Boomvang for O'day Ospray

Moderator: GreenLake

Boomvang for O'day Ospray

Postby William » Sun Dec 05, 2010 2:39 pm

I have heard that a boom vang is an important piece of rigging but my Ospray only has a simple downhaul. Problem is that the mast step on the Ospray is just forward of the cuddy and I can't see how a boom vang could be rigged without interference from the cuddy. I know there are a few Ospray owners on the forum. Has anyone put a boom vang or am I okay without one. I'm just a cruiser no racing in my future.
William in Millbury
1960? O'day Ospray
William
 
Posts: 14
Joined: Fri Sep 03, 2010 8:53 pm
Location: central MA

Postby algonquin » Mon Dec 06, 2010 12:45 am

I have only seen the Ospray in pictures. Very similar to the DS model.

The attached info shows an Ospray with a vang attached.
http://www.gjenvick.com/BangorPunta/ODa ... spray.html

If your boat is using end boom sheeting like the one in the picture I could see the value of adding a vang. If your boat is already set up with mid boom sheeting the vang is probably only adding minimal performance. The vang in the picture uses a steep angle from the mast base to the boom and doesn't appear to cause any interference with the cuddy.

For cruising only you can get away without a vang but if you have any inclination to race impromptu the vang will give you an edge. Brad
"Feather" DS1 #818
algonquin
 
Posts: 475
Joined: Sun Sep 30, 2007 9:16 pm
Location: Maine Highlands - Grand Lakes Region

Postby K.C. Walker » Mon Dec 06, 2010 1:57 pm

I don't race but I consider a boom vang almost essential equipment for my enjoyment of sailing. Being able to control mast bend and leech tension separately from sheeting, to me, makes a huge difference. I had a 5:1 vang set up which was adequate and then change to a 20:1 which I found was quite an improvement.

Now, I wouldn't say that I would refuse to go sailing on the boat without a vang, but I'd be talking to the skipper about it the whole time we were out. :-)
KC Walker, DS 1 #7002
K.C. Walker
 
Posts: 1335
Joined: Sun Jul 06, 2008 10:50 pm
Location: North Stonington, Connecticut

Postby GreenLake » Tue Dec 07, 2010 3:10 am

algonquin wrote:The attached info shows an Ospray with a vang attached.
http://www.gjenvick.com/BangorPunta/ODa ... spray.html

That geometry seems no worse than for a DS.
If your boat is using end boom sheeting like the one in the picture I could see the value of adding a vang. If your boat is already set up with mid boom sheeting the vang is probably only adding minimal performance.


OK, let's think that thought to its logical conclusion. The ideal sheeting position should then be next to the mast. :shock:

Clearly, if the sail pulls in a given direction, then the boom will move out and up until the sheet pulls in the opposite direction to the sail force. The direction of the sail force would, of course, depend itself on boom position and angle, but disregarding this for a moment, the center of the boom is closer to the centerline of the boat, which gives mid-boom sheeting a more vertical pull.

Upwind, the closer the boom gets to the horizontal and amidships position, the less difference there will be in the angle of pull of the two sheeting arrangements in absolute terms.

Downwind, there should be a bigger difference, but it could be that the situation is already so far from optimal by then, that sheeting position doesn't matter enough. That could account for the fact that many people, including racers, continue to sail with the bridle or rope traveler in the rear, but if they want to see improved performance they get religious about their vangs, like K.C..

I'm (still) vangless - but then I have a non-standard configuration at the mast partners that makes fitting a vang particularly challenging, and I need to puzzle out how I deal with that before I can proceed further. Reading the discussions has me convinced it's worth to put that on my list of possible future upgrades.
~ green ~ lake ~ ~
GreenLake
 
Posts: 5463
Joined: Mon Jun 18, 2007 3:54 am

Postby ctenidae » Tue Dec 07, 2010 2:08 pm

The one D&R sells for the Daysailer is 3:1- is that too little to be useful?
Formerly 28 cents
DS1 1114

Now, sadly, powered boating...
ctenidae
 
Posts: 243
Joined: Mon Oct 05, 2009 8:25 am
Location: Norwalk, CT

Postby GreenLake » Tue Dec 07, 2010 2:37 pm

ctenidae wrote:The one D&R sells for the Daysailer is 3:1- is that too little to be useful?

Not if you're strong! :lol:

A common thing for vangs is to rig them as a cascade as in this example
from the a West Marine article on vangs.

Image

The downside of a cascade is that you halve the range of possible adjustment with each stage of the cascade.

For a boom vang, that's not necessarily a huge issue, because the range over which you want to adjust the boom is limited.

The part sold at D&R doesn't look like it lends itself to being cascaded, because of the way the wire is fitted.
~ green ~ lake ~ ~
GreenLake
 
Posts: 5463
Joined: Mon Jun 18, 2007 3:54 am

Postby ctenidae » Tue Dec 07, 2010 2:49 pm

GreenLake wrote:
ctenidae wrote:The one D&R sells for the Daysailer is 3:1- is that too little to be useful?

Not if you're strong! :lol:



At the end of the day, strong smeilling is about the best I can do...

To a certain extent, if you're using the vang as security and stability more than for pure adjustable performance, you can really sort of set it and forget it, am I right? Just crank it down a bit when there's no tension on the boom, and leave it.

Unless I'm wrong, there's not a whole lot of trimming that has to be done with a vang, unless you're racing, right?

I've asked for the D&R vang for Christmas, and will call it off if a 3:1 vang is just pointless.
Formerly 28 cents
DS1 1114

Now, sadly, powered boating...
ctenidae
 
Posts: 243
Joined: Mon Oct 05, 2009 8:25 am
Location: Norwalk, CT

Postby algonquin » Tue Dec 07, 2010 3:48 pm

GreenLake wrote:
algonquin wrote:If your boat is using end boom sheeting like the one in the picture I could see the value of adding a vang. If your boat is already set up with mid boom sheeting the vang is probably only adding minimal performance.


OK, let's think that thought to its logical conclusion. The ideal sheeting position should then be next to the mast. :shock:



I don’t like logical conclusions. :cry: Sounds good but sail shape would suffer and the boom would tend to flail out of control and a hard hat would become necessary to keep the “BOOM” from living up to its name.

I have used a vang on all my boats and wouldn’t sail without the benefit of one. Even if only cruising. I do believe that the 3:1 vang would serve a purpose on a boat as light as the DS but I also prefer at least a 5:1 setup as KC suggests. A great benefit of our boat is that it really doesn’t take much muscle effort to trim any of the lines. Maybe with the exception of a deployed and stuck anchor. :wink:

GreenLake I really hope you don’t go vangless much longer. :P Brad
"Feather" DS1 #818
algonquin
 
Posts: 475
Joined: Sun Sep 30, 2007 9:16 pm
Location: Maine Highlands - Grand Lakes Region

Postby jeadstx » Tue Dec 07, 2010 6:33 pm

The boom vang D&R sells in similar to the one that came with my DS2. I believe mine is original to the boat. I have a similar one on my 1962 Rhodes 19. I haven't had any problems with it, works well.

John
1976 Day Sailer II, #8075 - Completed the 2011, 2012, and 2013 Texas 200
1952 Beetle Boat Swan Catboat
Early Rhodes 19
1973 Mariner 2+2, #2607 - Completed 2014, 2015 and 2016 Texas 200
1969 Day Sailer I, #3229
Fleet 135; Canyon Lake, Texas
jeadstx
 
Posts: 1216
Joined: Tue Jul 08, 2008 11:10 am
Location: Dripping Springs, Tx

Postby GreenLake » Tue Dec 07, 2010 7:10 pm

algonquin wrote:
GreenLake wrote:OK, let's think that thought to its logical conclusion. The ideal sheeting position should then be next to the mast. :shock:

I don’t like logical conclusions. :cry: Sounds good but sail shape would suffer and the boom would tend to flail out of control and a hard hat would become necessary to keep the “BOOM” from living up to its name.

Yeah, it would be a terrible sheeting position for purposes of controlling the boom sideways (primary job of a sheet after all).

In essence, though, that's what a vang is: optimized for downward pull w/o sideways component.

algonquin wrote:I have used a vang on all my boats and wouldn’t sail without the benefit of one.


Right, so you, K.C. and a number of smart people and fast sailors all agree that it's a useful thing. K.C. is an advocate of "vang sheeting", which apparently means using a strong vang not only downwind, but upwind as well (esp. in heavy air to keep the sail flat, while being able to let out some sheet to depower).

That requires a more powerful vang than the usual use off-wind to control sail shape and twist.

However, it would seem that being able to safely depower is something that should be of interest when cruising - especially if you can get stuck with more wind on your hands than you were counting on.

algonquin wrote:GreenLake I really hope you don’t go vangless much longer. :P Brad


Thaks, I hope so, too. As I mentioned, I'm not stuck at the "why" or "whether" but at the "how". Because of my mast-raising contraption (see my gallery), I can't fit the usual vang bail.

All my estimates about forces tell me that I can't anchor the vang on the cuddy top - which would be the alternative.
~ green ~ lake ~ ~
GreenLake
 
Posts: 5463
Joined: Mon Jun 18, 2007 3:54 am

Postby GreenLake » Tue Dec 07, 2010 7:53 pm

ctenidae wrote:
GreenLake wrote:
ctenidae wrote:The one D&R sells for the Daysailer is 3:1- is that too little to be useful?

Not if you're strong! :lol:



At the end of the day, strong smeilling is about the best I can do...

Was that supposed to be smelling or smiling? :wink:
ctenidae wrote:Unless I'm wrong, there's not a whole lot of trimming that has to be done with a vang, unless you're racing, right?

I've asked for the D&R vang for Christmas, and will call it off if a 3:1 vang is just pointless.


Lacking experience, I can't really advise you when you'd see a limit in a 3:1. All I know is that there are a number of people who swear by higher ratios - perhaps they are all more "active" sailors than you are planning to be. Counter that with John's experience.

I'm a bit in your situation, trying to figure out my options before committing.

The price is certainly better than what you'd have to pay if you tried to put together a 4:1 from Harken parts (that one would be at least 50% more). The kit at D&R also has the advantage of being a complete solution with all the parts included. Those may be deciding factors for you.

The advantage of rolling your own is that you can upgrade it to an 8:1 cascade at any point, should you feel that 4:1 isn't enough. With the D&R kit, you'd have to start over - at least I can't see from the picture how it could easily be adapted to work in a cascade.

Anyway, I hope you will have a verygood Christmas this year!
~ green ~ lake ~ ~
GreenLake
 
Posts: 5463
Joined: Mon Jun 18, 2007 3:54 am

Postby K.C. Walker » Tue Dec 07, 2010 9:59 pm

Hmm... I looked at the one from D&R and I must say it looks pretty bad. I once had one just like that and it was terrible. With a little fun shopping from eBay you could make a super vang for that kind of money or less. You really don't need large diameter blocks for a daysailer vang. I built mine out of Ronstan 20 mm and 30 mm blocks, the breaking strength for these blocks is over 1200 pounds… that's plenty. When you use blocks as multiples the block quality matters a lot. That block set up for the vang from D&R is really low quality.

Look at Phill Root's set up. I set mine up with two 20mm triple blocks. I used one of the sheaves of one of the triple blocks as a beckett giving me 5:1. I then cascaded it twice for 20:1. A lot of this can be made up with 1/8 inch spectra from West Marine for very little money and very little friction. I paid $12 for each of the 30 mm blocks and $14 for each of the 20 mm triple blocks. If I had gone with a cleat on the top of the cuddy as Phill did it would have come out about the same money or less and is far better quality and user-friendly.
KC Walker, DS 1 #7002
K.C. Walker
 
Posts: 1335
Joined: Sun Jul 06, 2008 10:50 pm
Location: North Stonington, Connecticut

Postby itsermam » Wed Dec 08, 2010 3:14 pm

There is a 15:1 dinghy vang on clearance at West Marine right now for about $90, if you are concerned about "rolling your own." I do not have this one, but it appears to be of decent quality and comes with everything already put together. Might make a good substitution on your Christmas Wish List.

I think having a decent vang is a good thing even if you do not race, and even if you have mid-boom sheeting, because it allows you to get a better sail shape for the conditions without over trimming/easing the main. Caveat - I am the kind of geek who read Sail Power from cover to cover when I got it. That said, my experience has been that utilizing the vang properly extends my wind speed range for sailing on a reach and lets me make the most of light air on a run. Guess that may matter more to a racer, but not bad things for a cruiser either.

My $0.02 for what it is worth.
DS I #3056
itsermam
 
Posts: 23
Joined: Sat Mar 27, 2010 11:36 pm
Location: Portland, OR

Postby itsermam » Wed Dec 08, 2010 3:20 pm

...and if I had read all of the preceding posts, rather than just the last one, I would have seen that I was restating what at least 5 other people had already said in one form or another. :oops:

Oh well, still my $0.02, and a few other peoples' as well. :)
DS I #3056
itsermam
 
Posts: 23
Joined: Sat Mar 27, 2010 11:36 pm
Location: Portland, OR

Postby GreenLake » Wed Dec 08, 2010 7:57 pm

itsermam wrote:...and if I had read all of the preceding posts, rather than just the last one, I would have seen that I was restating what at least 5 other people had already said in one form or another.


And I say that's not a bad thing - especially when you can add first-hand experience, as you did.
~ green ~ lake ~ ~
GreenLake
 
Posts: 5463
Joined: Mon Jun 18, 2007 3:54 am

Next

Return to Rigging

Who is online

Users browsing this forum: No registered users and 1 guest

cron