Pondering starship evolution

[Spinward Flow]

Okay ... this is a most unexpected and unanticipated result.



So I wanted to give my 24 ton Fighter design a concealable pop turret in order to make it a Type-FQ (Fighter, Decoy).
The TL=9 with model/3 computer version had a 1 ton cargo hold of "leftover space" that could be repurposed as the +1 ton required for a pop turret (just eliminate the cargo hold). So no real difficulty in making the modification there.

But the TL=A with model/4 computer version had no such tonnage margin available within it ... so ... what to do?
Obvious answer ... +1 ton of small craft hull and "redo" the whole thing as a 25 ton Fighter instead of a 24 ton Fighter.

But ... if it's a "decoy" of a 25 ton small craft ... what 25 ton small craft would it be masquerading as?
20 ton Launch =
20 ton Gig =
30 ton Ship's Boat =
40 ton Pinnace =
50 ton Modular Cutter =

Point being that any 25 ton small craft is going to need to have a different "class name" than any of the above (for disambiguation purposes, if nothing else, go figure, eh? ) ... but what among the wet navy nautical small craft naming types is left over to play with?

Behold ... the Jolly Boat (Type-QT) ... now a 25 ton small craft.

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Jolly Boat (Type-QT, TL=9)
25 ton small craft hull, configuration: 1 (MCr3, integral fuel scoops)
0 tons for Armor: 0 (TL=9, Composite Laminates, bulkhead thickness=18cm)
1 ton for LBB2.81 standard Maneuver-A (Agility=6 requires 1.5 EP) (MCr4)
4 tons for LBB2.81 standard Power Plant-A (EP=2) (MCr8)
1 ton for fuel
• Basic Power + 0.00 EP= 0.0125 tons of fuel consumption per 7d (560d 00h 00m endurance)
• Basic Power + 1.5 EP = 0.5375 tons of fuel consumption per 7d (13d 00h 33m endurance)
5 tons for bridge (2 crew acceleration couches, life support endurance: 12-24 hours) (MCr0.125)
0 tons for no computer (MCr0)
0 tons for 1x hardpoint: no fire control tonnage reserved, no turret, no weapons (MCr0.1) (LBB2.81, p23)
* External Docking: 0 tons capacity (MCr0)
2 tons for 1x Small Craft Cabin (MCr0.05, 2 person/weeks life support endurance)
12 tons for cargo hold: multi-purpose refit ready (MCr0)

= 0+1+4+1+5+0+0+2+12 = 25 tons
= 3+4+8+0.125+0.1+0.05 = MCr15.275

• 6G, Agility=6

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By way of cross-comparison with a 30 ton Ship's Boat ... the Ship's Boat costs MCr16 (volume production) to construct (LBB2.81, p18) with a 13.7 ton cargo hold that can reconfigured with whatever fittings are desired. The 25 ton Jolly Boat (shown above) costs MCr15.275 (single production) / MCr12.22 (volume production @ 80%) with a 12 ton cargo hold that can be reconfigured with whatever fittings are desired.

However, the Ship's Boat does not come with a Small Craft Cabin as standard equipment, while the Jolly Boat does, making it possible for the Jolly Boat to undertake interplanetary voyages shuttling cargoes and/or passengers. The 12 ton cargo hold can be refitted with 6x Small Craft Cabins to enable interplanetary passenger services (on the order of "business jet" type volumes of service per small craft).

It is possible to arm the (stock) Jolly Boat hull design with armament, but doing so requires the installation of a computer (consuming tonnage), a turret (consuming tonnage for fire control) and potentially an upgrade to the power plant installed if wanting to energize weapons that consume EP (lasers, etc.) ... all of which will rapidly "devour" the tonnage allocated to the cargo hold, quickly diminishing the transport capacity of the small craft. In the absence of a pilot/gunner on the crew roster, a pilot AND a gunner will be required crew, which ought to/will require a second Small Craft Cabin for single occupancy in commercial operations, further reducing the (usable) revenue tonnage fraction remaining for long haul transport services (up to and including interplanetary range operations).



So rather than the Fighter Escort (Type-FE) small craft of my Rule of Man merchant series of starship classes relying on a Fighter Provincial (Type-FP) basic hull that would have been (originally) developed for system defense ... I can have the Fighter Decoy (Type-FQ) small craft of my Rule of Man merchant series of starship classes be an evolutionary development of the Jolly Boat (Type-QT) group of commercial small craft instead.

 

[Spinward Flow]

So ... if I'm moving from a 24 ton Fighter to a 25 ton Fighter ... that's going to have ripple effects downstream on the designs of the merchant starships that include a +1 ton small craft in the internal hangar bay(s).

• 24 + 4*24 = 120 tons
• 25 + 4*24 = 121 tons

This also has implications for external loading.

• J2: 400 - 120 = 280 tons
  • 400 - 121 = 279 tons
• J3: 530 - 120 = 410 tons
  • 530 - 121 = 409 tons

The 280 ton J2/2G Long Trader capable of J2+2+2 was already "riding a knife edge" on viability for fuel reserves.
Reducing the hull size by -1 ton while simultaneously needing to increase the hangar bay size by +1 ton ... made things just a bit too tight for comfort.

But I still had one last "card" to play ... even though I didn't want to have to use it (unless I absolutely had to, which I now did).
Downsizing the starship's computer from a model/2 into a model/1bis ... and then tweaking the internal fuel tankage and cargo hold (with collapsible fuel tank stored inside of it) accordingly to make everything (still!) just barely fit within the 279 ton hull. However, to keep things "backwards compatible with LBB2 design principles honest" ... I included a "surcharge" for the cost of the Generate computer program (MCr0.8) into the construction cost of the class which could NOT be covered by the Standard Software Package allowance of MCr1 of computer programs delivered "free" with the purchase of a model/1bis computer.

I was able to redesign the Long Trader into a 279 ton J2/2G design with a 25 ton Fighter Decoy and 4x 24 ton Boxes and a 121 ton internal hangar bay. The internal fuel tankage is 81.7 tons and the cargo hold is 1.3 tons, containing a 122 ton capacity collapsible fuel tank (1.22 tons when empty). This means that the cargo hold has (up to) 0.07 tons of "wasted space" in it ... which amounts to 980 liters of volume for use in the "small package trade" (a euphemism for smuggling).

• 1 ton = 14m³ * 1000 = 14,000 liters
• 14,000 * 0.07 = 980 liters

This means that J2 @ 400 tons combined displacement costs 80 tons of jump fuel ... leaving 1.7 tons of fuel remaining for Basic Power and EPs dedicated to maneuvering to a refueling point. Perfectly adequate ... so long as nothing goes wrong while en route ...

If something DOES "go wrong" while en route ... the Fighter Decoy has sufficient external load capacity and maneuver drive capability to sustain a 0.4G maneuver towing rate for a few days, which (hopefully) ought to be enough to be able to effectuate a Self Recovery From Disaster™.
Bare minimum, it's better than being "out of options" as an alternative ...



Going to need to see what will "need to happen" to shrink the 410 ton Clipper down into a 409 ton form factor, but I suspect that will be "easier" based on the fact that the 410 ton starship had more "margin" left over in it from the start, so it'll be "less painful" to put the squeeze on it.



However, all of this is starting to make me wonder about the ... symmetries ... of the merchant designs I've been working out thus far.

• 280 279 ton J2/2G @ TL=9 with D/D/D standard drives and 121 ton hangar bay (25 + 4x 24 =121)
• 410 409 ton J3/3G @ TL=A with H/H/H standard drives and 121 ton hangar bay (25 + 4x 24 =121)

Kind of makes me wonder if there's a 519 ton J3/3G @ TL=B with K/K/K standard drives and 145 ton hangar bay (25 + 5x 24 = 145) that would "make sense" (economically/commercially) as the "Final Phase" of the upgrade path along this specific pattern of design and outfitting.

If so, I might need to "upgrade" the maximum external towing capacity for the 25 ton Fighters to account for needing to have a 571 ton maximum external loading.

• 571 / 1.1 = 519.090909 ≈ 519 tons of big craft