Alternate Ship Design Systems

[TKalbfus]

Here is my list of Rocket Drives, these drives are also power plants of the same type, they can either deliver 1 EP of energy or 50 tons of thrust per unit.

I've increased the mass of these rocket engines to reflect the fractional g accelerations available in a Solar System campaign

Maneuver Drives
Type_________________ TL Size____ Cost____ Fuel Usage
Fission (50 tons)____ 7_ 200 tons__ Mcr 6___ 2.9 tons/min
Fusion (50 tons)_____ 9_ 1500 tons Mcr 4.5_ 7 tons/hour
Fusion (50 tons)_____ 13 1500 ton___ Mcr 3___ 3.5 tons/hour
Fusion (50 tons)_____ 15 1500 ton___ Mcr 3___ 0.18 tons/hour
Fusion (50 tons)_____ 16 1500 ton___ Mcr 3___ 0.09 tons/hour
Antimatter (50 tons)_ 17 100 ton___ Mcr 1___ 0.015 tons/day antimatter + 0.015 tons/day hydrogen


Does this satisfy you. There are no jump drives under this system as everything is a STL starship.

 

[TKalbfus]

I need to elaborate some what. The size listed is the minimum size not the incremental size.

For a fission rocket the first drive unit weighs 200 tons and produces 50 tons of thrust. Each additonal drive unit weighs 1/10th of that number listed under size so a fission rocket that delivers 100 tons of thrust would weigh 220 tons and use up 5.8 tons of fuel and reaction mass a minute. One that delivers 200 tons of thrust would weigh 260 tons and use up 11.6 tons of reaction mass per minute.

For a fusion rocket the first drive unit would weigh 1,500 tons and the second drive unit would weigh 1/50th of that amount or 30 additional tons per drive unit.

For antimatter rockets the first drive unit weighs 100 tons and each additional driveunit weighs 10 tons Antimatter is horrifically expensive however. At $600 per gram, the 0.015 tons per day would cost $9,000,000.

 

[TKalbfus]

Now for the Generationship itself. An O'Neill Island Three Cylinder is 6.5 km in diameter and 32 km long with a half-sphere endcap on each end. Adding the volume of a sphere to the volume of a cylinder we get a total volume of:

1.20569 x 10^12 cubic meters

In Traveller terms the displacement tonnage is:

86,120,714,290 dtons. Add an equivalent tonnage of liquid hydrogen and we get:

172,241,428,600 dtons for the Starship fully fueled.

We want an acceleration of 0.01g so to produce that we need to generate:

1,722,414,286 tons of force.

We need 34,448,286 Maneuver Drive units from the above table to generate this force.

We'll use a TL16 fusion rocket.

The first Manever drive unit of this type weighs 1500 tons and with 34,448,285 remaining at 30 tons each we have:

1500 tons + 34,448,285 x 30 tons = 1,033,450,050 tons for the displacement of the fusion rocket engine. The fusion reactor runs along the interior of the habitation cylinder and is fed by the giant hydrogen fuel tank just ahead of the habitation cylinder on the otherside of the forward endcap. This hydrogen tank acts as a very effective shield against cosmic rays and micrometeors. the length of the rocket engine goes through the center of the hab cylinder and out through the other endcap where the magnetic rocket nozzle is. Unlike the designs of theIsland Three space colony there are no 3 giant solar windows to let in sunlight. Instead the sunlight is generated artificially an a tube of glowing plasma attached to the outside of the fusion rocket engine.. The rocket engine uses hald its fuel supply at a rate of:

3,100,345.74 tons per hour and the ship uses up half its fuel supply in:

27,777 hours
or 3.17 years and reaching a speed of:

27,777 hours x 60 minutes x 60 seconds x (0.01+0.02)/2* 10 m/sec = 14,999,580 meters per second or 14,999 km/second as the cruise velocity.

14,999 km/sec / 300,000 km/sec = 0.049 c.

It will take 88 years for this generation ship to reach Alpha Centauri. So its 3.17 years of acceleration, 88 years of cruise and 3.17 years of slowing down.

 

[aramis]

My alternate ship design methodology was MT derived; I integrated some FF&Sisms, and fuly integrated WWF&S, HT, and COACC.

I got it mostly done, tried several designs, and lost it to a HD crash.

What did I learn:
</font>

• Armor needs to take volume, or it throws ship density calcs WAY off.</font>
• reduced fuel useage provides for ships with multi-year operational allowances, or 2-3 jumps... the two are mutuallly exclusive.</font>
• save early, save often! save remotely, too!</font>

I've also tinkered with using Starfire and Full Thrust as ship design sequences. Unfortunately, BITS going for BIG ships made compatibility with SGII impossible at listed rates for FT.

Starfire's methodology is VERY different; it's easier to simply put TL9=HT1, and use Starfire tech thereafter... and make the Starfire I drive required for opening a warp point... To make it work with the existing maps, I set the warp point as requireing an I drive equal to the parsec distance, with printed routes being easier to navigate. Traveller's J Drive size is insignificnt to the smaller ships, and not terrifically big; it's the fuel requirements thaat get one... and a conversion to Starfire for this is a PAIN in the arse... Starfire drives become smaller percentages of hull for larger ships.

The Albedo ship deisign system can be ported right over as a J1 drive.... and it is fairly realistic, yet no harder than HG.