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  #106  
Old 04-02-2014, 11:33 AM
frank smith frank smith is offline
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Originally Posted by Angélique View Post
The 36' Loose Moose ‘‘36’ offshore cruising sharpie’’ (designed by Selway Fisher and commissioned by Bob & Sheila Wise) is that the predecessor of the 38' Loose Moose II designed by Phil Bolger and commissioned by the same couple . . .
- - 36' Loose Moose
Attachment 89942 - - - Attachment 89943
- - click pics to enlarge
I dont like it.
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  #107  
Old 04-02-2014, 12:46 PM
ImaginaryNumber ImaginaryNumber is offline
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Even though Hogfish Maximus and Loose Moose II (Bolger version) are both 38’-long cruising sharpies, their specifications are quite different.

Hogfish Maximus
Length: 38 ft
Beam: 11 ft
Draft: 27” (7’-6” with daggarboard)
Displacement: 31,000 lbs
Ballast: 8,000 lbs
Sail Area: 658 sq ft to 1200 sq ft
Pointy bow, forefoot below water
Deep kick-up rudder

Loose Moose II (Bolger)
Length: 38 ft
Beam: 8 ft
Draft: 1 ft (5 ft with centerboard)
Displacement: 10,000 lbs ?
Ballast: 3,000 lbs
Sail Area: 438 sq ft
Transom bow, forefoot above water
Shallow bottom-sweeping rudder with horizontal end plate

Given their similarities and their differences, how do you think each would sail to windward, or downwind, or on a reach? How would each handle heavy water, or react in a broach, a knockdown or a rollover?
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  #108  
Old 04-02-2014, 01:01 PM
frank smith frank smith is offline
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Loose Moose is a the AS29 stretched, so it might be better to compare the as29 with Hogfish.
The forefoot being below water is of little consequence IMO.
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  #109  
Old 04-03-2014, 12:01 PM
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Angélique Angélique is offline
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Quote:
Originally Posted by ImaginaryNumber View Post

Even though Hogfish Maximus and Loose Moose II (Bolger version) are both 38’-long cruising sharpies, their specifications are quite different.
[ . . . ]
Given their similarities and their differences, how do you think each would sail to windward, or downwind, or on a reach? How would each handle heavy water, or react in a broach, a knockdown or a rollover?
Click on ‘‘Chris' profile page’’, then click on ‘‘Find all posts by Chris Morejohn’’, then click on ‘‘the first line of the shortened quotes’’ that show up to go to that specific post.

Best start bottom up and see also the responses. Chris has 9 posts on the thread so far, including the info (at least some of ?) that you ask for, that is if I recall it right.
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  #110  
Old 04-03-2014, 12:50 PM
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Angélique Angélique is offline
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Quote:
Originally Posted by ImaginaryNumber View Post

. . . . (assuming the off-centerboard is raised) . . . .
AS-29, AS-39, Loose Moose II, have an (off) centerboard.

Hogfish Maximus has no board but chine runners instead which together with her hull form provide the leeward resistance.

For info about chine runners see the Yrvind thread post #382, pics of Hogfish Maximus' chine runners are linked in the post below it.

See also the thread "Chine-Runners" greatest invention of 20th century?

--------------------------------------------------------------------------

P.S. - - I've made an addition to post #99 on this thread.
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  #111  
Old 04-03-2014, 04:23 PM
ImaginaryNumber ImaginaryNumber is offline
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Quote:
Originally Posted by Angélique View Post
AS-29, AS-39, Loose Moose II, have an (off) centerboard.

Hogfish Maximus has no board but chine runners instead which together with her hull form provide the leeward resistance.

For info about chine runners see the Yrvind thread post #382, pics of Hogfish Maximus' chine runners are linked in the post below it.

See also the thread "Chine-Runners" greatest invention of 20th century?

--------------------------------------------------------------------------

P.S. - - I've made an addition to post #99 on this thread.
Hogfish Maximus does have chine runners, but it also has a board, giving it a total draft of 7'6", board down. You can see the board in the drawing Chris linked to in post #69.

Actually, that is a variant of Chris's HFM that is shown earlier in this thread. Here, I think, is a more accurate drawing.



But what I'm really curious about is LM2. Compared to many modern sailboats HFM has a pretty "normal" length to beam ratio of ~3.5:1. But LM2 is atypically narrow at ~4.75:1, resulting in far less form stability than HFM. And since LM2 has no ballasted keel and so carries her ballast very high (like many sharpies, if they have any ballast at all), and since she has high topsides compared to many sharpies, it makes me wonder what a stability curve for her would look like? Will she heel quite a bit more than a typical ballested keel boat before firming up?

How difficult would it be for someone with boat design software to do a quick model of LM2 and produce a stability curve? I have blueprints of LM2, so can give more accurate dimensions and scantlings, if someone were willing.
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  #112  
Old 04-03-2014, 09:57 PM
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DennisRB DennisRB is offline
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Quote:
Originally Posted by ImaginaryNumber View Post
Even though Hogfish Maximus and Loose Moose II (Bolger version) are both 38’-long cruising sharpies, their specifications are quite different.

Hogfish Maximus
Length: 38 ft
Beam: 11 ft
Draft: 27” (7’-6” with daggarboard)
Displacement: 31,000 lbs
Ballast: 8,000 lbs
Sail Area: 658 sq ft to 1200 sq ft
Pointy bow, forefoot below water
Deep kick-up rudder

Loose Moose II (Bolger)
Length: 38 ft
Beam: 8 ft
Draft: 1 ft (5 ft with centerboard)
Displacement: 10,000 lbs ?
Ballast: 3,000 lbs
Sail Area: 438 sq ft
Transom bow, forefoot above water
Shallow bottom-sweeping rudder with horizontal end plate

Given their similarities and their differences, how do you think each would sail to windward, or downwind, or on a reach? How would each handle heavy water, or react in a broach, a knockdown or a rollover?
I was shocked to learn how heavy HFM was (although lightship is not given). I do wonder what her performance is like? Such a simple boat could be VERY light, which was my attraction to these designs along with the beach-ability.

I wonder if the form could have been built with say 1/4 of the fixed ballast and used a weighted board? This would have a good positive increase in performance. CM probably thought about it and dismissed it, favoring the less complicated approach. But I would like to hear his thoughts on it.
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  #113  
Old 04-03-2014, 10:11 PM
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DennisRB DennisRB is offline
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Here is something slightly related.

http://www.yachtdepo.com/yacht-sale/...by-bruce-kirby
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  #114  
Old 04-04-2014, 02:02 AM
sharpii2 sharpii2 is offline
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Quote:
Originally Posted by ImaginaryNumber View Post
...But what I'm really curious about is LM2. Compared to many modern sailboats HFM has a pretty "normal" length to beam ratio of ~3.5:1. But LM2 is atypically narrow at ~4.75:1, resulting in far less form stability than HFM. And since LM2 has no ballasted keel and so carries her ballast very high (like many sharpies, if they have any ballast at all), and since she has high topsides compared to many sharpies, it makes me wonder what a stability curve for her would look like? Will she heel quite a bit more than a typical ballested keel boat before firming up?...
You might be surprised.

Form stability is dictated by average WL Beam as opposed to average hull depth.

LM2, although quite narrow, has her Beam spread out over a considerable portion of her Length. She also has quite a shallow Hull Draft in relation to her Beam.

HFM, on the other hand, has a greater Hull Depth in relation to her Beam.

It is quite possible that LM2 has more form stability for her weight than HFM. She may even have more form stability altogether.

HFM, on the other hand, may get more of her stability from weight distribution, due to her proportionately deeper Hull sections.

Not only can her ballast ride deeper, but much of her heavier stores can too.

Ultimate stability is ruled, more or less, by the distance between the Center of Gravity (CG) and the Center of Enclosed Volume vs. the capsized WL Beam.

With both vessels, this enclosed volume is considerably higher than in more conventional ones, but this makes little difference, if the capsized CG is higher than the vessel's capsized Meta Center Height (which is proportionate to her Deck Width) the vessel will roll back onto her feet

These are the only factors that really matter.

If the CG shifts further toward the low side, when the boat is tipped, than the Center of Buoyancy (CB), the boat will right.

Both boats are likely to pass this test, or at least be considerably more more stable right side up than upside down.

As a more graphic illustration of this principle, see my attachment below.

Imagine this scow, as silly as it is, having an enclosed hull. Now imagine trying to get it to float upside down, with inside ballast attached to its bottom.

HFM is probably closer to having just over minimum form stability and LM2 is probably closer to having just over minimum ultimate stability.
Attached Thumbnails
Hogfish Maximus - 44ish sailing sharpie?-7fpursescow.png  
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Last edited by sharpii2 : 04-04-2014 at 02:07 AM. Reason: typos
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  #115  
Old 04-04-2014, 06:20 AM
ImaginaryNumber ImaginaryNumber is offline
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Thanks for your critique, sharpii2. What do you think LM2s stability curve would look like in the first 30 degrees of heel (higher winds, rougher sea state), compared, say, to a similar length/displacement cruising ballasted-keel sailboat, or compared to HFM?
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  #116  
Old 04-05-2014, 06:29 AM
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Angélique Angélique is offline
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Quote:
Originally Posted by ImaginaryNumber View Post

Hogfish Maximus does have chine runners, but it also has a board, giving it a total draft of 7'6", board down.
I stand corrected and should have reread or better looked in the first place before responding, thanks for the info
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  #117  
Old 04-05-2014, 11:17 AM
goodwilltoall goodwilltoall is offline
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Greetings,

Will write more but shorter posts since the last one was long and then site asked me to login again and when I did was not able to go back so post was erased.

Anyways, Hogfish's immersed forefoot and fat stern (unbalanced hull) is what would cause concern for me. Chris Morejohn being a very experienced sailor and the very heavy displacement can offset those but it would definitely be more prone to broaching in heavy weather especially because its a sharpie and their design history says to keep the forefoot closer to waterline or above and narrower stern.
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  #118  
Old 04-05-2014, 11:31 AM
goodwilltoall goodwilltoall is offline
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Pronounced rocker and ends well above the waterline would cause LM to handle waves just like the rough water surf rafts using the same principle although the light displacement and windage due to tall sides would cause it to be a very corky ride. Its L-B ratio is the redeeming factor that caused the design to be an overall success.

LM vs. Hogfish is apples vs. oranges, huge difference in beam width and especially the 12" vs. 27" draft.
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  #119  
Old 04-05-2014, 11:35 AM
goodwilltoall goodwilltoall is offline
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Would like to hear from Bob Wise as to how LM handled knockdowns. It was design to sail at 10-15 degree so going to 30 degree means something is very wrong. I'm sure Bolger designed in a decent recovery time at 90 degree but the shape just seems it would be almost stable on its side.

Selway/Fisher design was abandoned in favor of Bolger's
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  #120  
Old 04-05-2014, 03:12 PM
sharpii2 sharpii2 is offline
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Quote:
Originally Posted by goodwilltoall View Post
Would like to hear from Bob Wise as to how LM handled knockdowns. It was design to sail at 10-15 degree so going to 30 degree means something is very wrong. I'm sure Bolger designed in a decent recovery time at 90 degree but the shape just seems it would be almost stable on its side.

Selway/Fisher design was abandoned in favor of Bolger's
Nope.

You have to consider weight distribution as well as sectional shape.

You're probably thinking of a box with its CG at or very close to its Center of Enclosed Volume.

Now imagine this same box with a bunch of books packed into the bottom half and held in place so they could not shift or or move, in any way, in the box. Let's say the books in question weigh twice as much as the empty box itself, and the combined weight sinks the box one eighth its width deep

Now let's give the box a deep rectangular section where the sides are higher than, say, half the box's width.

Now try to get said box to float on its side.
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Last edited by sharpii2 : 04-05-2014 at 03:24 PM. Reason: Added comments.
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