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  #11   Report Post  
Bart Senior
 
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Default Racing Question #23

Case 1:

The apparent wind would shift aft and increase slightly.

I'd ease the fine trim on the jib and the main, and trim
back in as I headed up.

Case 2
I assume you mean the true wind direction does not
change. That would not be immediately "apparent".

My immediate reaction would be to wait a bit and coast
while I studied the water upwind for clues.

In this case, I'd have the option of coasting in the same
direction hoping for the wind to fill in again--powering
through the lull with the momentum of the boat. Or, if
I felt the original puff was not representative of the
typical conditions of the day, I'd bear away slightly to keep
the boat in the groove, which you might be forced to do,
if the wind did not pick up immediately. I'd try to get a
little bit of coast on my present track before bearing away
to power up. At that point I would want fuller sails for
more power and make adjustments accordingly--easing
the backstay for example.

Nav wrote

Lets say you are racing hard on the wind with no boats near you and the
wind strength changes from 10 to 15 knots with the same direction.

Q1) As helm what should you first do first:

1) Nothing and wait
2) Immmediately change course to keep apparent wind direction the same
3) Counter increased weather helm but keep course the same
4) Reduce helm and let boat round up more quickly
5) None of the above -explain.


Q2. The wind drops to 10 knots again with no change in direction.

Your immediate reaction is to...



  #12   Report Post  
Nav
 
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Default Racing Question #23



DSK wrote:

Nav wrote:

Hey Doug here's a good helming question for you:


Lets say you are racing hard on the wind with no boats near you and
the wind strength changes from 10 to 15 knots with the same direction.

Q1) As helm what should you first do first:

1) Nothing and wait
2) Immmediately change course to keep apparent wind direction the same
3) Counter increased weather helm but keep course the same
4) Reduce helm and let boat round up more quickly
5) None of the above -explain.



It depends largely on the boat & crew. The difference between 10 knots
true wind and 15 knots true wind is rather substantial, at ten you're
still powering up and at fifteen you're depowering. In some boats you'd
be reefing.

In general, the response to a short term increase in wind is to feather
up slightly, traveller down slightly... also tighten the backstay, and
bring the jib sheet leads aft a bit. Then yell "Hike, dammit!" at the crew.


Q2. The wind drops to 10 knots again with no change in direction.

Your immediate reaction is to...



Undo everything above.


So, the helm does nothing? Oz will be disappointed in you!

Cheers

  #13   Report Post  
Nav
 
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Default Racing Question #23



Bart Senior wrote:

Case 1:

The apparent wind would shift aft and increase slightly.

I'd ease the fine trim on the jib and the main, and trim
back in as I headed up.


Very close. The trim should be carried out automatically by the
trimmer(s). When/how do you head up?


Case 2
I assume you mean the true wind direction does not
change. That would not be immediately "apparent".


Huh? The apparent wind changes immediately.

My immediate reaction would be to wait a bit and coast
while I studied the water upwind for clues.


In this case, your pragmatism is close to what I think is the best response.


In this case, I'd have the option of coasting in the same
direction hoping for the wind to fill in again--powering
through the lull with the momentum of the boat.


Yes. You keep the head slightly too high (due to the wind moving
forward) until boat speed drops to that expected for the wind conditions
and only then bear off slowly. The key is to hit the polar spot on with
minimal drag inducing helm changes (i.e. it's OK to take helm off but
not to add it). Your immediate reduction in helm applied that results
from the reduction in pressure helps the coast carry too. Less able
skippers cause the boat to bear off immediately to follow the apparent
wind shift by not immediately easing the helm or even worse by adding
it. Sail trim happens as the boat comes back onto her polar.

Or, if
I felt the original puff was not representative of the
typical conditions of the day, I'd bear away slightly to keep
the boat in the groove, which you might be forced to do,
if the wind did not pick up immediately. I'd try to get a
little bit of coast on my present track before bearing away
to power up. At that point I would want fuller sails for
more power and make adjustments accordingly--easing
the backstay for example.


Much better answers than Doug by the way. You can helm.

Cheers

  #14   Report Post  
Donal
 
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Default Racing Question #23


"Nav" wrote in message
...


OzOne wrote:


The answers fron others like Donal could be interesting :-)



Donal won't know.


You antipodeans are a snotty lot!


Anyway, I would ease the sheets .... assuming that I was already making the
mark. If I wasn't altready making the mark, then I would head up.




Regards


Donal
--



  #15   Report Post  
DSK
 
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Default Racing Question #23

Nav wrote:
So, the helm does nothing?


Did I say that?

... Oz will be disappointed in you!


Oh well, he can console himself with a nice sail on one of his yachts.

DSK



  #16   Report Post  
DSK
 
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Default Racing Question #23

Nav wrote:
Very close. The trim should be carried out automatically by the
trimmer(s).


You have automatic trimmers? I hope they are Linux machines for reliability.

... When/how do you head up?


Don't you know?


Yes. You keep the head slightly too high (due to the wind moving
forward) until boat speed drops to that expected for the wind conditions
and only then bear off slowly.


This is what's called a velocity header but it's a lot more noticable at
lower wind speeds.

... The key is to hit the polar spot on with
minimal drag inducing helm changes (i.e. it's OK to take helm off but
not to add it). Your immediate reduction in helm applied that results
from the reduction in pressure helps the coast carry too. Less able
skippers cause the boat to bear off immediately to follow the apparent
wind shift by not immediately easing the helm or even worse by adding
it. Sail trim happens as the boat comes back onto her polar.


A nice longwinded way of saying that if the wind drops suddenly, you'll
get a header into which you bear away slowly and gradually.

If the velocity header is a bad one, you should ease the jib to keep it
from slowing the boat down as it backwinds.


.... At that point I would want fuller sails for
more power and make adjustments accordingly--easing
the backstay for example.


Much better answers than Doug by the way. You can helm.


I knew you liked him better than me. And I said to ease the backstay,
you just weren't paying attention.

BTW do you not know what "feather" means when referring to steering?

DSK

  #17   Report Post  
Nav
 
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Default Racing Question #23



DSK wrote:

Nav wrote:

Very close. The trim should be carried out automatically by the
trimmer(s).



You have automatic trimmers? I hope they are Linux machines for
reliability.

... When/how do you head up?



Don't you know?


Yes. You keep the head slightly too high (due to the wind moving
forward) until boat speed drops to that expected for the wind
conditions and only then bear off slowly.



This is what's called a velocity header but it's a lot more noticable at
lower wind speeds.

... The key is to hit the polar spot on with minimal drag inducing
helm changes (i.e. it's OK to take helm off but not to add it). Your
immediate reduction in helm applied that results from the reduction in
pressure helps the coast carry too. Less able skippers cause the boat
to bear off immediately to follow the apparent wind shift by not
immediately easing the helm or even worse by adding it. Sail trim
happens as the boat comes back onto her polar.



A nice longwinded way of saying that if the wind drops suddenly, you'll
get a header into which you bear away slowly and gradually.

If the velocity header is a bad one, you should ease the jib to keep it
from slowing the boat down as it backwinds.


.... At that point I would want fuller sails for
more power and make adjustments accordingly--easing
the backstay for example.


Much better answers than Doug by the way. You can helm.



I knew you liked him better than me. And I said to ease the backstay,
you just weren't paying attention.

BTW do you not know what "feather" means when referring to steering?



No, but I know what it means when trimming or helming.

Cheers

  #18   Report Post  
Bart Senior
 
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Default Racing Question #23


Nav wrote

Bart Senior wrote:


I assume you mean the true wind direction does not
change. That would not be immediately "apparent".


Huh? The apparent wind changes immediately.


That was a joke! Meaning, how would you know the wind
was coming from the same direction?


  #19   Report Post  
DSK
 
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Default Racing Question #23

OzOne wrote:
Funny init?
In an Etchells going from 10 to 15kts, you'd allow the boat to climb
up on the gust and sheet IN!


OK, I'm guessing that the increased leach tension is going to bend the
mast a bit & flatten the sail?

Stuff like this is one reason why I said "It depends on the boat." Some
boats will not be fully powered up yet. Trapeze boats will notice the
increased chop more than the increased wind, largely because they'll be
going faster. Some boats would be on the verge of overpowered at 10
knots, so at 15 they'll be taking steps to not get knocked down.


At 10 kts we'll be set really soft to keep the head of the sails open
and flowing, the gust will pull them too open and you'll need to sheet
in to keep the power up.


What about adjusting the traveller and jib leads? One thing I don't like
about the Lightning is that the adjustments are quirky; a dual
adjustable bridle instead of a traveller and the jib sheet lead tracks
are neither straight nor aimed at the bow, so any adjustment affects
pointing & slot width as well as leach tension. Funky. Temperamental.
PITA until you get used to it.


If the breeze was holding, I'd be looking at another couple of steps
on the front mast block and removing all chocks from behind the stick.


Because you're shifting the mast aft or because you're holding the lower
section straight?

A tad more backstay would be needed to hold up the forestay and the
luff tension on the jib would come on as it would be well scalloped at
10kts.
Outhaul would be pulled outanother couple of inches.
Traveller may drop a tad but that would depend on the sea state.

And, as Doug suggested, all bums would be well over the side, forard
hand will be out to his knees with a foot locked undr the jib sheet
he's holding and middle would be there as well with the mainsheet in
hand, Skipper would hike as far as comfortable to maintain good
control and would have the backstay fine in hand to balance the helm
when small alterations are required.

Discussion would take place as to whether the breeze will stay in and
continue to freshen.
If so, forard hand will probably duck down to leeward and take about 3
or 4 turns on the lowers just before we tack next. He'll then do the
same after the tack to the other side and after we have the boat
settled on the new tack.
We'd possibly consider a jib change on the next run.....

Busy eh?


Sounds like a lot of damn work to me... OTOH I get frustrated sailing
with skippers who just lock everything down and drive it like a station
wagon...

Fresh Breezes- Doug King

  #20   Report Post  
Bart Senior
 
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Default Racing Question #23

Unless you head directly into the wind, as you would
shooting the line at the start, it is tough to tell exactly
where the wind is coming from. Of course
you could get a good idea if you were in the groove,
hard on the wind, but that would be after the fact.

OzOne wrote

On Thu, 08 Jul 2004 01:50:13 GMT, "Bart Senior"
scribbled thusly:


That was a joke! Meaning, how would you know the wind
was coming from the same direction?


That's what a compass and chinagraph are for :-)




 
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