Pros and cons of steel sailboats - Page 267 - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Boat Review and Purchase Forum
 Not a Member? 


Like Tree1636Likes
Reply
 
LinkBack Thread Tools
  #2661  
Old 12-05-2013
mitiempo's Avatar
Senior Member
 
Join Date: Sep 2008
Location: Victoria B.C. Canada
Posts: 7,013
Thanks: 0
Thanked 64 Times in 55 Posts
Rep Power: 7
mitiempo will become famous soon enough mitiempo will become famous soon enough
Re: Pros and cons of steel sailboats

Quote:
Originally Posted by Jeff_H View Post
But I think that the second sentence above is probably a typo. I suspect that probably (and would agree with you if) you meant to say, there are cruising boats with D/L ratios under 200 that are very conservative and not super light racers, in fact not racers at all.
Sundeer 60 has a D/L of 82 and cruising weights were part of the design from the beginning. Pretty conservative I think.



If you compare the Sundeer to the Morris 51 (Paine) the numbers are interesting.

Length Sundeer 60' Morris 51'
W/L 59' 45'
Beam 13.75' 14.25'
Disp 37,800 35,000
Sail Area 1240 1134
Hull speed 10.29 8.99
Sail area/disp 17.61 16.96
D/L ratio 82 171

The Sundeer is not lighter as its D/L ratio suggests.
__________________
Brian
Living aboard in Victoria Harbour

Last edited by mitiempo; 12-05-2013 at 05:46 PM.
Reply With Quote Share with Facebook
  #2662  
Old 12-05-2013
grumpy old man
 
Join Date: Apr 2011
Posts: 3,552
Thanks: 1
Thanked 72 Times in 68 Posts
Rep Power: 4
bobperry will become famous soon enough
Re: Pros and cons of steel sailboats

"Originally Posted by mitiempo
I" think that the Displacement/Length ratio has nothing to do with the weight of a boat

Wrong!
D/L has everything to do with the weigtht of the boat, weight relative to DWL. That's the point.
Don't kid yourself. That Sundeer is way overweight. Look at how it's dragging its transom. Do you think it was designed to ride like that?

Paulo:
"but you have completely misunderstood what I wanted to say."
( I say that to my wife all the time.)
I only know what you say. If you say it incorrectly I can understand. But I am not a mind reader. There is no way I can know what you "wanted to say". I did think it was a very odd thing for you to say. But no problem. Your English is far better than my Portuguese or Spanish or French (you probably speak Italian too). So I applaud you for being able to communicate in English at the level you do. You contribute a lot here. Technical subjects are very difficult in a 2nd language. I struggle with Mandarin Chinese but I wouldn't attempt a technical discussion. We are very lucky as a group to understand each other as well as we do.

I think I'll go design a boat. But I'll make dinner first.
PCP likes this.
__________________
Please visit my blog. It's fun to read.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Bob's Blog ....


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by bobperry; 12-05-2013 at 06:22 PM.
Reply With Quote Share with Facebook
  #2663  
Old 12-05-2013
Jeff_H's Avatar
Moderator
 
Join Date: Feb 2000
Location: Annapolis, Md
Posts: 6,542
Thanks: 5
Thanked 85 Times in 65 Posts
Rep Power: 10
Jeff_H has a spectacular aura about Jeff_H has a spectacular aura about Jeff_H has a spectacular aura about
Re: Pros and cons of steel sailboats

Quote:
Originally Posted by mitiempo View Post
Lets take a boat like the Alberg 37, D/L of 403 on a 26.5' waterline. If the waterline is drawn out to say 32' it would be heavier with the added material weight, not lighter. But it would have a lower D/L ratio.

Maybe I can explain it like this. First of all, if we are comparing boats which were designed to have equal displacements but one was designed to have a longer waterline the boat with the longer waterline would have a lower D/L but by definition, if the boats has equal displacements, the weigh the same thing. So if we compare the Alberg 37 in your example with a waterline of 25.5feet, a 16,800 lb displacement and an L/d around 400, to something like the shoal draft version of a Hanse 370, with a waterline length of 33.63 feet and close to the same displacement, (we will assume for the moment equal displacement) that same 16,800 lb displacement would result in a L/D around 186.

That is a big drop and most folks might assume that the Hanse is a much lighter boat and therefore have a less comfortable motion. But the science would suggest that the Hanse with its longer waterline should have a better motion going upwind and down, and with its better dampening, higher roll moment of inertia, and lower vertical center of gravity should have a gentler roll motion through a narrower roll angle.

That was my point,
Jeff
Brent Swain likes this.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Curmudgeon at Large- and rhinestone in the rough, sailing my Farr 11.6 on the Chesapeake Bay and part-time purveyor of marine supplies
Reply With Quote Share with Facebook
  #2664  
Old 12-05-2013
mitiempo's Avatar
Senior Member
 
Join Date: Sep 2008
Location: Victoria B.C. Canada
Posts: 7,013
Thanks: 0
Thanked 64 Times in 55 Posts
Rep Power: 7
mitiempo will become famous soon enough mitiempo will become famous soon enough
Re: Pros and cons of steel sailboats

Quote:
Originally Posted by bobperry View Post
Wrong!
D/L has everything to do with the weight of the boat.
Don't kid yourself. That Sundeer is way overweight. Look at how it's dragging its transom. Do you think it was designed to ride like that?
From Steve Dashew's "Cruising Encyclopedia"

"Because of our low D/L ratios,stern waves are quite small in magnitude and quickly move aft of the hull itself once the vessel in question has attained a relatively modest forward velocity.
As a result, we design some of our hulls to have a small amount of immersed transom at rest and at low speeds (typically below S/L ratios of one).
Practical experience has shown that this immersion costs us between 4% of speed at S/L ratios of .4 to .6 andhalf of this between an S/L ratio of .6 and .8.
While this is a huge number in racing terms, it seems nearly meaningless in a cruising context.
If we are talking about 4% or 4 knots , it is less than 4 miles in a 24 hour passage.
And when you look at the advantages (better performance at top speed, more efficient powering, much better prop characteristics when powering into head seas, higher longitudinal stability) this seems like a small price to pay, especially in light of the fact that with an efficient powering set-up, you are going to be motorsailing on passages during light airs anyway - regardless of how fast the boat sails in these conditions."

The book also has a series of pictures showing the stern wave still attached to the transom at S/L ratios under 1 and astern of the transom at S/L ratios of 1.125 while heavily loaded in a true wind speed of 10 knots.

So according to Steve it is designed to immerse the transom at rest and at slower speeds for gains at higher speeds of 25 to 40 miles per day.

His designs have been focused on one thing - offshore cruising with couples in mind. They have done this quite well I think. On his blog there is a chart showing his designs and their mileage. 32 boats, 21 circumnavigations (including the one I pictured) and an average mileage per boat of over 55,000 miles. They seem to do well what they are designed for.
SetSail» Blog Archive » Deerfoot and Sundeer History
Brent Swain likes this.
__________________
Brian
Living aboard in Victoria Harbour
Reply With Quote Share with Facebook
  #2665  
Old 12-05-2013
mitiempo's Avatar
Senior Member
 
Join Date: Sep 2008
Location: Victoria B.C. Canada
Posts: 7,013
Thanks: 0
Thanked 64 Times in 55 Posts
Rep Power: 7
mitiempo will become famous soon enough mitiempo will become famous soon enough
Re: Pros and cons of steel sailboats

Quote:
Originally Posted by Jeff_H View Post
Maybe I can explain it like this. First of all, if we are comparing boats which were designed to have equal displacements but one was designed to have a longer waterline the boat with the longer waterline would have a lower D/L but by definition, if the boats has equal displacements, the weigh the same thing. So if we compare the Alberg 37 in your example with a waterline of 25.5feet, a 16,800 lb displacement and an L/d around 400, to something like the shoal draft version of a Hanse 370, with a waterline length of 33.63 feet and close to the same displacement, (we will assume for the moment equal displacement) that same 16,800 lb displacement would result in a L/D around 186.

That is a big drop and most folks might assume that the Hanse is a much lighter boat and therefore have a less comfortable motion. But the science would suggest that the Hanse with its longer waterline should have a better motion going upwind and down, and with its better dampening, higher roll moment of inertia, and lower vertical center of gravity should have a gentler roll motion through a narrower roll angle.

That was my point,
Jeff
Thanks, I always appreciate your posts as well as Bob's.

That is my point as well. A smaller D/L ratio is assumed to be a lighter boat but as your example shows it isn't necessarily so. My favorite type of boat is long, lean, with a max waterline for its length. I do not think in terms of any racing rule and think a boat without overhangs is sensible for both ultimate speed and longitudinal stability.
__________________
Brian
Living aboard in Victoria Harbour
Reply With Quote Share with Facebook
  #2666  
Old 12-05-2013
grumpy old man
 
Join Date: Apr 2011
Posts: 3,552
Thanks: 1
Thanked 72 Times in 68 Posts
Rep Power: 4
bobperry will become famous soon enough
Re: Pros and cons of steel sailboats

I really don't care what Dashew says. That boat is overweight. Displacement figures are highly suspect especially when they are published by a promoter like Dashew.
And yeah, the perfect cruising boat for everyone is a 60' to 80' custom yacht. Right.

I was getting dinner ready and thinking about Paulo's "what I wanted to say" and I was reminded of a funny story: I can relate.

Years ago in Taiwan I had just returned to my hotel from a nice lunch and the girls behind the front deck asked me what I had eaten for lunch. I always try hard to reply in Mandarin so I told them, "Woa cher shiatze". They all got a very surprised look on their faces. I knew I had screwed up and asked, "She mo she?" What's the matter? The head girl said in English, "You say you eat blind person for lunch!"

Oh, No, I told them , in English this time, I had shrimp for lunch. Turns out "blind person" and "shrimp" are only a tonal distance apart and I had used the wrong tone.
__________________
Please visit my blog. It's fun to read.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Bob's Blog ....


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by bobperry; 12-05-2013 at 07:05 PM.
Reply With Quote Share with Facebook
  #2667  
Old 12-05-2013
mitiempo's Avatar
Senior Member
 
Join Date: Sep 2008
Location: Victoria B.C. Canada
Posts: 7,013
Thanks: 0
Thanked 64 Times in 55 Posts
Rep Power: 7
mitiempo will become famous soon enough mitiempo will become famous soon enough
Re: Pros and cons of steel sailboats

The point I am making is that a boat with a lower D/L for its displacement will gain in speed and comfort as well probably. Certainly be more fun to sail. And it doesn't have to be 60 feet long either. I think to be able to carry the load a cruising boat needs really low D/L ratios only work with larger boats. If you look at smaller boats with almost equal displacements two in a smaller size range are the Saga 43 (D/L 160) and the Westsail 32 (D/L 429). Extreme examples but I picked the Westsail because it is almost the same displacement as the Saga, a boat I have always liked. The Saga is a few hundred pounds heavier but its D/L would suggest to many that it is a light boat. The Saga will carry 1 1/2 times as much before immersing an inch so a cruising load is less of an issue as well.
__________________
Brian
Living aboard in Victoria Harbour
Reply With Quote Share with Facebook
  #2668  
Old 12-05-2013
SloopJonB's Avatar
Senior Moment Member
 
Join Date: Jun 2011
Location: West Vancouver B.C.
Posts: 10,623
Thanks: 56
Thanked 48 Times in 45 Posts
Rep Power: 4
SloopJonB will become famous soon enough
Re: Pros and cons of steel sailboats

Uh oh.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
I, myself, personally intend to continue being outspoken and opinionated, intolerant of all fanatics, fools and ignoramuses, deeply suspicious of all those who have "found the answer" and on my bad days, downright rude.
Reply With Quote Share with Facebook
  #2669  
Old 12-05-2013
mitiempo's Avatar
Senior Member
 
Join Date: Sep 2008
Location: Victoria B.C. Canada
Posts: 7,013
Thanks: 0
Thanked 64 Times in 55 Posts
Rep Power: 7
mitiempo will become famous soon enough mitiempo will become famous soon enough
Re: Pros and cons of steel sailboats

Quote:
Originally Posted by VFerreira View Post
BS
BS or not it certainly worked for all the Sundeer owners many of whom have circumnavigated.
__________________
Brian
Living aboard in Victoria Harbour
Reply With Quote Share with Facebook
  #2670  
Old 12-05-2013
PCP's Avatar
PCP PCP is offline
Senior Member
 
Join Date: Dec 2004
Location: Portugal, West Coast
Posts: 16,160
Thanks: 21
Thanked 95 Times in 79 Posts
Rep Power: 10
PCP will become famous soon enough
Re: Pros and cons of steel sailboats

Quote:
Originally Posted by VFerreira View Post
BS

You mean Brent S. or the other kind of BS and in that case you are referring to what the Dashew says or to what Bob says or to what both say?.

It seems that you have somebody else that likes to make cryptic comments. One was enough

Regards

Paulo
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 13 (1 members and 12 guests)
mr_f
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Hunter 36 Pros and Cons? turfguy Hunter 13 03-24-2014 09:34 AM
C & C 24 pros and cons chuckg Boat Review and Purchase Forum 11 04-06-2012 12:45 AM
Pros and Cons of Catalina 350?? turfguy C350 6 10-16-2009 05:17 PM
Watermakers—Pros and Cons Tom Wood Cruising Articles 0 06-11-2002 08:00 PM
Steel Hulls—Pros and Cons Sue & Larry Buying a Boat Articles 0 09-12-2001 08:00 PM


All times are GMT -4. The time now is 10:26 PM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.