Mast to cabintop turnbuckle

15 posts / 0 new
Last post
LeslieTroyer's picture
LeslieTroyer
Offline
Joined: 3/13/16
Posts: 533
Mast to cabintop turnbuckle

question regarding the turnbuckle inside the cabin connecting the mast and cabin top.   
1) when did Catalina start installing these??  By boat #92 doesn’t have one and there is no signs it ever did. 
2) is there a “tuning” guide for how tight to make it?
3) should I add one to my boat?  What difference does it make??

thanks

Les & Trish Troyer
Mahalo 
Everett, WA
1983 C-36 Hull #0094
C-36 MK 1 Technical Editor. 

Commodore

 

Chachere's picture
Chachere
Offline
Joined: 10/27/10
Posts: 826

Don't know the answers to #1 or 2; as to #3, my understanding is that it's purpose is to counteract the upward pressure that the halyard turning blocks exert on the deck, and that the early Mk1s didn't have the brace because all the halyards terminated at the mast.  A few prior threads on this that I recall reading may be helpful:

www.catalina36.org/forum/technical-discussion/what-brace-mast-cabin-roof

www.catalina36.org/forum/technical-discussion/under-deck-turnbuckle

www.catalina36.org/forum/general-discussion/mast-pressure-against-portside-bulkhead

Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY

LeslieTroyer's picture
LeslieTroyer
Offline
Joined: 3/13/16
Posts: 533

Thanks Matthew - 

Dont the two straps from the horse collar that are bolted to either side of the mast do the same thing??

Les & Trish Troyer
Mahalo 
Everett, WA
1983 C-36 Hull #0094
C-36 MK 1 Technical Editor. 

Commodore

 

pkeyser's picture
pkeyser
Offline
Joined: 5/18/13
Posts: 679

Per our surveyor's input- the turnbuckle should be only slightly snugged (just beyound hand tight). The purpose is to stregthen the cabin roof and minimize "oil canning" from the loads on the hull. Water pressure pushing against the hull sides wants to push the cabin roof upwards. The turnbuckle pulls the cabin roof down. He mentioned old sailing ships incorporated this design to increase strength. On some of the boats we looked at, the turnbuckle had been over torqued and the U Bolt nuts were compressing the cabin roof, creating stress cracks and possibly other damage. He pointed out Catalina should have used larger washers, or better yet, a stainless plate to spread the load- which is what we did. 

Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B

Attachments
AttachmentSize
Image icon fullsizeoutput_4d32.jpeg1.65 MB
Chachere's picture
Chachere
Offline
Joined: 10/27/10
Posts: 826

[quote=LeslieTroyer]Thanks Matthew - 

Dont the two straps from the horse collar that are bolted to either side of the mast do the same thing??[/quote]
Don't know what you are referring to, don't think we have that on our boat(perhaps post a picture?). 
Maybe it was a fix that was implemented by a prior owner?

Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY

LeslieTroyer's picture
LeslieTroyer
Offline
Joined: 3/13/16
Posts: 533

I️ will be up at the boat this weekend and get pictures
 

Les & Trish Troyer
Mahalo 
Everett, WA
1983 C-36 Hull #0094
C-36 MK 1 Technical Editor. 

Commodore

 

pkeyser's picture
pkeyser
Offline
Joined: 5/18/13
Posts: 679

Matthew-
Here's a partial view of the cabin/mast turnbuckle. I don't have a shot of the entire view.
Paul

Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B

Attachments
AttachmentSize
Image icon fullsizeoutput_4d71.jpeg676.69 KB
Chachere's picture
Chachere
Offline
Joined: 10/27/10
Posts: 826

-

Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY

LeslieTroyer's picture
LeslieTroyer
Offline
Joined: 3/13/16
Posts: 533

Here is a pic of the Port side of the mast/cabintop  I cant get a picture up too because of the mast boot. But the straps are welded to the ring that the halyard turning blocks attach to.  

Les

Les & Trish Troyer
Mahalo 
Everett, WA
1983 C-36 Hull #0094
C-36 MK 1 Technical Editor. 

Commodore

 

Attachments
Chachere's picture
Chachere
Offline
Joined: 10/27/10
Posts: 826

Les -
We don't have that setup on our 1985 boat, and I haven't seen that on others.  Either this was something that Catalina did on the early models instead of the turnbuckle, or more likely (from the appearances) it was something a prior owner fabricated.   Either way, it would seem to serve the same function as the turnbuckle.

Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY

LeslieTroyer's picture
LeslieTroyer
Offline
Joined: 3/13/16
Posts: 533

Thanks Matthew

I guess if some pre hull 100 pipes up here it will be a mystery - I don't know how many owners Mahalo has gone thru but quite a few - any of them could have done it, or it may have come from the factory that way..

Les

Les & Trish Troyer
Mahalo 
Everett, WA
1983 C-36 Hull #0094
C-36 MK 1 Technical Editor. 

Commodore

 

LeslieTroyer's picture
LeslieTroyer
Offline
Joined: 3/13/16
Posts: 533

Thanks Matthew

I guess if some pre hull 100 pipes up here it will be a mystery - I don't know how many owners Mahalo has gone thru but quite a few - any of them could have done it, or it may have come from the factory that way..

Les

Les & Trish Troyer
Mahalo 
Everett, WA
1983 C-36 Hull #0094
C-36 MK 1 Technical Editor. 

Commodore

 

pkeyser's picture
pkeyser
Offline
Joined: 5/18/13
Posts: 679

Here's a full picture of our mast to cabin turnbuckle.

Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B

Attachments
AttachmentSize
Image icon mast turnbuckle1.31 MB
LeslieTroyer's picture
LeslieTroyer
Offline
Joined: 3/13/16
Posts: 533

Thanks Paul.  I do know what they look like.  I’m wondering if we as an organization been a small write-up in the important notices section for the early boats that didn’t have them factory installed.  I think I have enough info for the post if I knew who to send it to for approval and posting

Les

Les & Trish Troyer
Mahalo 
Everett, WA
1983 C-36 Hull #0094
C-36 MK 1 Technical Editor. 

Commodore

 

pkeyser's picture
pkeyser
Offline
Joined: 5/18/13
Posts: 679

Les-
You can navigate via the tool bar at the top of the page- Go to Members-Technical-Submit Technical Article.
Paul

Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B

Log in or register to post comments