[C320-list] Inbalance port versus starboard tack

[Chris Burti]

Interestingly, I know of someone who tried measuring to the chain plates or stations and finally determined that his mast was 2” off center. After using the halyard as a plumb and allowing 1.5 inches for the sheave offset he was able to get his mast into plumb and get his vessel into more even trim… there are other factors such as whether the keel is mounted true to the centerline, whether the hull is symmetrical, etc., etc. that can contribute to non symmetric sailing characteristics… but an out of plumb mast will make a decided difference because the angle of attack for both sails with respect to the keel changes from side to side 

Thanks,
Chris Burti
Commitment #867
Farmville, NC

From: Warren Updike
Sent: Saturday, August 11, 2018 5:39 PM
To: c320-list at lists.catalina320.com
Subject: Re: [C320-list] Inbalance port versus starboard tack

One should be able to fairly true the mast using a main halyard, to a common point on the toe rail. I used a stanchion for that. And, yes, the main halyard sheave is not on center. I wouldn't think 1/4" difference between port and starboard could account for the differing performance to wind on port vs starboard. There are about 500 +/- inches from mast step to top, and 1/4" is 0.05% or 0.0005", nearly infinitesimal. I also find it difficult to believe that the port list would be the culprit as well. The forces to weather are so much greater than such effects IMHO. 

We would be grateful if someone with real expertise could shed some light on this.  

As for the port list, I bought 125 lbs of old chain, divided it in 3 parts. 1/3 went into a bucket in the stbd cockpit lazarette, 1/3 in a stbd storage hole in aft cabin, and the last 1/3 in a storage hole behind the salon settee back cushion. This helped quite a lot; but, did not completely eliminate the list. That said, now here is why I suggest that owners posting to this list sign with hull number... Our #62 has a 20 gal water tank under the port settee while newer models have that tank under the aft cabin. That change was, I believe, to partially offset the port list induced by the refer and galley counter tops to port. Do I still have a marked difference to weather? I wish I knew. I'm thinking of adding more chain just to keep the boot stripe out of the water. 

Warren and Pattie Updike
1994 C320 "Warr de Mar" #62
Middle River, MD (Chesapeake Bay)


-----Original Message-----
From: John Meyers [mailto:jcmeyers7 at gmail.com] 
Sent: Saturday, August 11, 2018 3:59 PM
To: C320-List at catalina320.com
Subject: Re: [C320-list] Inbalance port versus starboard tack

With respect to what Chris B recently wrote I don't really want to go up
the mast with a 50 foot tape measure (Chris did not imply that method) to
measure mast head to chain plate. Last year I tried another method because
I have what appears to be the same problem close hauled on different tacks.

I did suspect an out of plumb mast. To make a long story a bit shorter, I
used my spinnaker halyard with a 5 gallon pail of water to allow for the
same stretch and put a piece of masking tape on the halyard at the middle
of the rub rail. Switching back and forth a couple times I only measured a
quarter inch difference from one side to another.  Thinking that there
might be vector/gravity force difference if the mast was not perpendicular
to the water, a.k.a. a list, may have caused the very slight difference. I
didn't have anyone stand on the other pier to measure with a plumb line to
see if the mast was plumb while I measured the length on the halyard.

As I figured the one quarter inch difference it wasn't enough to account
for the noted or perceived difference in sailing closer to the wind.
Another factor that is only slightly related and causes in me a lack of
concern for perfection is that my 20 year old blown out mainsail is due to
be replaced which by itself would not cause the closer to the wind
difference on one tack verses the other. I do have a constant weather helm
to help me suspect that the main sail is not in good shape enough to sail
closer to the wind and that is another subject.

Another thought just occurred to me as I write this  is that the quarter
inch difference would be that the halyard sheave would not be on center as
neither halyards are on on center which I didn't take into account when I
measured and now I don't remember which side was shorter or longer. So I
don't know if my mast is perpendicular of off by a half inch of measurement
using the method described above.

John Meyers
1997 #406
Muskegon, MI

On Sat, Aug 11, 2018 at 8:14 AM, Chris Burti <clburti at gmail.com> wrote:

> When you checked the mast, did you confirm that it is plumb with the deck.
> An out of plumb mast is the usual culprit. Sometimes the mast base on a
> production sailboat is a bit off center and if plumb is checked by
> measuring it to the chainplates, it will be off…you will need to go to the
> top of the mast and use a plumb line.
>
> Thanks,
> Chris Burti
> Commitment #867
> Farmville, NC
>
> From: Rob Buitendijk
> Sent: Saturday, August 11, 2018 8:05 AM
> To: C320-list at catalina320.com
> Subject: [C320-list] Inbalance port versus starboard tack
>
> Hi,
>
> When we sail on starboard tack, we cannot go upwind (10-20 degrees
> difference) as far as sailing on port tack.
> Since we own our boat only since last year, we looked into things above
> deck, like the mast, sails, and so on, but nothing helped.
>
> Is anyone familiair with this problem? Has it something to do with weights
> of tanks and batteries on one side?
>
> Regards,
> Rob Buitendijk
> The Netherlands
> 2003 Catalina 320 #949
>
>