Reply
 
Thread Tools Search this Thread Display Modes
 
Old 07-04-2019, 01:02 PM   #1
Senior Member
 
wyoboater's Avatar
 
City: Clear Lake Shores,Tx
Country: USA
Vessel Name: In Disguise
Vessel Model: 1985 Mainship 40 DC
Join Date: Aug 2014
Posts: 485
Hull structural integrity

Ok, all you smart boat builder types:
I have a Luhrs Mainship 40DC. I want to basically gut the forward cabin, removing the platform the bed is made on...here's the question. Does that platform also perform double duty by strengthening and adding rigidity to the bow, or is it just a bed? Plan is to basically turn the forward cabin into a storage area for foodstuffs, etc when we do the Loop.
Thanks in response for your help.
__________________
Advertisement

wyoboater is offline   Reply With Quote
Old 07-04-2019, 01:39 PM   #2
Senior Member
 
fgarriso's Avatar
 
City: Desoto
Country: USA
Vessel Name: GOTCHA
Vessel Model: 1973 Alaskan 59-B PH
Join Date: Jun 2019
Posts: 170
Why no leave the platform in place and use as a storage platform.
__________________

__________________
Captain F. Lee - R.P.E.
USCG 200 ton Master
fgarriso is offline   Reply With Quote
Old 07-04-2019, 01:50 PM   #3
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 5,078
Quote:
Originally Posted by fgarriso View Post
Why no leave the platform in place and use as a storage platform.
+1. Then if you go to sell the boat you havenít killed the resale value of the boat.
Comodave is offline   Reply With Quote
Old 07-04-2019, 02:00 PM   #4
Senior Member
 
wyoboater's Avatar
 
City: Clear Lake Shores,Tx
Country: USA
Vessel Name: In Disguise
Vessel Model: 1985 Mainship 40 DC
Join Date: Aug 2014
Posts: 485
Because that's not my plan. I'm looking for an answer to a specific question.
wyoboater is offline   Reply With Quote
Old 07-04-2019, 02:03 PM   #5
Senior Member
 
fgarriso's Avatar
 
City: Desoto
Country: USA
Vessel Name: GOTCHA
Vessel Model: 1973 Alaskan 59-B PH
Join Date: Jun 2019
Posts: 170
Quote:
Originally Posted by wyoboater View Post
Because that's not my plan. I'm looking for an answer to a specific question.
Do you have all of the original engineering specs.
__________________
Captain F. Lee - R.P.E.
USCG 200 ton Master
fgarriso is offline   Reply With Quote
Old 07-04-2019, 02:46 PM   #6
Guru
 
psneeld's Avatar
 
City: AICW
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 19,633
While most boat structures usually add to some structural stiffness...really hard to say without pics or familiarity with the boat.


My guess .......removal might be OK but keep the boat out of an Atlantic hurricane....but if you need original boat integrity, only someone with specs or a great backyard engineering eye with pics can help.
psneeld is online now   Reply With Quote
Old 07-04-2019, 02:49 PM   #7
DDW
Guru
 
City: San Francisco
Country: USA
Join Date: Apr 2018
Posts: 818
Is the platform tabbed to the hull, or just set on the deck? If I was cutting things out tabbed to the hull, I would leave enough in place to act as stringers, or replace what I ground off with stringers. The usual concern is slamming loads, you want to break up the flat panels with something stiffer. The bed is not going to do much for torsion or bending in that area, but it may be substituting for stringers to resist slamming.
DDW is offline   Reply With Quote
Old 07-04-2019, 04:10 PM   #8
Guru
 
Join Date: Oct 2007
Posts: 838
Removing the bed completely will certainly lower the vessel value, regardless of whether it impairs hull integrity.
Not your plan but here is another idea!!
Leave the bed in place and cut access panels through the bed platform into the hull bilge area below. You might even be able to add a "floor" over that bilge section below the bed platform.
Chrisjs is offline   Reply With Quote
Old 07-04-2019, 04:31 PM   #9
Senior Member
 
fgarriso's Avatar
 
City: Desoto
Country: USA
Vessel Name: GOTCHA
Vessel Model: 1973 Alaskan 59-B PH
Join Date: Jun 2019
Posts: 170
I have no idea how much "stuff" you are planning on storing in the bow or what the gross weight is, but their is a couple of things you should consider.

The center of Gravity of the vessel.
The center of Bouncy of the vessel.
The stability curve of the vessel.

If not done you could wind up with a boat that no longer has enough bow lift for its displacement.
You may think everything is fine until you hit a big roller and find it on deck with you.

That is just my humble opinion, and means less than nothing as far as your boat goes.
__________________
Captain F. Lee - R.P.E.
USCG 200 ton Master
fgarriso is offline   Reply With Quote
Old 07-04-2019, 04:44 PM   #10
Guru
 
psneeld's Avatar
 
City: AICW
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 19,633
That could be true if he left the bed and added all the foodstuff as planned.
Removing the bed may help stability, but certainly structure is a definite concern as opposed to user operation.
psneeld is online now   Reply With Quote
Old 07-04-2019, 09:02 PM   #11
Senior Member
 
wyoboater's Avatar
 
City: Clear Lake Shores,Tx
Country: USA
Vessel Name: In Disguise
Vessel Model: 1985 Mainship 40 DC
Join Date: Aug 2014
Posts: 485
PS Sneed. I appreciate your answer, it seems the only one even attempting to address the question I asked. As far as hatch openings in the bed platform, they're already there, just a pia to get in and out of all the time..that's what I'm trying to fix. As far as weight distribution, I don't think that will be an issue. As far as the resale value, this boat was never purchased as an investment. We bought it to use and we want to make it as comfortable for US as possible..I wasn't asking for a critique of the idea, just if it was possible without sacrificing the seaworthiness of the vessel.
wyoboater is offline   Reply With Quote
Old 07-04-2019, 10:04 PM   #12
Guru
 
psneeld's Avatar
 
City: AICW
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 19,633
Thanks.. .it's just hard to give a better idea"old salt" opinion without seeing it.


Even resale is debatable as I know more than a few full time cruisers that convert now staterooms into storage, workshops, laundries, etc. And those boats get snapped up by other crusiers.
psneeld is online now   Reply With Quote
Old 07-04-2019, 10:51 PM   #13
Senior Member
 
Boat's Avatar
 
City: SchoolHouse Branch
Country: USA
Join Date: Jul 2018
Posts: 439
The difference between a partition and a bulkhead may be what you are looking for.

This link may not go to the best site but it gives you enough to get started.

https://www.yachtsurvey.com/HullFailPart1.htm


http://www.marinesurvey.com/yacht/Top25.htm
Boat is offline   Reply With Quote
Old 07-05-2019, 12:08 AM   #14
Guru
 
City: Boston
Country: US
Vessel Name: Adelante
Vessel Model: IG 30
Join Date: Nov 2016
Posts: 588
Quote:
Originally Posted by wyoboater View Post
I wasn't asking for a critique of the idea, just if it was possible without sacrificing the seaworthiness of the vessel.
And there is your answer. If you don't know if it's possible or not, then hire a marine architect who does know.
SoWhat is offline   Reply With Quote
Old 07-05-2019, 12:52 AM   #15
Guru
 
BruceK's Avatar
 
Join Date: Oct 2011
Posts: 9,822
Anything fixed to the inside of both sides of the hull is doing something,at the very least helping keep the two sides apart. Strength and stiffness too I expect. Don`t know how you determine how important or not it is, but tread carefully. Can you replace it with something less obtrusive or restrictive? An alloy tube laminated on?
As an analogy,we used to weld a steel tube between the McPherson Strut(?Slut) towers on rally cars.
__________________
BruceK
Island Gypsy 36 Europa "Doriana"
Sydney Australia
BruceK is offline   Reply With Quote
Old 07-05-2019, 05:19 AM   #16
Guru
 
O C Diver's Avatar
 
City: Fort Myers, FL... Summers in Crisfield, MD
Country: USA
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 7,424
Will you be putting anything back that could act as structural reinforcement? Wondering if you're plan might include cabinets or shelving that could be tabbed in for rigidity.

To your original question, I would look at the construction of the bed to see how strong the material is. When redoing my 35 Bruno and Stillman V berth area, it was quite clear that the material used and fabrication wasn't structural for the hull, but then most of those boats were built for commercial fishing, not charter boats.

Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
O C Diver is online now   Reply With Quote
Old 07-05-2019, 05:38 AM   #17
Senior Member
 
wyoboater's Avatar
 
City: Clear Lake Shores,Tx
Country: USA
Vessel Name: In Disguise
Vessel Model: 1985 Mainship 40 DC
Join Date: Aug 2014
Posts: 485
Thanks Ted
That's what made me think of the question. The structure of the bed platform seems pretty solidly built, as if it might be designed for dual purpose. Yes, I plan on cabinets, shelves, but nothing stretching across the entire space.
wyoboater is offline   Reply With Quote
Old 07-05-2019, 05:42 AM   #18
Senior Member
 
wyoboater's Avatar
 
City: Clear Lake Shores,Tx
Country: USA
Vessel Name: In Disguise
Vessel Model: 1985 Mainship 40 DC
Join Date: Aug 2014
Posts: 485
The Marine engineer idea has merit. I am just getting a general idea of the feasibility before I commit or not commit to the next step. Thanks.
wyoboater is offline   Reply With Quote
Old 07-05-2019, 06:15 AM   #19
Guru
 
O C Diver's Avatar
 
City: Fort Myers, FL... Summers in Crisfield, MD
Country: USA
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 7,424
Quote:
Originally Posted by wyoboater View Post
Thanks Ted
That's what made me think of the question. The structure of the bed platform seems pretty solidly built, as if it might be designed for dual purpose. Yes, I plan on cabinets, shelves, but nothing stretching across the entire space.
Can you confirm that the hull where the bed attaches, is shaped with compound curves? Also is there a floor under the bed and a substantial bulkhead that separates the chain locker from the cabin?

Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
O C Diver is online now   Reply With Quote
Old 07-05-2019, 07:32 AM   #20
Senior Member
 
wyoboater's Avatar
 
City: Clear Lake Shores,Tx
Country: USA
Vessel Name: In Disguise
Vessel Model: 1985 Mainship 40 DC
Join Date: Aug 2014
Posts: 485
Ted.
Yes to both.
__________________

wyoboater is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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





All times are GMT -5. The time now is 07:26 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012