Maybe a good way to start the maritime ships is by choosing hull form and
length.
Hull form could include planing, fine displacement (like a DD), full
displacement (like a cruiser), heavy displacement (like a BB), fat
displacement (like a merchant, maybe there'd be a super-fat displacement
for oil tankers, LSTs, etc.).
If you look at the naval architecture books, there should be some broad
general groups. Hull form would affect hull cost, volume available in the
hull, and then would be carried forward to a length table or formula.
In the table or formula you'd combine hull form with length and get a
maximum speed figure, because wetted area friction and wave generating
resistance would be a given. You'd also get a horsepower required to push
it at that speed, but it would be based on a given mass, i.e.,
displacement for that hull form, because extra mass above that pushes the
ship farther down into the water and increases friction. Then you'd know
how much hull volume you had to put things into. Then you'd have to look
and see what you had room for. That's why battlecruisers were both longer
than battleships of the same generation as well as having fewer turrets
and less armor, because they had to reserve that displacement/mass for
their massive powerplants.
That should actually work, and take some of the recursion out of the way
it actually worked historically. Historically, someone would say, "we want
a battleship with 9x16 inch guns, capable of 27 knots, and armored against
16 inch gunfire." and the designers would find out, "well, you can't build
that on the current length of a BB hull, or with current power plants, but
we can lengthen it..." This way you'd start with length and know what you
could do with it, and answer the question, "what can I fit into it?"
The system will still be relatively recursive, but it can actually get at
the real issues in ship design.
Certainly Enterprise, and many other carriers would be on cruiser hulls,
as well as Iowas. Which explains why Big E is so long, and has 8 reactors.
I don't believe that we would bother to get into wetness. Actually we
could, just by saying, hulls of this form above a certain % over their
base displacement would be wet, and that could be seen as -modifiers on
actions using them, such as gunnery from spray-covered mounts, ship
piloting tasks, etc.
We'd also have to deal with superstructure decks, which would obviously
add displacement. All carriers have at least one full superstructure deck,
and probably count the hangar deck and flight deck as two full
superstructure decks. Which is how the girls are so tall while at the same
time being so deep and heavy.
So what is required is coming up with the table/formula that says, given
this hull form and length, what is maximum speed and horsepower required
to meet that on base mass/displacement. That could be done.
If I had had that epiphany 18 or 19 years ago, there might be a FF&S
maritime ship design system. But I was either dumber then or too busy
solving other problems to give my brain a chance to work on it.
Dave
> Time to grab GURPS Vehicles, GURPS Traveller, and request a week of time
> off from work?
>
> Todd Kes
>
> --- On Tue, 7/3/12, John Potter wrote:
> FF&S doesn't really support it.
> Dave discussed this fact a week or so ago on this group list. In essence
> there is not way to account for the fluid dynamics required with
> interactions between water/fluid and the hull shape.
>
length.
Hull form could include planing, fine displacement (like a DD), full
displacement (like a cruiser), heavy displacement (like a BB), fat
displacement (like a merchant, maybe there'd be a super-fat displacement
for oil tankers, LSTs, etc.).
If you look at the naval architecture books, there should be some broad
general groups. Hull form would affect hull cost, volume available in the
hull, and then would be carried forward to a length table or formula.
In the table or formula you'd combine hull form with length and get a
maximum speed figure, because wetted area friction and wave generating
resistance would be a given. You'd also get a horsepower required to push
it at that speed, but it would be based on a given mass, i.e.,
displacement for that hull form, because extra mass above that pushes the
ship farther down into the water and increases friction. Then you'd know
how much hull volume you had to put things into. Then you'd have to look
and see what you had room for. That's why battlecruisers were both longer
than battleships of the same generation as well as having fewer turrets
and less armor, because they had to reserve that displacement/mass for
their massive powerplants.
That should actually work, and take some of the recursion out of the way
it actually worked historically. Historically, someone would say, "we want
a battleship with 9x16 inch guns, capable of 27 knots, and armored against
16 inch gunfire." and the designers would find out, "well, you can't build
that on the current length of a BB hull, or with current power plants, but
we can lengthen it..." This way you'd start with length and know what you
could do with it, and answer the question, "what can I fit into it?"
The system will still be relatively recursive, but it can actually get at
the real issues in ship design.
Certainly Enterprise, and many other carriers would be on cruiser hulls,
as well as Iowas. Which explains why Big E is so long, and has 8 reactors.
I don't believe that we would bother to get into wetness. Actually we
could, just by saying, hulls of this form above a certain % over their
base displacement would be wet, and that could be seen as -modifiers on
actions using them, such as gunnery from spray-covered mounts, ship
piloting tasks, etc.
We'd also have to deal with superstructure decks, which would obviously
add displacement. All carriers have at least one full superstructure deck,
and probably count the hangar deck and flight deck as two full
superstructure decks. Which is how the girls are so tall while at the same
time being so deep and heavy.
So what is required is coming up with the table/formula that says, given
this hull form and length, what is maximum speed and horsepower required
to meet that on base mass/displacement. That could be done.
If I had had that epiphany 18 or 19 years ago, there might be a FF&S
maritime ship design system. But I was either dumber then or too busy
solving other problems to give my brain a chance to work on it.
Dave
> Time to grab GURPS Vehicles, GURPS Traveller, and request a week of time
> off from work?
>
> Todd Kes
>
> --- On Tue, 7/3/12, John Potter wrote:
> FF&S doesn't really support it.
> Dave discussed this fact a week or so ago on this group list. In essence
> there is not way to account for the fluid dynamics required with
> interactions between water/fluid and the hull shape.
>