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Pondering starship evolution

So here's a fun little bit of math (and the rabbit holes it opens). :oops:

I'm looking at the TL=9 D/D/D starship and I've basically got "two goals" to shoot for as far as performance goes.
  • 800 / 1 = 800 tons = J1/1G/PP1
  • 800 / 2 = 400 tons = J2/2G/PP2
  • 800 / 3 = 266 tons = J3/3G/PP3
As worked out previously ... I can build a 250 ton starship, strap a 16 ton Escort Fighter to the exterior and get a 266 combined tons for a J3/3G performance profile. But what's especially interesting is how adding more 16 ton modules to that basic setup modifies drive performance as the external load increases.
  • 250 + 16 = 266 = J3/3G/PP3
  • 250 + 16 + 8*16 = 394 = J2/2G/PP2
  • 250 + 16 + 33*16 = 794 = J1/1G/PP1
Where things get really interesting is in the realm of "buddy towing" other starships of the same class (up to 2!), externally. Some of the other "not the same starship class" alternatives get interesting as well.
  • 250 + 1.1*100 + 2*16 = 392 = J2/2G/PP2
  • 250 + 1.1*250 + 17*16 = 797 = J1/1G/PP1
  • 250 + 1.1*250 + 1.1*250 = 800 = J1/1G/PP1
  • 250 + 1.1*400 + 6*16 = 786 = J1/1G/PP1
  • 250 + 1.1*500 = 800 = J1/1G/PP1
The downside to having a 250 ton starship design is the limited internal capacity for Boxes (no more than 4), which must be used for crew quarters (1 Box, minimum!) along with Passenger and Cargo capacity. So 3 Boxes for revenue tonnage @ J3 is a very tight fit, and remarkably limiting! 😖

However, for J2 performance, the revenue tonnage increases from 3 Boxes to up to 11 (3 internal, up to 8 external).
The internal hangar bay is 64 tons.


Compare and contrast that with what happens in a 350 ton starship that can strap on 3 more Boxes to the exterior and get a 398 combines tons for J2/2G performance profile.
  • 350 + 3*16 = 398 = J2/2G/PP2
  • 350 + 28*16 = 798 = J1/1G/PP1
In this case, the "buddy towing" capacity of other starships of the same class, externally, is limited to just 1 ... but at the same time, the math is working out such that it is still possible to do some rather interesting combinations.
  • 350 + 1.1*350 + 4*16 = 799 = J1/1G/PP1
  • 350 + 1.1*400 = 790 = J1/1G/PP1
What gets interesting here is the revenue tonnage fraction. To keep the comparison equal, assume a single Box must be used for crew quarters (minimum 1!) and another "Box slot" will be available to the Escort Fighter so it can be docked internally. The internal hangar bay space is 176 tons (11x Boxes worth) total, and there is still capacity for up to 3 more Boxes to be docked externally while retaining a J2 drive performance output.

So for J2 performance, the revenue tonnage starts at 9 Boxes (internal) and can be increased to as many as 12 (9 internal, up to 3 external).


As you can see, from the way that the math is adding up, the 250 ton J3/3G version is possible to do ... technologically ... but the economics may dictate (if not subsidized) that the starship operated in a J2 (privately owned, paid off on delivery) or in a J1 (bank financed) capacity in order to make ends meet on ticket revenues alone. The drawback is a small internal load capacity (64 ton hangar bay).

Conversely, the 350 ton J2/2G version has a much larger internal load capacity (176 ton hangar bay) and doesn't need to dock the Escort Fighter to the starship's exterior during interstellar jumps. That larger revenue tonnage fraction then makes it a lot easier to sell more passenger and cargo freight tickets, but that larger capacity can potentially be "wasted" on routes with immature markets on low population worlds (a "right sizing" to demand issue).



The trick here is to realize that rather than designing for a single starship design, I've accidentally stumbled onto a design concept that ideally wants to be TWO starships, not just one.😲

The 350 ton J2/2G design is better for "high end" markets with larger volumes of trade ... while the 250 ton J3/3G design is better for "low end" markets with smaller volumes of trade ... so as to be able to better balance the competing signals of supply versus demand. Both designs use the same set of standard drives (D/D/D), but the 350 ton design works better on "preset routes" to fill its J2 capacity, while the 250 ton design works best as a speculative goods arbitrage tramp that can sell tickets (and move xmail) to prop up the bottom line between lucrative arbitrage runs.



It's also not lost on me that the 250 ton J3/3G design would also happen to be the "better choice" as a Corsair for a professional pirate. 🏴‍☠️
Why?
Because of the larger external load capacity, enabling entire starships to be taken as prizes and jumped to unscrupulous shipyards that can liquidate the value of captures so as to turn them into credits and keep the party rolling. The Escort Fighter is just "too good" for most commercial shipping and thus there will always be the temptation to use them for nefarious ends. Also, the 3G maneuver performance is "what you'd want" in a Corsair anyway, in order to be able to intercept unsuspecting merchants more easily.
 
:unsure:

Taking a peek @ TL=10 once again, and THIS tumbled out of the math ...


307 tons starship hull
55 tons for LBB2.81 standard E/E/E drives (codes: 3/3/3, TL=10)
122.1 tons of total fuel: 307 tons @ J3 = 92.1 tons jump fuel + 30 tons power plant fuel
8 tons for TL=10 fuel purification plant (200 ton capacity is minimum)
20 tons for bridge
2 ton for model/2bis computer
97 tons for hangar berths capacity
  1. Stateroom Box = 16 tons
  2. Stateroom Box = 16 tons
  3. Laboratory Box (Type V-c regenerative biome life support) = 16 tons
  4. Environmental Box = 16 tons
  5. Cargo Box = 16 tons
  6. Cargo Box = 16 tons
  7. 97 tons capacity Collapsible Fuel Tank = 0.97 tons
External Docking Capacity: 672 tons
  1. Escort Fighter = 16 tons
2.9 tons for Cargo Hold(s)

= 55+122.1+8+20+2+97+2.9 = 307 tons + 16 tons (Escort Fighter) = 323 tons
5 Crew: Pilot/Navigator, Ship's Boat/Gunner, Engineer/Engineer, Steward/Steward, Medic
Revenue Tonnage: 3x high passengers + 16 tons environmentally controlled cargo + 32 tons standard cargo
Escort Fighter external


So why might that be an interesting result (mathematically speaking)? :rolleyes:
Well ...
  • 307 + 1*16 = 323 tons = J3/3G/PP3
  • 307 + 12*16 = 499 tons = J2/2G/PP2
  • 307 + 43*16 = 995 tons = J1/1G/PP1
Okay, that's "nice" for 16 ton small craft in modular blocks (of no more than 6x 16 tons = 96 combined tons each), but what about needing to externally tow big craft?
  • 307 + 1.1*100 + 5*16 = 497 tons = J2/2G/PP2
  • 307 + 1.1*160 + 1*16 = 499 tons = J2/2G/PP2
  • 307 + 1.1*307 + 1.1*307 + 1*16 = 998.4 tons = J1/1G/PP1
  • 307 + 1.1*600 + 2*16 = 999 tons = J1/1G/PP1


Compare and contrast ⬆️ that kind of performance with what is possible @ TL=9. ⬇️


250 tons starship hull
45 tons for LBB2.81 standard D/D/D drives (codes: 3/3/3, TL=9)
105 tons of total fuel: 250 tons @ J3 = 75 tons jump fuel + 30 tons power plant fuel
9 tons for TL=9 fuel purification plant (200 ton capacity is minimum)
20 tons for bridge
2 ton for model/2bis computer
64 tons for hangar berths capacity
  1. Stateroom Box = 16 tons
  2. Stateroom Box = 16 tons
  3. Cargo Box = 16 tons
  4. Cargo Box = 16 tons
External Docking Capacity: 550 tons capacity
  1. Escort Fighter = 16 tons
5 tons Cargo Hold
  • 4 tons for Air/Raft
  • 0.36 tons for 54 person/weeks Life Support Reserves
  • 0.64 tons for 64 tons capacity Collapsible Fuel Tank

= 45+105+9+20+2+64+5 = 250 tons
4 Crew: Pilot/Navigator, Ship's Boat/Gunner, Engineer/Engineer, Steward/Medic
4 high passengers, 32 tons standard cargo internal
Escort Fighter external


For the external towing of small craft, the breakpoints fall out like so:
  • 250 + 1*16 = 266 = J3/3G/PP3
  • 250 + 9*16 = 394 = J2/2G/PP2
  • 250 + 34*16 = 794 = J1/1G/PP1
And for big craft, you get the following:
  • 250 + 1.1*100 + 2*16 = 392 = J2/2G/PP2
  • 250 + 1.1*250 + 17*16 = 797 = J1/1G/PP1
  • 250 + 1.1*250 + 1.1*250 + 0*16 = 800 = J1/1G/PP1
  • 250 + 1.1*400 + 6*16 = 786 = J1/1G/PP1
  • 250 + 1.1*500 + 0*16 = 800 = J1/1G/PP1

So while it is POSSIBLE to build a J3/3G Clipper @ TL=9, it's really "too cramped for its own good" in terms of hangar bay capacity (and thus revenue tonnage fraction) when compared to the TL=10 alternative.

In terms of ticket revenues on a 100% manifest @ J3/3G:
  • TL=10 ... Cr30,000 for 3x high passengers + Cr48,000 for 48 tons cargo freight = Cr78,000 per jump
  • TL=9 ... Cr40,000 for 4x high passengers + Cr32,000 for 32 tons cargo freight = Cr72,000 per jump
However, a BIG difference is going to be the life support expenses between the two designs.
  • TL=10 ... Cr0 for 8 single occupancy staterooms (Type V-c regenerative biome life support) every 2 weeks
  • TL=9 ... Cr16,000 for 8 single occupancy staterooms every 2 weeks
Which means that the net balance (unsubsidized) at a 1 jump per 2 weeks tempo starts looking like this:
  • TL=10 ... 78,000 - 0 = Cr78,000
  • TL=9 ... 72,000 - 16,000 = Cr56,000
Subsidized service (50% rake of ticket revenues) makes the comparison look even worse for the TL=9 version's economics:
  • TL=10 ... 78,000/2 - 0 = Cr39,000
  • TL=9 ... 72,000/2 - 16,000 = Cr20,000
That's because under subsidy, the ticket revenues are cut in half (50% rake for the subsidizing government) but the operating expenses (crew salaries, life support, berthing fees, annual maintenance, etc.) all remain at 100%.

So on the TL=9 version, if you swap out 1 of the 2 Cargo Boxes for a Laboratory Box (Type V-c regenerative biome life support, you cut your cargo capacity IN HALF from 32 tons (barely adequate for speculative goods opportunities) all the way down to 16 tons (you'll miss out on a lot of speculative goods opportunities due to a lack of transport capacity).

Your ticket revenues would do this:
  • TL=9 ... Cr40,000 for 4x high passengers + Cr16,000 for 16 tons cargo freight = Cr56,000 per jump
Your unsubsidized net balance at 1 jump per 2 weeks tempo looks like this:
  • TL=9 ... 56,000 - 0 = Cr56,000
And your subsidized net balance at 1 jump per 2 weeks tempo looks like this:
  • TL=9 ... 56,000/2 - 0 = Cr28,000
So better on the ticket revenues, but (much) worse on the speculative goods arbitrage front due to the reduction in cargo capacity (hence why I considered and discarded the option for the TL=9 design @ 250 tons, there just isn't enough "spare room" to make it practical). However, this IS an example of how investment into regenerative biome life support options can "pay for themselves" in terms of offsetting life support overhead expenses for starship operators.



Obviously both ships would be working the "small time/low end" trading market, going to low(-ish) population worlds with limited demand for ticket services while configured for J3/3G. However, when the opportunity (or market demand) rises, loading up with external third party Boxes that need to be towed to a destination will always be an option, increasing ticket revenues in exchange for a reduction in drive performance.

It also highlights the notion that starships "need to be a certain minimum size" (and therefore, technology level) before a whole range of options for business models become available and/or practical. 🚀✨
 
Spinward Flow said:
97 tons for hangar berths capacity
  1. Stateroom Box = 16 tons
  2. Stateroom Box = 16 tons
  3. Laboratory Box (Type V-c regenerative biome life support) = 16 tons
  4. Environmental Box = 16 tons
  5. Cargo Box = 16 tons
  6. Cargo Box = 16 tons
  7. 97 tons capacity Collapsible Fuel Tank = 0.97 tons
Click to expand...
Okay.
Now I think I'm onto something here.

This 97 ton hangar bay for 6x 16 ton Boxes plus a 97 tons capacity Collapsible Fuel Tank is just ... elegant ... as a bit of mathematical design. Enough so that I'm thinking it ought to be the "standard feature" for a J2/2G design @ TL=9 AND for a J3/3G design @ TL=10. This would then create an "upgrade path" in capabilities when moving from TL=9 to TL=10 and represent a sort of natural progression.

Here's how the "spreadsheet math" for all of that works out on the napkin.


232 tons starship hull
35 tons for LBB2.81 standard C/C/C drives (codes: 2/2/2, TL=9)
67 tons of total fuel: 232 tons @ J2 = 46.4 tons jump fuel + 20 tons power plant fuel
9 tons for TL=9 fuel purification plant (200 ton capacity is minimum)
20 tons for bridge
2 ton for model/2 computer
97 tons for hangar berths capacity
  1. Stateroom Box = 16 tons
  2. Stateroom Box = 16 tons
  3. Laboratory Box (Type V-c regenerative biome life support) = 16 tons
  4. Environmental Box = 16 tons
  5. Cargo Box = 16 tons
  6. Cargo Box = 16 tons
  • 97 tons capacity Collapsible Fuel Tank = 0.97 tons
External Docking Capacity: 368 tons capacity
  1. Escort Fighter = 16 tons


2 tons for Cargo Hold
= 35+67+9+20+2+97+2 = 232 tons + 16 tons (Escort Fighter) = 248 tons

Crew = 5
1. Pilot-2/Navigator-2
2. Ship's Boat-2/Gunner-2
3. Engineer-1
4. Steward-1/Steward-1
5. Medic-3
Revenue Tonnage @ J2
• 3x high passengers
• 16 tons environmentally controlled cargo
• 32 tons standard cargo
• 48 tons additional cargo (when 1x Environmental and 2x Cargo Boxes moved to exterior)
Revenue Tonnage @ J2+2
• 3x high passengers
• 16 tons environmentally controlled cargo
• 32 tons standard cargo
Escort Fighter external


And to do the (now obligatory) math for external towing:
  • 232 + 1*16 = 248 tons = J2/2G/PP2
  • 232 + 4*16 = 296 tons = J2/2G/PP2
  • 232 + 23*16 = 600 tons = J1/1G/PP1
  • 232 + 1.1*200 + 9*16 = 596 tons = J1/1G/PP1
  • 232 + 1.1*232 + 7*16 = 599.2 tons = J1/1G/PP1
  • 232 + 1.1*300 + 2*16 = 594 tons = J1/1G/PP1

The incredible thing about THIS iteration is that it is capable of J2+2 by moving 3x Boxes (usually the Environmental and Cargo) from the interior hangar to exterior docking points, freeing up 48 tons of internal hangar volume to be occupied by a partial fill of the collapsible fuel tank with 48 tons of fuel.
  • 67 + 48 = 115 tons of combined total fuel load
Where things get interesting is computing the jump fuel demands.
  • (232+4*16)*0.2 = 59.2 tons for first J2 ... move 3x Boxes from exterior to interior during 16 hour routine drive maintenance after jump
  • (232+1*16)*0.2 = 49.6 tons for second J2
59.2+49.6 = 108.8 tons of jump fuel required for J2+2
115 tons of combined total fuel from point of origin

In other words, this design can J2+2 @ TL=9 at a "cost" of 48 tons of cargo freight ticket(s) revenue.



This looks REALLY PROMISING as a Long Trader design. :cool:
Being able to get 4 parsecs of range out of a TL=9 design makes all kinds of speculative goods arbitrage opportunities possible within reasonable time frames for tramp merchant operators.



The "upgrade" to that then becomes THIS @ TL=10 ...


307 tons starship hull
55 tons for LBB2.81 standard E/E/E drives (codes: 3/3/3, TL=10)
123 tons of total fuel: 307 tons @ J3 = 92.1 tons jump fuel + 30 tons power plant fuel
8 tons for TL=10 fuel purification plant (200 ton capacity is minimum)
20 tons for bridge
2 ton for model/2bis computer
97 tons for hangar berths capacity
  1. Stateroom Box = 16 tons
  2. Stateroom Box = 16 tons
  3. Laboratory Box (Type V-c regenerative biome life support) = 16 tons
  4. Environmental Box = 16 tons
  5. Cargo Box = 16 tons
  6. Cargo Box = 16 tons
  • 97 tons capacity Collapsible Fuel Tank = 0.97 tons
External Docking Capacity: 693 tons
  1. Escort Fighter = 16 tons
2 tons for Cargo Hold(s)

= 55+123+8+20+2+97+2 = 307 tons + 16 tons (Escort Fighter) = 323 tons
Crew = 5
  1. Pilot-2/Navigator-2
  2. Ship's Boat-2/Gunner-2
  3. Engineer-2/Engineer-2
  4. Steward-1/Steward-1
  5. Medic-3
Revenue Tonnage @ J3
  • 3x high passengers
  • 16 tons environmentally controlled cargo
  • 32 tons standard cargo
Escort Fighter external


And to do the (now obligatory) math for external towing:
  • 307 + 1*16 = 323 tons = J3/3G/PP3
  • 307 + 12*16 = 499 tons = J2/2G/PP2
  • 307 + 43*16 = 995 tons = J1/1G/PP1
  • 307 + 1.1*100 + 5*16 = 497 tons = J2/2G/PP2
  • 307 + 1.1*400 + 15*16 = 987 tons = J1/1G/PP1
  • 307 + 1.1*600 + 2*16 = 999 tons = J1/1G/PP1

The interesting thing here is that this TL=10 upgrade is capable of doing a J2+3 using its collapsible fuel tank, among other possible permutations depending on external load factors, making this upgrade version "even better" for a lot of speculative goods arbitrage tramp merchant operators. More range and increased load capacity (because of more powerful drives) makes for enough of a "step change" in capability as to be worthy of a revised and updated design. :cool:(y)



Which means that I think I've finally got my TL=9-10 design path details settled (finally). 😫
 
Piracy is just servicing an alternative market for goods at a low fiscal but high risk rate.

Star Citizen has a starship builder that specializes in dual purpose ships that can be rescue, haulers, LE, defense etc but has found a ready market in pirates. So they even play to that market with named ship classes like Cutlass, Corsair, etc.

starcitizen.tools

Drake Interplanetary - Star Citizen Wiki

Drake Interplanetary is a Human spacecraft manufacturer that designs, manufacturers and sells spaceships in the Star Citizen universe. It is headquartered in Odyssa...
starcitizen.tools starcitizen.tools

 
Last edited:
aramis said:
Spinward Flow - which ruleset are you using for these? (it makes HUGE differences in the math.)
Click to expand...
LBB2.81 (drives and weapons)
LBB3.81 (drive TLs and vehicles)
LBB5.80 (hull configurations, EP system, computers, fuel purification plants, sub-craft and hangars, etc.) (all the stuff that LBB2.81 "doesn't do")
LBB A5 (collapsible/demountable/drop fuel tanks)

Homebrew (to interpolate the gaps in CT RAWs)

ALL of these sources have been consistent (from me) during the continuity of this thread.

The reason why I didn't put a "CT Only" or even a "Rules Only" marker on this thread is because I'm blending in some homebrew into CT, so from a strictly purist/fundamentalist point of view, what I'm doing is merely "CT Adjacent" because I'm doing things that the RAW doesn't address (properly) in order to make a Cool New Thing™. :cool:



As for any kind of precedent to the notion that it's possible to "tow" external loads through jump (like I'm appealing to here) ... I give you LBB S9, p22-23 ... the Jump Ship ... which is a 5000 ton starship class designed to "tow" 1000 ton external pods or other "bulk matter" as needed.

Brown-class-Jump-Ship-RESIZE-J-Jaquays-Supp-9-CT_28-Aug-2019b.JPG


There's also the precedent (exceedingly poorly explained!) of External Demountable Tanks as well as Drop Tanks, both of which alter the displacement of craft and both of which can be retained through jump (Demountable Tanks must be retained, Drop Tanks can be optionally retained). The (confusing in its particulars) Gazelle-class is an example of a starship that has different drive performance levels depending upon external loading kept close to the hull.



Does that answer your question?
 
Spinward Flow said:
97 tons for hangar berths capacity
  1. Stateroom Box = 16 tons
  2. Stateroom Box = 16 tons
  3. Laboratory Box (Type V-c regenerative biome life support) = 16 tons
  4. Environmental Box = 16 tons
  5. Cargo Box = 16 tons
  6. Cargo Box = 16 tons
  • 97 tons capacity Collapsible Fuel Tank = 0.97 tons
Click to expand...
Here's what the contents of such hangar bays look like when drawn as deck plans, so that the context of what I'm building towards starts getting clearer.

u6kPdoJ.png


You have a double deck height hangar bay (left of picture is forward, right of picture is aft).
  • 3 Boxes dorsal (environment, cargo, cargo)
  • 3 Boxes ventral (stateroom, laboratory, stateroom)
Right now, I'm thinking that you would want to have a single aft door (horizontal axis hinge, ventral) which can be used as a ramp for loading/unloading from the ground ... while also having clamshell doors (split down the middle, open to port/starboard) on the dorsal for vertical "crane" lifting in/out of the hangar bay, such as by the Escort Fighter while the starship is parked in a gravity well or by starport facilities when in a berth.

Obviously, the next step is to start drawing the hangar bay facilities "around" the Boxes, which will also include the built in collapsible fuel tank "stuffs™" ... but this at least forms the core of what the rest of the starship design(s) needs to get built around. It therefore makes for a decent beginning for everything that follows after as I build towards completed deck plans for TWO starship classes that will have this specific hangar bay detail in common between them.
  • 232 ton starship with C/C/C drives delivering J2/2G/PP2 performance @ TL=9
  • 307 ton starship with E/E/E drives delivering J3/3G/PP3 performance @ TL=10

Out of curiosity, I test the notion of "extending the run" to J/J/K drives delivering J4/4G/PP4 performance @ TL=11 ... and ran into a problem.

98 tons for LBB2.81 standard J/J/K drives (codes: 4/4/4, TL=11) (Agility=4)
40 tons power plant fuel
7 tons for TL=11 fuel purification plant (200 ton capacity is minimum)
20 tons for bridge
4 ton for model/4 computer (requires EP=2, hence why power plant-K is required)
97 tons for hangar berths capacity

  1. Stateroom Box = 16 tons
  2. Stateroom Box = 16 tons
  3. Laboratory Box (Type V-c regenerative biome life support) = 16 tons
  4. Environmental Box = 16 tons
  5. Cargo Box = 16 tons
  6. Cargo Box = 16 tons
  • 97 tons capacity Collapsible Fuel Tank = 0.97 tons
98+40+7+20+4+97 = 266 "uncompressible" tons

If I take that 266 tons number and then divide by 0.6, so as to calculate the minimum tonnage needed to include a 40% jump fuel fraction, the answer that comes out of the math is ... 266/0.6 = 443.333 ... round up to 444 tons minimum.

J-drives for jump and maneuver have the following performance breakpoints:
  • Code: 1 @ 1800 tons
  • Code: 2 @ 900 tons
  • Code: 3 @ 600 tons
  • Code: 4 @ 450 tons
The problem is that there isn't enough "margin" left over, between 444 and 450 tons, for the Escort Fighter to be carried externally any more.
😓
At that point, you either have to trade in one (or both) of the Cargo Boxes for either a TL=9 Escort Fighter (1 Box) or a TL=11 Escort Fighter (2 Boxes) so that the Escort Fighter can be carried internally.

In other words, "carrying the trend this far forward" into TL=11 is ... problematic ... especially since +1 Engineer position is required for drives of that size, reducing the high passenger stateroom accommodations from 3 to 2, so not only is the starship getting a LOT more expensive, the revenue tonnage fraction is dropping as well, pushing everything towards being uneconomical @ J4 on ticket revenues alone (which is not surprising, all things considered).


Alternatively, I could do this:

105 tons for LBB2.81 standard K/K/K drives (codes: 4/4/4, TL=11) (Agility=3, Emergency Agility=4)
40 tons power plant fuel
7 tons for TL=11 fuel purification plant (200 ton capacity is minimum)
20 tons for bridge
4 ton for model/4 computer (requires EP=2, hence why power plant-K is required)
97 tons for hangar berths capacity

  1. Stateroom Box = 16 tons
  2. Stateroom Box = 16 tons
  3. Laboratory Box (Type V-c regenerative biome life support) = 16 tons
  4. Environmental Box = 16 tons
  5. Cargo Box = 16 tons
  6. Cargo Box = 16 tons
  • 97 tons capacity Collapsible Fuel Tank = 0.97 tons
105+40+7+20+4+97 = 273 "uncompressible" tons

If I take that 273 tons number and then divide by 0.6, so as to calculate the minimum tonnage needed to include a 40% jump fuel fraction, the answer that comes out of the math is ... 273/0.6 = 455 (exactly).

K-drives for jump and maneuver have the following performance breakpoints:
  • Code: 1 @ 2000 tons
  • Code: 2 @ 1000 tons
  • Code: 3 @ 666 tons
  • Code: 4 @ 500 tons
From a "buddy towing" other starships of the same class perspective, 460 tons is probably the "sweet spot to land on, because:
  • 460 + 1.1*460 + 2*16 = 998 tons = J2/2G/PP2 (Agility=1, Emergency Agility=2)
Once you go past 1000 tons of combined displacement, small craft stop being carried at their own tonnage (LBB5.80, p32) ... but if they're "docked together" in sufficient quantities (100+ combined tons per "block" of Boxes), then they can be externally towed as Big Craft (110%) rather than as Small Craft (130%) due to packing efficiencies.

And it's at this point that 460 tons of starship with K/K/K drives starts looking like QUITE the "sweet spot" mathematically speaking. 🤓
Why? :unsure:
Well ... because ...
  • 2000 - 460 = 1540 / 1.1 = 1400 tons of big craft external towing capacity @ J1/1G/PP1 (Agility=0, Emergency Agility=1)
The math starts getting a bit complex with all of the possible permutations of external loading :eek:, but suffice it to say that 460 tons @ TL=11 is looking like the "natural end point" for the Trend Line of capabilities that I've been researching here. The revenue tonnage fraction of the overall hull (at J-max) is getting increasingly small, while the construction costs are ballooning quite dramatically(!) ... so RANGE HAS ITS PRICE in this context. However, it would be possible (potentially even desirable!) to operate such a starship as a speculative goods arbitrage tramp, in order to sustain a profitable merchant operation. Additionally, the external load capacity starts getting SO LARGE that you start moving out of the ACS realm of penny ante Free Trader operations and start needing to move into the structured merchant company operations model that needs more extensive "support" in terms of outside expertise (and third party relationships) in order to fill manifests economically.

In other words, the "small time operator" paradigm starts breaking down by TL=11 and you start needing to move towards more of a "bulk freighter" mindset that the Big Boys™ use (see: megacorporations). At that point, the "speculative goods arbitrage" is what is driving everything, but the starship operators aren't "controlling" the production and procurement of the speculative goods ... instead, third parties are doing that (or in the case of megacorporations, other divisions within the same company). That way, the starship (and her crew) can be operated "at a loss" on the books, while the (speculative goods cargo) freight gets transported at a profit ... potentially enough of a profit to cover the operational overhead expenses incurred by the operation of the starship ... at which point net profits turn into a bit of a shell game going on between multiple aligned interests/divisions within the same company (or affiliated companies). Even a profit sharing arrangement with third parties, allowing starship operators to "take a cut" of any speculative goods arbitrage the third party is engaging in, can easily manage to "balance the books" for a tramp merchant that is prioritizing partner business relationships on each world that the starship routinely visits (one of those "keep it in the family" deals). 🤫
 
Spinward Flow said:
Okay.
Now I think I'm onto something here.

This 97 ton hangar bay for 6x 16 ton Boxes plus a 97 tons capacity Collapsible Fuel Tank is just ... elegant ... as a bit of mathematical design. Enough so that I'm thinking it ought to be the "standard feature" for a J2/2G design @ TL=9 AND for a J3/3G design @ TL=10. This would then create an "upgrade path" in capabilities when moving from TL=9 to TL=10 and represent a sort of natural progression.
Click to expand...
I was looking at math for both of these designs ... and thinking that I was close to optimal, but there was still a little bit of wiggle room to squeeze out a smidgen more capability.

The key point was the "leftover 2 tons" for the cargo hold in both designs, which seems like a strange thing to quibble over, I know.

But after taking some more time to think about it, I realized that what I REALLY wanted there was actually a 5 ton cargo hold, not just 2 tons.
So why 5 tons? :rolleyes:
Well ... :unsure:

A 5 ton cargo hold is "conveniently sized" to be either an x-mail vault ... or an air/raft berth with a 1 ton remainder for anything else that might "fit" into that space (including 2x low berths or 1x emergency low berth). The convenience there is that not every starship is going to be eligible for postal contracts (or want to deal with the "hassles" of carrying x-mail), or the mission profile for an individual starship will make a poor fit for making x-mail deliveries (such as a Search & Rescue equipped ship and crew). The important point is to make the OPTION available, even if that option is not exercised in every instance by every operator of the class. The flexibility to make that choice an option is what is important.

Likewise, for some tramp operators (particularly those who flirt with illegality), when speculative goods arbitrage on the fringes of civilization is a priority, being able to dabble in the "small package trade" (a euphemism for smuggling) from time to time starts becoming rather attractive. Operators who intend to service "austere" locations (D and E starports mainly, but we don't talk about type X starports) where local services can be "lacking" ... bringing along your own air/raft as a vehicle runabout and cargo marshaling assistant makes a lot more sense.

So I bumped the tonnages for both designs upwards just enough to be able to fit a 5 ton cargo bay into the J2/2G/PP2 TL=9 and the J3/3G/PP3 TL=A versions. Here's how the spreadsheet for both classes shakes out when doing the math.


Rule of Man Long Trader (TL=9)
236 tons starship hull, configuration: 1
35 tons for LBB2.81 standard C/C/C drives (codes: 2/2/2, TL=9)
68 tons of total fuel: 232 tons @ J2 = 47.2 tons jump fuel + 20(.8) tons power plant fuel
9 tons for TL=9 fuel purification plant (200 ton capacity is minimum)
20 tons for bridge
2 tons for model/2 computer
97 tons for hangar berths capacity
  1. Environmental Box = 16 tons
  2. Cargo Box = 16 tons
  3. Cargo Box = 16 tons
  4. Stateroom Box = 16 tons
  5. Laboratory Box (Type V-c regenerative biome life support) = 16 tons
  6. Stateroom Box = 16 tons
  • 97 tons capacity Collapsible Fuel Tank = 0.97 tons
* External Docking: 364 tons capacity
  1. Escort Fighter = 16 tons


5 tons for Cargo Hold

= 35+68+9+20+2+97+5 = 236 tons + 16 tons (Escort Fighter) = 352 combined tons

Crew = 5
  1. Pilot-2/Navigator-2
  2. Ship's Boat-2/Gunner-2
  3. Engineer-1
  4. Steward-1/Steward-1
  5. Medic-3
Revenue Tonnage @ J2
  • 3x high passengers
  • 16 tons environmentally controlled cargo
  • 16+16+5=37 tons standard cargo
  • 48 tons additional cargo (when 1x Environmental and 2x Cargo Boxes moved to exterior)
Revenue Tonnage @ J2+2
  • 3x high passengers
  • 16 tons environmentally controlled cargo
  • 16+16+5=37 tons standard cargo
Escort Fighter external

Drive Performances with External Loading
  • 236 + 4*16 = 300 tons = J2/2G/PP2
  • 236 + 22*16 = 588 tons = J1/1G/PP1
  • 236 + 1.1*100 + 15*16 = 586 tons = J1/1G/PP1
  • 236 + 1.1*200 + 9*16 = 600 tons = J1/1G/PP1
  • 236 + 1.1*236 + 6*16 = 591.6 tons = J1/1G/PP1
  • 236 + 1.1*300 + 2*16 = 598 tons = J1/1G/PP1

Escort Fighter (TL=9)
16 ton small craft hull, configuration: 1
5 tons for LBB2.81 standard A/A drives (codes: 6/6, TL=9, EP=2) (Agility=6)
1 ton for fuel (09d 21h 17m endurance)
4 tons for bridge (includes 2x acceleration couches for 2x workstations)
3 tons for model/3 computer (TL=9, EP: 1)
1 ton for mixed triple turret: missile, sandcaster, missile (TL=9, codes: 1/2/1, EP: 0)
2 tons for 1x small craft stateroom
* External Docking: 184 tons capacity

= 5+1+4+3+1+2 = 16 tons

Crew = 1
  1. Ship's Boat-2/Gunner-2

Rule of Man Clipper (TL=10)
310 tons starship hull, configuration: 1
55 tons for LBB2.81 standard E/E/E drives (codes: 3/3/3, TL=A)
123 tons of total fuel: 310 tons @ J3 = 93 tons jump fuel + 30 tons power plant fuel
8 tons for TL=10 fuel purification plant (200 ton capacity is minimum)
20 tons for bridge
2 tons for model/2bis computer
97 tons for hangar berths capacity
  1. Stateroom Box = 16 tons
  2. Stateroom Box = 16 tons
  3. Laboratory Box (Type V-c regenerative biome life support) = 16 tons
  4. Environmental Box = 16 tons
  5. Cargo Box = 16 tons
  6. Cargo Box = 16 tons
  • 97 tons capacity Collapsible Fuel Tank = 0.97 tons
* External Docking: 690 tons capacity
  1. Escort Fighter = 16 tons
5 tons for Cargo Hold

= 55+123+8+20+2+97+5 = 310 tons + 16 tons (Escort Fighter) = 326 combined tons

Crew = 5
  1. Pilot-2/Navigator-2
  2. Ship's Boat-2/Gunner-2
  3. Engineer-2/Engineer-2
  4. Steward-1/Steward-1
  5. Medic-3
Revenue Tonnage @ J3
  • 3x high passengers
  • 16 tons environmentally controlled cargo
  • 16+16+5=37 tons standard cargo
Escort Fighter external

Drive Performances with External Loading
  • 310 + 1*16 = 326 tons = J3/3G/PP3
  • 310 + 11*16 = 486 tons = J2/2G/PP2
  • 310 + 43*16 = 998 tons = J1/1G/PP1
  • 310 + 1.1*100 + 5*16 = 500 tons = J2/2G/PP2
  • 310 + 1.1*200 + 29*16 = 994 tons = J1/1G/PP1
  • 310 + 1.1*300 + 22*16 = 992 tons = J1/1G/PP1
  • 310 + 1.1*310 + 21*16 = 987 tons = J1/1G/PP1
  • 310 + 1.1*400 + 15*16 = 990 tons = J1/1G/PP1
  • 310 + 1.1*500 + 8*16 = 988 tons = J1/1G/PP1
  • 310 + 1.1*600 + 1*16 = 986 tons = J1/1G/PP1

Escort Fighter (TL=A)
16 ton small craft hull, configuration: 1
5 tons for LBB2.81 standard A/A drives (codes: 6/6, TL=9, EP=2) (Agility=6)
1 ton for fuel (09d 21h 17m endurance)
4 tons for bridge (includes 2x acceleration couches for 2x workstations)
3 tons for model/3 computer (TL=9, EP: 1)
1 ton for mixed triple turret: missile, sandcaster, missile (TL=A, codes: 1/3/1, EP: 0)
2 tons for 1x small craft stateroom
* External Docking: 184 tons capacity

= 5+1+4+3+1+2 = 16 tons

Crew = 1
  1. Ship's Boat-2/Gunner-2

The tech levels (9-A) on these designs are "low enough" to be plausible Solomani Second Imperium (pre-Long Night) tramp merchant classes competing with the older Vilani J1 Free Trader and J2 Far Trader class designs.

There isn't anything "inherently special" about these starship classes, in terms of unique technologies that are only found in limited pockets of charted space (or whatever). There's no "hyper military grade" technology involved (necessarily) which can be classified as "state secrets" that would prevent the class details from being copied/duplicated/recreated by different shipyards in different regions in different eras using local industrial bases. By the time that TL=C is starting to become widespread, both of these starship classes (TL=9-A) would very much be considered "civilian commercial grade" tech.

The Escort Fighter will undoubtedly have paramilitary (if not outright military) tech involved with its bridge/computer and weapon systems, since it IS a fighter design (go figure... :rolleyes:), but as technology levels advance beyond 9-A it will rapidly become "obsolete" in comparison to (cutting edge, higher tech level) military fighters on par with their tech level (which will need bigger displacements to accommodate increasingly powerful computers and larger power plants to supply the necessary EP for everything).
 
Spinward Flow said:
So I bumped the tonnages for both designs upwards just enough to be able to fit a 5 ton cargo bay into the J2/2G/PP2 TL=9 and the J3/3G/PP3 TL=A versions. Here's how the spreadsheet for both classes shakes out when doing the math.
Click to expand...
And ... I just finished doing up the construction costs for both versions.


J2/2G/PP2 TL=9 @ 236 ton starship + 16 ton Escort Fighter + 2x Stateroom Box + 1x Laboratory Box + 1x Environment Box + 2x Cargo Box
Single Production (100% construction cost): Cr155,881,700
Volume Production (80% construction cost): Cr125,394,000


J3/3G/PP3 TL=10 @ 310 ton starship + 16 ton Escort Fighter + 2x Stateroom Box + 1x Laboratory Box + 1x Environment Box + 2x Cargo Box
Single Production (100% construction cost): Cr218,857,700
Volume Production (80% construction cost): Cr175,774,800


All things considered, that is not too shabby ... even if I do so say so myself. :sneaky:

The J2/2G/PP2 version is not that far off the construction price of a J1 Fat Trader @ MCr101.035 (LBB2.81, p19 and LBB S7, p47) plus the MCr14 for the latter's 20 ton Launch small craft (LBB S7, p47).

So, basically, the Rule of Man Long Trader class costs MCr10.359 more in volume production construction price ... but you get a much more capable and well protected ship that can "survive" more easily on routes to backwater/low population star systems and operate more "easily" as a tramp merchant pursuing speculative goods arbitrage opportunities in "less permissive/friendly environments" when compared to Vilani designs. Being able to J2+2 also makes a pretty significant difference in "reach" capabilities, compared to the J1 Fat Trader when it comes to "marrying up" sources of supply with destinations of demand in the arbitrage of speculative goods.

The J3/3G/PP3 version, known as the Rule of Man Clipper class, is commensurately more expensive than its predecessor (+40.2% actually), but the increase in external load capacity and/or range makes the upgrade a rather dramatic improvement in capabilities and options, even at these relatively modest tech levels.



Of course, rivals to and detractors of the classes will style them as the Ramshackle Long Trader and the Ramshackle Clipper classes (respectively), but that's typically taken as a sign of envy and jealousy (of the "telling on yourself" variety) towards the classes and their crews, rather than as an honest criticism of the merits of each class (let alone their capabilities). ;)
 
Was doing a little bit more Review & Evaluation of the deck plans for the core of this modularized Box transport idea and decided to "shave off the corners" of those TL=9 Boxes. I would like to think that the results, while superficial (and superfluous) to spreadsheet work in the Naval Architect's Office, will make for an overall much more pleasing presentation when I start building everything up into actual deck plans for the TL=9 and TL=10 starships.

Cargo and Environment Boxes
ohy6MhJ.png


Laboratory Box (regenerative biome life support type)
kofipJT.png


Stateroom Box (multiple types)
YlPm6ZP.png

OGBWnHI.png

67n821w.png


So the modification at the outer corners can barely be seen in the above images. The bevel/rounding of the outer corners is extremely easy to overlook, but it is there.

However, it gets a lot easier to discern and see when the Boxes get put into their proper context of a 3x2 double deck stack of them for loading into a hangar bay (or cargo hold) as a 6x16=96 tons combined "package" of Boxes.

1qI2Z7D.png


So it's still a subtle change, but one that modifies perception just enough to be aesthetically pleasing.
For comparison, here is the previous "hangar bay layout" image with rigidly square outer corners on the Boxes.

u6kPdoJ.png


Just wanted to share that extremely minor tidbit of deckplan design engineering. :cool:
 
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