Mass of an ISD

andrewgpaul · Post by **andrewgpaul** » 2005-02-21 05:00pm

is the actual mass of an ISD listed anywhere? a quick goggle didn't find anything; Saxton's site only seems to list external dimentsions.

Nearest I could find is B5tech saying an Omega (which is a similar length, although it looks to have a smaller volume) masses 44.6 million tonnes. However, given that it contradicts the show (it reckons B5 is 9billion tonnes, rather than 2.5 million (unless I'm misunderstanding the opening voiceover)), I'm reluctant to use that as a basis for a guess.

Post by **NecronLord** » 2005-02-21 05:38pm

Trillions. Maybe even Quadrillions or Quintillions of tons. Neutronium Armour isn't your friend.

andrewgpaul · Post by **andrewgpaul** » 2005-02-21 06:46pm

hmmm, back to the drawing board, then

I take it quadrillions and quintillions are 10e15 and 10e18, respectively?

Asst. Asst. Lt. Cmdr. Smi · Post by **Asst. Asst. Lt. Cmdr. Smi** » 2005-02-21 10:07pm

andrewgpaul wrote:hmmm, back to the drawing board, then

I take it quadrillions and quintillions are 10e15 and 10e18, respectively?

Yes. And I'm sure fuel would add a good bit of mass to the ship (IIRC, the AotC ICS said that the fuel stores on the Acclamator are orders of magnitude heavier than the rest of the ship).

Enforcer Talen · Post by **Enforcer Talen** » 2005-02-22 12:45am

by god, I want to crash one into a city.

Crayz9000 · Post by **Crayz9000** » 2005-02-22 01:29am

Admiral Daala wanted to ram one into Coruscant fresh out of hyperspace. She thought it would crack the planet's crust, although I severely doubt it would do that much damage. But whatever it would do, it would likely make a huge crater and trash most of one hemisphere.

Lone_Prodigy · Post by **Lone_Prodigy** » 2005-02-22 01:49am

A quintillion-ton spear smashing into a planet at significant fractions of c? That would certainly fuck up any planet to rediculous levels.

Post by **Vympel** » 2005-02-22 03:10am

NecronLord wrote:Trillions. Maybe even Quadrillions or Quintillions of tons. Neutronium Armour isn't your friend.

Well, that's a misnomer- it's not neutronium armor, the dura-armor is impregnated with neutronium pellets. How many is another question ...

Post by **NecronLord** » 2005-02-22 04:01am

Vympel wrote:Well, that's a misnomer- it's not neutronium armor, the dura-armor is impregnated with neutronium pellets. How many is another question ...

Yeah. I know. But still. It's armour. It has Neutronium in it. Thus, Neuronium armour.

Sarevok · Post by **Sarevok** » 2005-02-22 04:12am

Does the AOTC ICS say anything about the mass of an Accamalator ? If so maybe that mass can be scaled upto an ISD size to guess what the mass of an ISD might be.

Spanky The Dolphin · Post by **Spanky The Dolphin** » 2005-02-22 04:17am

No, it doesn't.

Murazor · Post by **Murazor** » 2005-02-22 04:22am

Mr Saxton has in his page a formula for power generation of ships using relativistic particles as impulse. It is IIRC: P = F * c, where F = mass of the ship * acceleration. There is an estimate for ISD's moving at top acceleration (calculated from Endor, I suppose) of ~1E25 w. Use it in combination with known accelerations for the Acclamator class, and you will get your answer, I suppose.

Murazor · Post by **Murazor** » 2005-02-22 05:56am

Murazor wrote:Mr Saxton has in his page a formula for power generation of ships using relativistic particles as impulse. It is IIRC: P = F * c, where F = mass of the ship * acceleration. There is an estimate for ISD's moving at top acceleration (calculated from Endor, I suppose) of ~1E25 w. Use it in combination with known accelerations for the Acclamator class, and you will get your answer, I suppose.

1E25 = (m * 3E4) * 3E8 = 1.1E12 kg or a trillion tons, for an average density of 12.345 g/cm^3 using the 9E7 cubic meters of the main site, which fits quite nicely with the presence of hypermatter and neutronium. If I screwed with the acceleration figure, it might be somewhat lower.

Connor MacLeod · Post by **Connor MacLeod** » 2005-02-24 01:06am

NecronLord wrote:Trillions. Maybe even Quadrillions or Quintillions of tons. Neutronium Armour isn't your friend.

Actually the vast majority of a the vessel's mass is going to be fuel. In fact, the mass of the ship itself is an insignfiicant fraction of it (orders of magnitude difference according to the AOTC ICS.

Connor MacLeod · Post by **Connor MacLeod** » 2005-02-24 01:13am

Murazor wrote:
Murazor wrote:Mr Saxton has in his page a formula for power generation of ships using relativistic particles as impulse. It is IIRC: P = F * c, where F = mass of the ship * acceleration. There is an estimate for ISD's moving at top acceleration (calculated from Endor, I suppose) of ~1E25 w. Use it in combination with known accelerations for the Acclamator class, and you will get your answer, I suppose.
1E25 = (m * 3E4) * 3E8 = 1.1E12 kg or a trillion tons, for an average density of 12.345 g/cm^3 using the 9E7 cubic meters of the main site, which fits quite nicely with the presence of hypermatter and neutronium. If I screwed with the acceleration figure, it might be somewhat lower.

Assuming 100% efficiency, an ISD is going to consume around e8 kg worth of fuel for each second of maximum output (ie e25 watts) given it can probably maintain this for several hours (about 3 I believe), the ship is going to contain a total mass of around e12 kg. Using the fuel/ship mass ratio mentioned in the AOTC ICS, we're probably talking an (empty) mass in the neighborhood of tens of millions of tons.

Another way to work it out is to figure the momentum of the ion stream (from the energy release - the e25 watt max output for the reactor corresponds to maximum acceleration, the most energy-intensive feat for the ship - therefore the ion strream ejected out the back of the ship should release e25 joules every second.) Knowing approximate acceleration (30 km/s^2 IIRC) and the momentum of the ion engine stream, one can figure out the mass.

EDIT: For the record, about 2e25 joules of relatavistic KE corresponds to a relatavistic mass of 8.2e16 kg*m/s. Divide the momentum by 3e4 m/s^2 acceleration and you get a ship's mass (including fuel) of 2.73e12 kg, or nearly 3 billion tons. This corresponds to a dry ship's mass of around 27 million tons.