I like this a lot. My players have a scout ship (the Highndry) that they refitted with scavenged J-3 jump drive, computer, and power plant from a wreck. I'm at work right now, but I should plug in the numbers to see what their fuel consumption is, as I hadn't thought of that.For full transparency, I've posted my "reinterpretation" of the CT Beltstrike fuel consumption formula that is mathematically backwards compatible with LBB2, but redone to make things easier/simpler when working with a LBB5.80 paradigm that relies on Energy Points (EP).
7 days of fuel consumption (tons) = (Hull Tonnage / 2000) + (EP * 0.35)
So a 2000 ton hull requires 1 ton of fuel consumption per 7 days/1 week for Basic Power (what I like to think of as housekeeping). This is essentially your life support (lights, atmospheric recirculation, etc.) along with keeping the heat pumps running (L-Hyd fuel remains cryo chilled so it doesn't boil off, inhabited spaces remain "shirtsleeves warm" for passengers and crew) as well as whatever other various and sundry plumbing and services need "power" to stay operational.
EPs are used for maneuver drives, computers, weapons and screens.
Producing 1 EP for 7 days costs 0.35 tons of fuel.
Plug in values for a 100 ton Type-S Scout/Courier and you get:
The formula works for "everything" from small craft to million ton tenders.
- (100/2000) + (2*0.35) = 0.75 tons of fuel consumption per 7 days @ 2 EP output from Power Plant-A drive
- (100/2000) + (1*0.35) = 0.40 tons of fuel consumption per 7 days @ 1 EP output from Power Plant-A drive
- (100/2000) + (0*0.35) = 0.05 tons of fuel consumption per 7 days @ 0 EP output from Power Plant-A drive
And just to be even clearer, my "research" into the Modular Box containerization system (in this thread) is predicated upon the notion that the Boxes are (natively) "unpowered" because they do not have a power plant (of any size) installed into them. So instead, the Basic Power requirement for any and all Boxes needs to be supplied by the "parent" transporting craft ... whether that be a small craft or a big craft (or a hangar/starport berth).
So if a 24 ton Box (any type) is docked to a 24 ton Fighter Escort, for example ... the Basic Power requirement for the combination is 48 tons of hull (obviously) which needs to be "paid for" out of the Fighter Escort's fuel reserves, in addition to whatever EP generation is going on.
Likewise, a 280 ton starship with 4x 24 ton Boxes docked externally to it has a Basic Power requirement of a combined 280+24*4=376 tons of hull ... not just 280 tons of starship hull. However, if those same 4x 24 ton Boxes are loaded internally into a hangar (or cargo) bay, with no external load(s) docked to the exterior ... then the Basic Power requirement is calculated using the 280 tons of the starship's hull.
Point being that "there's no free lunch" when it comes to the amount of tonnage requiring Basic Power ... and the more tonnage you have (or need to support), the higher the fuel consumption (per week) to maintain nominal operating conditions for that tonnage.
Pondering starship evolution
- Thread starter Spinward Flow
- Start date
Spinward Flow
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LBB2.77, p5-6:
LBB5.79, p32:
LBB2.81, p14-15:
Basically, by the time LBB2.81 got printed, the entire "jump governor" issue got thrown away as an "unnecessary complication" that wasn't worth maintaining, especially since LBB5.80 had "fixed" the problem already as well.
So technically it's an issue for craft designed using LBB2.77 (see: X-Boats) ... but is not an issue for craft designed using LBB2.81.
Spinward Flow
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So ... LBB2 standard drives are "baseload" power plants that have only 2 settings ... ON (full blast) and OFF.
LBB5 custom drives can "throttle up/down" as power plants between 0% and 100% ... no problem.
Sounds ... legit ...?
Spinward Flow
SOC-14 5K
It basically works for any and all craft.
The fun part is when you need to do any kind of "run silent" type of maneuvering. You can charge up the jump capacitors (i.e. "battery power") and use them for power instead (for a limited duration) to reduce your signature on sensors (no neutrino emissions from a fusion power plant) which can then lead to misidentification by opposing sensor operators as you innocuously drift past a sensor net. Then when you've "finished" your inertial drift move, you fire up the power plant and "make your move" with an element of surprise.
Alternatively, you can just simply "lie low" in hiding somewhere, running on Basic Power only ... until the sensor sweeps have moved on and you're free to maneuver again.
Or you're wanting to undertake a long duration assignment somewhere and need endurance more than speed, so knowing how economical your rate of fuel consumption is becomes a matter of "can we do THIS or not?" in terms of practicality in planning.
Spinward Flow
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{ temporary topic derail } Knowing what I know (now) about the CT Beltstrike fuel consumption formula, along with a few other various bits of various and sundry knowledges relevant to CT ... if *I* were to redesign the Type-S Scout/Courier with that greater understanding NOW I would make some very small tweaks to the design, which would yield the following:
For those who like to track changes against the LBB2.77/81 baseline assumptions:
- Fuel tankage increased by +1 ton from 40 tons to 41 tons
- Computer upgraded from model/1bis to model/2, allowing the Generate program to be included in the standard software package
- 3 ton cargo hold + 4 air/raft berth consolidated/shrunk to 5 ton multi-purpose cargo hold
- Bridge "upgraded" to manage 200 tons of total displacement, plus exterior hull "strengthened" to enable external docking of up to 100 tons of sub-craft for maneuver and/or jump towing to increase mission tasking flexibility
The computer model upgrade may, at first blush, seem like something of an extravagance ... until you realize that a model/1bis computer installation cannot afford the Generate program as part of the basic software package.
LBB2.81, p40:
Since a (stock, original) Type-S Scout/Courier is capable of Jump-2, but does not come with a Generate program as part of its standard package of software (LBB2.81, p41) because it CAN'T ... obtaining the Generate program has to be an "aftermarket upgrade" rather than a stock feature of the craft. This means that every time a (stock, original) Type-S Scout/Courier wants to jump, until a Generate program can be obtained ... there is an additional charge of Cr10,000 (J1) or Cr20,000 (J2) to obtain a jump cassette.
Simple mathematics will show that the "price" of a mere 40x J2 jump cassettes will equal the +MCr0.8 cost to obtain a Generate program.
Likewise, a (mere) 250x J2 jump cassettes will equal the +MCr5 construction cost price differential between a model/1bis (MCr4) and a model/2 computer (MCr9) installation at the time of construction. Volume production (90% construction cost) actually lowers this to 225x J2 jump cassettes equivalency (+MCr4.5).
Now ... ask yourself ...
How many times do you expect a 100 ton Scout/Courier to jump during a "nominal" operational lifespan in service of 40 years before being unloaded onto the surplus market?
- 250 / 40 = 6.25 jumps per year over 40 years
Yes, the construction cost is slightly higher going with the model/2 than the model/1bis ... but you wind up recouping that in terms of overhead expenses avoided on every jump the craft needs to make. It's either pay (some) more NOW at construction or pay (a lot!) more LATER when actually operating the craft. In other words, the life cycle costs are LOWER with the model/2 than with the model/1bis ...
And that's assuming jump cassettes are even "available" everywhere you go (see: type E-X starports, especially in low tech star systems).
The fuel tankage upgrade from 40 to 41 tons may seem like a "cute, but what's your point?" modification ... until you realize that with the CT Beltstrike fuel consumption formula in play, that extra +1 ton of internal fuel capacity makes J2+2 range a realistic possibility in actual operational practice. That "extra 1 ton" of fuel is enough for "over a week" of 2G continuous acceleration after making a J2+2 transit.
Likewise, that "extra 1 ton" of fuel capacity is enough for a J2+2 (origin > destination 1 > destination 2) through an intermediate location where refueling (starport, wilderness, whatever) is simply Not Available™ for whatever reason. This makes it possible to make "round trips" before needing to refuel.
If we assume that each "jump week" consumes 0.05 tons of fuel for Basic Power (see calculation in post #736 of this thread), that would leave a fuel margin of 0.9 tons of endurance for normal space operations after 2 jumps. Depending on EP demand ...
- 2 EP demand (continuous) = 0.9 / 0.75 * 7 days = 08d 09h 36m
- 1 EP demand (continuous) = 0.9 / 0.40 * 7 days = 15d 18h 00m
- 0 EP demand (continuous) = 0.9 / 0.05 * 7 days = 126d 0h 0m
Oh and ... side note ... jump cassettes for destinations 4 parsecs away would cost Cr40,000 per J2+2 jump, so ... even more reason to upgrade to a model/2 computer with a Generate program installed natively during construction.
Dropping the (dedicated) air/raft berth and replacing it with a "multi-modal" cargo hold ... which can accommodate EITHER an air/raft + life support consumable reserves (for longer duration exploration duty) OR a mail vault (for x-mail courier duty) ... just makes way too much sense to me. I figure that all you need are IISS "standard modules" that can be loaded into the 5 ton cargo hold space in order to "hot swap" mission duty tasking (Scout OR Courier) and you're "good to go" from a service perspective.
Note that 1 ton of cargo hold space is sufficient for 150 person/weeks of life support reserves (Cr150,000 cost to buy). With a 4 person occupancy of the starship, that's sufficient for a mission duration of 150/4=+37.5 weeks above and beyond the "standard" 4 person/weeks of life support endurance that a starship stateroom is capable of providing ... so maximum endurance of 39.5 weeks with a "full crew" of 4 persons aboard on an exploratory mission basis as far as life support goes (fuel endurance is a different issue).
Alternatively, the 5 ton cargo hold could have an additional 1x single occupancy stateroom installed instead of an air/raft berth, enabling VIP (or priority prisoner) passenger transport options.
Basically, you can "do more" with a 5 ton cargo hold than you can do with a 3 ton cargo hold + a 4 ton air/raft berth, in terms of options when it comes time for flexible outfitting for specific missions and assignments, as odd as that may sound.
The "external docking" modification makes it possible to take advantage of the 24 ton Box modular transport system that I've been working up in this thread, allowing the Type-S2 Scout/Courier to operate as a J1/1G transport with up to 4x24=96 tons of external load capacity ... which "could come in handy" in a wide variety of "second order/backup" operational tasking options, in which the Type-S2 Scout/Courier is "the only craft in the neighborhood" capable of hauling that kind of tonnage due to local logistics constraints (emergency or otherwise).
Note that a J1/1G "external transport" option makes the (redesigned) class work exceptionally well as a micro-jumper courier transport, in addition to all of the other potential capabilities built into the basic design parameters of the (updated) class.
{ we now return you to your regularly scheduled topic on Pondering Starship Evolution, already in progress ... } 
Yes but...Or to put it another way ... how long can you idle your petroleum product fueled ground car for, compared to how long you can drive it at highway speeds? The fuel tankage is exactly the same, but the fuel consumption rate due to the difference in demand load for power output is completely different. I would not expect the idle time endurance to be exactly equal to the highway driving endurance ... and I suspect that you wouldn't expect the fuel consumption rates to be the same in both contexts either.
If the power plant number is equal to the M-drive rating, and four weeks of fuel is based on that number, then the power plant would be working at a rate to supply the requisite power to the drive at that power setting for the four weeks. Not idling as the vessel coasted along, but supplying Pn for Mn. I agree with you that there is an oversimplification of needs, as there's no power listings for enviro and other life support systems including g-plates that crew walk upon, shielding against interplanetary debris that hits or is run through by the vessel, the computer and avionics, or the watts spend on the endless Z-box holo-games that Karl spends his time on instead of doing the One Job he had...
So maybe it's up to the ref to spitball how much fuel they think was used with the ship landed at the Class D port for two weeks. Could it run on batteries, or would it run at a reduced level? Could they run at a normal rate, sell the electricity to the local utility provider then skim later from a handy location? How much does this need to be codified? How you you handle all of that in YTU?
Spinward Flow
SOC-14 5K
Or you could just use the very simple formula provided in post #736 which I derived from CT Beltstrike and have something that is computationally consistent.
Well, in the Traveller context of craft construction, this would mean Jump Capacitors (which can be charged/discharged).
The answer is "yes" ... but ... the endurance of that power loading is limited.
The way I look at it is that fusion power plants generate (up to) their rated EPs every single LBB5.80 combat turn (20 minutes duration) for days/weeks at a time ... they just need fuel in order to be able to do generate those EPs.
Jump capacitors (36 EP per ton, as per LBB5.80, p42) will need to supply the EP demand every combat turn (20 minutes duration) until their stored EPs are exhausted. So a 1 EP continuous load would require 3 EP per hour of supply (from either a power plant or jump capacitors). Therefore ... 1 ton of jump capacitors filled with 36 EP can supply a demand load of 1 EP for 12 hours ... which is noticeably shorter than "4 weeks" like the default expectation for fusion power plants installed into starships.
Obviously, if you vary the load demand you can extend the endurance of the EPs stored in the jump capacitors (0.5 EP load takes 24 hours to consume 36 EPs of stored capacity), but you're still not getting into the "multi-week" range of endurance without having a very low power load demand.
And just for reference, the CT Beltstrike fuel consumption formula also includes an equivalency between Basic Power and EPs in it.
- 7 days of fuel consumption (tons) = (Hull Tonnage / 2000) + (EP * 0.35)
- (700 tons of hull / 2000) = (1 EP * 0.35) ... as far as fuel consumption rates go ...
The "fudge" here is the notion that power plants are rated for the "excess" EPs they generate for agility, computers, weapons and screens ... not the "total" EPs they generate for Basic Power + EP demand loads (agility, computers, weapons and screens).
With a suitable "berth-side hookup" ... sure. A craft's fusion power plant COULD supply (electrical) energy to a local power grid, if necessary. Taken to its logical conclusion, so long as the jump capacitors "aren't completely full" of EPs (so there's some "headroom" for intake as well as output), it ought to be possible to use a craft (with jump capacitors installed) for grid power conditioning to smooth out unwanted harmonics in grid supply/demand loading.
With a "large enough starport" with sufficiently occupied berths hosting craft with jump capacitors installed in them (participating in the program), this could potentially be a "side benefit industry service" of that starport infrastructure to a local power grid.
Depends on how "deep" you want the Life In Space Simulator™ to go, I guess.
First ... you start with the CT Beltstrike fuel consumption formula that I've provided in post #736 ... and work your way out from there, as needed.
And from this we can get an idea of how much electricity costs in Traveller. Unless I'm way off, the cost to the producer is about Cr0.0004 per kW-hr 'unit' at TL7-8, dropping to Cr0.0001 at TL15. The costs of transmission (lines and their maintenance and so on) would massively outweigh power-plant and fuel, so for the retail consumer power itself is effectively free, but the line 'rental' is not. This also means there's very little incentive to make more power efficient consumer and business devices, or to conserve power. The fuel cost at retail prices is such a small part of this that it disappears in the rounding, though a power utility providing power to a city and its industries probably won't think that way.
FWIW using TNE/T4 numbers it's something like Cr0.0006 at TL9-12 dropping to Cr0.0002/unit at TL15, so in the same order.
Spinward Flow
SOC-14 5K
Well ... maybe, maybe not. It really depends on how the local power grid is structured for billing its consumer/prosumer base. Even if the cost to generate power is ... marginal to negligible ... the cost to maintain the infrastructure will not be (as you've correctly cited). So what you could wind up with is billing based on how many kwh "move" between the grid and the entities hooked up to that grid. If you "move" a lot of power (in or out) across the grid then your bill goes up ... which then creates an incentive structure aimed in the direction of efficiency and load balancing (the real objective).
So there's more than one way to square that circle.
True, but that's an artificial structure designed to encourage something the actual costs do not. Which is not to say that it won't happen, of course - we have taxes and fees set up to encourage and discourage various activities all the time. I could also see a consumption tax on power to cover the cost of mitigation the environmental impact of the waste heat, for another thing.
But overall, Traveller's fusion plants make power astoundingly cheap, even paying the reactors off using ship mortgage rates and a planetary government or government-owned utility should be able to get better rates than that. I'd just never worked out how cheap it actually would before.
Spinward Flow
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The external towing option certainly expands the mission capability set, but there's still a "logistics problem" (of sorts).
There's no internal (hangar) capacity remaining for any externally docked 24 ton Box modules to be loaded INTO the class design so that craft of the class can be their own orbital transfer shuttle through atmosphere from orbit to surface ... which could be an important consideration in austere locations (with no orbital shuttle services available) at type D-X starports.
So the obvious solution is to do a bit of creative "rearranging" of the internal tonnage allocations to make it possible to have a 24 ton internal hangar bay (in a 100 ton starship!
) into which 24 ton Box modules can be loaded, enabling the (redesigned) Scout/Courier to operate (via relays) as its own orbital shuttle through atmosphere for any externally docked 24 ton Box modules.What comes out the other end of such an effort is ... well ... THIS ...
Scout/Courier (Type-SP, TL=9)
100 tons standard starship hull (MCr2) (LBB2.81, p22)
Atmospheric Streamlining, includes fuel scoops (MCr1) (LBB2.81, p15)
0 tons for Armor: 0 (TL=9, Composite Laminates, bulkhead thickness=20cm)
10 tons for LBB2.81 standard Jump-A drive (code: 2, TL=9, Scout, Jump Capacitor EP limit=36) (MCr10) (LBB2.81, p22)
1 ton for LBB2.81 standard Maneuver-A drive (code: 2, TL=9, Scout, Agility=2 requires EP=2) (MCr4) (LBB2.81, p22)
4 tons for LBB2.81 standard Power Plant-A drive (code: 2, TL=9, Scout, EP=2) (MCr8) (LBB2.81, p22)
30 tons for internal fuel (MCr0)
20 tons for bridge (200 ton rating, MCr1)
2 tons for model/2 computer (TL=7, CPU=3, Storage=6, EP=0) (MCr9) (LBB2.81, p22)
- Standard software package (MCr2 budget for programs) (LBB2.81, p41)
- Maneuver (Space=1, MCr0.1)
- Jump-1 (Space=1, MCr0.1)
- Jump-2 (Space=2, MCr0.3)
- Navigation (Space=1, MCr0.4)
- Generate (Space=1, MCr0.8)
- Library (Space=1, MCr0.3)
- 0.1+0.1+0.3+0.4+0.8+0.3 = MCr2
24 tons for internal hangar bay (MCr0.048)
- IISS Courier Box (24 tons)
8 tons for 2x single occupancy starship staterooms (MCr1) (LBB2.81, p23)
0 tons for cargo hold
0+10+1+4+30+20+2+1+24+8+0 = 100 tons
2+1+10+4+8+1+9+0.6+0.48+0.2+1 = MCr37.28
IISS Courier Box (Type-AU, TL=9)
24 ton small craft custom hull, configuration: 4 (MCr1.44)
0 tons for Armor: 0 (TL=9, Composite Laminates, bulkhead thickness=20cm)
11 tons for internal fuel (MCr0)
* External Docking: 6x 24 = 96 tons capacity (MCr0.288)
8 tons for 2x single occupancy starship staterooms (MCr1) (LBB2.81, p23)
5 tons for cargo hold (4 ton air/raft berth + 1 ton life support consumables reserves ... or ... 5 ton mail vault conversion ready) (MCr0)
= 0+11+8+5 = 24 tons (7.5m L x 7.5m W x 6m H = 337.5m³ / 14 = 24.10714286 tons ≈ 24 tons @ 5:5:4 dimensional ratio)
= 1.44+0.288+1 = MCr2.728
Single Production (100%): 37.28+2.728 = MCr40.008
Volume Production (90%): (37.28+2.728)*0.9 = MCr36.0072
Adds just slightly under MCr2 to the construction cost per copy, relative to the previous design in post #745 ... but solves a potential logistics bottleneck at type D-X starports when needing to move external loads through atmosphere from orbit to surface. So on balance. I'm figuring that the "upgrade" will be (well) worth the added cost in terms of logistics marshaling bottlenecks avoided.
Moving 2x starship staterooms, the 5 ton cargo hold and 11 tons of fuel capacity "into" the 24 ton Box form factor solved a lot of problems while avoiding any (major) consequences in terms of total fuel load or (aggregate) mission capability. The "standard package" of accommodations and 2J2 range potential is all still there ... except that now the starship can "docking swap" the 24 ton Box loaded into the internal hangar bay for orbital transits through atmosphere from orbit to surface in order to deliver external loads from orbit to surface without needing to rely on external (shore) support. This then makes it possible to pick up/deliver "outpost" Box modules (of any outfitting) to remote/austere locations for long duration mission assignments.
Spinward Flow
SOC-14 5K
This combination yields a direct competitor to the 200 ton J1/1G Free Trader and 200 ton J2/1G Far Trader ... in the form of a 100+4x24=196 tons combined J1+1/1G "Courier Trader" which would simply need to "add 24 ton Boxes" with the business model advantageous fittings installed in order to become a (quite) viable merchant starship.
Without an external load, the Type-SP can be commercially profitable as a mail courier (only) ... using the 5 ton cargo hold for x-mail deliveries (Cr25,000 revenue upon delivery, per LBB2.81, p9) ... which is "plenty sufficient" to pay for all operational expenses. The crew must include a Gunner and the (dual) turret would require armament (a single pulse laser will do @ MCr0.5), and under LBB2.81 (p41) an additional MCr1 outlay would need to be made to purchase the Target computer program allowing the pulse laser to engage hostiles ... so a MCr1.5 outlay beyond the stock configuration would be needed.
But with a "mail only" business model (and no capacity for speculative goods arbitrage), "Courier Traders" wouldn't need to conduct a "week of business" at each destination along their route(s), so a higher than ordinary operational tempo ought to be quite achievable. Even something as simple as a single jump per 9 days average rate of operation could mean as many as up to 39 jumps per year(!) ... leaving 2 weeks/14 days for annual overhaul maintenance within a calendar year.
- 9 * 39 = 351 + 2 * 7 = 365
@ 39 jumps per year, gross revenue doing mail (only) courier services would amount to 39*25,000=MCr0.975 per year ... which after 40 years would yield MCr39 in gross revenues, meaning that the starship class could pay for itself amortized over a 40 year "nominal" service life when working purely as a mail courier.
However, that external load capacity would still be present and could be chartered by third parties ("going my way?").
Even at (third party) charter rates, 4x 24=96 tons of external loading would yield an additional 96*1000*0.9=Cr86,400 per jump.
At a more "nominal" 2 weeks per jump cadence and making only 24 (single) jumps per year, that could yield (up to) ... 24*25,000+24*86,400=MCr2.6736 per year in gross revenues, when making only single jumps to 24 destinations.
If routing is a "pure double jump to every destination" type of circumstance, there would be 32 jumps required to reach 16 destinations, which could yield (up to) ... 16*25,000+32*86,400=MCr3.1648 per year in gross revenues, when making only double jumps to 16 destinations.
Both the 24 single jumps per year and 16 double jumps per year operational tempo leaves sufficient time at each destination to conduct (almost) a week of "business" before departing for the next jump point ... and leaves enough remaining days in the calendar year to complete annual overhaul maintenance.
Point being that with the external load capacity being chartered, the MCr36.0072+1.5=37.5072 volume production cost (90%) could be recouped within ~12 years (double jumping 16 times a year, 96 tons of external load chartered) or within ~14.5 years (single jumping 24 times a year, 96 tons of external load chartered).
That's what I would consider to be a "viable commercial business plan" ... even if the "sexy" option of speculative goods arbitrage is walled off from the range of possibilities.
Which then opens up a question of Range Architecture in terms of products and services, with regards to starship class designs.
If a 100 ton starship can operate as a J2+2 with a minimal allocation of revenue tonnage, but be "expandable" via external loading up to being a 100+4x24=196 combined tons that can operate as a J1+1 with 96 tons of external loading ...
... what should the "next step up" in terms of jump range ought to be?Enter the 280 ton starship which can operate as a J2+2+2
with up to 4x high passengers and 24 tons of environmentally controlled cargo capacity, but which could also be externally loaded with 21x 24 ton Boxes and operated as a J1+1+1 merchant hauling up to 280+21*24=784 combined tons.But both of those are J2/J1 options, in terms of Range Architecture.
So obviously, the "next step up" on the economics food chain ought to be a J3/J2 extended range (multi-jump capable without needing L-Hyd Drop Tanks) starship, which keeps its maximum combined tonnage limit to 1000 tons or less.
The 100 ton Type-SP Scout/Courier can be built @ TL=9.
The 280 ton Type-AP Rule of Man Long Trader can be built @ TL=9.
The ??? ton Type-AP Rule of Man Clipper will undoubtedly require TL=A (drives: E-H) or TL=B (drives: J-K) ... would complete the Range Architecture of merchant class ACS designs.
Silverhawk
SOC-12
So I would think that initially you would be looking at every ship being a custom build even if there are multiple examples being built. Think steam locomotives where the railroad might have a set of specifications or go with the builders plans. Small batches for just what the customer needs.Which then opens up a question of Range Architecture in terms of products and services, with regards to starship class designs.
By comparison the diesel locomotive was more like an automobile where the manufacturer decides on the model and specs and markets it to the customer. General Motors won the market for diesel locomotives in the 1950's by providing models that could do multiple jobs. They worked not the mechanical and engineering offices instead they worked the financial people by showing the numbers that this model could do these jobs and save the company on a whole variety of expenses. Meantime the old steam locomotive manufacturers built their own diesels but using the same old methods for construction and sales.
In the end they all left the market and only General Motors and General Electric were left.
I think in my traveller universe the initial tech level (maybe two) of starships is going to look a lot like building locomotives in the 19th and early 20th centuries (RL) ships that are or almost are custom built even if the plans are 'standard'. Later levels will feature more standard model types of ships where there are variants but the basics are the same.
Spinward Flow
SOC-14 5K
To be fair ... EVERY (new) class of starship starts out this way.
A single production example that needs to "prove itself" in actual operation before the Better Mousetrap Consequence™ becomes undeniable.
The discrepancy there is that steam locomotives kinda sorta HAD TO be specialists rather than generalists in terms of design/features/functionality. Steam propulsion had a "best efficiency" operating range for load balancing reasons designed into each locomotive, so they could excel in specific roles but were sub-optimal in a variety of other roles. Even something as simple as the "Tender? (Y/N)" question made a lot of difference for what a steam locomotive could be optimized for.
With regards to starships, if you've got a specific route that you're trying to optimize for (the Kessel Run in less than 12 parsecs, perhaps?
) then there are a variety of details that you can OMIT once you know the specific details of the route to be optimized for. In that case, you CAN design and operate around a specialist class intended for that specific context.However, when you're looking at a "generalized, frontier tramp merchant" type of application, with no specific locale, route or purpose in mind ... things change a bit, since at that point you want a "generalist" type of class that's "good enough" to get the job done (almost anywhere), rather than a "perfect" class that can do the best(est) job along a single specific route interfacing with a limited array of markets.
In some respects, that basically comes down to a dichotomy between LBB2 and LBB5 drive system paradigms.
Both are valid, but each plays to different strengths.
LBB2 is a "make the hull fit the standard drives" paradigm.
LBB5 is a "make the custom drives fit the hull" paradigm.
Spinward Flow
SOC-14 5K
Think I've found the right balance point for a TL=A J3/3G Clipper design ...Which then opens up a question of Range Architecture in terms of products and services, with regards to starship class designs.
Have a look.
Rule of Man Clipper (Type-AP, TL=A)
410 tons starship hull, configuration: 1 (MCr49.2)
0 tons for Armor: 0 (TL=A, Crystaliron, bulkhead thickness=10cm)
85 tons for LBB2.81 standard H/H/H drives (codes: 3/3/3, TL=A, EP=16) (MCr176) (LBB2.81, p22)
161 tons of total fuel: 410 tons @ J3 = 123 tons jump fuel + 30 tons power plant fuel
0 tons for fuel scoops (MCr0.41)
8 tons for TL=A fuel purification plant (200 ton capacity is minimum) (MCr0.036)
20 tons for bridge (1000 ton rating, MCr5)
2 tons for model/2bis computer (MCr18)
120 tons for hangar capacity (MCr0.24)
- Fighter Gunned (Type-FG, TL=A) = 30 tons
- Stateroom+ Box = 30 tons (pilot/gunner, pilot/gunner, navigator, engineer/engineer, engineer) (5x staterooms, V-c life support for 5)
- Stateroom+ Box = 30 tons (purser/purser, steward/steward, medic, 2x high passengers) (5x staterooms, V-c life support for 5)
- Environment Box = 30 tons
- 1.34 tons for 134 ton capacity collapsible fuel tank storage (MCr0.067)
= 0+85+161+8+20+2+120+14 = 410 tons
= 49.2+176+0.41+0.036+5+18+0.24+1.18+0.067 = MCr250.133
= MCr250.133+(65.302)+(6.66*1.8)+(5.16) = MCr332.583 * 1.0 = MCr332.583 single production
= MCr250.133+(65.302)+(6.66*2)+(5.16) = MCr333.915 * 0.8 = MCr267.132 volume production
Crew = 8 (Cr44,610 per 4 weeks crew salaries)
- Pilot-3/Gunnery-2 (chief) = (6000*1.2)+(1000*1.1/2)*1.1 = Cr7805
- Pilot-3/Gunnery-2 = (6000*1.2)+(1000*1.1/2) = Cr7750
- Navigator-1 = (5000*1.0) = Cr5000
- Engineering-2 (chief)/Engineering-2 (chief) = (4000*1.1)*1.1+(4000*1.1/2)*1.1 = Cr7260
- Engineering-1 = (4000*1.0) = Cr4000
- Steward-1 (purser)/Steward-1 (purser) = (3000*1.1)*1.1+(3000*1.1/2)*1.1 = Cr5445
- Steward-1/Steward-1 = (3000*1.1)+(3000*1.1/2) = Cr4950
- Medical-3 = (2000*1.2) = Cr2400
- J3, 3G, Agility=3: 410 + 123 = 533 combined tons
- J2, 2G, Agility=2: 410 + 390 = 800 combined tons
- J1, 1G, Agility=2: 410 + 590 = 1000 combined tons
Fighter Gunned (Type-FG, TL=A)
30 ton small craft hull, configuration: 1 (MCr3.6, integral fuel scoops)
0 tons for Armor: 0 (TL=A, Crystaliron, bulkhead thickness=10cm)
1 ton for LBB2.81 standard Maneuver-A (Agility=6 requires 1.8 EP) (MCr4) (LBB2.81, p22)
10 tons for LBB2.81 standard Power Plant-C (EP=6) (MCr24) (LBB2.81, p22)
1 ton for fuel
- Basic Power only = 0.015 tons of fuel consumption per 7d (466d 16h 0m endurance) for Agility=0, no computer, no lasers
- Basic Power + 1.8 EP = 0.645 tons of fuel consumption per 7d (10d 20h 27m endurance) for Agility=6, "model/2 computer", no lasers
- Basic Power + 3.8 EP = 1.345 tons of fuel consumption per 7d (5d 04h 54m endurance) for Agility=6, model/4 computer, no lasers
- Basic Power + 5.8 EP = 2.045 tons of fuel consumption per 7d (3d 10h 09m endurance) for Agility=6, model/4 computer, dual beam lasers
4 tons for model/4 computer (TL=A, EP: 2) (MCr30)
1 ton for hardpoint+dual turret: beam laser, beam laser (TL=A, batteries: 1, code: 2, EP: 2) (MCr2.6)
* External Docking: 451 tons capacity (MCr0.902)
2 tons for 1x small craft cabin (life support endurance: 2 person/weeks) (MCr0.05)
5 tons for cargo hold (multi-purpose conversion ready, including mail vault)
= 0+1+10+1+6+4+1+2+5 = 30 tons
= 3.6+0+4+24+0.15+30+2.6+0.902+0.05 = MCr65.302 single production
- 0.4G, Agility=0: 481 - 30 = 451 tons external load (451/1.1=410 ton big craft)
- 1G, Agility=1: 200 - 30 = 170 tons external load (5x 30 ton Boxes)
- 2G, Agility=2: 100 - 30 = 70 tons external load (2x 30 ton Boxes)
- 3G, Agility=3: 66 - 30 = 36 tons external load (1x 30 ton Box)
- 4G, Agility=4: 50 - 10 = 20 tons external load
- 5G, Agility=5: 40 - 30 = 10 tons external load
- 6G, Agility=6: 33 - 30 = 3 tons external load
Stateroom+ Box (Type-RU, TL=A)
30 ton small craft hull, configuration: 4 (MCr1.8)
0 tons for Armor: 0 (TL=A, Crystaliron, bulkhead thickness=10cm)
20 tons for 5x single occupancy starship staterooms (MCr2.5)
10 tons for regenerative biome life support laboratory (Type: V-c) (MCr2)
* External Docking: 6x 30 = 180 tons capacity (MCr0.36)
0 tons for cargo hold
= 0+20+10+0 = 30 tons
= 1.8+2.5+2+0.36 = MCr6.66 single production
Laboratory Box (Type-LU, TL=A)
30 ton small craft hull, configuration: 4 (MCr1.8)
0 tons for Armor: 0 (TL=A, Crystaliron, bulkhead thickness=10cm)
30 tons for laboratory (MCr6)
* External Docking: 6x 30 = 180 tons capacity (MCr0.36)
0 tons for cargo hold
= 0+30+0 = 30 tons
= 1.8+6+0.36 = MCr8.16 single production
Environment Box (Type-LU, TL=A)
30 ton small craft hull, configuration: 4 (MCr1.8)
0 tons for Armor: 0 (TL=A, Crystaliron, bulkhead thickness=10cm)
30 tons for environment tank (MCr3)
* External Docking: 6x 30 = 180 tons capacity (MCr0.36)
0 tons for cargo hold
= 0+30+0 = 30 tons
= 1.8+3+0.36 = MCr5.16 single production
Cargo Box (Type-AU, TL=A)
30 ton small craft hull, configuration: 4 (MCr1.8)
0 tons for Armor: 0 (TL=A, Crystaliron, bulkhead thickness=10cm)
* External Docking: 6x 30 = 180 tons capacity (MCr0.36)
30 tons for cargo hold
= 0+30+0 = 30 tons
= 1.8+0.36 = MCr2.16 single production
9.15m x 7.65m x 6m = 419.985m3 / 14 = 29.9989 tons ≈ 30 tons (61:51:40 dimensions ratio)
6.1 x 5.1 deck squares area @ 1.5m2 per deck square scaling
Obviously, for this particular iteration, I "had to" abandon the 24 ton form factor of the previous iterations of modular Boxes for a 30 ton form factor for the modular Boxes ... because the Fighter needed to be "that big" in order to fit a model/4 computer into its hull ... but ultimately, that wound up being something of a "non-problem" when working with a baseline assumption of a 120 ton internal hangar bay balance point for minimum "viable" operations.
- 5x 24 tons = 120 tons
- 4x 30 tons = 120 tons
I'm figuring that the 30 ton Box would be a "Solomani standard" form factor, while the 30 ton Modular Cutter Module is more of a "Vilani standard" type of form factor. Same "job" but using a different shape (obviously). The "box" form factor is better for stacking in arrays with minimal packing losses between them (unlike piles of cylinders) when it comes to mass transport of modular shipping containers.
And as is typical for this design project, this 410 ton J3/3G Rule of Man Clipper design is capable of J3+3 without use of L-Hyd Drop Tanks, with "plenty" of fuel margin to spare (just move the Fighter and 3x Boxes to docking points on the outer hull) and fill the internal hangar bay with the collapsible fuel tank.
- (410+4*30)*0.3 + 410*0.3 = 282 tons of jump fuel consumption
- 161 tons of internal fuel + 121 tons of collapsible fuel tankage = 282 tons of total fuel
- Collapsible fuel tankage can go up to 134 tons of capacity ... so up to 13 tons of fuel reserve potential
Transport capacity @ J3+3 will be minimal (5 tons cargo or mail, 30 tons environmentally controlled cargo, 2x high passengers) ... with the "right speculative goods opportunities" that can potentially be "all you need" to make some windfall profits via arbitrage between widely separated (main)world markets.
On the crew side, I decided to go for "interchangeable hot shots" in the pilots, so that either can pilot the starship (no need for gunnery skill on an unarmed craft, so Pilot-3 means +1 Agility in combat) OR the fighter (functionally Ship's Boat-1 and Gunnery-1 skill yield throughput). This allows for tandem flying of both craft in convoy through normal space and allows both pilots to "swap craft" as needed or depending on circumstances. The basic idea here is that this arrangement allows both pilots to "keep their skills sharp/fresh" and prevents "boredom" that can result from having only a single type of craft to fly. Game mechanically, it's "no big deal" ... but in a roleplaying/life simulator context, I can easily imagine the sort of teamwork/crew loyalty/morale booster that can result from having this kind of arrangement.
After all, sometimes you just want to get out of the Big Craft and take a spin in the Small Craft, you know?
kilemall
SOC-14 5K
The history of that is more complex as many of the competitors provided superior options but marketing and standardization won out. GM didn’t get to their GP series until nearly being beaten down by ALCO for instance. They got their lead by being the only locomotive builder allowed to produce big runs during the war. GE didn’t emerge as a main builder until near the end of ALCO.
The point is well taken about diesel electric vs steam. Each steam design had very particular characteristics specced per locomotive class per railroad operating needs and route profile.
Your universe of course, my take is that IRL we had mass production ships like the wartime freighters, but now very specialized container ships and other designs built very specifically for routes and business plans. I would expect something similar for the big ship Traveller lines.
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