HG '79 was a beta release avant la lettre, though they didn't realize it at the time.
The Xboat is a HG2 design
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Everyone: Page numbers, please. If you're going to claim text from the books says X, give book, page, and paragraph, please.
Not picking on Mike alone - a bunch of you are paraphrasing things you think are there, but which may or may not be. (Mike is usually better about it than in this thread.)
The corollary: yes, you ARE expected to look it up!
mike wightman
SOC-14 10K
Yup, and according to frank Chadwick and Dave Nilsen the CT m-drive was always intended to be a reaction drive, not the reactionless interpretation of HG80 and into MT.
Condottiere
SOC-14 5K
I would speculate the electricity is to create a gravitic field that is focussed on pushing, so wouldn't need fuel.
In the end it's a cost benefit question, for commercial operators, which type has less expenses over a specific financial period.
In the end it's a cost benefit question, for commercial operators, which type has less expenses over a specific financial period.
Just running the numbers...And at the 5.2AU orbit of Jupiter it would be 48W/m2, which at 750,000m2 amounts to 0.144EP/second (or 1EP per 7 minutes/8.64EP per hour).
At the 1 AU orbit of Terra, it would be 1300W/m2, which at 750,000m2 amounts to 3.9EP/second (or 234EP per hour).
It does make a difference where you collect ...
1 HG EP is 20 minutes × 250 MW... 20×250=5000 MW·minute = 5000*60 MW·Sec=300,000 MW·Sec = 300 GW·Sec or 0.3 TJ...
Time from CT B5-81 p 38 ¶7; conversion to watts is Striker Bk2 p41-42 rule 75.C.(1,2).
48 watt-minutes per minute is 48 watts... 7.5e5×4.8e1 =36e6 36 MW...
And an EP is 3e11 W·S... (3/3.6)×10^(11-6)=0.8333×10^5=83333sec, some 23 hours..., not 1 per 7 minutes.
Do you have any references to this? Because if that was a the case, they did a spectacularly poor job of conveying it. I've always considered it to be reactionless, though I must certainly admit I wasn't parsing every word or letter back in the day of the ruleset. But even in hindsight, it's not that glaringly obvious.
They had several opportunities to correct this, but apparently didn't.
And even with the numbers in Beltstrike, fuel consumption was completely marginal. Using the Beltstrike numbers, a Free Trader with 10 tons of non-jump fuel can accelerate for 208 DAYS. Ship could go over 5000AUs in that time.
I appreciate that they switched in TNE, and that they did it for cause, but that's not necessarily the same thing as "they always wanted it this way".
mike wightman
SOC-14 10K
Yes, it is mentioned in the epic ask Dave Q&A on these very boards.
Spinward Flow
SOC-14 5K
CT Beltstrike, p5:
CT Beltstrike, p5:
CT Beltstrike, p11:
Added for reference.
Note that the table is in fuel consumption per 100 tons of craft.
At 0.002 tons of fuel per 100 tons of craft per G of acceleration per hour ... you have an equivalency of 50,000 G-ton-hours per 1 ton of fuel.
50,000 G-ton-hours per 1 ton of fuel means:
Therefore, a 100 ton Type-S Scout/Courier performing a continuous 2G acceleration burn for 4 weeks would consume 2 tons of fuel for power plant fusion (LBB5.80 formula) and 2.688 tons of fuel for the HEPlaR reaction thrust (Beltstrike formula) with a recommended 3 ton fuel allocation for adequate reserve (my quick houserule eyeballing the situation) over and above the basic power plant fusion support requirement (LBB5.80 formula).
In other words, a 100 ton Type-S Scout/Courier can consume up to 5 tons of continuous 2G maneuver+power plant fuel per 4 weeks ... or up to 3.5 tons of continuous 1G maneuver+power plant fuel per 4 weeks.
CT Beltstrike, p5:
CT Beltstrike, p11:
Added for reference.
Note that the table is in fuel consumption per 100 tons of craft.
At 0.002 tons of fuel per 100 tons of craft per G of acceleration per hour ... you have an equivalency of 50,000 G-ton-hours per 1 ton of fuel.
50,000 G-ton-hours per 1 ton of fuel means:
- 100 ton ship = 500 G-hours per ton of fuel spent maneuvering
- 500 hours @ 1G
- 250 hours @ 2G
- 125 hours @ 4G
- 100 hours @ 5G
- 200 ton ship = 250 G-hours per ton of fuel spent maneuvering
- ... etc.
Therefore, a 100 ton Type-S Scout/Courier performing a continuous 2G acceleration burn for 4 weeks would consume 2 tons of fuel for power plant fusion (LBB5.80 formula) and 2.688 tons of fuel for the HEPlaR reaction thrust (Beltstrike formula) with a recommended 3 ton fuel allocation for adequate reserve (my quick houserule eyeballing the situation) over and above the basic power plant fusion support requirement (LBB5.80 formula).
In other words, a 100 ton Type-S Scout/Courier can consume up to 5 tons of continuous 2G maneuver+power plant fuel per 4 weeks ... or up to 3.5 tons of continuous 1G maneuver+power plant fuel per 4 weeks.
- (Tons/100) * (Pn + G*1.5) = continuous acceleration for 4 weeks using HEPlaR reaction thrust fuel consumption maximum
And I just handwave it by using the TCS power-down rule broken down into weeks rather than months (this is a house rule) so the Type S can do 1J2 and an extra 1J1 if it keeps to 1G while in normal-space (that is, 1 week at Pn=2 for the J2, 2 weeks at Pn=1 for the J1 and the runs to/from Jump Limit).
Thinking about XBoats again because I'm looking to re-use the XBoat's drive package (J+PP) in an A2 Far Trader variant (as setting fluff, mostly).
The '77 version exists as an edge case. That ruleset arguably doesn't require a power plant (and its fuel) if there's no maneuver drive, and a Jump Drive B enables use of the 100Td Standard Hull (non-streamlined, of course). Convenient! On the other hand, it only needed a Mod/2 computer, and one crew member. That'd leave 19Td after fuel, controls, and living space. So, why no maneuver drive?
Pn=Gs (but not Jn, yet). Minimum propulsion package under the ship design rules is MD-A/PP-A, 5Td. Plus (RAW) 20Td fuel since it's Pn=2. 25Td isn't going to fit into 19Td -- sorry.
But, that 20Td of fuel is for one trip (2 weeks), why can't we split that? Because in '77, it's all maneuver fuel -- and only a week's worth at that (see the small craft fuel burn rate, and note that the mention of 288 turns is a minimum, while 1000kg/Pn matches 1 week of small craft acceleration).
What if it's only 1G, and only needs 10Td fuel? Because RAW doesn't provide for it (and if you try to extrapolate the drives from LBB2, the maneuver drive vanishes -- 0.0 Td). Can't even use a MD-A with an extrapolated PP-0.5A (which the math suggests doesn't violate in-universe physics even if you can't normally buy one). So, nope.
We're done here, no maneuver drive. The XBoat is an XBoat. Stuff in an extra stateroom or two and some data banks and call it a day.
... then you get High Guard (either one, doesn't matter) and their new Pn=Jn rule. Build it at TL-13 (because it's J-4) and you can fit two staterooms in, even with the now-requisite Mod/4 computer, and still have room for up to 3G maneuver drives (8Td) without bending any rules. This is not an edge case! Drop it to 1G and there's room for a mail vault and a turret (plus there's already a stateroom for the gunner)! Perfectly legal, but absolutely not an XBoat, and enough of an improvement that you probably won't build XBoats...
... then you get LBB2'81, with that 10Pn fuel allocation lasting for 4 weeks including Jump. It's an edge case again -- it works if you only carry 7.7 days of power plant fuel (11Td) instead of 4 weeks (40Td)*, and this time there isn't room for a maneuver drive (and the data banks will need to be tiny). You have to build XBoats as XBoats because that's all that can fit into a 100Td hull.
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*House rule. This violates the "must have 4 weeks of fuel" requirement, but the derived fuel burn rate of 2.5Td*Pn per week means that the extra (almost) three weeks of fuel would never be used -- thus, there are no adverse effects from not carrying them, merely a rule that says you must do so regardless.
The '77 version exists as an edge case. That ruleset arguably doesn't require a power plant (and its fuel) if there's no maneuver drive, and a Jump Drive B enables use of the 100Td Standard Hull (non-streamlined, of course). Convenient! On the other hand, it only needed a Mod/2 computer, and one crew member. That'd leave 19Td after fuel, controls, and living space. So, why no maneuver drive?
Pn=Gs (but not Jn, yet). Minimum propulsion package under the ship design rules is MD-A/PP-A, 5Td. Plus (RAW) 20Td fuel since it's Pn=2. 25Td isn't going to fit into 19Td -- sorry.
But, that 20Td of fuel is for one trip (2 weeks), why can't we split that? Because in '77, it's all maneuver fuel -- and only a week's worth at that (see the small craft fuel burn rate, and note that the mention of 288 turns is a minimum, while 1000kg/Pn matches 1 week of small craft acceleration).
What if it's only 1G, and only needs 10Td fuel? Because RAW doesn't provide for it (and if you try to extrapolate the drives from LBB2, the maneuver drive vanishes -- 0.0 Td). Can't even use a MD-A with an extrapolated PP-0.5A (which the math suggests doesn't violate in-universe physics even if you can't normally buy one). So, nope.
We're done here, no maneuver drive. The XBoat is an XBoat. Stuff in an extra stateroom or two and some data banks and call it a day.
... then you get High Guard (either one, doesn't matter) and their new Pn=Jn rule. Build it at TL-13 (because it's J-4) and you can fit two staterooms in, even with the now-requisite Mod/4 computer, and still have room for up to 3G maneuver drives (8Td) without bending any rules. This is not an edge case! Drop it to 1G and there's room for a mail vault and a turret (plus there's already a stateroom for the gunner)! Perfectly legal, but absolutely not an XBoat, and enough of an improvement that you probably won't build XBoats...
... then you get LBB2'81, with that 10Pn fuel allocation lasting for 4 weeks including Jump. It's an edge case again -- it works if you only carry 7.7 days of power plant fuel (11Td) instead of 4 weeks (40Td)*, and this time there isn't room for a maneuver drive (and the data banks will need to be tiny). You have to build XBoats as XBoats because that's all that can fit into a 100Td hull.
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*House rule. This violates the "must have 4 weeks of fuel" requirement, but the derived fuel burn rate of 2.5Td*Pn per week means that the extra (almost) three weeks of fuel would never be used -- thus, there are no adverse effects from not carrying them, merely a rule that says you must do so regardless.
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Spinward Flow
SOC-14 5K
The 4 weeks of power plant fuel endurance is a Generic Requirement for craft that are meant to fly freely.
XBoats are hyperspecialized starships that do NOT fly freely ... and are therefore a special case due to their actual use when in operation.
In the absence of a Tender service, XBoats WOULD require a 4 week fuel endurance capacity ... but with a Tender service, that 4 week fuel endurance responsibility in effect gets offloaded onto the Tenders, rather than remaining with the XBoats themselves.
What you really want for XBoat fuel endurance is 10 days (jump plus a couple days for recovery by Tender).
PP-B = 40 tons for 28 days endurance = 14.3 tons for 10 days endurance
40 * 10 / 28 = ~14.3
However, by adding a power plant (LBB2.81) you're throwing away the cost savings of using a 100 ton standard hull.
Then there's the question of the Tenders themselves and how they ought to be built/organized.
I would argue that the TL=10 drive-H/H/H (85 tons) is the correct choice under LBB2, but the hull size ought to be 800 tons. This then yields a Jump-2, 2G, Power plant-2 performance profile. 2 parsecs of jump fuel is 160 tons for the Tender, plus another 20 tons for 4 weeks of power plant endurance. A TL=10 fuel purification plant for 200 tons of fuel will require 8 tons.
A hangar bay for 100 ton big craft will require 110 tons per internal docking space, so 4 such hangar berths would require 440 tons from the Tender.
- 85 tons drives (H/H/H = 2/2/2)
- 160+20=180 tons fuel
- 8 tons fuel purification plant
- (100*1.1)*4=440 tons hangar bay
- 20 tons bridge
- 4 tons model/4 computer
- 4 tons collapsible fuel tanks (400 ton capacity, occupies empty hangars when not in use)
Personally, I think that an even smarter play for the Tenders would be to reduce the 100 ton berths from 4 to 3 in order to add an organic small craft fighter/maneuver tug element plus fuel shuttle service to the operation (so you don't need to assign scout/couriers to making fuel runs for Tenders). That way the Tenders act more like "motherships" that remain on station in orbit while letting the small craft handle any defense requirements (at a distance) and fuel transport servicing from whatever fuel resource is locally available (water ocean, gas giant, etc.).
You want a small craft that is "small enough" to zip around at 6G and operate as a credible (TL=10) fighter asset which can also dock with and maneuver tow a 100 ton XBoat so as to maneuver rendezvous with a Tender in the least amount of time. You'll need multiple fighters so as to maintain 24/7 defense patrols in addition to having a reserve fighter (or two) available for maneuver tug services for XBoats both before jump (outbound) and after jump (inbound). The fuel shuttle just needs to "skim and lift" to deliver fuel to the Tender for fuel processing to be used in the drives of the Tender and the XBoats.
With no XBoats loaded into the internal hangar bays and the collapsible fuel tanks filled up, the Tender would be capable of self deployment across 4 parsec gaps in the Express Network so as to rotate in and out of service for maintenance and overhauls.
Indeed. But '81 says you need one, so it has to have one.
I expect the XBoat hull (100Td unstreamlined, with a 22Td drive bay) will also be a standard hull for cost and build time due to the sheer number needed, but only ever used for XBoats. (It wastes half a Td if using a matched set of A.5 drives*.)
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* custom (interpolated) LBB2 drives yielding a rating of 3 in a 100Td hull. House rule, for those who care about such things.
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Actually, that might explain why the unstreamlined XBoat's canonical hull shape looks almost streamlined. It's so it doesn't need much modification to become a streamlined one that uses those A.5 drives...
And now I have another project.
(Half fuel for power plant -- house rule! -- 2bis computer from '77, 2 staterooms, turret, no cargo.)
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Or build a TL-13 Type S in HG that does J3/2G, and call it a day. Uses an ordinary 100Td standard hull.
...but then you need to bring in HG.
Spinward Flow
SOC-14 5K
This would be my preference.
15 tons of drives + 33 tons of fuel + 20 tons bridge + model/2bis = 70 tons allocated
You then have 30 tons remaining to spread around among crew accommodations, vehicle/cargo/lab volume and cargo.
Certainly makes for a compelling TL=13 alternative.
In a "both/and" universe, it's the obvious choice when TL-13 is available. It can be J3/3G at the cost of the 3Td cargo bay OR one stateroom OR the Air/Raft. (Add 1Td cargo for either of the latter two options).
For reference:
Type S3 Far Scout/Courier (link to my design).
No deck plans, and it really doesn't need them. Just use your preferred set of Type S plans, and say the fuel processor and extra Td of computer are somewhere in the fuel tanks.
Type S3 Far Scout/Courier (link to my design).
No deck plans, and it really doesn't need them. Just use your preferred set of Type S plans, and say the fuel processor and extra Td of computer are somewhere in the fuel tanks.
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AnotherDilbert
SOC-14 1K
It's hardly worth it.
The J-2 Scout is TL-9 and MCr ~29. Cheap, robust, and repairable.
The HG J-3 Scout is TL-13 and MCr ~57, or MCr ~74 at J-4. Expensive, supply chain problem, and only marginally better.
Still barely useful payload...
Better make it a TL-15 surplus Navy scout (J-4 & M-4) for MCr 68?
With a drop tank it can peek into a nearby (J-4) star system and jump back without exposing it to intercept it by refuelling.
It can do three J-2 with a 100 Dt exterior tank and two J-3 with a 50 Dt exterior tank.
Or remove some interior demountable tanks for extra cargo space. J-4 + 2 Dt cargo? J-3 + 42 Dt cargo? Two J-2 + 40 weeks duration + 42 Dt cargo? Take your pick, or reconfigure in a few weeks for a fraction of a MCr.
Still expensive and a supply chain problem, but the Navy already has the TL-15 supply chain and the use-case (fleet reconnaissance). As a surplus ship without much of an economic use case, it should be pretty affordable?
The J-2 Scout is TL-9 and MCr ~29. Cheap, robust, and repairable.
The HG J-3 Scout is TL-13 and MCr ~57, or MCr ~74 at J-4. Expensive, supply chain problem, and only marginally better.
Still barely useful payload...
Better make it a TL-15 surplus Navy scout (J-4 & M-4) for MCr 68?
With a drop tank it can peek into a nearby (J-4) star system and jump back without exposing it to intercept it by refuelling.
Code:
SC-1644441-000000-00000-0 MCr 67,5 100 Dton Ag=2
SC-2632341-000000-00000-0 MCr 67,5 150 Dton
SC-2622241-000000-00000-0 MCr 67,5 200 Dton
bearing Crew=1
batteries TL=15
Low=1 Cargo=2 Fuel=44 EP=4 Agility=1 DropT=100
Single Occupancy 2 84,4
USP # Dton Cost
Hull, Streamlined Custom 1 100
Configuration Flattened Sphe 6 8
Scoops Streamlined 0,1
Drop Tanks 100 Dton 0,1
Total tonnage 200 Dton
Jump Drive 2 1 6 24
Manoeuvre D B 2 1 3 8
Power Plant 2 1 4 12
Fuel, #J, #weeks J-2, 4 weeks 2 4
Purifier 1 3 0,0
Bridge 1 20 0,5
Computer m/4 4 1 4 30
Staterooms 3 12 1,5
Low Berths 1 0,5 0,1
Cargo 2
Demountable Tanks J-2 1 40 0,0
Collapsible Tanks 50 Dton 1 0,5 0,0
Empty hardpoint 1 1
Nominal Cost MCr 84,36 Sum: 2 84,4
Class Cost MCr 17,71 Valid ≥0 ≥0
Ship Cost MCr 67,48It can do three J-2 with a 100 Dt exterior tank and two J-3 with a 50 Dt exterior tank.
Or remove some interior demountable tanks for extra cargo space. J-4 + 2 Dt cargo? J-3 + 42 Dt cargo? Two J-2 + 40 weeks duration + 42 Dt cargo? Take your pick, or reconfigure in a few weeks for a fraction of a MCr.
Still expensive and a supply chain problem, but the Navy already has the TL-15 supply chain and the use-case (fleet reconnaissance). As a surplus ship without much of an economic use case, it should be pretty affordable?
It's explicitly just a Type S that can do Jump-3, if a scenario or campaign calls for one. It can also be used if a Scout character gets multiple ship results on mustering out, or the upgrade/replacement granted as a reward for exceptional service during play.
Supply chain problems can be either handwaved (as with high-TL Navy ships), or used as adventure hooks.
1. The bargain-basement versions of the J3/3G streamlined-XBoat have only a Mod/3; and either no turret or 1.5 staterooms and 1Td cargo.Actually, that might explain why the unstreamlined XBoat's canonical hull shape looks almost streamlined. It's so it doesn't need much modification to become a streamlined one that uses those A.5 drives...
And now I have another project.
(Half fuel for power plant -- house rule! -- 2bis computer from '77, 2 staterooms, turret, no cargo.)
2. They only make sense as governmental couriers in a LBB2-only TU. Maybe there's a 22Td drive package from HG that fits and yields something more useful, though.
3. Both the (house-ruled) "second-standard 100-ton" hull and the (also house-ruled) drives to fit it are the result of applying the IISS's massive demand for the hulls to a reasonable market. The hulls are cheap because the Scouts need so many of them. The drives get built because there's a glut of cheap used hulls into which they fit.
3a. Yes, this is a daisy-chain of house rules. On the other hand, the XBoat Loophole is the only way to reconcile Pn>=Jn for it while keeping it a functionally possible LBB2'81 design, as it canonically is -- otherwise, it's just broken.* The rest follows from the resulting necessary drive package.
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*At least one of these characteristics must be invalidated: Pn=Jn, it's a LBB2 design, or 4 weeks fuel.
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Was it derived from a LBB2'77 Trade Route map, perhaps?
