Spaceships: Missile launchers and their individual mass

[d_ns]

Pardon if this has been covered elsewhere...

Oh, and warning! Math ahead!

So, according to the Spaceships PDF, as missiles increase in diameter by initially 4cm, and eventually 8cm at a time, their mass increases by a factor no higher than 2.0. At the same time, based on the unloaded mass calculations, launchers themselves, increase in mass by a factor no less than 3.0.

Is this as expected? Is the machinery required to deal with launching missiles likely to increase in size more rapidly than the missiles themselves? The numbers begin to get, well, pretty crazy over time:

Missile  Unloaded   Missile   Missile   Magazine  Magazine  Total Ammo  Launcher  Launcher
 Size      Mass    Unit Mass  Multiple  Capacity  Multiple     Mass       Mass    Multiple
-------  --------  ---------  --------  --------  --------  ----------  --------  --------
20cm       1.5        0.20       --         7        --         1.40       0.10      --

24cm       5.0        0.33      1.67       10       1.43        3.33       1.67     16.7

28cm      15.0        0.50      1.5        15       1.50        7.50       7.50      4.5

32cm      50.0        1.00      2.0        20       1.33       20.00      30.00      4.0

40cm     150.0        2.00      2.0        30       1.50       60.00      90.00*     3.0

48cm     500.0        3.00      1.5        50       1.67      150.00     350.00*     3.9
 
56cm    1500.0        4.00      1.33       70       1.40      280.00    1220.00*     3.5

64cm    5000.0        7.50      1.88      100       1.43      750.00    4250.00*     3.5

*  Weapons at this size begin to include workstations; 1 at 40cm, 3 at 48cm, 10 at 56cm and 30 
   at 64cm. Working from somewhere between a Control Room station and a Passenger Seat, we can 
   call this roughly one ton per workstation, reducing the size of the weapon itself by insignificant 
   numbers (from just over 1% to just over 0.7%)

Imagine my surprise; I started this project thinking that smaller missile launchers ought to have larger magazines than the big ones - boy was I wrong!

In point of fact, I begin to think that the magazine size for these launchers needs to be growing at a much higher rate, to keep the launchers themselves (and the attendant hardware, etc) from growing beyond all common sense.

Thoughts?

[mearrin69]

Hmmm. I don't really do math. :) BUT...each higher size launcher also includes quite a few more (larger) missiles and that means a lot of structure for racking them, transporting them, etc. Take a look at the deckplans I made for our Star Trek game (hope you can see it without being a member):

http://www.cartographersguild.com/al...chmentid=39236

This is based on some plans I found on the Internet, but I think they're licensed and thus approved by Paramount. We never see inside a ST ship's torpedo bay in any show but I'd say this machinery looks plausible...and there's a lot of it. That would be a pretty bulky bunch of tritanium or duralloy or whatever. The ship is a Nova-class, which I'm pegging at SM+12 and the Spaceships worksheet I'm using gave me 56cm torps.

Don't know if that helps at all. I'm just using spaceships for a rough framework but I've been happy with the way the weapons/shields/armor have scaled. It turned out very Star Trek like without a lot of work on my part.
M

[Fred Brackin]

Originally Posted by mearrin69

http://www.cartographersguild.com/al...chmentid=39236

This is based on some plans I found on the Internet, but I think they're licensed and thus approved by Paramount. We never see inside a ST ship's torpedo bay in any show but I'd say this machinery looks plausible...and there's a lot of it.

The plan looks like the offcial stuff used in DecipherTrek Not that I consider the Paramount stamp proof of accuracy. Paramount does not appear to given a Regulan Silme Worm's end segment about any of this.

We do see a torpedo bay insides in Wrath of Khan and then.... I think the 6th movie. A photon torpedo casing is about the size of a coffin if the edges were rounded off.

Of course, Voyager only hit the Delta Quadrant with about 40 of the things so doctrine may be much more important to StarFleet than physical possibilities.

I didn't try and look at the math too closely becasue I know the mass of a Spacships Missile Launcher (all things included) is always 5% of the ship's nominal mass (300 tons, 1000 tons. 3000 and so on). That's just the way Spacships works.

<shrug? Maybe I've missed the point.

[d_ns]

each higher size launcher also includes quite a few more (larger) missiles and that means a lot of structure for racking them, transporting them, etc.

Yup, I definitely allow for larger missiles (by mass) and more of them. I'm just not sure that the machinery to move 4-ton missiles would go up to 1,220 tons, even if they are 56cm in diameter, when the 2-ton missiles were being managed by gear that massed 90 tons. It seems excessive to me.

I'm all for automation machinery and storage systems with heavy bulkheads and large, airy open rooms for the crew to work around the systems in, but this is inconsistent and that's what bothers me most.

I didn't try and look at the math too closely becasue I know the mass of a Spacships Missile Launcher (all things included) is always 5% of the ship's nominal mass (300 tons, 1000 tons. 3000 and so on). That's just the way Spacships works.

<shrug? Maybe I've missed the point.

Yeah, but I'm the first to admit it's pedantic.

A Major Weapon weighs 5% of the ship's mass, including it's ammunition. When we subtract that ammunition, the amount the actual launcher and associated non-ammunition machinery starts out at 1/3 of a percent of the mass, and goes up from there, eventually getting to the point that it's over 4% of the mass of the ship. For missiles that aren't, honestly, that much bigger in diameter.

Maybe the lengths are significantly more? But then, it's the missiles that should weigh more, not the launchers...

[Fred Brackin]

Originally Posted by d_ns

A Major Weapon weighs 5% of the ship's mass, including it's ammunition. When we subtract that ammunition, the amount the actual launcher and associated non-ammunition machinery starts out at 1/3 of a percent of the mass, and goes up from there, eventually getting to the point that it's over 4% of the mass of the ship. For missiles that aren't, honestly, that much bigger in diameter.

Maybe the lengths are significantly more? But then, it's the missiles that should weigh more, not the launchers...

Sorry, can't answer this one. Spaceships module design is non-transparent, even in playtest.

If this were the old days when G:Traveller modules were designed with Ve2 I could tell you something.

[Cuddle_Fish]

This touches on something I've been wondering for awhile - missiles, if one looks at both aircraft and naval vessels, in my understanding typically aren't carried in launchers that are reloaded in operation. You don't [as far as I am aware] have a magazine of 20 missiles to go with a single launcher system, you have an array of launchers - or just a few missiles, much larger relative to the platform carrying them than Spaceships missiles seem to be.

I've been wondering how to make something more like an Osa Class missile boat (http://en.wikipedia.org/wiki/Osa_class_missile_boat) - a small ship which carries a few very large, powerful missiles with the expectation being that once it fires it's payload it bugs out and goes home / is sunk / achieves some other form of resupply.

How would you guys represent this sort of "Single Missile / Small Number of Missiles" system in Spaceships? Similarly - is the "Magazine" of missiles intended to represent a large number of launchers rather than something where it's reloaded? If so, shouldn't the rate of fire be higher than that of a large gun, given you only need the time to lock a new target, prepare the missile to fire, etc?

[roguebfl]

Originally Posted by mearrin69

We never see inside a ST ship's torpedo bay in any show but I'd say this machinery looks plausible...

Actully we did see the inside of the one Torpedo Bays of the NX-01 the 'Armory' was part Torpedo Bay, we even saw the torpedos load a few times in combat when Lt. Reed was working from there instead of the Bridge.

[ericbsmith]

Originally Posted by roguebfl

Actully we did see the inside of the one Torpedo Bays of the NX-01 the 'Armory' was part Torpedo Bay, we even saw the torpedos load a few times in combat when Lt. Reed was working from there instead of the Bridge.

In Star Trek 2 they load Spock's body into a Torpedo Tube and fire it; the funeral scene just before it take place in the Torpedo Bay. There were several scenes in the Torpedo Bay prior to the funeral as well. In the big battle at the end of Star Trek 6 Spock performs surgery on a Torpedo while it's on the loading track then loads it into a tube to fire. In the Next Generation episode In Theory Data begins to court a crewwoman who apparently is a Torpedo Bay operator, as several of the scenes take place in the Torpedo Bay. OK, I had to look the last one up, but remembers the other two

[vierasmarius]

Something to consider in regards to nuclear warheads is the "Taming Explosions" damage option in Pyramid 3/34. This changes large explosives (above 100lb TNT equivalent) to use cube root of weight instead of square root, so they scale better with the HP of large vehicles. This drops the 25kt warhead from dDam 4d x 1000 (in vacuum) to around dDam 4d x 140. Not sure if a proximity blast should remain at 1/100 damage; if so, a 16cm nuke is far less scary, inflicting only about 20 dDam from a proximity detonation.

[Ulzgoroth]

Originally Posted by vierasmarius

Something to consider in regards to nuclear warheads is the "Taming Explosions" damage option in Pyramid 3/34. This changes large explosives (above 100lb TNT equivalent) to use cube root of weight instead of square root, so they scale better with the HP of large vehicles. This drops the 25kt warhead from dDam 4d x 1000 (in vacuum) to around dDam 4d x 140. Not sure if a proximity blast should remain at 1/100 damage; if so, a 16cm nuke is far less scary, inflicting only about 20 dDam from a proximity detonation.

Proximity detonation of nukes is a relatively unimportant consideration, really. The +4 to hit is nice but the really important thing about prox detonation is delivering large numbers of fragments to overwhelm PD, and nukes don't do that regardless.

However, it does allow for really large vehicles enduring or even (with extremely heavy armor) shrugging off small nukes.