I'm going to point out something I haven't seen anyone mention. The issue of
system complexity. A larger system is a more complex system and this applies
in pretty much any area of engineering. A large ship has the same problems a
small ship does, but not just on a larger scale. It has an increased level of
interconnectivity between combat systems, it has a whole raft of problems
never seen in smaller ships which mean more engineering and possibly more
expense to solve (often differing systems), and it has to not only be more
costly in proportion to its increase in mass, but probably in proportion to a
power of the increasing mass. Anyone who has worked on systems on small
vessels and large vessels, or on small planes and large planes knows that some
of those systems need to be scaled up and the increase in complexity is not
linear.
Additionally, I suspect shipyard space, even if it is orbital, increases in
cost at more than a linear cost. Maybe less so than in aquatic equivalents,
due to the difference between orbit where I can slap similar yard modules
together and the ground where I need a bigger slip. But there is still an
increasing number of personel involved and coordination on these projects.
Anyone who has worked for IBM, Sun, Mutual Life, etc. (or the army) will
realize that as your work force gets larger, management increases. Not just in
numbers, but in levels. You get middle management. You get more overhead per
person. This isn't just waste, it represents the difficulties of coordinating
large worker pools. Also, as you get these larger groups, a screw up by one
person or group holds up a larger number of people and hence costs more than
on a smaller project. Hence your large ship constructions will run longer and
cost more just due to organizational complexity.
Must this be the case? Hmmm. I don't think we have one good example of where
it isn't. This relies more on the nature of large complex electronic,
mechanical, and human systems and organizations than it does on the
particulars of making any one subsystem (such as a beam 1
or beam 4). It is _possible_ that you could PSB
away these problems (or characteristics), but I don't think this has been
historically supported.
All one has to do is look at the Canadian Navy's relatively modest effort to
construct 12 frigates and how badly cost overrun and delayed some of the
systems have been (anyone heard of the HMCS Ville De Quebec?) to illustrate
the point. These are not huge ships. They aren't terribly more complicated
than many smaller vessels. They (if the people who believe in cheap large
projects and scaling linearly with mass are right) should have been
constructed far sooner, with far fewer problems, and with far less cost. It
didn't happen. This is only ONE example of this. Many exist.
The other thing is, on large scale projects, despite people making derisive
noises, the costs escalate due to the Military Industrial Complex's billing
and project management. On larger projects, managers fear larger looming
unknowns. (This applies to construction of a known class almost as much as to
construction
of a new class - note that rarely are two ships
of the same design truly the same due to continous upgrades during
construction which throw wrenches into things and these are consistently
occuring). So they budget in not just more gross amounts of time, but more
percentage wise. This also tends to increase the profit margin, because that
is a factor applied to the overall budget. So if the budget goes up due to
complexity or schedule fears, and if penalty payments and stuff go into it,
and profit is a percent of that, the whole gets more
expensive in a not-linear-with-mass way.
It isn't that it isn't (theoretically) possible to construct large ships in an
automated assembly
line fashion for a proportionate-to-mass cost. It
has just (AFAIK) been not done yet, or if so, done a heck of a lot fewer times
than the other
option (disproportionate-to-larger-mass costs).
Ultimately, this comes down to doing what you want. The costs in the game are
not quite right for one off combat, and work for small campaigns. They
probably aren't great for large scale campaigns (strategic games spanning
years or decades), but they were never meant to be. In general, they balance
(mostly) against one another if you use FB ships. If you design your own,
you'll have to apply good sense to realize where the system is likely to
break.
As I said, if you're building ships bigger than you have ever built, there is
extra r&d and lots of hidden pitfalls. This is not true if you're building
further copies of a ship that has already been built once in a size that is a
known quantity.
I'll bet the Ticonderoga was considerably more of a job than say the Hornet of
WWII because carriers were already fairly common then, whereas the Ticonderoga
was the first Aegis ship with the spy 1 radar and the combat information
center designed to control a carrier fleet. Point is that big ships don't
necessarily mean more complexity than small ones.
Plus what makes you think FT ships are constructed with a big workforce? Even
now robots almost completely construct some cars and computers, maybe the
shipyards are highly automated. So managing a big workforce may not be a
problem.
I don't know much about the Canadian navy, but if they were working on a class
of ship they're used to working on, and they weren't trying to do anything
they hadn't done before, then I don't think size would have that much to do
with their overruns.
> Plus what makes you think FT ships are constructed
That's fine, if you're building 10,000+ of the same
model. You can work out the bugs (logical, mechanical, and process) in your
assembly program on the first 100 to 500 units, just like the auto companies
do. But if you only build 30 vessels in the same class, with 60 customizations
(giving 17 configurations), you'll still be debugging the process when you
finish the last unit.
- Sam
Nobody builds 10000 of any ship. But as much of an assembly line as you have
in shipbuilding you can have with much smaller numbers. Plus I think we can
count on robots being more sophisticated in the future such that they can be
quickly reprogramed to do new tasks (something which is probably hard today).
And even today, you wouldn't actually have an SDN assembly line, you'd have an
assembly line building beam components, and hull plates, and furniture for
crew quarters and electronic consoles. Then you'd have the final assembly take
place in as modular a fashion as possible at the shipyard.
> --- Samuel Reynolds <sam@spinwardstars.com> wrote:
> On Fri, 29 June 2001, David Griffin wrote:
> I don't know much about the Canadian navy, but if
Even if you have a robotic ship building facility, complexity still increases
with size, and as Tom pointed out it isn't linear.
As the ship gets bigger, you have more "connectors" (whether it be points
where load bearing members connect and have to be welded, or
points where wires/fibres connect, or weapon mounts, what have you). You
have more of them, because your ship is bigger. Each one of these is a
potential point of failure. If you have 10 connectors in a destroyer and 100
connectors, you have 10 times the number of failure points in the larger ship.
The larger ship will likely have 10 times the failures of these parts.
However, there is a cascade relationship happening. One part breaks down,
resulting in stresses on other parts. This cascading effect is worse in the
big ship, and is the reason the complexity isn't linear.
Anyone in engineering, or in programming, knows this. A 500,000 line program
is more than 10 times more prone to failure than a 50,000 line program.
Now, throw into the mix the fact that other people are TRYING to make these
things break. They are warships, after all.
Even if building them is automated, a bigger ship will be more complex than a
smaller ship, and more than just in proportion to the size difference.
The question isn't is a Battleship more complex and harder to build than a
Destroyer. The question
is is a 200 mass battleship more trouble/complex/
expensive to build than 4 50 mass destroyers all put together. Are there
really more points of failure between say 1 big engine and 4 smaller engines?
Is it easier to maintain 2 small honda motorcycle engines than 1 larger honda
car engine?
Ok, so I'm not a naval architect or a construction engineer on ships. Is there
anyone on the list who
DOES have actual direct experience -- i.e. who is
a real expert? If not, all we have is speculation.
Remember I've already conceded that if you're trying to build a 250 mass ship
and you've only ever built 150 mass ships, you'll definitely have more than a
linear collection of problems. But if you're say the US and you decide you
need another Aircraft Carrier, that at least is something you've done before.
You may add some improvements, and some of those could have their
difficulties, but the basic job has already been done many times over. Our
shipbuilders already know how to build our nuclear aircraft carriers.
Likewise if you're building your first aircraft carrier and you've never done
carrier air operations before and you've never built a catapult before and
you've never had ships with that many crew before etc etc etc. THEN you better
stand by for many times your weight in wildcats (or Kzinti).
> --- agoodall@canada.com wrote:
> On Fri, 29 June 2001, David Griffin wrote:
> The question isn't is a Battleship more complex
Yes. As Tom and I both pointed out, it's not linear. 4 mass 50 destroyers are
4 times as complex than 1 mass 50 destroyer. 1 mass 200 battleship is more
than 4 times as complex as 1 mass 50 destroyer.
> Are there really more points of
Yes. For one thing, there's that whole question of inverse square and inverse
cube laws. Why can an ant carry many multiple times its own weight in food
when humans can't? A human being could never survive being 50 feet tall
because human bones just aren't strong enough (even if they were
proportionately bigger).
In a sphere, the surface area goes up as a cube of the diameter. This means
that a sphere twice the diameter has 8 times the surface area, and requires 8
times the material to cover that area.
> Is it easier to maintain 2 small honda
I'd say yes. That's a good example. It's far easier to lift a motorcycle
engine off its mounts than it is to lift a car engine. The car engine is just
too heavy. You need special tools, and correspondingly more time to lift a car
engine than a motorcycle engine.
> Ok, so I'm not a naval architect or a construction
Well, we're speculating about starships, so it will always be just
speculation. However a number of us work in technology industries where
complexity does not scale linearly.
I did some checking on the web. The only references I could find were to CVN
71 "Abraham Lincoln" and DDG 82 "Lassen". Now, the Lincoln was built in 1988,
the Lassen in 1999. It took 40 million manhours to build the Lincoln before it
was christened, and 2 million manhours to build the Lassen before she was
christened. Their masses are about 104,000 tons and 8500 tons, respectively
(though I also saw a reference to over 9000 tons for the Lassen).
This works out to 384.6 manhours per ton for the Lincoln, but only 234.3
manhours per ton for the Lassen. If complexity was linear with mass, those two
numbers should be about the same.
In another set of web sites, I found that the Lincoln cost approximately
US$4.5 billion to build. DDG 100 will cost $338.2 million. Note that this does
not take into account inflation and the true value of the dollar compared to
the building times. DDG 51, the first in the same class, was built in the
early 90s for $143 million.
In other words, the Lincoln is 12 times the mass of the Lassen. Yet, the
Lincoln took 20 times as long to build, and cost between 13.3 and 31.5 times
the price (with the higher number being more accurate, as it's in dollars of
about the same inflationary value).
So, while not exactly scientific, I think it shows that in today's real
world applications, a bigger ship costs more to build -- in time and
money -- per ton than smaller ships.
> David Griffin wrote:
> I don't know much about the Canadian navy, but if
> agoodall@canada.com wrote:
> On Fri, 29 June 2001, David Griffin wrote:
Your bad, this implies that surface area is linearly proportional to
volume, which is FALSE. The reason that the square-cube law prevents
fifty foot humans is that twice the height means eight times the mass,
but the cross-sectional area of the bones has only increased by a factor
of four, so the bones must handle twice the stress. Doubling the radius
of a sphere increases its volume by a factor of eight (4PiR^3)/3, but
only increases its surface area by a factor of four (4PiR^2), so a ship that
has twice the linear dimensions as another ship only needs half of the mass
per unit volume to skin the vessel.
Larger engines are easier to build to exacting tolerances than smaller
engines. It is hard to build a four stroke engine for a model plane, as the
absolute manufacturing precision is large compared to a 1.0 cubic inch engine
(a monster in RC flight), but marine diesels with displacements measured in
cubic meters can still have their parts manufactured to within 20 microns of
the spec, for a precision of one part in fifty thousand.
> > Ok, so I'm not a naval architect or a construction
The Lincoln has nuclear reactors and steam turbines, compared to the gas
turbines of the Lassen. The Lincoln also has a number of finicky systems that
are not found on destroyers, particularily deck edge lifts, ordnance handling
equipment, catapults and arrestor cables. A closer comparison is the
Enterprise and Long Beach. Your straight comparison also assumes that there
were no productivity improvements between 1988 and 1999.
> This works out to 384.6 manhours per ton for the Lincoln, but only
Note that this does not take into account inflation and the true value of the
dollar compared to the building times. DDG 51, the first in the same class,
was built in the early 90s for $143 million.
> In other words, the Lincoln is 12 times the mass of the Lassen. Yet,
On Fri, 29 Jun 2001 22:06:50 -0400, Richard and Emily Bell
> <rlbell@sympatico.ca> wrote:
> Your bad, this implies that surface area is linearly proportional to
D'oh! You're right!
> The Lincoln has nuclear reactors and steam turbines, compared to the
That's quite true. How much of the reason behind the reactors is because the
Lincoln is huge, and has huge power requirements for running the facilities
for launching aircraft? These would all partly go towards a ship of X mass
being more expensive than 4 ships of 1/4 X mass. The larger ships have
different requirements.
In other words, an FT SDN should cost more than 4 destroyers of 1/4 it's
mass, partly due to the stresses and strains on a huge ship, but also because
you DO pack things like fighter bays and huge weapon systems into them.
> A closer comparison is the Enterprise and Long Beach. Your straight
True. Couldn't find the information for those ships, though. But, the DDG 51
is the same clas as the Lassen. It was completed around '93. It's a closer
comparison than the Lassen, and it was the ship that only cost $143 million.
And, again, I didn't take into account 11 years worth of inflation.
Oh, and some of the systems on the Lassen are much more modern than the DDG
51, which goes towards explaining it's larger price tag.
> The problem is that the Lassen uses simpler propulsion and was the
DDG-51 was first in the class and about the same tonnage. It was less
than
1/30 the cost of the ship 12 times its mass. I think my comparison still
stands, particularly if you are looking to abstract some campaign ideas as to
why a big ship should cost more per ton than a small shp.
> Proper comparisons (if you could find them) would be between heavy
I think that's a good idea! Actually, I'm smacking my head. I have Conways
right here from 1860 to 1905. I would argue, though, that going too far back
you'd miss the impact of construction technology, which will accelerate in the
future. But it could provide an interesting comparison if the prices and times
could be found.
[quoted original message omitted]
> "Lexington/Saratoga" CVL
D`oh, I don`t know why I put CVL, when they were CVa`s or CVS (unsure which).
Probably a better example would be the Franklin D Roosevelt. Laid
down 1/12/43, compleated 27/10/45, full load displacement of 55000 tons,
at a cost of $90000000. It isn`t stated wether this includes fighters, but I
dought it.
On Sat, 30 Jun 2001 08:46:24 +0100, "Bif Smith"
<bif@bifsmith.fsnet.co.uk> wrote:
> How about this for a comparison of the costs Vs mass of ships, taken
Good information...
> This shows a big difference in costs as the size of the ship goes up,
Part of the problem is that early CVs were converted from other ships, with a
flat deck plopped on top.
The problem is that you don't have the actual important data: manhours. You
have time it was laid to the time it was completed. You have no way of telling
how many people actually worked on the vessel or for how long. Manhours gives
you the more accurate number.
But it's interesting information, nonetheless.
[quoted original message omitted]
On Mon, 2 Jul 2001 06:24:03 +0100, "Bif Smith"
<bif@bifsmith.fsnet.co.uk> wrote:
> That`s why I included the FDR in the second post. It was designed and
I replied before I saw the followup.
> I thought that during the war, these ships would all be built at the
They were built based on resources and strategic need. Remember that prior to
Coral Sea and Midway, the use of carriers was still pretty much theoretical,
Pearl Harbor not withstanding. The naval war in the Atlantic was an entirely
different beast with an emphasis on submarines and more "traditional" surface
ships. Carrier building accelerated incredibly in the latter part of the war.
The US had, what, 4 carriers in 1941? I remember from my World War II history
class at university that they had 140-odd carriers by war's end, with
another 50 in some stage of construction.
As for resources, early in the war ship construction was competing for steel
with the army. Carriers would also be pegged to the construction of naval
aircraft and the training of navy pilots. My point is that ship construction
wouldn't have been as fast as absolutely possible, nor would it necessarily be
as fast early in the war as later in the war.
Your data, though, is very, very useful. Thank you.