Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 05-06-2023, 11:07   #1
Registered User

Join Date: Jun 2023
Posts: 5
imbalanced Tartan 34 C

I noticed that my recently purchased Tartan 34 C is slightly imbalanced (~3-5 degree leaning to port) when in the water. The Tartan is a "classic plastic" centerboard monohull boat built in the 70-ties.

I am worried that I have ~90 liters or more of sea water that has penetrated by a hidden leak into the ballast space on the backboard side. Filling the water tank on starboard did not reduce the imbalance. I have no leak into the cabin or bilge, though.

I wondered if the imbalance (~3-5 degree leaning to port) could come from replacing the original atomic 4 engine with a Universal M4-30 diesel some 20 or 30 years ago (the engine is installed off the centerline in the Tartan 34 C). This would not be worry some I suppose. This is somewhat supported by the discovery the fact that the keel stepped mast is adjusted to almost touch the cabin roof on the starboard side. Does anybody know about such imbalance?
fjweke is offline   Reply With Quote
Old 06-06-2023, 22:37   #2
Moderator
 
Don C L's Avatar

Join Date: Sep 2014
Location: Channel Islands, CA
Boat: 1962 Columbia 29 MK 1 #37
Posts: 13,560
Images: 66
Re: imbalanced Tartan 34 C

Hello fjweke, welcome aboard! I don't know the Tartan 34c specifically but I do see that the engine is on the port side as is the head (and holding tank I presume.) And batteries? where are they? A heavier engine could certainly be partly to blame, with the centerboard she's not very deeply ballasted. Where is it you think water has leaked into? I don't see where enough water could have gone, undetected, to cause this. If someone in the past had moved the mast to be more plumb, I'd be inclined to put it back where it belongs. It is not so uncommon for boats to be out of balance that way sometimes (Usually because of how they are loaded) and I don't see a problem with it unless you are racing. You'll just sail a little better on one tack. However, I would check to see if the holding tank is empty and whether you can move batteries to the starboard to help balance.
__________________
DL
Pythagoras
1962 Columbia 29 MKI #37
Don C L is offline   Reply With Quote
Old 06-06-2023, 22:55   #3
Registered User

Join Date: Aug 2020
Posts: 740
Re: imbalanced Tartan 34 C

I worried about my boat when I first put it in the water, but later discovered that with no wind and no current, it evened out. So make sure you might not be seeing the effects of one of those.
markxengineerin is offline   Reply With Quote
Old 07-06-2023, 10:29   #4
Registered User

Join Date: Jun 2023
Posts: 5
Re: imbalanced Tartan 34 C

Thanks for your thoughtful comments.

I calculated from the amount the boat is leaning to port that the imbalance of buoyancy corresponds to 250 liters (~70 gallons) of water in the ballast volume
on the portside. This is a space of 40'' X 20" X 20" for example. Maybe not impossible for a boat with a ~28' waterline-LOA and a beam of 9' at the waterline.
(I saw once a YouTube video of a old Person that had its ballast tank completely flooded)

Maybe 500 lb is the differential value of the engine with between
Atomic 4 and Universal M4-30. But the offset of the c.o.m of the engines
from the boat's centerline is only 4-8 inches while I assumed 16 inches to calculate the waterfilled volume. This reduced lever arm would require a maybe twice as large weight difference (impossible).

So I am worried, the assumed water in the ballast space will at some point penetrate into the cabin and sink the boat.
fjweke is offline   Reply With Quote
Old 07-06-2023, 10:44   #5
Registered User

Join Date: Aug 2020
Posts: 740
Re: imbalanced Tartan 34 C

Can you not drill a hole in said ballast space, to prove there is or is not water in there? Something you can easily plug later on with any number of methods.
markxengineerin is offline   Reply With Quote
Old 07-06-2023, 10:50   #6
Registered User
 
Starbuck's Avatar

Join Date: May 2005
Location: Long Beach, CA
Posts: 860
Re: imbalanced Tartan 34 C

Step 1: determine whether this assumed water actually exists or not.

IF, solve for water.

ELSE, abandon theory.
__________________
s/y Elizabethó Catalina 34 MkII
"Man must have just enough faith in himself to have adventures, and just enough doubt of himself to enjoy them." ó G. K. Chesterfield
Starbuck is offline   Reply With Quote
Old 07-06-2023, 15:18   #7
Moderator
 
Don C L's Avatar

Join Date: Sep 2014
Location: Channel Islands, CA
Boat: 1962 Columbia 29 MK 1 #37
Posts: 13,560
Images: 66
Re: imbalanced Tartan 34 C

So I am wondering where this ballast space is. I have an encapsulated ballast too and there is likely very little empty space trapped in there, and it would be around the lead ballast. If there is water in there I'd never know, and actually I wouldn't mind a little extra weight there. In my own case the boat is 60 years old and hasn't sunk yet if there is water in there, so I don't lose sleep over it.
__________________
DL
Pythagoras
1962 Columbia 29 MKI #37
Don C L is offline   Reply With Quote
Old 07-06-2023, 16:42   #8
Registered User

Join Date: Sep 2009
Location: Maine
Boat: Tartan 37
Posts: 143
imbalanced Tartan 34 C

Just taking a look at the layout of the boat, there is a lot of storage and quarter berth on starboard side, make sure itís not full of heavy items. Maybe transfer some to the port side.

I doubt there is some cavity full of water somewhere, but itís unevenly loaded. Wouldnít take more than 40-80 lbs in an outboard locker.
ABJ87 is offline   Reply With Quote
Old 07-06-2023, 17:00   #9
Registered User

Join Date: Mar 2016
Location: San Francisco
Boat: Morgan 382
Posts: 2,137
Re: imbalanced Tartan 34 C

I don't see how you could have 70 gallons of water in your boat, and have it not be obvious. On a 34' boat, I would expect 70 gallons to be over the floorboard. On my 38' boat, only about 15 gallons will fit in the bilge before it is over the floor. So, I don't see how you could have 70 gallons there.

Also on a 34' boat, probably only 100 lbs. would be enough to make it list 3-5 degrees if that weight is near the rail. Heavy items, batteries, anchor and chain, tools, a full holding tank, etc. would all contribute to this.

Lastly, how are you measuring list? Sometimes production boats are not symmetrical. Maybe the mast isn't plumb and in column. Maybe the floor itself isn't perfectly level. Get a level, and check in multiple places. My boat often "feels" like it is listing to starboard, and the way I pack it sometimes it does. But checking it carefully, it isn't as bad as it feels and nothing to worry about.
__________________
-Warren
wholybee is offline   Reply With Quote
Old 07-06-2023, 18:35   #10
Registered User

Join Date: Jun 2023
Posts: 5
Re: imbalanced Tartan 34 C

thanks Warren for your comments.

Your question: How to measure?
The waterline is marked with a white line. On one side, the line is about 2 inches above the water, on the other side, it is slightly submerged.
The boat is about 112'' wide at the water line (boom is 10 feet). This gives a 1.5 degree angle.
The mast is leaning to port consistent with that angle. That is clearly visible.
displaces 5 t. Making some assumptions how the ballast and other materials are distributed (I don't have drawings) then allows to calculate the additional mass on the port side. This mass is about 500lb.

What I do not understand: the boat seems on average above the marked waterline (2.5") and thus is NOT more submerged as a missing buoyance or an additional weight would suggest. So it looks there is missing mass on the starboard side. I have no idea what this "missing mass" could be. (The water tank on the starboard side (~50 gallons) is nearly full.
fjweke is offline   Reply With Quote
Old 07-06-2023, 19:00   #11
Registered User

Join Date: Mar 2016
Location: San Francisco
Boat: Morgan 382
Posts: 2,137
Re: imbalanced Tartan 34 C

Quote:
Originally Posted by fjweke View Post
thanks Warren for your comments.

Your question: How to measure?
The waterline is marked with a white line. On one side, the line is about 2 inches above the water, on the other side, it is slightly submerged.
The boat is about 112'' wide at the water line (boom is 10 feet). This gives a 1.5 degree angle.
The mast is leaning to port consistent with that angle. That is clearly visible.
displaces 5 t. Making some assumptions how the ballast and other materials are distributed (I don't have drawings) then allows to calculate the additional mass on the port side. This mass is about 500lb.

What I do not understand: the boat seems on average above the marked waterline (2.5") and thus is NOT more submerged as a missing buoyance or an additional weight would suggest. So it looks there is missing mass on the starboard side. I have no idea what this "missing mass" could be. (The water tank on the starboard side (~50 gallons) is nearly full.
It really sounds like the boat is just packed heavier on one side. Or built heavier on one side. Maybe it was built to be balanced with the tank full, but missed the mark. Lots of boats list 1.5 degrees. My boat lists to starboard by about that. That is a lot less than the 3-5 you originally said. It is difficult to design and build a boat exactly balanced port/starboard, so would just be fixed by how you pack it. A boat that size might have 1000lbs of gear. That is a lot of weight you can choose where goes to balance it. Also, the waterline can be very difficult to paint. The painted waterline should be a couple inches above the true waterline. I have seen them as much as 6 or 7 inches above, to an inch below. So that isn't an indicator of missing or extra mass.

Where are your batteries? How many and what type? You could easily have a couple hundred lbs of weight from them which probably was not part of the original design. Inverter? Tools? Diesel tank? Spare anchor or chain?

It is good to get to know your boat and investigate something like this. Maybe there is a real problem. But also possible, you might not find anything wrong. Did you get a survey before purchase?
__________________
-Warren
wholybee is offline   Reply With Quote
Old 07-06-2023, 19:08   #12
Registered User
 
malbert73's Avatar

Join Date: Jun 2008
Boat: Tartan 40
Posts: 2,341
Re: imbalanced Tartan 34 C

I am sure this is nothing to do with water in your keel which is full of lead and filler or fiberglass. I am sure itís gear or tankage or the engine. Just store some heavy stuff on the high side to level it and go sailing.
You could also join the Groups IO Tartan owners group and post there. This may be a T34 thing
malbert73 is offline   Reply With Quote
Old 07-06-2023, 19:20   #13
Registered User

Join Date: Dec 2007
Location: Hawaii
Boat: Tartan T4400
Posts: 358
Re: imbalanced Tartan 34 C

Fjweke have you tried asking this on the 34 Classic Association web page? (https://tca34.clubexpress.com/) Have you looked on the Tartan Yachts page in the classic section at the drawing and owners manual. You might call Tartan and aks them, they have a wealt of knwedgle. Also the Tartan Owneners group of New Egland is helpful.
__________________
Aloha
Mike
Gudgeon is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
imbalanced Tartan 24C fjweke Multihull Sailboats 6 05-06-2023 11:57
To Tartan or not to Tartan Cap Morgan Monohull Sailboats 67 02-03-2022 06:33
For Sale: Tartan Sailboat Sails 1979 Set 27'Tartan Sailboat August West General Classifieds (no boats) 0 29-09-2021 21:53
Tartan 34 and Morgan 32 maui Monohull Sailboats 3 15-01-2016 21:28
Tartan 34 maui Monohull Sailboats 3 02-02-2014 14:17

Advertise Here


All times are GMT -7. The time now is 16:16.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2023, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2023, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.