Pondering starship evolution

[Spinward Flow]

Without reading through 400+ posts ... why are the "boxes" 16 dtons? (Why not 20 dTons or 10 dTons or 36 dTons or any other base value?)

The answer to that question lies within the 400+ posts that you're not reading.
But you're asking for a summary as a latecomer to the thread ... which is a fair ask.

For any kind of modularized "shipping container" useful for interstellar commerce, you first need to establish what is the "minimum useful displacement" for the job you want to be doing. The "solution" to this particular balancing act has multiple possibilities, each of which have their own strengths and weaknesses.

I started my research into this topic with some Traveller immutable assumptions.

• Major cargoes are 10 tons (minimum) per lot (LBB2.81, p8) (TTB, p53)
• Minor cargoes are 5 tons (minimum) per lot (LBB2.81, p8) (TTB, p53)
• Incidental cargoes are 1 ton (minimum) per lot (LBB2.81, p8) (TTB, p53)

This means that any "cargo container module" of less than 10 tons displacement would "not be useful" for shipping major cargoes, rather effectively defeating the purpose. So a 10 ton displacement becomes something of a "hard" lower bound for interstellar modularized container transport.

The next consideration to take account of is the possibility of putting staterooms (for crew or passengers) into these modular containers that are being designed. This becomes both a spreadsheet (multiples of 4 tons) and a deck plan "interior design" problem. For example, it's EASY to specify in a spreadsheet that a 12 ton cylindrical "tube" hull has 3 staterooms in it, but when you try to draw up deck plans for that, every gets WONKY and WEIRD really quickly because there's going to be so much "wasted space" involved around the curves of the tube shape. Even if you do a "two decks in the tube" with an over/under on one side and a "mid-deck access hallway" running along one side (to waste as little volume as possible) you still have a variety of mobility and access issues getting into those staterooms ... not to mention the odd number of them (3). Sure, that can be partially solved by making 4 compartments (3 quarters plus 1 common area) in order to try and balance things out, but the deck plan arrangement of "stuff" gets FUGLY really fast.

Also, if you're building "tubes" those don't exactly "stack neatly" into arrays with minimal packing losses between them, even if you're doing hexagons.

So rectilinear shapes (meaning Configuration: 4, close structure) became the obvious choice for the purpose.
Basically, one of these ... (albeit with different dimensions):

For a while, the 12 ton Box seemed like it would be the optimal choice, because it would be the "right size" for 3 staterooms while also being able to load at least 10 tons of cargo.

Additionally ... 12*14/3/1.5/1.5 = 24.89 ... in other words, a 5x5 deck squares deck plan, which worked out beautifully for 2x2 arrays of "square" boxes (rotate the top layer 90º and you only need a single central corridor access along with a single central vertical access).

So the deck plan for a 12 ton Stateroom Box would look like this (3 crew or passenger quarters plus 1 common area):

The problem with that "solution" was that it was nearly impossible to build a useful fighter craft within those constraints (tonnage and form factor). This created a "wrong size mismatch" problem of interchangeability when using modularization at this scale. It was good for Stateroom Boxes, but little else.

Then in post #246, I got the bright idea to try a 20 ton form factor instead, to help resolve the differences in displacement between Boxes and Fighter.

At that point, the Stateroom Boxes turned into this:

The Escort Fighter went from looking like this:

To looking like THIS in order to fit into the new form factor constraint:

And then THIS:

But all of that work was being done on a foundational assumption of building a TL=10 starship using LBB2.81 E-H drives (of some variety) and a TL=10 escort fighter that could have been originally designed for system defense patrols, which then gets adapted and redesigned (deckplan only, not spreadsheet numbers) for use as a mobile defense for merchant starships that need to go "across the border" outside of imperial controlled space.

I was still working on the assumption of doing an "odd number plus one" in order to make the interior design deck plans have bilateral symmetry to them, in terms of where the internal bulkheads/partitions ought to go. So that's how you wind up with 5 staterooms (20 tons) that collectively yield 1 common area (either a lounge/galley/laundry, or a sick bay/medical).



However, after doing all of this (and building another complete starship deck plan) ... I started wondering about backwards compatibility, from TL=10 down to TL=9. Dropping -1 TL like that would put some pretty severe constraints on the design parameters (no model/4 computer for the fighter, fuel purification plants are 9 tons minimum rather than 8 tons, LBB2.81 drives are limited to A-D, etc.), so ensuring "backwards compatibility with the Stone Age J1 Discovery Era" meant questioning all of the assumptions I'd been making yet again.



And then in post #364, I was basically "forced" by the backwards compatibility criterion with TL=9 to re-evaluate and came to the conclusion that I should have been working in 16 ton Box form factors all along.

Why?
Because a TL=9 Escort Fighter armed with lasers (so it doesn't have ordnance resupply issues) and a model/2 computer plus bridge just so happens to weigh in at 16 tons of displacement. And Agility=6 in a 16 ton form factor costs 16*0.06=0.96 EP, leaving 1 EP (power plant-A drive generates 2 EP) or 3 EP (power plant-B drive generates 4 EP) available to power weaponry+computers (model/2 consumes 0 EP).
Additionally, 16 tons means 4 staterooms.

The challenge then was to figure out how to get 4 staterooms plus common area(s) into a deck plan that made sense.

Furthermore ...

• 1 Major Cargo (10 tons) + 1 Minor Cargo (5 tons) + 1 Incidental Cargo (1 ton) = 16 tons

The new form factor is 392 pixels long by 304 pixels wide on the deck plans (corner to corner).
That means that when 60 pixels=1.5m the dimensions are 9.8m x 7.6m x 3m (~29% longer than wide).
9.8*7.6*3/14 = 15.96 ≈ 16 tons

Without reading through 400+ posts ... why are the "boxes" 16 dtons? (Why not 20 dTons or 10 dTons or 36 dTons or any other base value?)

TL;DR
By process of Pondering Starship Evolution ... and thinking in terms of more than one tech level (specifically, TL=9-10).

Side benefit ... this means that I can design a TL=11 Medium Fighter "upgrade" that is 32 tons (2x 16) which has a model/5 computer in it while still using LBB2.81 standard drives.

• LBB2.81 Power Plant-C drive generates 6 EP
• Agility=6 in a 32 ton form factor consumes 32*0.06=1.92 EP
• Computer model/5 consumes 3 EP
• 1x Pulse Laser consumes 1 EP
• + (6) - (1.92-3-1) = 0.08 EP remaining surplus

This would then represent the "zenith" for system defense fighter performance, since at TL=12+ small craft fighters become less and less relevant for military fleet on fleet use. After TL=11, it becomes increasingly difficult to justify the "expense" that fighters represent, since they're basically "flying computers with only a single turret" while big craft (100+ tons) can mount more weapons per computer (and are thus a more efficient use of limited budgets).

Does that (adequately) answer your question?

 

[atpollard]

Does that (adequately) answer your question?

Yup. Thank you.

Setting aside the Fighter (which I would have to test the design to see if a 16 dT TL 9 fighter made sense or not and if a "cube" is a "cool" form for it; but giving it the benefit of the doubt) ... The arguments that 16 dTons = CARGO (1 major + 1 Minor + 1 incidental) = STATEROOMS (4 staterooms) provides innate merit to 16 dTons over other values.

 

[Spinward Flow]

The arguments that 16 dTons = CARGO (1 major + 1 Minor + 1 incidental) = STATEROOMS (4 staterooms) provides innate merit to 16 dTons over other values.

Suffice it to say, it wasn't an abritrary decision nor a capricious one.
Instead, it's the result of searching among a confluence of factors to strike the right balance between them. It's a matter of "following the math" when taking account of lots of different competing inputs.

There's also a desire to min/max in order to find the "biggest small" that is also the "smallest big" (or words to that effect).
The fact that 100/6=16.6667≈16 is also thrown into the mix. That way, Agility=6 @ 16 tons costs 0.96 EP ... which is as close to 1 EP, without going over, as you can get.

So there's multiple overlapping breakpoints which make 16 tons a decent compromise to settle upon.

 

[atpollard]

The fact that 100/6=16.6667≈16 is also thrown into the mix. That way, Agility=6 @ 16 tons costs 0.96 EP ... which is as close to 1 EP, without going over, as you can get.

THAT makes a 16 dTon small craft a figure of merit [whether a FIGHTER or just a FERRARI].

IN MY UNIVERSE (where there exists a Half-A Drive because 100 dTon hulls at Factor 1 just make sense), that suggests a 6G performance at 16 dTons.

 

[Spinward Flow]

THAT makes a 16 dTon small craft a figure of merit [whether a FIGHTER or just a FERRARI].

"Trust me. I know what I'm doing."

that suggests a 6G performance at 16 dTons.

Yup.
That's the idea.
6G Agility=6 for 1EP @ 16 tons.

Which means, that 16 tons is the Just Right™ size for:

• 1x Major Cargo lot (10 ton minimum) + 1x Minor Cargo lot (5 ton minimum) + 1x Incidental Cargo lot (1 ton minimum)
• 4x Staterooms (16 tons)
• 6G Fighters (1 EP needed for Agility=6)
• 2x G-Carriers (8 tons each)
• 1x G-Carrier (8 tons) plus 2x Air/Rafts (4 tons each)
• 2x Speeders (6 tons each) plus 1x Air/Raft (4 tons)
• 4x Air/Rafts (4 tons each)
• 1x Mail Vault (5 tons) plus 1x Speeder (6 tons) plus 10x Low Passenger Berths (5 tons)
• ... and even more possible combinations ...

So in terms of "hitting a sweet spot" ... 16 tons is a pretty sweet spot to be in.

 

[RossWinn]

lovely ideas, but there are no closets or room for any luggage of any kind.

 

[kilemall]

lovely ideas, but there are no closets or room for any luggage of any kind.

He has one.

 

[Spinward Flow]

there are no closets or room for any luggage of any kind.

Actually, that's not true.
Each stateroom has a closet for use by the occupant.
If you're not familiar with the visual language of Geomorphs, that's fine ... I don't mind explaining what isn't intuitively obvious at a first glance.

The Galley has a refrigerator/freezer (forward is picture left) and a dry stores "pantry" (aft is picture right) in it for the storage of foodstuffs. The galley has a sink + countertop forward as well as a 4 "burner" magnetic induction stove top convection oven (by the entrance) next to a heat pump washer/dryer laundry machine (by the stores), the top of which can be used for additional counter/staging space when cooking. The Galley space is "barely a closet" itself, in terms of having room to move about it in, but it's adequate to meet the needs of 4 single occupancy staterooms when it comes to meal preparations and laundry services.

 

[TamsinP]

lovely ideas, but there are no closets or room for any luggage of any kind.

I'm assuming there would be drawers underneath each of the bunks and cupboards under (and possibly on the wall above) what I assume to be the desk for storage of luggage.

 

[Spinward Flow]

I'm assuming there would be drawers underneath each of the bunks and cupboards under (and possibly on the wall above) what I assume to be the desk for storage of luggage.

That ... would not be a correct assumption.

The bunks are a "loft" type of arrangement over the sitting area, comparable to (but not exactly like) what you see in Amtrak passenger trains.

The "sitting area" under the "loft bunk" has a retractable into the floor table between two couch seats on either side. The couches can be folded out to create a bed for a second occupant (like is shown in the above image) if double occupancy is required.

These updated deck plan images, which "remove" the loft bunks at the bottom of the images (for clarity, the bunks are still there), helps make this a bit easier to see.

The outer bulkhead has a window and a privacy screen/retractable curtain (which also doubles as a radiation shield), allowing occupants to visually see vistas and spectacles outside when the Stateroom Box is docked externally to other craft.

Closet space is provided against the interior bulkhead wall of each compartment, opposite the private fresher in each stateroom. A portion of each closet is dedicated to the storage of a vacc suit and rescue ball, in case of a need to depressurize interiors in preparation for combat (vacc suit) or in case of unplanned emergency (rescue ball), permitting a "shelter in place" option until rescue can arrive. The remainder of the floor to ceiling closet space is available for stateroom occupants to fill with their personal effects and luggage.

Each stateroom compartment is "pressure isolated" from other sections, allowing occupants of each stateroom to control environmentals (temperature, gravity, etc.) individually as desired.

 

[aramis]

It was never "a rule" (per se), but it has always been a Default Assumption in almost every version of Traveller published. It even extends down into small craft, such that all small craft "have to be" Multiples Of 10 in their tonnages.

Every single design sequence in CT adhered to these "rules" for design (LBB2, LBB S4, LBB S7, LBB S9, LBB A1, LBB A4, LBB A8, LBB A10, CT AM1-8, etc.). It simply became Accepted Conventional Wisdom™ that all displacement tonnages come in Multiples Of 10 (small craft) or 100 (big craft).

In fact, one of the precious few designs to break with this pattern is (of all things) the Colonial Cruiser (LBB S9, p19) ... weighing in at 1250 tons ... instead of the 1200 tons published in LBB A1.

So everyone got into the habit of using Multiples Of 10 or 100 every time ... because that's what the published designs did.

You've cherry picked and/or missed a few. The first ed of Bk5 has fighter sizes that don't match.
TL7-9 fighters are 9 tons, not 10. TL10+ are 10, but not the early ones. (but also, no small craft design.)

Bk5 second ed has a 1250 Ton example... page 51
And a 35 ton Pinnace on the next page.

AHL includes details on the Rampart fighter, Supplement 5, page 40. 15 Td.

Further Bk2, both editions, allows for hulls of interim sizes... but without any benefit for unlisted tonnages, and it's only 100 to 1000 where its by hundreds. it's thousands to 5k.
And Bk5, the size table does support a log function... hundreds to 1000, thousands to 10k, 10k to 50k, 25k from 50k to 100k, then 100k to 1M.

These are clear proof your thesis is wrong.

The design sequences in Bk5 do set some granularity that matters...
Given that it's round up to 1 ton for ships means that JDrives round up by the 50 ton... for even drive numbers; per hundred for odd.
Maneuver Drives optimize by the 100 ton as well.
Turrets likewise optimize by the 100 ton, excepting when using bays. (A common misinterpretation of Bk5 is that tonnage of bays simply doesn't count towards turret ratios, rather than preventing 1000 tons from counting for turrets, and thus blocking 10 turrets each. So a 1050 Td, under that misinterp, could have 1× 50 Td and 10× Turrets or barbettes.)

Now, aside from Bk5-79, I've not seen published small craft in units other than 5 Td, nor ships other than in 50 ton increments. That counts the GW, GDW, and JG pubs for CT.

Also worth noting: TNE includes a few of 50-ton increment designs, so GDW felt no compunctions about breaking the "100 ton rule"... RCES Equipment guide has...
Aurora Clipper: 600/1080/2080 tons (depending upon configuration)
Maggert Clipper: 850/2750 tons (d.o.c.)
3 Ton Socket Lifeboat
5 Ton Liferaft
Wildbat/Foxbat matched fighter and "pathfinder" - both 16 tons.
Fury Assault Lander: 7 tons.
Hiver Tender: 4800/5000 tons

Regency sourcebook adds
RQS Faith Class 150 Ton quarantine cutter.

 

[mike wightman]

Here are a couple more.
The fighters carried by the Broadsword cutter fighter frame are 6 tons each
And the fighters carried by Zhodani patrol craft are 8 tons.

 

[Condottiere]

Obviously going for minimum tonnage, for a given payload.

Observing spacecraft design (component) minimums, depending on edition.

 

[Spinward Flow]

Here are a couple more.
The fighters carried by the Broadsword cutter fighter frame are 6 tons each
And the fighters carried by Zhidani patrol craft are 8 tons.

Trick question.
What can you put into small craft that are that small?

Given that the minimum size for components is 1 ton for drives and fuel and so on ... what can you fit into hulls that small?
Oh and don't forget that weapons REQUIRE a computer to be installed. Bridge only, no computer means no weaponry.

So, what do we have as the absolute bare de minimus fit for armed small craft?

• 1 ton for maneuver drive
• 1 ton for power plant (@ TL=9-14 this produces less than 1 EP)
• 1 ton for fuel
• 1 ton for turret (missile and/or sandcaster only, not enough EP for a laser)
• 1 ton for model/1 computer
• 0.5 tons for acceleration couch

1+1+1+1+1+0.5 = 5.5 tons

So a 6 ton fighter probably has 2 acceleration couches for a crew of 2 (pilot, gunner).
However, a 6 ton fighter would have "very short legs" because crew endurance is constrained by the life support allocation of the acceleration couches (12 hours in combat, double that for non-combat).

I'm thinking that the 8 ton Zhodani fighter that you cite simply adds a small craft cabin (2 tons) in order to overcome the life support endurance limitation, enabling the Zhodani fighter design to "range more freely" around the parent carrier/patrol craft hosting them.

Now, I'm going to ask a highly relevant question about these two "napkin math" design parameters.
Ready?

1. In LBB2.81 combat, where Computer Programming IS a relevant and controlling factor of combat capabilities ... how "useful" is a model/1 computer to a combatant who engages with an opponent?
   • My answer: It's better than "nothing" but not by much. At best it can "harass" and delay other craft until the parent ship arrives.
2. In LBB5.80 combat, where Computer Programming is NOT relevant to nor a controlling factor of combat capabilities ... how "useful" is a fighter with the equivalent to a model/0 computer (because no bridge means computer -1) to a combatant who engages with an opponent?
   • My answer: It's better than "nothing" but not by much. At best it can "harass" and delay other craft until the parent ship arrives.

In either case, the "microlight" fighters are so stripped down of capabilities that they're little more than recon assets, since their combat capabilities are so meager.

CAN it be done?
Sure. Obviously.

Are they good investments for the money they cost and the crew they require?
Not ... exactly ...
They're better than "nothing" ... but not by much enough for most combatant relevant mission roles.

In a "permissive" environment lacking "serious" opposition they can make decent fire support platforms (sort of a "pocket artillery") against the unarmed and unprotected. Against anything "fit for purpose" as a space combatant/naval asset ... these things will FOLD faster than pre-creased origami rice paper.



Or to put it another way, I would rather fly a 16 ton TL=9 Light Fighter with a bridge and a model/2 computer, armed with lasers against any kind of 8 ton TL=9-13 Zhodani Fighter with no bridge, a model/1 computer (that because of a lack of a bridge functions as a model/0 in combat), armed with missiles (that have a limited ammunition capacity).
You can even have TWO Zhodani Fighters compared to my ONE Light Fighter ... and I would still pick the Light Fighter over the Zhodani alternative if there is going to be a combat engagement.

 

[atpollard]

your thesis is wrong
Bk2, both editions, allows for hulls of interim sizes... but without any benefit for unlisted tonnages, and it's only 100 to 1000 where its by hundreds. it's thousands to 5k.
And Bk5, the size table does support a log function... hundreds to 1000, thousands to 10k, 10k to 50k, 25k from 50k to 100k, then 100k to 1M.

1k/10k/25k/50k/100k/etc. are still multiples of 10 or 100.

The post was restored without the exchange with aramis, which has been edited down and included above if you want to continue it.

NOTE: The point that aramis was making is the progression is a LOG FUNCTION rather than a simple multiple of 10 or 100. You should respond to that (or not).

 

[mike wightman]

The Broadsword fighter
CP-10798.91 Fighter F F-0106611.000000-00001-0 MCr7.245 6 tons
Crew=1. Passengers=0. Fuel=1. EP=0.36. Agility=6. No bridge. TL=12.

The Zhodani fighter.
Fighter FM-0106D21-000000-00003-0 Mcr19.155 8 tons
one battery of missiles TL=13. Crew=1
Cargo=0. Fuel=1.4. EP=1.04. Agility=6.

 

[Spinward Flow]

a 16 ton TL=9 Light Fighter with a bridge and a model/2 computer, armed with lasers

Hmmm.

16 ton hull, configuration: 1 (MCr1.92)

• 1 ton for Maneuver-A drive (TL=9) (code: 1 @ 200 tons, code: 6 @ 33 tons) (Agility=6 requires 0.96 EP) (MCr4)
• 7 tons for Power Plant-B drive (TL=9) (code: 1 @ 400 tons, code: R @ 16 tons) (generates 4 EP) (MCr16)
• 1 ton for fuel (120 hours endurance @ 4 EP output)
• 4 tons for bridge (includes 2 acceleration couches for crew, life support endurance 12-24 hours) (MCr0.1)
• 2 tons for model/2 computer (TL=7, consumes 0 EP) (MCr9)
• 1 ton for triple turret (3x pulse laser, 1 battery @ code: 2) (requires 3 EP) (MCr2.6)
• External docking capacity: 17.6 tons (MCr0.352)

1+7+1+4+2+1 = 16 tons
1.92+4+16+0.1+9+2.6+0.352 = MCr33.972 (100% single production cost)

Under LBB5.80 combat rules, a code: 2 beam weapon has a base to hit roll of 7+ on 2D from the weapon battery.
A model/2 computer modifies that to be 5+ on 2D before and defensive modifiers get thrown into the equation.
After that, it's "all downhill" with defensive Size DM and defensive computer model and defensive agility getting factored in.

Point being that a small craft (-2 DM for size) with Agility=6 (-6 DM) and computer/0 (-0 DM) would have a combined defensive modifier of -8.
That would require a 13+ roll on 2D in order to hit ... a statistical impossibility ... if fighting a micro-fighter (10 tons or less).

By contrast, against a J1 Free Trader or a J2 Scout/Courier, things are dramatically different.
The size modifier for 100-1000 tons displacement is -1.
The relative computer size modifier for model/1(bis) is also -1.
Agility is anywhere from 0 to 2, depending on weaponry loadout ... so -0 to -2.
Under those conditions, a 16 ton light fighter armed with a triple pulse laser turret would need to roll a 7-9+ (depending on defending agility rating) in order to hit.

In other words, it "works" against non-military targets, but the performance can be a bit "hit or miss" depending on the skills (and EP budget) of the opponent being engaged.

---

So ... analysis of alternative(s).

16 ton hull, configuration: 1 (MCr1.92)

• 1 ton for Maneuver-A drive (TL=9) (code: 1 @ 200 tons, code: 6 @ 33 tons) (Agility=6 requires 0.96 EP) (MCr4)
• 4 tons for Power Plant-A drive (TL=9) (code: 1 @ 200 tons, code: C @ 16 tons) (generates 2 EP) (MCr8)
• 1 ton for fuel (240 hours endurance @ 2 EP output)
• 4 tons for bridge (includes 2 acceleration couches for crew, life support endurance 12-24 hours) (MCr0.1)
• 3 tons for model/3 computer (TL=9, consumes 1 EP) (MCr18)
• 1 ton for mixed triple turret (missile, 1 battery @ code: 1 @ TL=9) (sandcaster, 1 battery @ code: 2 @ TL=9) (missile, 1 battery @ code: 1 @ TL=9) (requires 0 EP) (MCr3.85)
• External docking capacity: 176 tons (MCr0.352)
• 2 tons for small craft stateroom (extends crew life support endurance) (MCr0.05)

1+4+1+4+3+1+2 = 16 tons
1.92+4+8+0.1+18+3.85+0.352+0.05 = MCr36.272 (100% single production cost)

So a missile/sand/missile turret backed by a model/3 computer costs only +MCr2.3 more to construction (ordnance supply expenses not included).
36.272 / 33.972 = +6.77% construction cost (not including ordnance supply expenses)

That seems ... worthwhile ... given the modulation in combat capability/lethality as well as offense/defense potential (primarily from the upgrade to model/3, but also the addition of a sandcaster). In addition, the endurance (fuel consumption rate and crew life support) are also dramatically improved ... from 5 days of fuel/12-24 hours for crew when armed with pulse lasers and a model/2 computer ... to 10 days of fuel/10 days for crew when armed with missile/sand/missile and a model/3 computer.

Under LBB5.80 combat rules, a code: 1 missile weapon has a base to hit roll of 6+ on 2D from the weapon battery.
A model/3 computer modifies that to be 3+ on 2D before and defensive modifiers get thrown into the equation.
After that, it's "all downhill" with defensive Size DM and defensive computer model and defensive agility getting factored in.
However, the mixed turret option means that there are 2x code: 1 missile batteries, instead of 1x code: 2 pulse laser battery.
There's also the 1x code: 2 sandcaster for defense (if needed).

Against a small craft (-2 DM for size) with Agility=6 (-6 DM) and computer/0 (-0 DM), that would mean a combined defensive modifier of -8.
That would require a 11+ roll on 2D in order to hit ... a distinct possibility, especially with 2x missile batteries bearing per combat turn ... if fighting a micro-fighter (10 tons or less).

By contrast, against a J1 Free Trader or a J2 Scout/Courier, things are dramatically different.
The size modifier for 100-1000 tons displacement is -1.
The relative computer size modifier for model/1(bis) is also -1 (to hit).
Agility is anywhere from 0 to 2, depending on weaponry loadout ... so -0 to -2.
Under those conditions, a 16 ton light fighter armed with a mixed missile/sand/missile turrent would need to roll a 5-7+ (depending on defending agility rating) in order to hit ... which would be a LOT more combat effective (particularly with 2x missile batteries compared to 1x pulse laser battery).

Ordnance launching weapons in turrets have 1 salvo "ready to fire" with 2 reloads ready per weapon installed into a turret.

1. Missile = 3 salvos
2. Sandcaster = 3 salvos
3. Missile = 3 salvos

Individual turrets have the capacity for 12 reloads, to be divided amongst the weapons installed into the turret.
So the way I would expect the standard loadout for a missile/sand/missile turret to be arranged would look like this:

• Missile = 3 salvos + 6 turret reloads
• Sandcaster = 3 salvos + 0 turret reloads
• Missile = 3 salvos + 6 turret reloads

Idea being that due to the small craft size modifier (-2 DM) and Agility=6 (-6 DM) and computer model modifier (-3 DM) ... in order to be able to achieve a 12+ on 2D hit roll, the attacker needs a combination of weapon code to hit+computer model modifiers that yield a 1+ to hit score before defensive modifiers get applied.

At TL=9 with model/3 computers, that requires either a missile code: battery (6 triple missile turrets per battery) or a laser code: 8 battery (10 triple beam laser turrets per battery).
Obviously, with better combinations of battery codes and computer size modifiers, that "stack of defensive modifiers" gets easier to overcome as technology levels increase, but in the TL=9-11 range it's still pretty decent performance for a TL=9 Light Fighter weighing in at the 16 ton displacement level.

Either way, the sandcaster is "unlikely to need to be used" against most combatants, except when the TL=9 Light Fighter is outclassed and overmatched by higher technology competition. Still, having it available "when needed" would undoubtedly be comforting to crews (irrelevant to how "effective" a code: 2 sandcaster might be when actually needed).

 

[mike wightman]

House ruled design - doesn't count.

 

[kilemall]

House ruled design - doesn't count.

Count for what?

This isn’t publication RAW stuff. He lists it as his own take, those that might be interested can pay attention and duct tape it in their way, those that don’t want to don’t have to.

 

[Spinward Flow]

250 ton hull

• 45 tons for D/D/D drives (code: 3/3/3 @ 266 tons, TL=9)
• 105 tons for fuel (J3@250=75, PP3=30)
• 9 tons for fuel purification plant (TL=9, 200 tons capacity)
• 20 tons for bridge
• 2 tons for model/2bis
• 64 tons for hangar bay
  1. 16 tons for Stateroom Box (pilot/navigator, ship's boat/gunner, engineer/engineer, steward/medic)
  2. 16 tons for Stateroom Box (4x high passengers)
  3. 16 tons for Cargo Box
  4. 16 tons for Cargo Box
• External Docking capacity: 550 tons
  • 16 tons for Escort Fighter
• 1 ton for cargo hold(s)
  • 0.64 tons for 96 ton capacity collapsible fuel tank (occupies hangar bay when filled)
  • 0.36 tons for life support consumables reserves (54 person/weeks = 10.8 weeks for 4+4=8 persons)
  • 4 tons for vehicle berth (Air/raft, TL=9)

45+105+9+20+2+64+5=250

---

So although it is POSSIBLE to break into the J3 Clipper market with a TL=9 design, the revenue tonnage is rather severely limited inside a 250 ton hull.

800 / 3 = 266.66666667≈ 266 tons

400 - 266 = 134
134 / 16 = 8.375


9 * 16 = 144
400-144 = 256
800 - 256 = 544
544 / 16 = 34

256 * 1.1 = 281.6
256+281.6+281.6 = 819.2


800 / 3.2 = 250
250 * 1.1 = 275
250 + 275 + 275 = 800
800 - 250 = 550 / 1.1 = 500

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250 ton hull

• 45 tons for D/D/D drives (code: 3/3/3 @ 266 tons, TL=9)
• 105 tons for fuel (J3@250=75, PP3=30)
• 9 tons for fuel purification plant (TL=9, 200 tons capacity)
• 20 tons for bridge
• 2 tons for model/2bis
• 64 tons for hangar bay
  1. 16 tons for Escort Fighter
  2. 16 tons for Stateroom Box (pilot/navigator, ship's boat/gunner, engineer/engineer, steward/medic)
  3. 16 tons for Stateroom Box (4x high passengers)
  4. 16 tons for Cargo Box
• External Docking capacity: 550 tons
  • 1x 16 ton Box external: 250+16=266 combined tons, J3/3G/PP3 drive performance
  • 9x 16 ton Boxes external: 250+9*16=394 combined tons, J2/2G/PP2 drive performance
  • 34x 16 ton Boxes external: 250+34*16=794 combined tons, J1/1G/PP1 drive performance
  • 1x 250 ton big craft + 17x 16 ton boxes: 250+250*1.1+17*16=797 combined tons, J1/1G/PP1 drive performance
  • 2x 250 ton big craft: 250+2*250*1.1=800 combined tons, J1/1G/PP1 drive performance
  • 1x 500 ton big craft: 250+500*1.1=800 combined tons, J1/1G/PP1 drive performance
• 5 tons for cargo hold(s)
  1. 0.64 tons for 64 ton capacity collapsible fuel tank (occupies hangar bay when filled)
  2. 0.36 tons for life support consumables reserves (54 person/weeks = 10.8 weeks for 4+4=8 persons)
  3. 4 tons for vehicle berth (Air/raft, TL=9)

45+105+9+20+2+64+5=250

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J3 context (1 ticket)

Revenue tonnage (internal):

• 4x high passengers
• 16 tons hangar bay capacity available for cargo

Revenue tonnage (external):

• 1x 16 ton cargo box

100% manifest ticket revenues: Cr72,000

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J2 context (1 ticket)

Revenue tonnage (internal):

• 4x high passengers
• 1x 16 ton cargo box

Revenue tonnage (external):

• 4x high passengers
• 8x 16 ton cargo box

100% manifest ticket revenues: Cr224,000 (if owning all boxes)
100% internal manifest, external tonnage cargo charter for third parties ticket revenues: Cr185,600

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Point here being that although the ship isn't exactly profitable to operate on ticket sales exclusively when configured by external loading for J3 ... ticket revenues can basically 2x to 3x by simply adding more boxes to external docking points, trading range for revenue.

So although the design CAN be used as a J3 Clipper, in a merchant context it is most likely to be used as a J2 (or even J2+2) Tramp Trader. The external towing capacity could either be filled by the starship operator owning the extra Boxes to be docked and towed externally, or that external docking capacity can be chartered by third parties (at Cr900 per ton cargo transport rates) on interstellar tickets.

---

Crew salaries: 9075+5775+6600+3900 = Cr25,350 per 4 weeks

• Pilot-2/Navigator-2: ((6000*1.1)+(5000*1.1))*0.75 = Cr9075
• Ship's Boat-2/Gunner-2: ((6000*1.1)+(1000*1.1))*0.75 = Cr5775
• Engineer-2/Engineer-2: ((4000*1.1)+(4000*1.1))*0.75 = Cr6600
• Steward-1/Medic-2: (3000+(2000*1.1))*0.75 = Cr3900

Life Support overhead (including 4x high passengers): 8*2000 = Cr16,000 per 2 weeks = Cr32,000 per 4 weeks
Berthing Fees (6 days per port of call): Cr100 per 2 weeks = Cr200 per 4 weeks

Monthly Overhead Expenses (2 ports of call per 4 weeks): 25,350+32,000+200 = Cr57,550
2x J3 100% manifest ticket revenues under subsidy (2 ports of call per 4 weeks): Cr72,000
Net profit per 4 weeks potential (under subsidy) for operator: Cr14,450 (does not include annual overhaul maintenance expenses)

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In other words, even at J3 ... with a subsidy contract, it would be extremely easy for an operator remain "in the black" and operating/profitable without needing to resort to a contract for x-mail (which would consume 5 tons of cargo capacity). Any kind of speculative goods arbitrage operation @ J3 would be some pretty small time "penny ante" stuff (since only up to 32 tons of cargo capacity would be available for use) ... but depending on the speculative goods, that might potentially "be enough" for most of the savvy/wily operators out there who know how to wheel & deal with the Big Boys™ out there.



The thing that gets me about this is that it's a TL=9 J3/3G Clipper ... that has a "variety of modes" of operation to it, all because of how the modularized container transport business model works and the flexibility it makes possible.

Note that the basic concept could be outfitted with up to 33x Boxes and the Escort Fighter docked externally, using the internal hangar bay to hold additional fuel in order to enable J1+1 microjumping within a single star system (or just jumping to a neighboring star system) as a regular "passenger liner service" circulating on a routine schedule.

• 33x Stateroom Boxes = 132 single occupancy staterooms
• Starship Crew (4): pilot/navigator, ship's boat/gunner, engineer/engineer, steward/medic
• Passenger Liner Crew (8): 1x purser, 6x steward/steward, 1x steward (trainee)
• High Passengers: 120

Yeah. That'll work.
100% full manifest ticket revenues would be MCr1.2 per J1 jump. 12 round trips per year (24 jumps) would yield up to MCr28.8 per year in ticket revenues for such an operation.

That'll work as an in-system "circulator" of passengers between worlds within a star system or between adjacent star systems. A bit akin to the interplanetary/interstellar equivalent of a Concorde type experience. Very much a "locked in by contracts" type of commercial venture, rather than a Traveller-esque use and role for the design, but certainly something that would work remarkably well as part of the backdrop to a campaign setting. That way, NPCs use the design this way, rather than the PCs.



Other "grunt blue collar/space trucker work" applications could include using the design as a fuel harvester/tanker/transport. Load up the design with Cargo Boxes (all with specs as "fuel tanks") and you can start hauling 480+ tons of fuel around externally (30x Boxes worth) per trip @ J1/1G and still be capable of J1+1 (because of the internal collapsible fuel tank) if you need to make round trips.



Yeah.
That'll play.