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Keel optimization

Printed From: myHanse.com
Category: Hints & Tips
Forum Name: 400
Forum Description: 400 Hints, Tips and News
URL: https://www.myhanse.com/forum_posts.asp?TID=10459
Printed Date: 28 March 2024 at 16:01
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com


Topic: Keel optimization
Posted By: Mary400e
Subject: Keel optimization
Date Posted: 22 September 2017 at 12:17

Hi

I'm considering an optimization of the keel, to improve the upwind performance.

Do anyone have the VPP scheme for the L-shape and the new T-shape (iron).

I have the original lead keel (L-shape).

 

BR Jesper

 



Replies:
Posted By: iemand
Date Posted: 22 September 2017 at 15:07
 I talked to J&V the other day about the keel differences (it was about the Hanse 470) He said that the L-Shape iron/lead keel will always have better performance than the iron T-Shape keel. The wetted surface of the T-Keel is much higher. 
A Lead T-Keel might be different but not the iron standard T-keel.

BR Thomas


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Hanse 312 MJ 2004 - Hanse 370e MJ 2007


Posted By: H8jer
Date Posted: 23 September 2017 at 13:01
Hi

More on keel shapes - paper from Swedish research:
http://publications.lib.chalmers.se/records/fulltext/148387.pdf" rel="nofollow - http://publications.lib.chalmers.se/records/fulltext/148387.pdf
uploads/2746/chalmers_se_keel_shapes.pdf" rel="nofollow - uploads/2746/chalmers_se_keel_shapes.pdf
//
The results as analyzed throughout chapter 3 to 5 has
consistently shown that for both these cases the T-bulbed keel performs best of the bulbed keels, and
also better than the fin keel in higher wind speeds.
//


I would think it is a waist of time and money going for a new keel.
What about the sails? If you're still using self-tacker, it would be more wise to get a headsail with overlap.

/H8jer


-------------
Hanse 370#487 30HP 3-cabin


Posted By: Mary400e
Date Posted: 25 September 2017 at 12:21

Hi

Thanks for the reply’s. I have looked in the provided technical documentation (Swedish research), very interesting.

Regarding the difference between L and T-shape keels and what is possible/realistic will I still try to get some more information (VPP) about the performance of the T-keel. Another solution is to modify/improve the L-keel to get a more optimal shape.  

My main problem today, is lack of performance upwind. My drift (heading is the same) is 5-7 degree lower than other boats, and the speed is fine above +6m/s. I’m using custom made overlapping headsail (racing) with inhaul to get headsail closer to the centerline.

BR Jesper

       



Posted By: Peter-Blake
Date Posted: 25 September 2017 at 16:28
If you have the original L-Keel with lead, than you have the best keel you can get for a Hanse!
As Thomas stated the lead L-Keel is in all 5% better than the T-Steel keel. That was what J&V told me aswell in 2008 when i had a discussion with them.

In truth the diffrence is very low  between my boat (L-lead-keel) and a similar Hanse 370e with a t-steel-Keel. We sailed a long leg of about 20 miles parallel and there was nearly no diffrence in speed. OK my boat is a standard 370 and the other one was a epoxy version. Maybe thats why i was on the same speed, as the epoxy version is a lot lighter (400kg).....

Check if you have the same pointing problems on both sides. Sometimes the keel is not perfect in line. Than there is one side faster than the other.

Pointing is a question of a lot diffrent components. A wonderful sail not perfect trimmed can act like a break. Try to play with the sailshape, traveller, cunningham etc.

It is on my 370 also very important (in low winds) to get the boat running on speed first, and than head into the perfect angle. if i do not do this, than it takes a long time to get the boat on speed!

if everything does not work, than you could check the keel shape.....but do at first all other options!


-------------
Blake 370


Posted By: Rubato
Date Posted: 25 September 2017 at 17:44
Hi Jesper
I have a few questions before I make any comment
- what size is your main (relative to the original North Dacron)?
- what size is your overlapping foresail and where do you sheet it to (I'm confused by your statement of using an innerhauler as the normal sheeting position is to the track on the side deck behind the shrouds and the shrouds will make it impossible to use an innerhauler
- what boats are you comparing yourself to?
- what wind speeds do you normally race in, is your pointing ability poor in all wind speeds?
- Do you have the sparcraft rig?
- have you followed the rig tuning guide from North?
- what tension are the various shrouds?

Steve


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Steve

Hanse 400e, #168


Posted By: Mary400e
Date Posted: 26 September 2017 at 10:00

Hi Steve and others

Thanks for all your good questions/suggestions etc.

In below will I try to clarify:

Racing headsail (overlapping 37 m2 with batten), is sheeted inside the shrouds, and by using the inhaul is it possible to sheet closer to the centerline.

The main is also custom made with max size.

I have the Sparcraft rig, with high tension and pre-bend and the mast is straight (on starboard/port) up to the point where the upper shrouds ends, to make sure the forestay is tight. The rig is position in the center, before the rig is tighten.

When racing, the speed is approx. 6,8-7,2 knob in +6-7 m/s, and when tacking the speed is not below 5 knob, and we accelerate the boat before tighten in. In general, the boat perform better in higher wind +10 m/s
We have very good speed and performance on all other Wind angles (code-1 and spinnaker) when racing

Due to the Danish rating system, a large headsail (genua 1) not possible

The boat seem to be sailing with les drift on starboard, compared with port. The rudder pressure, is light on both starboard and port. Typically we are racing against fast boats like: X-40, X4, Luffe 40, IMX 38, Faurby 393

BR Jesper

 

 



Posted By: Rubato
Date Posted: 26 September 2017 at 18:25
Hi Jesper

Have a look at this tuning guide http://www.northsails.be/RADUploads/MastSetup400.pdf
Follow it to the letter, it's super important. For the first couple of years of having the boat I followed the local advice and riggers on how the boat should be setup and the boat performed awful. Once I followed this guide using the Loos tension gauge things improved drastically. Mast rake is super important and cap shround tension is super important as well.

We regularly race in light to medium winds; 6 - 14 knots.  The boats we compete against are: J35, J36, J37, J109, X119, C&C115, Bene36.7, Express 37, Schock 35. Initially, we only had a 108% (41 sq m) jib. The sheet point was just inside and behind the shrouds and we tried to use inner haulers to bring the sheet point further inboard. Nothing worked well. We then put cabin top tracks in place (there are backing plates built in) and followed the tuning guide; this achieved a huge improvement. However, we were still not competitive under 12 knots - we could achieve speed but not enough point. Under 10 knots even the speed fell off. Then I bought a proper overlapping headsail, 138% (53 sq m), and this really helped. We still aren't pointing with the other boats when the wind is under 7-8 knots but around 9-10 we still have a lot of fun. We can carry that big foresail up to 13-14 knots. Anything above 11 and we are pointing like crazy. If the wind is down at 6 knots we might as well break out the gin and tonics. Above 14 knots we put the 105% on. Above 20 knots and we have a reef in and then above 28 we have 2 reefs in the main. 

So back to your situation:
If you are sheeting inside the shrouds, your foresail is quite small and isn't overlapping much at all. In fact, a 100% jib is 38 sq meters so you are less than that. That seems quite small for wind under 12 knots. Regardless though, if the sheeting position and rig setup isn't right it will make it much worse. 

That's pretty much my experience. One thing we have to accept is that the boat is big and heavy so it will never be a light wind contender. It's even more difficult to stay with the fleet downwind!

Hope that helps
Steve


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Steve

Hanse 400e, #168


Posted By: jracoffman
Date Posted: 26 September 2017 at 19:33
I echo Steve's comments.  I would seriously consider a larger overlapping headsail for winds below 12kts, and subsequently spend time on rig tune to ensure it is perfect. 
Racing with the self-tacking jib in my mind is largely a waste of time, unless it is blowing 20+kts.  Since winds in Western LIS are generally lite, I have a 155 genoa has my main foresail, I go to a 109% jib with vertical battens that I shift to at winds above 15kts. 
 
When my rig is tuned well, I can generally point well when winds are above 10kts, but if they go lite, foregettabout it.  Have to foot off for some boat speed...
 
I can't imagine doing major work to the keel would be worth it from an expense and improvement perspective.
 
 


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James C
Gemini, Hanse 375 #644
USA 60468


Posted By: silversailor
Date Posted: 26 September 2017 at 22:14
This year I shifted from the North tuning guide to a much looser set up recommended by the Evolution sailmaker in Canada. Additionally, I had new sails made by Ullman Detroit (Fiberpath Race with tafetta on one side), including a new main, 135 and 155 genoas.  I use the 155 up to about 11 knots, then switch to the 135.  Above 16 knots I look to take a reef in the main. Everything improved...speed, pointing ability, light air sailing, sail shape, etc.  Don't know how much was due to the new tuning guide or the new sails.  Whatever it was I'm sticking to it.  Just got off Lake Michigan.  TW at about 10.  TWA at 90. Just pleasure sailing with my bride at a steady 7.8-8.0 knots. Doesn't get much better. We have the shoal draft (5'2") 370e.


-------------
Silversailor
South Haven, MI USA
S/V Legacy
2010 Andrews 28


Posted By: Mary400e
Date Posted: 27 September 2017 at 10:01

Hi All

I have collected Danish (DH) rating information from a Danish Hanse 400e using a genua 1 (approx. 51 m2). When I make a comparison, will my rating be "lowered" with 4,5 sec/nm. Meaning I need to sail approx. 4,5 sec faster pr. nm on circle track (distance racing).

I think with the high stability of the boat, a genua 1 might be the solution, together with an additional look/verification of the rig setup.

What do you think?

BR Jesper

 


Posted By: Rubato
Date Posted: 27 September 2017 at 18:19
Originally posted by Mary400e Mary400e wrote:

What do you think?

 

Thumbs Up

Quite a few rating systems (non VPP types), have "steps" in the penalty for larger sails. Make sure you get the biggest sail you can if you're going to take a penalty. For example, a rating system might give you a penalty of 3 sec/nm for a foresail in the range 110 to 125%. As such, it would be silly to have a 112%, you would go to 125%.....


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Steve

Hanse 400e, #168


Posted By: Rock
Date Posted: 27 September 2017 at 21:42
Steve,
You put your first reef in at 20 knots true or apparent wind?

At 16+ knots true wind I have to seriously loosen the main sheet, not to loose rudder grip.
400e lead L shoal keel and still using the original north main and self tacker.
Not taken the step to spring for new sails yet as I think the boat sails very well, pointing at upto 30-31 degrees apparent wind angle.
Admitted I don't race, although any other boat going in the same direction becomes   a race.
I find waves have a huge impact on the performance.
Last year kept an x40 behind me for 2 hours in 16 knots true wind, pointing highl, relatively flat water.
Regards, Peter

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Hanse 400e "M-square2" #0241


Posted By: Rubato
Date Posted: 28 September 2017 at 17:21
Hi Peter
The original North main is actually not a bad sail. I raced with it for about 2 years after the first "high tech" main that I had fell apart and I didn't want to spend the money for a new one yet.

To answer your question, I'm talking true wind speed. Once we get in the higher teens, the main traveller (in the cockpit, not cabin top) has to be all the way to leeward, the mainsheet is on very hard, and the backstay is on very hard as well. This makes the sail very flat. In addition, the boom vang will be on tight as well which is important for the next part...  In gusts, you ease the main sheet so the main luffs a little and then put it back on when the gust has passed (the vang holds the tension on the boom so the sail stays flat as you ease the sheet). Lastly, quite often under these conditions, I can actually pinch (point too high) just a couple of degrees which also flattens the boat and takes a little bit of power out of the sails - this is difficult to do effectively in rough water.

Steve


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Steve

Hanse 400e, #168


Posted By: Rock
Date Posted: 28 September 2017 at 21:07

Got ya, traveler to lee (on the coach roof though, does that make a big difference ?) and backstay on, I do.
Pinching works for me too.
I dont use the boomvang much, so will pay more attention to that going forward.



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Hanse 400e "M-square2" #0241


Posted By: Rubato
Date Posted: 28 September 2017 at 21:54
Traveler on the coach roof - I haven't looked closely but I believe that the cockpit traveler allows the boom to be further off center while the main sheet is on very hard. To get the equivalent setting with the coach roof traveler, you would put the vang on very hard to hold the boom down and then ease the sheet.



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Steve

Hanse 400e, #168


Posted By: Mary400e
Date Posted: 27 November 2017 at 13:30
Hi All
I have ordered a new 150% racing genua (Quantum 50m2). Now I just have to wait for spring. It's going to be a long winter :-)
PS Will not make changes to the L-keel.
Best regards
Jesper  


Posted By: Koppiekrou
Date Posted: 18 March 2018 at 10:27
Hi Silversailor,

Thanks for your update. I was wandering if you have any problem pointing due to the shoal draft of 5’2? And did you ever sailed her against a deeper draft Hanse or similar sailing boat? Also do you think that due to the shoal draft you have to put in a reef earlier?

Thank you for your answer.

Frank



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