Announcements
New Discussions
Previous Thread
Next Thread
Print Thread
Rate Thread
Hop To
pitchpole #239383
10/26/11 03:40 PM
10/26/11 03:40 PM
Joined: Sep 2007
Posts: 8
ISRAEL
S
segev Offline OP
stranger
segev  Offline OP
stranger
S

Joined: Sep 2007
Posts: 8
ISRAEL
we had a spectecular pitchpole with our Nacra F20C last friday, runing with the spi in ~17knots wind and ~0.8m waves.
The helm was sitting near the back beam and the crew was out on the trapeze with the chiken line, behind the helm, but it was not enough to avoid losing control and capsizing.
What are the reasons for pitchpolling and what are the best ways to avoid it?


Segev Eyal
Nacra F20C
Sdot Yam
ISRAEL
-- Have You Seen This? --
Re: pitchpole [Re: segev] #239386
10/26/11 04:09 PM
10/26/11 04:09 PM
Joined: Nov 2005
Posts: 1,203
uk
TEAMVMG Offline
veteran
TEAMVMG  Offline
veteran

Joined: Nov 2005
Posts: 1,203
uk
how far down were each of the boards?
how hard was the main sheeted?
how far out was the traveler?


Paul

teamvmg.weebly.com
Re: pitchpole [Re: TEAMVMG] #239387
10/26/11 04:13 PM
10/26/11 04:13 PM
Joined: Sep 2007
Posts: 8
ISRAEL
S
segev Offline OP
stranger
segev  Offline OP
stranger
S

Joined: Sep 2007
Posts: 8
ISRAEL
boards about 40cm up. main fully sheeted in with traveller centered.


Segev Eyal
Nacra F20C
Sdot Yam
ISRAEL
Re: pitchpole [Re: segev] #239392
10/26/11 05:07 PM
10/26/11 05:07 PM
Joined: Jun 2002
Posts: 806
Toronto, Ontario
pitchpoledave Offline
old hand
pitchpoledave  Offline
old hand

Joined: Jun 2002
Posts: 806
Toronto, Ontario
surprised about that..Done that many times with a lot bigger waves and never had a problem. What was your total crew weight?

Re: pitchpole [Re: segev] #239407
10/27/11 06:58 AM
10/27/11 06:58 AM
Joined: Jun 2001
Posts: 12,310
South Carolina
Jake Offline
Carpal Tunnel
Jake  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 12,310
South Carolina
Originally Posted by segev
we had a spectecular pitchpole with our Nacra F20C last friday, runing with the spi in ~17knots wind and ~0.8m waves.
The helm was sitting near the back beam and the crew was out on the trapeze with the chiken line, behind the helm, but it was not enough to avoid losing control and capsizing.
What are the reasons for pitchpolling and what are the best ways to avoid it?


It's going to be hard to comment on that because very few of us have experience with that boat and the curved boards. I think maybe it's possible that you had your weight too far back. Did the bows happen to leap up away from the water before it plunged back in?


Jake Kohl
Re: pitchpole [Re: Jake] #239411
10/27/11 08:08 AM
10/27/11 08:08 AM
Joined: Dec 2001
Posts: 5,590
Naples, FL
waterbug_wpb Offline
Carpal Tunnel
waterbug_wpb  Offline
Carpal Tunnel

Joined: Dec 2001
Posts: 5,590
Naples, FL
Originally Posted by Jake
Did the bows happen to leap up away from the water before it plunged back in?


I was going to ask the same question...


Jay

Re: pitchpole [Re: waterbug_wpb] #239417
10/27/11 09:53 AM
10/27/11 09:53 AM
Joined: Nov 2008
Posts: 69
L
Lost in Translation Offline
journeyman
Lost in Translation  Offline
journeyman
L

Joined: Nov 2008
Posts: 69
As I understand it, if the boat gets bow down the curved boards actually make the pitchpole more likely. The boards are now pulling down on the boat and exaggerating the typical pitchpole.

As long as you aren't jumping up as Jake notes above, weight farther back is better and boards up more can help as well in very steep chop I guess. Krantz or other folks who did the GT300 are experts in this now I think.

Re: pitchpole [Re: pitchpoledave] #239420
10/27/11 01:03 PM
10/27/11 01:03 PM
Joined: Sep 2007
Posts: 8
ISRAEL
S
segev Offline OP
stranger
segev  Offline OP
stranger
S

Joined: Sep 2007
Posts: 8
ISRAEL
total crew weight about 165kg.
there was no bouncing of the bows. they just dived in.

Last edited by segev; 10/27/11 01:06 PM.

Segev Eyal
Nacra F20C
Sdot Yam
ISRAEL
Re: pitchpole [Re: segev] #239421
10/27/11 01:20 PM
10/27/11 01:20 PM
Joined: Jan 2010
Posts: 22
southern germany
S
stampede Offline
stranger
stampede  Offline
stranger
S

Joined: Jan 2010
Posts: 22
southern germany
Hi Segev,
i own a F20C and my observation is:
when you sail vertical to the waves which means ahead of the wind and you are quicker than the waves the boat tends to dive in because there is little volume in the front. Normally you can dive in up to the front beam and she will come up without capsizing because she's an extreme wavepiercer hull. That is complete different from some F18 !!! If you are getting nervous while she dives in an pull or push the rudder you will capsize, just depower the gennacker a bit.

Re: pitchpole [Re: segev] #239471
10/28/11 12:21 PM
10/28/11 12:21 PM
Joined: Mar 2009
Posts: 932
Solomon's Island, MD
S
samc99us Offline
old hand
samc99us  Offline
old hand
S

Joined: Mar 2009
Posts: 932
Solomon's Island, MD
Random BAMF gust? I've seen boats go from upright to pitchpole instantly , nothing you can do in certain situations. Otherwise, did the crew dump the shoot or was he/she holding onto the sheet for dear life, aggravating the situation? Also, did the helm drive down if the rudders weren't cavitated?

Last edited by samc99us; 10/28/11 12:22 PM.

Scorpion F18
Re: pitchpole [Re: samc99us] #239505
10/30/11 09:59 AM
10/30/11 09:59 AM
Joined: Sep 2007
Posts: 8
ISRAEL
S
segev Offline OP
stranger
segev  Offline OP
stranger
S

Joined: Sep 2007
Posts: 8
ISRAEL
random gust? perhaps. The crew was not able to let the sheet off - it happened too fast. The helm drove down, the rudders did not seem to be cavitated.


Segev Eyal
Nacra F20C
Sdot Yam
ISRAEL
Re: pitchpole [Re: segev] #239520
10/31/11 03:08 AM
10/31/11 03:08 AM
Joined: Jan 2010
Posts: 22
southern germany
S
stampede Offline
stranger
stampede  Offline
stranger
S

Joined: Jan 2010
Posts: 22
southern germany
If the crew was not able to let the sheet off because it happened to fast it definitly was a uninspected gust. I had this one time and can't even imagine what my fault was or what i could have done different to prevent the incident.
have fun sailing her hard....

Re: pitchpole [Re: segev] #239530
10/31/11 09:18 AM
10/31/11 09:18 AM
Joined: Jun 2002
Posts: 1,658
Florida Suncoast, Dunedin Caus...
catman Offline
Pooh-Bah
catman  Offline
Pooh-Bah

Joined: Jun 2002
Posts: 1,658
Florida Suncoast, Dunedin Caus...
Did you rake your mast foward at all or too much?


Have Fun
Re: pitchpole [Re: catman] #239737
11/04/11 04:57 AM
11/04/11 04:57 AM
Joined: Sep 2007
Posts: 8
ISRAEL
S
segev Offline OP
stranger
segev  Offline OP
stranger
S

Joined: Sep 2007
Posts: 8
ISRAEL
our mast was raked as in the NACRA guide for the F20C. at this position we have neutral helm. we consider taking it backwards, although there is not too much to take since the side stays are almost fully shortened.


Segev Eyal
Nacra F20C
Sdot Yam
ISRAEL
Re: pitchpole [Re: segev] #239767
11/05/11 01:58 PM
11/05/11 01:58 PM
Joined: Aug 2001
Posts: 1,307
Asuncion, Paraguay
Luiz Offline
veteran
Luiz  Offline
veteran

Joined: Aug 2001
Posts: 1,307
Asuncion, Paraguay
Originally Posted by segev
boards about 40cm up. main fully sheeted in with traveller centered.


Do you use elastics to keep the boards in place? How do you rig them (pulling in what direction)?
If you rig the elastics so they pull the top of the boards forward, you are reducing their angle of attack for vertical lift, making the boat more capsize prone.
Try rigging the elastics so they pull the top of the boards back, which increases that angle of attack and, consequently, the vertical component of lift.
The more you need vertical lift from the boards, the more you want the top of the board pulled back. Enlarge (sand) the cases in the fore and aft direction if you feel that more vertical lift is necessary.


Luiz

Moderated by  Damon Linkous 

Search

Who's Online Now
0 registered members (), 474 guests, and 116 spiders.
Key: Admin, Global Mod, Mod
Newest Members
Darryl, zorro, CraigJ, PaulEddo2, AUS180
8150 Registered Users
Top Posters(30 Days)
Forum Statistics
Forums26
Topics22,405
Posts267,058
Members8,150
Most Online2,167
Dec 19th, 2022
--Advertisement--
Powered by UBB.threads™ PHP Forum Software 7.7.1