Pondering starship evolution

[Spinward Flow]

or just enough so that life support is no longer viable. Draw straws to see who you toss out the airlock?

Hardly.
My basic operating assumption is that (4 ton) staterooms come with a "built in standard" 2 week buffer of life support reserves (hence why you need to keep paying the Cr2000 per person "tax" every 2 weeks on a rolling basis, ordinarily). Deplete slowly over the course of 2 weeks and then replace at the next port of call.

For anyone pedantic enough to want numbers ... according to CT Beltstrike, life support reserve consumables weigh in at Cr150,000 for 150 person/weeks and requires 1 ton of cargo space to store. In 2 week increments for stateroom construction purposes, that's 2/150=0.013333333333333 displacement tons (186.67 liters) equivalence incorporated into the 4 tons per stateroom budget. For double/triple/etc. occupancy rates, simply multiply the amount accordingly. Note that you will need to have 3.75 persons per stateroom to even approach 0.05 tons out of the 4 tons per starship stateroom allocation ... and since triple occupancy "wasn't a thing" in CT the whole thing effectively "rounded to zero" in the nearest 0.1 ton granularity of stateroom tonnage accounting in the spreadsheets at the naval architect's office. In other words, the "2-4 person/weeks of life support reserves" capacity comes built in standard with typical staterooms.



So it's not like fuel and a power plant ... no fuel, power plant shuts down immediately (because no fuel) ... no power, dead hulk in space with nothing but battery power (which will be inadequate to maneuver with, so... ).

If a regenerative biome life support laboratory gets damaged/destroyed (for whatever reason) ... you've got 2 weeks to go somewhere that you can pay the Cr2000 per person "tax" every 2 weeks before the life support reserves for the (now excess) staterooms runs out and those staterooms need to be evacuated (since they cannot remain inhabited). It's not like a set of staterooms INSTANTLY loses all life support (air, water, food, etc.) and goes dark when a life support laboratory gets damaged/destroyed. In other words, the regenerative biome life support is "paying for the upkeep on a rolling basis" rather than being any sort of "instant LIVE" system with no buffer capacity whatsoever. Starship staterooms come standard with a 2-4 person/week life support reserve buffer capacity (2 weeks for single occupancy, 4 weeks for double occupancy).

If you assume that every stateroom can potentially be double occupancy "for any reason at any time" (a relatively safe assumption to make at the naval architect's office when drafting blueprints) then every single stateroom will automatically have a 4 person/week life support reserves capacity ... which ironically would also equal the 4 weeks minimum endurance power plant fuel requirement for starships (go figure, eh? ).



So ... NO.
Loss of a regenerative biome life support laboratory facility is not INSTANT DEATH for anyone that facility had been providing life support for.

However, it would mean that the "rolling renewal" of life support reserves that the facility offered (past tense) would no longer be available to "pay for upkeep" of those life support services (because the facility is "offline") ... so it's back to paying the Cr2000 per person per 2 weeks "tax" until you get the regenerative biome life support laboratory facility repaired/replaced. You'll basically have 4 person/weeks of reserves per associated staterooms before depleting all of your reserves for the associated staterooms, rendering them uninhabitable.

or just enough so that life support is no longer viable. Draw straws to see who you toss out the airlock?

It's only after 2 (double occupancy) or 4 (single occupancy) weeks of NOT doing anything about the problem that the "draw straws to walk the airlock" solution you're referring to would become relevant. Under most (nominal) circumstances, that is plenty of time for a rescue or an evacuation to take place, let alone effectuating jury rigging in order to limp to a starport where you can repair/replace losses and start to stabilize your situation and circumstances.

It would still be a LOSS to capacity, but the crew harm would come slowly/later ... rather than instantly/right now.

 

[Condottiere]

The only way that life support can work in Traveller, is to pay it forward.

 

[Spinward Flow]

The only way that life support can work in Traveller, is to pay it forward.

And paying it forward has a direct implication of a buffer reserve capacity for the consumables involved ... because starships are not hooked up by umbilical to starport life support services the whole way through maneuver/jump/maneuver between points of origin and destination.

 

[Condottiere]

Since the supply chain is cut the moment that the umbilical is not hooked, just in time logistics is no longer in play.

So while life support consumption equates with current number of living beings and their respective applied lifestyle, you have to carry those supplies onboard, usually prepaid, not on credit.

 

[Spinward Flow]

Exactly.
However, if you bring a regenerative biome life support laboratory with you on your journeys, you CAN have "just in time" logistics (freshly recycled air, freshly recycled water, fresh vegetables, fresh meat, you get the idea) with the more stereotypical "contained in the stateroom tonnage allocation" life support buffer amounting to "emergency rations" in the event of a mishap/accident/problem with the life support laboratory facilities ... giving you a standby backup option for safety.

 

[Condottiere]

 

[whartung]

I thought this is why bulwarks were designated in the blueprints, to separate sections of the ship to create air bubbles, so it doesn't sink.

Works great with high explosive and even, some what, armor piercing shells. Doesn't work so well with lasers, which is more akin to death by a dozen knitting needles. Lots of little hole poking into sensitive things.

 

[Condottiere]

Good thing that at technological level nine, the hull becomes self sealing.

 

[Spinward Flow]

When you're absolutely convinced that if you had to redo your deck plans, there must have been a better way/room for improvements over the previous draft.

Wanted to do a touch up redesign of my 25 ton Laser Fighter into a 24 ton form factor AND redo the deck plan for it so that the remodel will FIT EXACTLY into the hangar space form factor needed for 2 adjacent (and linked) 12 ton module boxes, for increased interchangeability. Rather pleased with how everything rebalanced nicely after doing so.

Still, the redesign looks more like a "beefy boy" than the previous "cigar shaped spindle" shape I was using previously.
Having 10 tons of LBB2.81 Power Plant-C to power the twin beam lasers (2EP) and model/4 computer (2EP) in a 24 ton form factor while still having sufficient reserve power for Agility=6 (1.44EP) will tend to do that to a small craft's deck plan.

Side note ... that small craft cabin is actually slightly smaller than 2x2 deck squares, yet it has a fresher (behind the only wall partition and sliding door. The cabin is designed for double occupancy (ship's boat pilot and gunner) with bunk beds and a closet located between the beds and the pressure door leading to the decontamination airlock.

The grav lift forward and the vertical access iris valves in engineering are EXACTLY spaced (and placed) to match the locations for external vertical docking access with 12 ton modules. The vertical iris valves in engineering are normally kept locked, but are included for rapid escape from the engineering section if/when necessary. The grav lift shaft runs through the single deck small craft (as do the iris valves in engineering) for better load balancing when docked with and towing collections of 12 ton modules.

The (previously) dorsal dual turret has been moved into a (now) stern chaser position in line with the single deck for the mounting of the twin beam lasers, which are organized as a single battery. The entire turret assembly can rotate on its axis so as to spin relative to the hull and bring the individual beam lasers to bear on targets forward while maneuvering evasively at up to 6G, leaving relatively few blind spots. The single twin beam laser battery can be controlled either from the turret itself or from the gunnery workstation on the bridge.

Primary fuel tank(s) capacity has been reduced to the 1 ton minimum (which is still sufficient for more than 3 days of endurance at combat power loads), but a pair of 0.1 ton demountable fuel tanks are now included standard as an emergency backup fuel reserve compartmentalized apart from the primary fuel tanks. All of the fuel tanks now reside mid-ship to act as an additional buffer of shielding against any stray radiation that might be produced by the laser fighter's drive systems.

 

[kilemall]

What does DFT stand for?

 

[Spinward Flow]

What does DFT stand for?

D emountable
F uel
T ank

On the spreadsheet, it counts as a 0.2 ton cargo bay with a 0.2 ton demountable fuel tank installed in it.
The reason for using a demountable fuel tank instead of a collapsible one is that the tonnage is so small (0.2 tons) that it can't be meaningfully used for anything else and because as per LBB A5, p14 the fuel contents are available "immediately" if needed without requiring pumping transfer into the primary fuel tanks.

So basically there's a compartmentalization of fuel (1 ton primary tank, 0.2 tons reserve demountable tank). That way, if there's a "hit" taken to fuel, the 1 ton (or less) gets completely lost (because 1 is less than 10 minimum) but the 0.2 ton backup reserve remains unaffected and remains available to the power plant, keeping the computer, turret beam lasers and maneuver drive "alive" and powered.

In the LBB2 combat paradigm (LBB2.81, p30), it takes 2 hits (1 fuel, 1 hold) to completely vent the laser fighter's fuel ... and in LBB2 combat, small craft do not take hits to fuel or hold.

In the LBB5 combat paradigm (LBB5.80, p48), Fuel-n results on the Surface Explosion Damage Table will vent the primary fuel tank (because 1 is less than 10 minimum) while leaving the 0.2 ton demountable fuel tank (in the "cargo hold") intact and available for immediate use by the power plant. A Fuel Tanks Shattered result from the Interior Explosion Damage Table will vent ALL fuel (primary and demountable fuel tanks, both) in a single hit. I would also argue/house rule that a Hangars/Boat Deck Destroyed result from the Critical Hit Table would also destroy the demountable fuel tank reserve (although, if you're taking critical hits and get that result, you're getting off lucky!).

 

[kilemall]

Shrug, your universe your rules. The way I figure it, a CT hit that takes out 10 tons of fuel isn’t stopped by flimsy walls between tanks. Pretty much every small craft is dead first couple hits on them by most any RAW version I am aware of.

Closest I ever came to something like this was internal bulkhead rules, effectively doubling up the armor to limit internal damage hits from meson guns. In that scenario I went with the HG assumption of fuel tanks as surface hits, which works with most starships but small craft just don’t have that much surface area to work with.

But maybe in scenarios like limited fuel designs like this one, you can see your way to wrap a 1-3 ton fuel supply around the ship and get more internal volume.

I assume that in most ships for radiation shielding benefits anyway, with some tanks being more classic large plan ones for rapid pumping needed for jump, something small craft don’t need.

 

[Spinward Flow]

The way I figure it, a CT hit that takes out 10 tons of fuel isn’t stopped by flimsy walls between tanks.

Question:
If you take a hit to a fuel tank, does that hit also automatically destroy contents of the cargo hold as well (for free)?

If your answer is NO ... (followed by a "don't be silly!") ... then ask yourself the requisite follow up question.
If you take a hit to a fuel tank, does that hit also automatically destroy a demountable fuel tank occupying tonnage in the cargo hold as well (for free)?

If your answer is STILL NO ... then those "flimsy walls between tanks" that you referred to aren't that flimsy after all like you were just automatically assuming (appropos of ... I have no idea).

Pretty much every small craft is dead first couple hits on them by most any RAW version I am aware of.

Depends on the small craft design.
It IS possible to design small craft with some pretty significant armor so they can "tank hits" somewhat effectively, but a lot of the focus for fighter combatant designs (especially under LBB5.80) is put on NO GET HITSU!! "evasion tanking" performance. After all, if "everything misses" your fighter (or chances to be hit are exceptionally low) then you don't NEED armor to tank hits (that you won't be taking).

Needless to say, the most significant factors in small craft fighter performance are:

1. Computer Model (this is +offense AND +defense)
2. Agility (this is +defense and engagement/pursuit)
3. Battery Factor(s) (this is +offense and critical hit threat to opposing craft)
4. Armor (this is +protection for tanking hits)
5. Ship Tactics Skill (this is +offense AND + defense)
6. Ship's Boat Skill (this is +defense)
7. Fleet Tactics Skill (this is +initiative to control range)

In the final analysis, small craft fighters are usually best deployed against turret weapons. Bay weapons will tend to have sufficient weapon factor to make small craft fighters vulnerable (although there are obviously edge case exceptions).

 

[aramis]

Did you account for the 10% loss on your DFT? (See A5 TCS)

 

[Spinward Flow]

Did you account for the 10% loss on your DFT? (See A5 TCS)

CONTEXT with SPECIFICITY, PLEASE!!

"Did you account for the {waves vaguely in the direction of an entire book without clarity of intent, purpose or meaning}?"

I've already cited LBB A5, p14 in post #71.
Perhaps you could provide a page number reference citation for LBB A5?

 

[Spinward Flow]

When you're absolutely convinced that if you had to redo your deck plans, there must have been a better way/room for improvements over the previous draft.

Decided to rework some of the power plant machinery in the aft engineering section of the laser fighter deck plan first posted in #69 above.

This new arrangement "turns things around" in a "flip horizontal" kind of way relative to the previous machinery arrangement of components (same parts, different assembly). However, this new placement moves the drive systems just enough outboard to do two things.

The first is that there is now enough space in the center aisle access to put in a fully enclosed grav lift/airlock for complete dorsal/ventral pass through of grav lift services between 12 ton modules docked above and below both fore and aft. Ironically, this means that during a 12m walk from bridge to turret (8 deck squares), there is a total of 7 iris valves to pass through.

The second is that the "mid machinery" piece is rotated to link up outboard to the inductive fusion reactors (hat tip: Helion) in order to draw off energy from the fusion reactions for use by the laser fighter's onboard computer and laser weapon systems through the power conditioning and distribution bus.

This does (of course) mean that the machinery spaces (port and starboard) are a bit more crowded than in the previous iteration, but overall it's a slightly better looking deck plan layout for the LBB2.81 TL=10 Power Plant-C standard drive system ... and I was able to avoid having the grav lift shaft be "naked" in the middle of the engineering room, allowing a preservation of anti-hijack security that was not present (to the same extent) in the previous iteration.

 

[kilemall]

Question:
If you take a hit to a fuel tank, does that hit also automatically destroy contents of the cargo hold as well (for free)?

If your answer is NO ... (followed by a "don't be silly!") ... then ask yourself the requisite follow up question.
If you take a hit to a fuel tank, does that hit also automatically destroy a demountable fuel tank occupying tonnage in the cargo hold as well (for free)?

If your answer is STILL NO ... then those "flimsy walls between tanks" that you referred to aren't that flimsy after all like you were just automatically assuming (appropos of ... I have no idea).

I actually did look into a computer simulation like damage system as part of my continuing quest to create a fully integrated CT/HG resolution system. So a damage ray trace like line could run through one of the fuel tanks and depending on incoming direction run through the DFTs and into the other fuel tank or run into the cargo bay.

In that case there wouldn’t be ‘free’ hits for adjoining systems unless they fell along that ray line, the idea being energy hits AND kinetic missiles/railguns would be brilliant lances to use the game title.

Only meson guns and nuclear detonations would be area effect in nature. And missile magazine detonations if one modeled those. Ship destroyed results probably do fine for the latter.

The idea was to incorporate angled armor effects, and thus affect ship design and battle maneuver. For instance, Type S has the wedge body so would get armor 1 as long as the pointy end was oriented towards incoming fire.

It would give a very visceral damage effect feeling, really seeing and feeling the ship hurt.

In addition I could model bulkhead armor effects, limiting internal hit damage. So yes there would be a difference between a DFT just hanging behind a partition and a full bulkhead. So I’m very aware of potential armor differences between the two.

I ultimately abandoned this line as not being worth the time cost during gameplay and before with requiring deck plans done for everything.

Instead I have a two system damage per hit sequence, and just draw a descriptive line through them to provide a narrative as needed. I had settled on this before getting Brilliant Lances and seeing the surface-internal-surface outgoing system. I stuck with 50/50 because it’s simpler to divide damage by 2 and I also felt many hits would run along the surface rather then just all punch through.

Not happy with the ridiculous armor potential of fighters, I have a fix for that. But it’s more important to manage that since I have armor being more effective, flat out stopping damage and ability to punch through drop by range.

Evasion is less of an option because I’m doing actual ship maneuver so part of the game is dividing maneuver drive output between agility and accel.

 

[whartung]

So a damage ray trace like line could run through one of the fuel tanks and depending on incoming direction run through the DFTs and into the other fuel tank or run into the cargo bay.

Brilliant lances does this. The only detail is that it essentially maps all hull onto a sphere. But, if you want to punch rays into a ship BL does this already.

 

[kilemall]

Brilliant lances does this. The only detail is that it essentially maps all hull onto a sphere. But, if you want to punch rays into a ship BL does this already.

Ya I know but I don’t like it for simplicity reasons and again the assumption is surface-in, interior and surface-out when I think it equally likely damage will go along the skin.

Meson guns are the exception, interior damage first then 50/50 whether more interior or surface damage.

 

[Spinward Flow]

After several abortive tries, false starts, mistaken assumptions and various other exercises in pointless pontification ... I think I might have stumbled upon yet another Island of Stability in the design space under CT (with some documented house rules posted on these forums thrown in for good measure to keep things interesting ).

So if the E/E/E drives = code: 1 @ 1000 tons version "landed" on a starship main hull of 303 tons with a 96 ton internal hangar bay and 8 modules of 12 tons each ... where do things "evolve" to when moving up to

F/F/F drives = code: 1 @ 1200 tons ... scaling back from the H/H/H drives = code: 1 @ 1600 tons that I started this thread with ... and the new Island of Stability lies in a (custom) 400 ton hull.

Here's what the napkin math for what that looks like.

65+120+30+8+1.2+20+2+4+24+120+5.8+0 = 400

• 1200 = J1
  • 400 + 0*1.1 + (0+10+40)*12*1.3 = 1180 (+20) (5 high, 48+480=528 tons cargo, 2J1) or (5 high, 120+48+480=648 tons cargo, 1J1)
  • 400 + 500*1.1 + (0+10+6)*12*1.3 = 1199.5 (+0.5) (5 high, 48+72+500=620 tons cargo, 2J1) or (5 high, 120+48+72+500=740 tons cargo, 1J1)
• 600 = J2
  • 400 + 0*1.1 + (0+10+6)*12*1 = 592 (+8) (5 high, 48+72=120 tons cargo, 2J2) or (5 high, 120+48+72=240 tons cargo, 1J2)
• 400 = J3
  • 400 + 0*1.1 + (0+0+0)*12*1 = 400 (+0) (5 high, 48+0=48 tons cargo, 1J3)

Compare that with the napkin math for what that looks like in the original 303 ton form factor.

55+90.9+30.1+8+0.96+20+2+96+0+0.04 = 303

• 1000 = J1
  • 303 + 0*1.1 + (2+8+48)*12 = 999 (+1) (5 high, 24+576=600 tons cargo, 2J1) or (5 high, 96+24+576=696 tons cargo 1J1)
  • 303 + 500*1.1 + (2+8+2)*12 = 997 (+3) (5 high, 24+24+500=548 tons cargo, 2J1) or (5 high, 96+24+24+500=644 tons cargo 1J1)
• 500 = J2
  • 303 + 0*1.1 + (2+8+6)*12*1 = 495 (+5) (5 high, 24+0+72=96 tons cargo, 2J2) or (5 high, 24+96+72=192 tons cargo, 1J2)
• 333 = J3
  • 303 + 0*1.1 + (2+0+0)*12*1 = 327 (+6) (5 high, 24+0+0=24 tons cargo, 1J3)

An easier way to look at this comparison is probably with a table chart for the results for the two alternatives in terms of revenue tonnage (high passengers and freight cargo capacity).

	2J1​	1J1​	2J2​	1J2​	1J3​
400 ton starship F/F/F drives	5 high, 528 tons cargo 5 high, 620 tons cargo	5 high, 648 tons cargo 5 high, 740 tons cargo	5 high, 120 tons cargo	5 high, 240 tons cargo	5 high, 48 tons cargo
303 ton starship E/E/E drives	5 high, 600 tons cargo 5 high, 548 tons cargo	5 high, 696 tons cargo 5 high, 644 tons cargo	5 high, 96 tons cargo	5 high, 192 tons cargo	5 high, 24 tons cargo

Now, what's interesting about this marginal bump up in starship hull size and revenue tonnage yields the following differential relative to the 303 ton E/E/E drive baseline performance:

	2J1​	1J1​	2J2​	1J2​	1J3​
400 ton starship F/F/F drives	- high, -72 tons cargo - high, +72 tons cargo	- high, -48 tons cargo - high, +96 tons cargo	- high, +24 tons cargo	- high, +48 tons cargo	- high, +24 tons cargo
400 ton starship F/F/F drives	0% high, -12% cargo 0% high, +13% cargo	0% high, -7% cargo 0% high, +15% cargo	0% high, +25% cargo	0% high, +25% cargo	0% high, +100% cargo

The interesting thing here in the Analysis of Alternatives (AoA) sense is that for a relatively marginal change in drives (+1/+1/+1 drive letter) yields an almost parity in cargo capacity @ J1 ... but a useful increase in cargo capacity @ J2 and J3. In other words, because when crossing the 1000 ton threshold small craft count as being 130% of their tonnage for transport (LBB5.80, p32) but big craft are always carried at 110% of their tonnage at all times, the net result of the change is to "hold the maximum" while simultaneously "raising the minimum" cargo capacity at different jump performance profiles, making the J2 and J3 transport capacities more flexible options (particularly in the speculative trade arena).

The other thing that I was noticing as a result of this scaled back F/F/F drives @ 400 tons "balance point" relative to previous iterations around the H/H/H drives @ 496 tons "balance point" was that upgrading further by additional +1-2 letters on the drives got rather EXPENSIVE while not delivering that much of an increase in performance yield (because drives and hull are the most expensive components of the build).

• 303 tons w/ E/E/E drives yields 8x12 ton modules + 24 ton laser fighter capacity @ 1J3
• 400 tons w/ F/F/F drives yields 10x12 ton modules + 24 ton laser fighter capacity @ 1J3
• 496 tons w/ H/H/H drives yields 16(+1)x12 ton modules + 24 ton laser fighter capacity @ 1J3

But then when you compare what you're getting for the construction costs (of just the starship), things take a rather interesting turn.

• 303 tons w/ E/E/E drives = MCr167.848 starship cost (100%)
• 400 tons w/ F/F/F drives = MCr202.9308 starship cost (100%)
• 496 tons w/ H/H/H drives = MCr259.2024 starship cost (100%)

In terms of the economics, using the 303 tons w/ E/E/E drives baseline, what you get is this for results:

• 400 tons w/ F/F/F drives = +20.9% construction cost / +100% cargo @ J3 / +25% cargo @ J2 / -7% to +15% cargo @ J1
• 496 tonsw/ H/H/H drives = +54.4% construction cost / +3 high / +350% cargo @ J3 / +137.5% cargo @ J2 / ~ +46% cargo @ J1

Point being that the "big" H/H/H drives alternative was bigger, but also a fair bit more expensive for the added capacity. In fact, the 496 ton H/H/H drives version was winding up shoehorning itself into a role of being "a bit too big for the job" in that there could be challenges to filling up shipping manifests on a consistent enough basis. There was also the question of whether or not a single copy 496 ton H/H/H drives version "made sense" when compared to a business running two copies of the 303 ton E/E/E drives version instead for a reasonably close approximation of costs and expenses (a difference of concentration versus diversification of transport capacity).

By contrast, the 400 ton F/F/F drives variant was delivering only a marginal +20.9% increase in starship construction cost, while offering a comparatively useful increase in shipping manifest capacity @ J2 and J3 which would enable some pretty significant gains in potential profits from speculative goods arbitrage when needing to travel 3-8 parsecs in order to reach highly favorable market destinations. The result is a kind of "right sizing" that balances towards lower end markets (non-industrial trade codes) where demand for transport services can be met without an excess of overcapacity. Basically something suitable for BTN-8 or less trade routes would be the intended business model, although one which could operate relatively safely along the fringes where system defense protection may be lacking/underfunded. Essentially a "frontier tramp free trader" type of starship class (most easily adapted for use as an ACS by Referees).



So despite Going Big™ to start with (H/H/H drives) ... I'm now coming around to the notion that a more modest "right sizing" upgrade to F/F/F drives @ 400 tons ticks a few too many boxes on being worth the added expense for the capability upgrade @ J2 and J3, without getting "too heavy" to survive absent high volumes of passengers and cargo freight demand for tickets. It's a very (VERY!) delicate balancing act to achieve something that's "the biggest small starship" capable of doing the job at a price point that isn't entirely ruinous.