A question about boat weight and displacement
 

A question about boat weight and displacement
 

"Ante Topic Mimara" ] wrote
Exactly where to I have to go to find out what the requirements
for trailering are?

Are you in USA? which state?

A question about boat weight and displacement
 

"Ante Topic Mimara" ] wrote
Exactly where to I have to go to find out what the requirements
for trailering are?

Are you in USA? which state?

A question about boat weight and displacement
 

On 1 Apr 2004 14:14:19 -0000, Ante Topic Mimara wrote:


I am having trouble attempting to determine the weight
of a boat, with limited information about it.
[snip]

Here is the information I have on this vessel:

Displacement: 6,075 lbs

When its design displacement is 6075 lb of water, it weighs 6075 lb.

Just because you don't understand why, doesn't mean the answer is
wrong.

If you don't want to weigh the boat, but you can find the actual
waterline - say a scum line? and can work out the SUBMERGED volume
[that means the volume of hull that is under the waterline,]
then multiply that volume by the weight per volume of the local water,
you have a reasonably accurate weight for the boat as configured,
i.e. an ACTUAL displacement.

Brian Whatcott Altus OK

A question about boat weight and displacement
 

On 1 Apr 2004 14:14:19 -0000, Ante Topic Mimara wrote:


I am having trouble attempting to determine the weight
of a boat, with limited information about it.
[snip]

Here is the information I have on this vessel:

Displacement: 6,075 lbs

When its design displacement is 6075 lb of water, it weighs 6075 lb.

Just because you don't understand why, doesn't mean the answer is
wrong.

If you don't want to weigh the boat, but you can find the actual
waterline - say a scum line? and can work out the SUBMERGED volume
[that means the volume of hull that is under the waterline,]
then multiply that volume by the weight per volume of the local water,
you have a reasonably accurate weight for the boat as configured,
i.e. an ACTUAL displacement.

Brian Whatcott Altus OK

A question about boat weight and displacement
 

Brian Whatcott wrote:

When its design displacement is 6075 lb of water, it weighs 6075 lb.

Just because you don't understand why, doesn't mean the answer is
wrong.

I have read many reviews of new boats by architects and others, and
unfailingly the review features a discussion of how close the actual boat
(i.e., the "thing" that is launched and refuses to sink) comes to the
architect's design specifications. Rarely does the "design displacement"
coincide with the weight (i.e., mass) of the boat in the water.

I am speaking of a new vessel before the owner has gotten his slimy hands on
it and starting loading the "must haves," before the sailmaker has bent on
the "absolute minimum" inventory, loading all the while the remaining bags
in the vee birth where "I thought that's where we were going to sleep," etc.

This seems to be the case not only for one-offs, but also for production
boats with long runs . My boat had (has?) a design displacement of 9000
pounds. I once had her picked somewhere in Florida by a crane with a load
sensor, and the empty boat was much heavier that the "dd." I am trying to
be fair and take into account whatever I myself did to make things heavier,
but even when I do this the difference is very significant. Very.

It's the rare architect who can do a good match between "design
displacement" and the actual weight of the vessel. Certainly a lot of the
difference must be attributed to the builder and what happens in the mold
shop and elsewhere along the way. Just to be an old codger about all this,
I'd say that most of the architects who could do this have been dead for
some time now.


--
Good luck and good sailing.
s/v Kerry Deare of Barnegat
http://kerrydeare.home.comcast.net/

A question about boat weight and displacement
 

Brian Whatcott wrote:

When its design displacement is 6075 lb of water, it weighs 6075 lb.

Just because you don't understand why, doesn't mean the answer is
wrong.

I have read many reviews of new boats by architects and others, and
unfailingly the review features a discussion of how close the actual boat
(i.e., the "thing" that is launched and refuses to sink) comes to the
architect's design specifications. Rarely does the "design displacement"
coincide with the weight (i.e., mass) of the boat in the water.

I am speaking of a new vessel before the owner has gotten his slimy hands on
it and starting loading the "must haves," before the sailmaker has bent on
the "absolute minimum" inventory, loading all the while the remaining bags
in the vee birth where "I thought that's where we were going to sleep," etc.

This seems to be the case not only for one-offs, but also for production
boats with long runs . My boat had (has?) a design displacement of 9000
pounds. I once had her picked somewhere in Florida by a crane with a load
sensor, and the empty boat was much heavier that the "dd." I am trying to
be fair and take into account whatever I myself did to make things heavier,
but even when I do this the difference is very significant. Very.

It's the rare architect who can do a good match between "design
displacement" and the actual weight of the vessel. Certainly a lot of the
difference must be attributed to the builder and what happens in the mold
shop and elsewhere along the way. Just to be an old codger about all this,
I'd say that most of the architects who could do this have been dead for
some time now.


--
Good luck and good sailing.
s/v Kerry Deare of Barnegat
http://kerrydeare.home.comcast.net/

A question about boat weight and displacement
 

On 1 Apr 2004 14:14:19 -0000, Ante Topic Mimara
] wrote:

writes:

Ante Topic Mimara wrote:

I am having trouble attempting to determine the weight
of a boat, with limited information about it.
[snip]

Here is the information I have on this vessel:

Hull Material: Wood
LOA: 28'
Beam: 10'-6"
Displacement: 6,075 lbs
Draft: 2'-2"

With a beam of 10' 6" won't you will be towing an oversize
load which will require a special permit and special
arrangments each time that you tow this boat only during
daylight hours?

This is something I had not considered...

Exactly where to I have to go to find out what the requirements
for trailering are? I appreciate your having brought this up, and
I would also like to see you address the questions I originally
raised. How do you determine the actual WEIGHT of the vessel,
without being there to weigh it?

---
If the displacement given is correct, it is exactly the weight of the
boat when she floats to her designed lines. Often it is the catalog
weight of a boat, since they don't try to guess the weight of people,
etc.

It could be in error by half a ton either way, but that should be
close enought for trailering purposes.



Rodney Myrvaagnes NYC J36 Gjo/a


"Curse thee, thou quadrant. No longer will I guide my earthly way by thee." Capt. Ahab

A question about boat weight and displacement
 

On 1 Apr 2004 14:14:19 -0000, Ante Topic Mimara
] wrote:

writes:

Ante Topic Mimara wrote:

I am having trouble attempting to determine the weight
of a boat, with limited information about it.
[snip]

Here is the information I have on this vessel:

Hull Material: Wood
LOA: 28'
Beam: 10'-6"
Displacement: 6,075 lbs
Draft: 2'-2"

With a beam of 10' 6" won't you will be towing an oversize
load which will require a special permit and special
arrangments each time that you tow this boat only during
daylight hours?

This is something I had not considered...

Exactly where to I have to go to find out what the requirements
for trailering are? I appreciate your having brought this up, and
I would also like to see you address the questions I originally
raised. How do you determine the actual WEIGHT of the vessel,
without being there to weigh it?

---
If the displacement given is correct, it is exactly the weight of the
boat when she floats to her designed lines. Often it is the catalog
weight of a boat, since they don't try to guess the weight of people,
etc.

It could be in error by half a ton either way, but that should be
close enought for trailering purposes.



Rodney Myrvaagnes NYC J36 Gjo/a


"Curse thee, thou quadrant. No longer will I guide my earthly way by thee." Capt. Ahab