Ship Design Philosophy

[Condottiere]

An interesting entry from Traders and Gunboats, from the Antique In-Systems Hauler TL8.

"They are large, use primitive versions of gravitic drives, and rely on dirty fission powerplants.

Manoeuvre Drive G.7, 26 tons and cost 42 MCr.

Compare to:

Fusion Rocket G, 13 tons and 28 MCr.

Assuming the above isn't a typo, large grav drives are double the size and cost 50% more in comparison.

 

[F33D]

Acceleration, G Forces and Human Tolerances


1. A little research shows that a trained, fit fighter pilot in a G-suit can remain conscious at upto 9 gees.

Only for a few seconds. It's only counted in seconds for 6 G's...

 

[Condottiere]

1. Mermaids - female pilots in acceleration tanks. Suddenly Arial seems appropriate.


2. Smallest jump drive.

It's kinda obvious that there five tons added on to each jump drive, though whether it's control panels, shielding or bracing, no idea. A little calculation shows that a commercial run would be 7.5 tons for jump 1 for a hundred ton starship, probably at 7 MCr. A bespoke version might be 6 tons at 12 MCr.

Why a Jump One Drive for a hundred ton ship? A small yacht, with the possibility of insystem jumps, or a business jet. Or even a commuter.

 

[F33D]

1. Mermaids - female pilots in acceleration tanks. Suddenly Arial seems appropriate.

That wouldn't help with G-loc. You still experience the acceleration in or out of water.

 

[phavoc]

1. Mermaids - female pilots in acceleration tanks. Suddenly Arial seems appropriate.

That wouldn't help with G-loc. You still experience the acceleration in or out of water.

I think a gel of some sorts would work. Would be messy, but should absorb some of the acceleration.

 

[Condottiere]

Which begs the question, what's the usual sustained acceleration a trained fit human fighter pilot can endure at six minutes, and for an hour stretch.

 

[darue]

1. Mermaids - female pilots in acceleration tanks. Suddenly Arial seems appropriate.

That wouldn't help with G-loc. You still experience the acceleration in or out of water.

I think a gel of some sorts would work. Would be messy, but should absorb some of the acceleration.

well, at that point you'd want to be breathing a hyper-oxygenated liquid too.

 

[F33D]

I think a gel of some sorts would work. Would be messy, but should absorb some of the acceleration.

Nope. Unfortunately that wouldn't work. You have to have something that will absorb for longer than a fraction of a second. Which is what padding, of any kind does. Only inertial compensators (Trav magic) works. Just basic physics. The same reason you don't get that weightless (funny stomach falling feeling ) sensation in water (or gel) is the same reason it doesn't work...

 

[phavoc]

I think a gel of some sorts would work. Would be messy, but should absorb some of the acceleration.

Nope. Unfortunately that wouldn't work. You have to have something that will absorb for longer than a fraction of a second. Which is what padding, of any kind does. Only inertial compensators (Trav magic) works. Just basic physics. The same reason you don't get that weightless (funny stomach falling feeling ) sensation in water (or gel) is the same reason it doesn't work...

I was referring to a gel that would absorb more pressure as it was applied, not like liquid gel soap. I've heard of some seats that have a gel-like substance in them that as you apply more pressure they get harder. It's got something to do with the hydrostatic pressure in the pockets of the material, and that as more pressure is applied, it resists it more. Kind of like you can't compress water. But I'm not a materials science guy, that's the best description I know of for it. I think the usage is because the gel has a curve of sorts in absorbing the force, so it's better than say foam which compresses more.

 

[Condottiere]

1. I recall one Scifi novel where they had spherical interceptors and pilots in acceleration tanks. Probably TL9 setting.


2. Smallest starship fusion powerplant

Again there's some sort of shielding, control panel overhead of a ton, which smallcraft seem to need only 0.9 tons of. The generic version is 2.5 tons and costs 4 MCr. This jives with the smallcraft equivalent sE at 2.4 tons but costing 5 MCr.

Striker and FF&S established economies of scale for power plants; the standard tables veer heavily away from that concept.



3. Bespoke fusion plants.

You'll notice that overhead applies with one percent fixed, plus half a percent for each value, until you reach five where there's a jump of one percent. Interestingly, there's a similar increased difference for fusion rockets.

That would imply that the most efficient values are factor four, which doesn't make much sense.


4. Most efficient smallcraft power plant - sK.

5. Most efficient smallcraft gravitic drive - sK.

6. Most efficient smallcraft rocket drive - sR.

 

[Condottiere]

Austere Pirate Skiff

1. Acceleration nine gees, or ten if the passenger acceleration couch compensates, I forget.

2. Turret, not fixed armament - you may want to shoot while coming and going.

3. Hot bunking in three shifts - I recall you used to be able to squeeze in six bunks in a stateroom, so eighteen maximum crew. Refresher facilities should be sufficient.

4. Low passage berths - for prisoners

5. Crew: pilot, sensor/EW tech, gunner, engineer, medic; eleven boarders.

6. Airlock. Breaching tube, docking clamp, ship's locker optional.

7. Stealth, solar panels.

Thirty tons, sB fusion, sQ rocket, missile launcher.

Squeezing it all in would be challenging, but the most expensive parts of smallcraft tend to be the drives. While the crew size isn't fixed, you do need a pilot, you need someone to detect spacecraft and jam their communications, and you need someone that when shooting doesn't accidentally blow it to hell. An engineer in case you take over the ship.

A more elaborately outfitted boarding craft could be had for upto sixty tons.

 

[F33D]

I was referring to a gel that would absorb more pressure as it was applied, not like liquid gel soap.

Still wouldn't work.

 

[rust]

I was referring to a gel that would absorb more pressure as it was applied ...

While this could reduce some of the unwelcome side effects of a high
acceleration, it would not solve the major problem, which takes place
inside the human body. For example, during an acceleration of 6 G the
blood inside the body moves into one direction with six times the nor-
mal force, which causes severe stress for the heart and the blood ves-
sels.

 

[Condottiere]

1. I still need a guide for:

a. Maximum sustained gee force that doesn't create any medical problems for humans. 1'm guessing between 1.5 to 2.

b. Maximum sustained gee force for around six hours.

c. Maximum sustained gee force for about an hour. I'm guessing three gees.

d. Maximum sustained gee force for six minutes. I'm guessing less than sixteen gees.


2. The definition of fighter could be narrowed to smallcraft that exceed six gees in acceleration.

 

[rust]

1. I still need a guide for:
(...)

The human body is well adapted to a surface gravity of 1 G, any
higher gravity or acceleration causes severe stress for the cardio-
vascular system. For short periods of time and with the best pos-
sible equipment (acceleration seats, g-suits, etc.) an acceleration
of up to 6 G carries only a minor medical risk, but for longer peri-
ods of time even 2 G would be dangerous - the heart and blood
vessels are just not made to do twice their usual job, the risk of
a heart failure or of the rupture of a blood vessel (potentially re-
sulting in a stroke) would increase considerably. So, for six minu-
tes even 3 G would be much, for about an hour 2 G would be much,
and for any longer period of time the acceleration should remain
significantly below 2 G.

Edit.: If you want some more information, you could take a look a
the book "The Biology of Human Survival: Life and Death in Extre-
me Environments" by Claude A. Piantadosi, a professor of environ-
mental medicine at Duke University.

 

[Condottiere]

Compactest Capital Ship

1. Apparently, 2001 tons in two sections

2. Smallest components based on 2050 tons:
a. 2 x 11 ton bridges
b. 41 ton Jump drive factor 1
c. 31 ton fusion power plant factor 1
d. 21 ton manoeuvre drive factor 1, or 41 tons of thruster plates
e. 2 x 100 ton drop tanks (not dropped)
f. Core/3 computer
g. Theoretically, three bay weapons, 28 turrets
h. 1000 tons TL15 Meson A, though I vaguely recall some limitations due to power plant size
i. Crew command 10, 1 or 2 engineers, 7 service
j. Theoretically, 10 spinal, 6 bay, dampers 4, turrets 28

3. 41 ton jump drive
a. jump 1 - 2050 tons
b. jump 2 - 1366 tons
c. jump 3 - 1025 tons
d. jump 4 - 820 tons
e. jump 5 - 683 tons
f. jump 6 - 585 tons

4. 31 ton fusion plant
a. factor 1 - 2066 tons
b. factor 2 - 1550 tons
c. factor 3 - 1240 tons
d. factor 4 - 1033 tons
e. factor 5 - 775 tons
f. factor 6 - 620 tons

5. 21 ton fusion rocket
a. factor 1 - 2100 tons
b. factor 2 - 1680 tons
c. factor 3 - 1400 tons
d. factor 4 - 1200 tons
e. factor 5 - 840 tons
f. factor 6 - 646 tons

6. 41 ton gravitic drive
a. factor 1 - 2050 tons
b. factor 2 - 1640 tons
c. factor 3 - 1366 tons
d. factor 4 - 1171 tons
e. factor 5 - 820 tons
f. factor 6 - 630 tons


Acceleration: Why it is relevant

1. At 10, you could outrun missiles.

2. The faster an assault shuttle lands, the less likely it is to being shot down.

3. Interception of fugitives, or at least getting in range to knock out the engines before they jump.

 

[locarno24]

Theoretically, three bay weapons, 28 turrets

Two. A Fusion-1 plant can support one bay weapon per 1000 dTons.

1 Turret per 100 dTons not allocated elsewhere, so 20 less the volume of heavier weapons.

1000 tons TL15 Meson A, though I vaguely recall some limitations due to power plant size

Correct. You need a minimum of a Fusion-2 to support spinal weapons.



In terms of pursuing fugitives; this is one of the only good reasons to take a (non-heavy) missile weapon on a proper warship: the ability to fling a spread of jumpbreaker missiles at a fleeing ship.

 

[Condottiere]

1. Sub-10t hulls

Should be possible, may require 5% given to Reinforced Structure.


2. Compactest Capital Ship

I guess you can't game around actual physical structures with virtual values.

Assuming you have to locate the second command module in another section, where would that be in a dispersed structure? I'd stick it into the escape module.

It also brings up the question why the bridges don't match with those in the Core book, since I assume the 11 ton bridge can control a 2kT ship, with the other bridges acting as relays.

Considering Smallcraft design, that's probably three comfortable workstations and four guys standing around.


3. Compactest Bridge

Again, harking back to Smallcraft:

a. As stated, 8.25 tons
b. Probably 3 x 1.125 tons equals 3.375 tons, plus 4 x 0.5 tons, which would be just short of 5.5 tons.

 

[Condottiere]

I'll have another go at the smallest fighter possible.

1.125 ton compact cockpit (dm-1), model one computer (or an iPad), 1.2 ton sA power plant, standard electronics, apparently you don't need fire control for fixed weapons. 0.25 tons for an sA fusion rocket, and half a ton for a missile rack, you get 3.075 tons. 0.258 tons fuel, which is around 7.7% of 3.333 tons.

So you have a 3.333 ton ultra light fighter, which will require an experienced pilot (skill 1), armed with smart missiles (therefore no gunnery) and an acceleration of six gees with ten turns.

So that's 140'000 credits for the cockpit, probably 500'000 for the hull, 1'450'000 for the drives. 2'090'000 credits for a barebones fighter with six to ten missiles.

 

[Condottiere]

Smallcraft and Carriers

The Solomani. following the MgT rules, are correct in the heavy emphasis on carrier warfare, as the gravity drive powered smallcraft have more endurance than fusion rocket powered adventure and capital sized ships, where their primary tactic would be to make their opponents use up their fuel in endless manoeuvrings.

They are wrong in their heavy reliance on battlecruisers, unless their Navy Staff believed all they faced were border skirmishes and Cold War posturing.


Light Fighters

Under MgT, between ten to twenty tons, and manned variants would seem to be limited to ten gees. This is one of the occasions where you build around the engines, rather than let the hull dictate the performance, which makes fourteen tons the ideal size for an energy equipped interceptor.

Rocket fusion driven examples only make sense sub ten tons, and then only as point defense interceptors, but open the possibility to emphasizing on pilot training and using the craft as a platform for smart missiles, making it essentially a point and click weapons system. You could call them Mouse fighters.


Medium Fighters

Start at forty tons, since you can have two weapon slots.


Heavy Fighters

At fifty tons, more expensive and yet not much greater performance wise than a medium fighter. It probably ranges to sixty tons, but would require minimum two crew. I'd keep it at fifty, both due to lower crew requirement, and standardizing launch tube size, since the same argument goes for utility craft.


Sixty ton Smallcraft

Largest size that can exceed six gees. That extra crew member should give pause.


Seventy ton Smallcraft

Smallest size that can carry a fifty ton bay; while this seems attractive, I'd skip this size, even for military variants, except possibly planetary bombardment and as a rather large armed satellite.


Eighty ton Smallcraft

Have no opinion one way or the other; could be if there's an attractive combination of performance and drive costs.


Ninety ton Smallcraft

As shuttles, due to their size matching up to the maximum allowed for five ton docking clamps. Possible military variants. Long range patrol boats; also would use this size for bay equipped gunboats.


Hundred ton Smallcraft

Largest recipient of grav drives, also with five weapon slots makes this an attractive gunship. Grav drives make this the most economical for commercial usage.

Though my calculations indicate that sZ only provides 4.8 gees.