction.
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Postby Lea Foster on Wed Dec 01, 2004 6:21 pm

This all fantastic information, thankyou!!!!!!!!!!!!!
But I'm chock full of questions. Now with regard to the traveller arrangement - the looser the line, the closer the traveller block comes to midline as the sail is sheeted in is that right? So there is not only lateral adjustment but also angle of pull?
Lea 1679
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Location: Northern Rivers,NSW

Postby fitzwarryne on Wed Dec 01, 2004 6:59 pm

In theory, the more the the traveller is let off, the more centered becomes the mainsheet boom block so you can point higher. Thus you would have the traveller tighter in stronger winds resulting in a flatter wider set sail. More power less drag.

With end boom sheeting , like on the Laser, the theory works well in practice.

With centreboom sheeting, especially with a high-set boom, in practice there is no effective difference. The exceptions are when you can have a windward sheeting system like in sports yachts where the traveller car is pulled up to windward on each tack, or in some dinghies like the 505 which developed a 'loveday' loop which resulted in the blocks being a minimum distance apart on a rigid loop.


In the case of the Sabre, the practical advantages are minimal. Most top skippers having the traveller out as long as possible in all weathers, with the limit such that when the mainsheet is pulled at maximum tension there is stilll a slight gap between the top and bottom blocks. If is too loose the blocks would jam together before you could fully power up the main. But if you enjoy fiddling go ahead as long as you still have time to think of other minor matters such as windshifts!
Last edited by fitzwarryne on Thu Dec 02, 2004 6:38 am, edited 5 times in total.
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Postby Lea Foster on Wed Dec 01, 2004 7:48 pm

Well, I don't know quite a lot I think and I definitely don't want to fiddle. What is good for most top skippers is going to be just great for me so that |I do have time to concentrate on more important matters as you say. Nevertheless that has cleared up one of the matters that had me a bit bamboozled. I used to own an old LazyE. I had a bit of a chat to Rick deJong who builds new GRP ones and they use the loveday loop system so I can see the benefit, as you say, of leaving the traveller setting well out. Thanks for the input!
Lea Foster
 
Posts: 26
Joined: Wed Aug 18, 2004 4:39 pm
Location: Northern Rivers,NSW


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