GT ISW Ship Design System [FAQ and Problems]

[nik1979]

Clarification

Fixed Equations (Fxd):
Small Craft Pilots and Crew
Small Craft Technicians
Flight Control Crewman
Engineering
Command Section
Ship Troops
Cargo Service Section
Gunnery Section


Non-Fixed Equations
Maintenance Section (Mnt)
Medical Section (Med)
Life Support Section (Lif)
Workshops (Wrk)
General Service Section (Gen)

My Problem with the non-fixed equations is that they are co-dependent on each other and I think its possible to calculate for their value BUT not with layman math.

Total Crew (Crw)

Fxd + (Mnt = (Crw/40)) + (Med = (Crw/40)) + (Lif = (Crw/80)) + (Wrk = (Crw/60)) + (Gen = (Crw/60)) = Crw

See My problem?, the variables are dependent in the final output variables.
Does the Errata or FAQ people have any answers to this.

If not, I recommend making Mnt like Engineering section but dependent on other elements (dtons of ?), Lif, Med, and Gen depend on Ship Quarters (and a way to generate recommended working ship quarters), and Wrk depend on Mnt.


(why is it that 3e has more stuff on this?)
ECM system rules
EW system rules
Convert the 3e Shipdesign Tables? At least an unofficial one, because there is no ISW plan in the future. I'm making a consolidated table set, combining 3e and 4e ship designs, but there is so much left to interpretation of doctrine I'm thinking of basing the TL10s on Honorverse-ish.

A few Other things..

• Since there are missile construction rules in 3e, how about and drone construction? The rules as is can actually created 10dTon EW/ECM drones.
• I've been reading the senor rules, it seems that it is either 1/0 when it comes to detecting something in range. I've scanned through the book and there seems to be no bonuses detecting anything closer or penalties at the edge of range (or any mention of Range modifiers to scanning)? My problem with the rules as is, is that it is a "save-or-die" situation for free-traders (vs missiles, fighters, enemy missile boats).

Scenario. Pirate warnings with idle or missile probe/Beacons. Instead of broadcasting, pirates can dictate their demands with the probe/beacon (using them as to relay tight beam messages) while maintain silent running. Worst case senario for the pirates, they use decoys to confuse the prey of thier actual vector and force a "detection" reroll for the Scan officer or the scan officer will fail to see the "switch" (if he makes it, he will see two opfors and will have to make a large enough margin of success to determine which is the enemy ship). This basically lets a 20dton assault craft sneak up on a free trader (like in somalia's coast) and board.

Even if probes will cost as much as 1M-3M its worth the cash win of a intact prize.

[Anaraxes]

Fxd + (Mnt = (Crw/40)) + (Med = (Crw/40)) + (Lif = (Crw/80)) + (Wrk = (Crw/60)) + (Gen = (Crw/60)) = Crw

Not really dependent, but total crew does show up on both sides of the equation. So gather it together. Leaving out the labels like "Mnt" and doing some algebra on the formula you posted:

Crw = Fxd + Crw/40 + Crw/40 + Crw/80 + Crw/60 + Crw/60

Crw = Fxd + 6 Crw / 240 + 6 Crw / 240 + 3 Crw / 240 + 4 Crw / 240 + 4 Crw / 240

Crw = Fxd + 23 Crw / 240

240 Crw = 240 Fxd + 23 Crw
217 Crw = 240 Fxd

Crw = 240 Fxd / 217

Check my work...

(why is it that 3e has more stuff on this?)

It has more pages, including a whole book just on starships, instead of one section?

[nik1979]

Originally Posted by Anaraxes

Not really dependent, but total crew does show up on both sides of the equation. So gather it together. Leaving out the labels like "Mnt" and doing some algebra on the formula you posted:

Crw = Fxd + Crw/40 + Crw/40 + Crw/80 + Crw/60 + Crw/60

Crw = Fxd + 6 Crw / 240 + 6 Crw / 240 + 3 Crw / 240 + 4 Crw / 240 + 4 Crw / 240

Crw = Fxd + 23 Crw / 240

240 Crw = 240 Fxd + 23 Crw
217 Crw = 240 Fxd

Crw = 240 Fxd / 217

Check my work...

It has more pages, including a whole book just on starships, instead of one section?

Thanks for the algebra, man i forgotten too much of it when I realized this is the LCD and the GCM usage.

the Variable Crew is about 10.6% of the fixed value crew.
Fxd x 10.6% = Crw

Then i divide this by
.26 x Crw = Maintenance
.26 x Crw = Medical
.13 x Crw = Life Support
.17 x Crw = Workshop
.17 x Crw = General Services


So If I have a fixed crew of 600
I have a variable crew of 64+ (rounded to a whole person of course)

17 = Maintenance
17 = Medical
8 = Life Support
11 = Workshop
11 = General Services

Wow, got it! Thanks Anaraxes! I'm embarrassed by how much I forgot.

I wish they put it in the book in simpler terms.

[nik1979]

Playing with GTISW stats again.

I've noticed that 100spaces and Tons of Repulsors are = to 100 spaces worth of missile racks. Since I could mount missile racks as a bay weapon, i could just match repulsors dTon to dTon but have the flexibility to use my missile superiority against other enemy units.

Also Ive noticed that there are allowances for redundancy in Ship Scanners and Command Positions. Does that mean I can have up to 3 Separate Scanners and 3 opportunities to roll for detection?

Interestingly, in GM's fiat I've noticed that scanners actually serve the same role as communications equipment and EW. So by this reason, I can have a dedicated scanner serve the role of EW. EW can probably do the job of sensor disruptor in UT. They screw up missile targeting and detection adding a ton of noise and false info that would screw up identification.


20-DTON Heavy Fighter
This small craft was used by both Imperial and Terran forces for missile screening (point defense, reconnaissance) and to add to the missile volley for larger missile batteries
Tech Level: 10.
Hull: 20-dton Needle/Wedge Airframe hull (6.6ksf, 6.6tons, $2.4), dDR 13 armor (42.9tons, +$0.5148), Stealth (+1.54tons, +$0.462).
Systems: 4.5 Maneuver Drive (4.5dtons, 90MW, 900tons of thrust, 18tons, $4.5), Standard Bridge (2.5dtons, 12tons, $1) (80-man days), Model-3 Sensors (Scan 18) (2dtons, 24tons, $8, -8MW), Heavy Turret (2dtons, $0.2, 1.5 tons) (2 Pulse Lasers) (2dtons, $1M, 6tons, 20MW), 3 Missile Racks (3dtons, 8.4tons, $3.33 ), 6-1/2
Fusion Power (6.5dtons, 26tons, $19.5, 130MW), 1/2 Bunk (1dton, $0.005, 0.25tons), 1/2 Cargo (5).
Statistics: EMass 143 tons, Lmass 148 tons, Cost M$40, SM +6, ASig +0, Hull dHP 25, life support capacity 5, sAccel 6 G, no jump
capacity, Top Air Speed 4,500 mph.
Crew: Command Section (3 officers), Gunnery Section (2 crewman) .Total 3 officer, 2 crewman

5-DTON Stealth Sensor and EW Drone
The stealth sensor drones are meant to go in advance, hide and watch with powerful passive sensors, direct Screening Pod action, or act as a valuable last ditch ship ECM decoy.
Typically deployed with launch tubes.
Tech Level: 10.
Hull: 5-dton Needle/Wedge Airframe hull (3ksf, 3tons, $1), dDR 10 armor (0.77tons, +$0.01), Stealth (+0.75tons, +$0.225).
Systems: 1 Maneuver Drive (1Dtons, 20MW, 200tons of thrust, 4tons, $1), Hardened High Capacity Mainframe (complexity 11) (0.5dtons, 0.2tons, $0.6), Model-3 Sensors (Scan 18) (2dtons, 24tons, $8, -8MW), Fusion Power (1.5dtons, 6tons, $4.5, 30MW).
Statistics: EMass 39 tons, Lmass 39 tons, Cost $15M, SM +2, ASig -4, Hull dHP 15, no life support capacity, sAccel 5 G, no jump
capacity, Top Air Speed 4,500 mph.
Crew: Command Section (3 officers), Gunnery Section (2 crewman) .Total 3 officer, 2 crewman.

5-DTON Screening Pod.
The screening Pod is meant to be strategically deployed to screen for missiles and enemy movement and add to missile volley. They also serve as mobile turrets adding to the point defense force numbers.
Typically deployed with launch tubes. A carrier usually can launch up to 100 of these.
Tech Level: 10.
Hull: 5-dton Needle/Wedge Airframe hull (3ksf, 3tons, $1), dDR 10 armor (0.77tons, +$0.01), Stealth (+0.75tons, +$0.225).
Systems: 1/2 Maneuver Drive (0.5Dtons, 10MW, 100tons of thrust, 2tons, $0.5), Hardened High Capacity Mainframe (complexity 11) (piloting, artillery, and gunnery) (0.5dtons, 0.2tons, $0.6), Model-0 Sensors (Scan 14) (0.5dtons, 6tons, $2, -2MW), Fusion Power (0.5Dtons, 2tons, $1.5, 10MW), 2 Missile Racks (2dtons, 5.6tons, $2.22 ), TL9 Pulse Laser (1dton, 3tons, $0.5, -2.5MW).
Statistics: EMass 23 tons, Lmass 23 tons, Cost $8.6M, SM +2, ASig -4, Hull dHP 15, no life support capacity, sAccel ; 2.5G with full compliment 2.2G (4G w/ M-drive only; 3.2G M-drive and Scan), no jump capacity, Top Air Speed 4,500 mph.
Crew: None

Interesting Ship Doctrines from Honorverse to Traveller:
10,000Dton Missile Pod carriers armed with jump-2 x2, 200 missile racks, 70 Pulse Lasers (for long ranged point defense), Accell-5G. To carry and launch as much as 120 missile pods in 1 round mixed with sensor and EW drones 1800dton. Missile Saturation can reach as much as 400. Point Defense has as much as 310 (+EW if possible) and high mobility.

If Sensor EW Drones can act as Decoys together with the 3 maneuver limit of missiles, ships can evade clusters of missiles at the cost of a drone.

Different Factions could possibly have "racial" advantages. Like +1 to EW, +1 to Sensors, +0.5G to drive efficiency, +1 to gunnery... etc. to save on added paper work on simulating slight differences in technological advantage.

[nik1979]

Confusing Hangar Creation Rules:

Originally Posted by ISW 195

Regardless of the size of any small craft to be stored within a hangar bay, the necessary equipment takes up 1.5 spaces, has a mass of one ton, has negligible cost, and uses negligible power. The hangar bay must then be allocated two spaces for every dton of capacity; this extra space has no mass, cost, or power requirement.

* Hangar Bay Dtons = (Ships Dtons*#Ships*3) + (#Ships*1.5)
Hangar Bay Mass = #Ships *1Ton

So a carrier with around an average of 100 small craft of variable size and numbers will have X dtons?

Its kind of confusing. Is there a better way to state this formula?

[daryen]

Originally Posted by nik1979

Confusing Hangar Creation Rules:


* Hangar Bay Dtons = (Ships Dtons*#Ships*3) + (#Ships*1.5)
Hangar Bay Mass = #Ships *1Ton

So a carrier with around an average of 100 small craft of variable size and numbers will have X dtons?

Its kind of confusing. Is there a better way to state this formula?

Close

Hangar Bay Volume = ((Craft Dtons * #Craft) * 2) + (#Craft * 1.5)

So, the total number of dtons taken up is basically double the size of the craft to be carried. E.g., if you are going to carry 100 10dton fighters, you need 2150 dtons of hangar volume.

Hangar Bay Mass = (#Craft * 1ton) + (#Craft * Craft tons)

Yes, the hangar itself only has mass equal to the first part, but your maneuver drive (and whatever else) had better be rated to handle a loaded hangar.

[nik1979]

Trying to fill in the gaps of ISW, GT3e and UT4e.

How i calculated the damage:
[Dice x 3.5 (dice average) x 10 (from deca scale) ]^3 to get energy
from 250mm to 500mm magnitude factor of 3
Then ^1/3 the energy to get the damage, and divided it by 3.5 to get the dice.

HEMP 250mm missile $0.03M dDmg TL9-6dx2(10) cr inc, TL10-6dx2+12(10) cr inc; Range 3 maneuvers; Wt. 0.15T
HEMP 500mm missile $0.1M dDmg TL9-6dx3(10) cr inc, TL10-6dx3+18(10) cr inc.; Range 5 maneuvers; Wt. 0.5T

Fine Missiles, +1 Guidance roll, x2 Cost
Very Fine Missiles, +2 Guidance roll, x5 Cost

Nuclear Missiles UT156
Cost x1,000
Nuke 250mm (10 Kilo-Ton) $30M dDmg 6dx400 cr (8400 dmg)
Nuke 500mm (1 Mega-Ton) $100M dDmg 6dx2000 cr (42,000 dmg)
Special note of Nuclear Missiles: It usually does proximity kills, allowing them to overcome repulsors.

One can Simplify it by giving it a Proximity damage progression of the sort. Like: +5 to ram, dDmg 6dx30 250mm or 6dx50 for 500mm

X-Ray Laser Heads: basically a missile that can attack a number of hexes away.
Cost x10
X-Ray Laser Heads 250mm Gunnery-15+2Acc, dDmg 4d(5) burn, ROF20, range 2/6
X-Ray Laser Heads 500mm Gunnery-15+2Acc, dDmg 7d(5) burn, ROF20, range 2/6

Originally Posted by How to make Nukes Work

This attack assumes the missile wasn't stopped outside the ships hex. Until I figure out a simpler system this is the math I can think off that would make sense of the use of Nukes (because their minimum damage will wipe out any ship).

Glossary of Variables:
Proximity Attack Value (ProxA). This is the range a missile needs to detonate to deal enough damage to the defender that would matter. This is a ramming bonus for the missile.
Attack Superiority (AS). this determines how much damage the ship may take relative to how successful his defense is.
Penetration Value (Pen) - this is penetration bonus an attack has to overwhelm defenses. Usually Equal to the no. Of penetration aids, missile attacks, and
Point Defense Value (PD) - this is the Point Defense strength of the defender. Usually equal to the no. of point defense guns and screening elements x defender's point defense gunnery margin of success.
Nuclear Damage


First, Get the Attack Superiority (AS). This is equal to the Penetration (Pen) divided by Point Defense (PD) Value. Pen/PD = AS.

Second, Get the Proximity Attack Value (ProxA). This is equal to the Nuclear Attack Average dDmg divided by AS/DS x HP and DR.

Nuke dDmg/ [ (dHP*DS) + dDR] = ProxA

Look up the ProxA under the size table, that value will be the bonus of the Nuke to get close enough to the area of the ship.

Last, resolve Damage. Damage is equal to the Ship's dHP x AS. Of course the lower the attack superiority the better the chances the ship can survive a nuclear attack.

Example:
In a squadron engagement, the Vilani Fleet launches a light nuke along with penetration aids equal to x20 (EW missiles along with the nuke to confuse point defense targeting and acquisition).

The Terran Fleet's are bracing for the attack, allocating half the squadrons point defense ability 30. The Terrans make a margin of 3 with the Point Defense. The defense Reducing the Attack Superiority to 0.22.

The Missile just needs to within 50m to deal 154dDmg (or 15dDmg past the armor). This gives the missile a +8 bonus because of the proximity size to ramm the ship. Failure means no damage at all or the ship takes the damage.

EW Drone 500mm $0.16M, Accel 6, Mass 0.5Tons,
Drones causes all Targeting and Scanning Electronics that pass by their affected area (1 hex) to Make a "Save" or lose acquisition (roll the missile's guidance system skill, which is typically 15). The Save Penalty is equal to Drone's EW rating (-3 at TL9, -4 at TL10). Cost x2 for a Fine EW Drone (improve the drones effectiveness by 1), Cost x5 for a Very Fine EW Drone (improve the drone's effectiveness by 2). $0.16M each.

[Mgellis]

Originally Posted by nik1979

Trying to fill in the gaps of ISW, GT3e and UT4e.

How i calculated the damage:
[Dice x 3.5 (dice average) x 10 (from deca scale) ]^3 to get energy
from 250mm to 500mm magnitude factor of 3
Then ^1/3 the energy to get the damage, and divided it by 3.5 to get the dice.

HEMP 250mm missile $0.03M dDmg TL9-6dx2(10) cr inc, TL10-6dx2+12(10) cr inc; Range 3 maneuvers; Wt. 0.15T
HEMP 500mm missile $0.1M dDmg TL9-6dx3(10) cr inc, TL10-6dx3+18(10) cr inc.; Range 5 maneuvers; Wt. 0.5T

Fine Missiles, +1 Guidance roll, x2 Cost
Very Fine Missiles, +2 Guidance roll, x5 Cost

Nuclear Missiles UT156
Cost x1,000
Nuke 250mm (10 Kilo-Ton) $30M dDmg 6dx400 cr (8400 dmg)
Nuke 500mm (1 Mega-Ton) $100M dDmg 6dx2000 cr (42,000 dmg)
Special note of Nuclear Missiles: It usually does proximity kills, allowing them to overcome repulsors.


X-Ray Laser Heads: basically a missile that can attack a number of hexes away.
Cost x10
X-Ray Laser Heads 250mm Gunnery-15+2Acc, dDmg 4d(5) burn, ROF20, range 2/6
X-Ray Laser Heads 500mm Gunnery-15+2Acc, dDmg 7d(5) burn, ROF20, range 2/6



EW Drone 500mm $0.16M, Accel 6, Mass 0.5Tons,
Drones causes all Targeting and Scanning Electronics that pass by their affected area (1 hex) to Make a "Save" or lose acquisition (roll the missile's guidance system skill, which is typically 15). The Save Penalty is equal to Drone's EW rating (-3 at TL9, -4 at TL10). Cost x2 for a Fine EW Drone (improve the drones effectiveness by 1), Cost x5 for a Very Fine EW Drone (improve the drone's effectiveness by 2). $0.16M each.

I actually put the standard missile at 200 mm. (See the article I just published in JTAS.) The reason is that, if you're using the ship design system in GT:IW, the damage is 12d(10) when using the d-damage scale, or 6d x 20 (10) in the normal damage scale. This is twice the damage of the 100 mm. TL 9 HEAT round from Ultra-Tech, which suggests the missile is 200 mm. since damage seems to scale directly with warhead diameter.

It's also a lot easier to scale up the warheads since there is a 100 mm. warhead in Ultra-Tech. 8 x mass and cost of a 100 mm. warhead for a 200 mm. warhead, and effects are either x2 or x2.8, depending on the type of warhead.

If you look at missile weights in Spaceships, a 200 mm. missile is 250 lbs. and a 240 mm. warhead is 500 lbs., so 200 mm. is a better match for the .15 tons of the standard missile on that scale, too.

Suffice that, for a 4e GURPS Traveller campaign, I've made the argument that the missiles are 200 mm. And Loren seemed happy to publish it that way.

Interestingly, the missiles in Traveller are quite small, considering they're anti-ship weapons. I guess the idea is that you fire a lot of them, since lasers will probably get most of them, but it's like battleships fighting with AMRAAMs instead of Harpoons. :)

Mark

[nik1979]

Thanks Mark,
hehehe, your making it hard to ignore that subscription. I've placed my order at e23 now.
Any plans of making Mass Combat Stats for Traveller Ships?

The change from 200mm actually doesn't change my calculations that much. After accumulating all this data and having a naval doctrine down pat, I'm surprised there was no CCG designed after that. Once you have the established doctrines and technological paths set, you can pretty much design an Abstract fleet action and naval Strategy Card Game by it.

The CCG could possibly accommodate both fleet doctrines of Lost Fleet and Honorverse.

Asset Cards for Ships, Captains, Elite Fighter Squadrons, Bases, Shipyards, and Locations.
Action Cards for Special Fleet Maneuvers (Which need certain requirements), EW or ECM actions and drones, special attacks, traps, mines/pods, ambushes, random chance, etc.
Faction Cards. Grants a special advantage to the player. Like bonuses over generic ship stats (the difference between faction Y and W EW, Accel, Attack Range, or special maneuvers)
and with 3d6 resolutions for some elements (target number resolution so that its upward progression).

I'm trying to build some default ship stats based on ISW's

BTW, I've noticed ramming is not that hard given the factors of ship size and proximity explosions.
Ramming a ship like the Indomitable with size +13 offsets much of the +15 contested skill advantage.
If screening ships are able to pin point an enemy ship (augmenting the effective detection range of the launching ship to almost double): Scan-16(model-0) + Scan-24(model-9) can allow a missile to travel an 8 (w/c requires 9 rounds to max out accel) space vector towards a targeted ship.
I've begging to notice the usefulness of "ships of the wall". Basically dreadnaughts with a 6 point defense laser slots per heavy turret or up to about 396 point defense slots.


This means that Point Defense (PD) will be occurring at the ship's hex as part of the PD phase. Screening ships, will have a -4 (at the safest range of 12, or less at 2), +2 (accell), +13 (size) vs the repulsor-ed ship of +15 and other bonuses depending on the Penetration Aids for the Missiles or the EW/ECM abilities of the warship.

High Explosive Proximity Kill Missiles like Nukes, makes the job easier for the missiles.

[Mgellis]

Originally Posted by nik1979

Thanks Mark,
hehehe, your making it hard to ignore that subscription. I've placed my order at e23 now.
Any plans of making Mass Combat Stats for Traveller Ships?

The change from 200mm actually doesn't change my calculations that much. After accumulating all this data and having a naval doctrine down pat, I'm surprised there was no CCG designed after that. Once you have the established doctrines and technological paths set, you can pretty much design an Abstract fleet action and naval Strategy Card Game by it.

The CCG could possibly accommodate both fleet doctrines of Lost Fleet and Honorverse.

Asset Cards for Ships, Captains, Elite Fighter Squadrons, Bases, Shipyards, and Locations.
Action Cards for Special Fleet Maneuvers (Which need certain requirements), EW or ECM actions and drones, special attacks, traps, mines/pods, ambushes, random chance, etc.
Faction Cards. Grants a special advantage to the player. Like bonuses over generic ship stats (the difference between faction Y and W EW, Accel, Attack Range, or special maneuvers)
and with 3d6 resolutions for some elements (target number resolution so that its upward progression).

I'm trying to build some default ship stats based on ISW's

BTW, I've noticed ramming is not that hard given the factors of ship size and proximity explosions.
Ramming a ship like the Indomitable with size +13 offsets much of the +15 contested skill advantage.
If screening ships are able to pin point an enemy ship (augmenting the effective detection range of the launching ship to almost double): Scan-16(model-0) + Scan-24(model-9) can allow a missile to travel an 8 (w/c requires 9 rounds to max out accel) space vector towards a targeted ship.
I've begging to notice the usefulness of "ships of the wall". Basically dreadnaughts with a 6 point defense laser slots per heavy turret or up to about 396 point defense slots.


This means that Point Defense (PD) will be occurring at the ship's hex as part of the PD phase. Screening ships, will have a -4 (at the safest range of 12, or less at 2), +2 (accell), +13 (size) vs the repulsor-ed ship of +15 and other bonuses depending on the Penetration Aids for the Missiles or the EW/ECM abilities of the warship.

High Explosive Proximity Kill Missiles like Nukes, makes the job easier for the missiles.

I think you will enjoy JTAS. At $20, it's a great deal. Even if you don't like some of the articles, I'm sure you will get $20 worth and more over two years.

I have Mass Combat and it looks interesting, but I haven't played around with it too much. Right now, I'm finishing up some JTAS articles and playing around with ideas for new ones. I've got a few "Ships of the Third Imperium" article ideas that I'll probably flesh out in the next few months. More in my master plan to publish a GURPS Traveller: Third Imperium for 4e GURPS book as a large series of JTAS articles. :)

The 3e GT missiles were actually 250 mm. and 500 mm., but when I compared them to warheads in 4e Ultra-Tech, etc., 200 mm. made more sense. And it is easier to figure things out.

I've tried very hard to stay close to canon, but I also think that modifying Traveller for 4e GURPS is a great opportunity to streamline things, reinvent things that were clunky or odd, etc.

I'm not really that into CCGs, but I like your ideas. There might be licensing issues with Traveller, but maybe SJG will develop a Spaceships CCG.

As far as ramming goes...I'm not sure the Third Imperium would do this, but I wouldn't be surprised if some space navies relied on robot fighters as "I don't care how much armor you have" missiles. :) No warhead, just a cockpit, a computer with NAI software, some sensors, and lots of maneuver drive. Crank that baby up to maximum speed and kamikaze in. A hundred of those things would cost a pretty penny, but they would probably overwhelm a dreadnought's defenses and a dreadnought costs a lot more, so the guys with the big robot missiles win. :)

I think nukes (clean fusion weapons that can't be turned off by dampers) would serve as the "equalizer" in naval combat and makes the game more interesting. Dreadnoughts will usually beat little ships, even those armed with nukes, but at the little ships will have a chance. And that makes it interesting.

Mark