Type ST Transport Scout: 199Td, J4/2G (LBB2 2nd Ed.)

[AnotherDilbert]

But the fundamental issue is that using LBB5 where LBB2 is called for is cheating. Yes, it's a legitimate rule set, but that's not the point. The point is that LBB5's construction rules are integrated with its abstract combat system and technology paradigm, which is markedly different from the one in LBB2 and LBB3.

Sorry, not sorry, I don't subscribe to rule system mysticism. It's perfectly legitimate to use LBB5 to build Scouts or Free Traders (they just tend to be more expensive than LBB2 counterparts). And perfectly possible to use LBB5 ships in LBB2 combat, see the original Gazelle JTAS article.

High jump range can be accomplished relatively easily in LBB5 (TL permitting) because that design system imposes lower (size and credit) costs for it to compensate for its higher (size and credit) costs of combat-relevant components. It's difficult in LBB2 because that system was designed to make things that are useful to player characters in an RPG context (high jump range, for example) costly and difficult.

No, it's more difficult for small ships in LBB2. It's actually easier for large ships, cf. the magic of the Z drive.

Note that below TL 15 power plants tend to be a large and expensive in LBB5.

Compare a large (for an adventurer) J-6 ship:

LBB5: MCr 1368, 75 Dt overtonnage:

XT-B366662-000000-00000-0      MCr 1 368       2 000 Dton
bearing                                           Crew=22
batteries                                           TL=15
                       Cargo=0 Fuel=1320 EP=120 Agility=5

Single Occupancy                                  -  75     1 368
                                     USP    #      Dton      Cost
Hull, Part Streaml  Custom             B          2 000          
Configuration       Cylinder           3                      200
Scoops              Partial                                     2
                                                                 
Jump Drive                             6    1       140       560
Manoeuvre D                            6    1       340       170
Power Plant                            6    1       120       360
Fuel, #J, #weeks    J-6, 4 weeks            6     1 320          
Purifier                                    1        20         0

LBB2: MCr 803, 368 Dt free:

XT-B366662-000000-00000-0        MCr 803       2 000 Dton
bearing                                           Crew=20
batteries                                           TL=15
                     Cargo=368 Fuel=1260 EP=120 Agility=5

Single Occupancy    LBB2 design                     368       803
                                     USP    #      Dton      Cost
Hull, Part Streaml  Custom             B          2 000          
Configuration       Cylinder           3                      200
                                                                 
Jump Drive          Z                  6    1       125       240
Manoeuvre D         Z                  6    1        47        96
Power Plant         Z                  6    1        73       192
Fuel, #J, #weeks    J-6, 4 weeks            6     1 260

Much cheaper and much more free space with LBB2.



Here is why you don't generally use LBB5 to build e.g. Scouts:

SC-12222R1-000000-00000-0       MCr 51,7         100 Dton
bearing                                            Crew=1
batteries                                           TL=11
                          Cargo=15 Fuel=22 EP=2 Agility=2

Single Occupancy                                   15        51,7
                                     USP    #     Dton       Cost
Hull, Streamlined   Custom             1          100            
Configuration       Cone               2                     11  
Scoops              Streamlined                               0,1
                                                                 
Jump Drive                             2    1       3        12  
Manoeuvre D                            2    1       5         3,5
Power Plant                            2    1       6        18  
Fuel, #J, #weeks    J-2, 4 weeks            2      22            
Purifier                                    1       7         0,0
                                                                 
Bridge                                      1      20         0,5
Computer            m/1bis             R    1       1         4  
                                                                 
Staterooms                                  4      16         2  
                                                                 
Cargo                                              15            
                                                                 
Empty hardpoint                             1       1            
                                                                 
Air/raft            4 Dton                  1       4         0,6
                                                                 
Nominal Cost        MCr 51,73            Sum:      15        51,7
Class Cost          MCr 10,74           Valid      ≥0          ≥0
Ship Cost           MCr 41,50

Sure, you get some more free space, but it's much more expensive...

 

[AnotherDilbert]

Flight plan? But of course!
12 hour 2G burn to 100D (estimated, from the chart in LBB2), Then jump-4, then 12 hours 2G deceleration to the destination. Assume a 7.7 day Jump and round up, that's 9 days with the power plant running. Even if it's running at Pn=4 the whole time, there will still be 12 days reserve at full power -- enough to go to and from the 100D limit 12 more times.

You are going to carry passengers with an illegal, insufficient amount of fuel? [turn on the shock rod] Intentionally? [screaming...]

It doesn't matter. There is no rule or regulation requiring you to have any special amount of fuel left when you dock.

And coming back to the yacht thing. A Type Y doing back-to-back jumps across 2 parsecs comes out of the second jump with about the same reserve duration (15% higher). If it's going to jump at standard cadence without refueling (1 jump every two weeks), it'll have significantly less.

Doesn't matter. There is no rule or regulation requiring you to have any special amount of fuel left when you dock.


You are inventing a meta-rule about fuel reserves that are not in the game. The rules only say you must have four weeks PP fuel in standard tankage, no fudging with drop tanks, demountable tanks, or collapsible tanks.

 

[AnotherDilbert]

Not quite. The constraint is literally "Any given power plant is less fuel efficient when installed in a smaller ship".

That's a side effect of a clumsy rule.

This is the actual rule "at a minimum, ship fuel tankage must equal 0.1MJn+10Pn":
A 400 Dt ship with a PP-2 requires 20 Dt (5%) fuel.
A 1000 Dt ship with a PP-2 requires 20 Dt (2%) fuel.

The larger ship (& drive) is more efficient. That the same drive uses different amount of fuel in different sizes of ships is not considered. The LBB2 system is very simplistic.

Yet it is good enough that we are discussing it forty years later.

I do call it those things. And because of that, I feel entitled to exploit other arbitrary features of the setting to work around the arbitrary impediments in ways that foster internal consistency.

Yes, that is what we do in RPGs. We make house rules when we don't like the official rules. But that does not make your house rules how the official system works.

You don't like the official rules? Fine!
You change them with house rules? Fine!
You say that is how the official rules should work? Nope.



Why am I so pigheaded about this? Because the carried amount of fuel is a major check on spacecraft performance. If we can get away with carrying less fuel our ships are much more efficient than published ships, basically making all other ships useless (well, hopelessly inefficient). It's still too easy to build better ships...

So, in order to maintain compatibility with published ships, other referees, and forums like this I use the standard fuel rules strictly. And complain like a broken record when you say you can carry less fuel under the official rules.

 

[kilemall]

You have way too much power plant fuel. It only needs 40Td, not 160 (LBB2 needs 10 tons per PN, not 10% per PN).

Drop tanks and making like it's a Seeker (counting the fuel shortfall against Jump fuel to keep the 4-week power plant fuel reserve, on paper), then never bothering to install the drop tanks, gives you a "legal" way to use the 3-week fudge.

Two points:
1. The drop-tank dodge can't work for J-1 ships. By analogy it should, but we're only talking 5-10 tons at most (for LBB2 ships) so it's a moot point.

2. It could possibly be stretched to a "2-week fudge", but unless you're building an XBoat (see the spoilered part of my post upthread) that might be as far as you ought to go..

Well that's embarrassing, I think you're right. Circle back to do this again in a sec.

 

[robject]

... I don't subscribe to rule system mysticism. It's perfectly legitimate to use LBB5 to build Scouts or Free Traders [...]

Rules matter if we're doing art. We declare our basis and submit our work for constructive criticism. e.g. Correcting one's reading of the construction rules used, and suggesting alternative rules.

* * *

HOWEVER:

For ALL of the games I've ever refereed, a starship built using ALMOST ANY rule system could be brought in line with the Traveller assumptions of my game.

I mean, heck, they could have had a Far Trader built using Space Master ship design rules (I glanced at one of its design sheets once, and I swear it looked like a highly modified variant of High Guard...).

** As long as we could evaluate the design sheet and map its effects from Space Master ship-nature to Traveller ship-nature, it would've been perfectly fine.

(THERE's a challenge to anyone who owns Space Master)

 

[whartung]

Rules matter if we're doing art.

Correct, rules only matter as a baseline for comparison. So, like, you said, "here's what I squeezed out using XXX rules". If you freely change the rules, that baseline is void.

They're also important in competition.

Other than that, they're essentially not important.

I don't ever seem to see threads about the differences between a 40 and 50 gallon water heater in a house design, or even whether to go tankless or not.

Even though houses fill a similar role as ships.

 

[kilemall]

Corrected freehand-



[FONT=arial,helvetica]Quick freehand LBB2 400-ton Scout Transport J-4. M-3.


H Jump 45 tons
F Maneuver 11 ton
H Power 25 tons
Fuel Jump 160 tons
Fuel Month 40 tons
Bridge 20 tons
Computer 4 tons
4 Turrets/FC 4 tons
Staterooms 40 tons[/FONT]
[FONT=arial,helvetica] Cargo 50 tons[/FONT]
[FONT=arial,helvetica]Emergency berth 1 ton
[/FONT]
[FONT=arial,helvetica]
MUCH MUCH more comfortable margins.
[/FONT]
[FONT=arial,helvetica]
[/FONT]
[FONT=arial,helvetica]I went as high as 10 staterooms because I figure anyone going cross sector or more will NOT be getting off at most stops and is important enough to need protection including the 4 turrets. Big enough to haul black globes or other time critical gear, otherwise normally priority mail, people and resources.[/FONT]
[FONT=arial,helvetica]
[/FONT]
[FONT=arial,helvetica]Since the maneuver to 3-G was so cheap and already powered, went ahead and added it in.
[/FONT]
[FONT=arial,helvetica]
[/FONT]
[FONT=arial,helvetica]Higher computer models, armor, power particularly if using double fire or something like plasma/fusion are justifiable since this is all Imperial priority cargo/people.[/FONT]
[FONT=arial,helvetica]
[/FONT]
[FONT=arial,helvetica]Now let's try fitting into a 300-ton economodel using LBB2. I am assuming rather the opposite of the rules lawyers, you exceed 200 tons you are rated on the 400-ton line.[/FONT]
[FONT=arial,helvetica]
[/FONT]
[FONT=arial,helvetica][FONT=arial,helvetica]H Jump 45 tons
F Maneuver 7 ton
H Power 25 tons
Fuel Jump 120 tons
Fuel Month 40 tons
Bridge 20 tons
Computer 4 tons
4 Turrets/FC 3 tons
Staterooms 24 tons[/FONT][/FONT][FONT=arial,helvetica] Cargo 11 tons[/FONT]
[FONT=arial,helvetica]Emergency berth 1 ton[/FONT]
[FONT=arial,helvetica]
[/FONT]
[FONT=arial,helvetica]Had to drop 3-G back to 2-G, and still get knocked back to 6 staterooms and 11 tons cargo. Almost doesn't seem worth it.[/FONT]
[FONT=arial,helvetica]
[/FONT]
[FONT=arial,helvetica]On the power plant fuel being rendered superfluous the bigger you go item, it should be pointed out that the bridge minimum has the same effect.[/FONT]
[FONT=arial,helvetica]
[/FONT]
[FONT=arial,helvetica]Finally if you play the power plant powerdown fuel game, it should be an engineering roll to speed up crash powering to part/full power faster then the one turn per level, with failures causing potentially damage and/or shutdown. TANSTAAFL.
[/FONT]
[FONT=arial,helvetica] [/FONT]

 

[Grav_Moped]

Rounding tonnage up to the next listed size (150->200, 500->600, 1250->2000, etc.) for drive performance calculations is standard LBB2.
Jump fuel consumption is by actual tonnage. (150Td uses 15Td*Jn per jump.)
Powerplant fuel consumption is by Pn (not tonnage) but Pn is determined by hull tonnage. A Size B powerplant in a 150Td hull is Pn-2 (stats as if it were in a 200Td hull) and uses 20Td fuel/month. In a 250Td hull it's Pn-1 (stats as if it were in a 400Td hull) and uses 10Td fuel/month.

 

[aramis]

LBB5 is a lot more sensible, but has the same arbitrary 4-week power plant fuel minimum. It's just not as noticeable because of the much lower fuel burn rates in LBB5 ACS sized-ships. That said, a fixed standard minimum endurance is not unreasonable for ships designed as combatants.

But the fundamental issue is that using LBB5 where LBB2 is called for is cheating.

Bk5 specifies that all components from Bk2 remain available with their specified performances. It does NOT say you can't use it with smaller than 5KTd ships... just the opposite, even.

A HG XBoat is simple...

Td MCr Item
020 00½ Bridge
005 020 JD4
008 024 TL 13 PP
004 000 PP Fuel
040 000 Jump Fuel
008 001 Staterooms ×2
004 030 Computer Model 4
011 000 Cargo
=== ===
100 075 Totals

now, if we want to have the claimed massive computer banks from the descriptions...
15 tons of computers and max model 7. We can only get to 14 tons by big....
a model 5 and a model 7.
But, per storage point?
Let's math...
Mod 1: 4 per ton (4s/1Td) TL5
Mod 2: 3 per ton (6s/2Td TL7
Mod 3: 3 per ton (9s/3Td) TL9
Mod 4: 3¾ per ton (15s/4Td) TLA
Mod 5: 5 per ton (25s/5Td) TLB
Mod 6: 5 per ton (35s/7Td) TLC
Mod 7: ~5½ per ton (50s/9Td=5.55555) TLD
Mod 8: 6.3636363 per ton (70s/11td) TLE
Mod 9: ~6.9230 per ton (90s/13Td)

So import that TL 14 Model 8 as a data computer. Perhaps houserule a data variant that's 1/2 cost, and has 0 CPU but adds twice the lost CPU to Storage... and can be accessed by any specified at construction other computer onboard?

But we probably should consider a variant computer line that's neither sensor nor jump enabling. For that, T20 is our friend... because it's canonical.

The computer can be a model 4111 at 1.3 Td, and MCr2, TL10.
Data computers are model 4001 at at 0.6 Td and MCr0.5 each, fitting in the 13.7 tons available. Which means 22 of them. This changes the costs by -28 (for the flight unit) and +11 for a net MCr -17... MCr58, 1 ton cargo, perfectly legal design, and really an odd duck. LOADS of bandwidth at short range.

(All HG-80 legal designs are in fact T20 legal designs, but not the reverse, due to the computer and airframe changes.)

 

[Grav_Moped]

...
Yes, that is what we do in RPGs. We make house rules when we don't like the official rules. But that does not make your house rules how the official system works.

You don't like the official rules? Fine!
You change them with house rules? Fine!
You say that is how the official rules should work? Nope.



Why am I so pigheaded about this? Because the carried amount of fuel is a major check on spacecraft performance. If we can get away with carrying less fuel our ships are much more efficient than published ships, basically making all other ships useless (well, hopelessly inefficient). It's still too easy to build better ships...

So, in order to maintain compatibility with published ships, other referees, and forums like this I use the standard fuel rules strictly. And complain like a broken record when you say you can carry less fuel under the official rules.

I am indeed saying that this is how the rules should work.
You make a good case that they don't work like that.
It still doesn't convince me.

The way I see it, following the black-letter rules lets you ignore power plant fuel use -- just refuel every 28 days and you can do whatever you want. Interplanetary trips, visiting asteroid belts, whatever, just so long as you can get to a refueling point by day 28. Heck, even if you're dealing with an extreme case of a world orbiting inside its star's 100D limit where getting in and out takes a few weeks, I'd say that's enough fuel even if the whole trip lasts more than a month, since LBB2 never mentions the issue. Obey rules-as-written and you get the benefit of the doubt.

Most ships should be (and are) designed to that criterion for valid in-universe reasons, and also for the out-of-universe reason that it saves a lot of bookkeeping and math. This is a role-playing game, after all.

I'm ok with rules-as-implied, in addition to the rules-as-written. The Type Y can do a normal interstellar flight with as little as two weeks of fuel on board, which implies that only two weeks fuel supply is necessary to do so. The LBB2 fuel use rules (even without reaching out to TCS) imply that fuel consumption rates for a given standard-size power plant aren't fixed. These are why I think the rules should work as I'm suggesting. But that's not the end point.

The end point is that while the implied rules are valid, using them instead of the black-letter rules takes you outside the "safe harbor" wherein the benefit of the doubt lies. This means that instead of presuming there's enough fuel for a flight, it's necessary to do the calculations to see if that trip is possible using standard procedures (this should be on the players, the referee need only check the math and the assumptions). If it's not, it's not possible without a plausible explanation -- perhaps a couple of days acceleration followed by coasting for a couple of weeks completely powered-down, running the life support (but not artificial gravity!) off batteries until powering back up for the braking maneuver. Referees can have fun with this if the players haven't thought it out ahead of time, and to some extent even if they have...

Spoiler

- 0-G disorientation checks at each meal until they get the hang of it. Minor failures just make a mess, critical failures are medical emergencies (choking) or a glob of liquid floats into electronics and does damage.
- 0-G disorientation checks at each bathroom visit until they get the hang of it. Eww...
- Is the ship even set up for extended habitation without artificial gravity? Showers aren't going to work, the usual food supplies don't lend themselves to meal prep in 0-G so it's emergency rations for you... There will be an emergency 0-G porta-potty in the ship's locker, but see above.
- Spend long enough in 0-G and it'll affect Str and End, at least temporarily. Dex will be affected for a while (wait, things fall down again now?)
- Passengers aren't going to tolerate this without a really steep discount to the fare -- and likely, not even then.

 

[Grav_Moped]

Bk5 specifies that all components from Bk2 remain available with their specified performances. It does NOT say you can't use it with smaller than 5KTd ships... just the opposite, even.

A HG XBoat is simple...

Spoiler

Td MCr Item
020 00½ Bridge
005 020 JD4
008 024 TL 13 PP
004 000 PP Fuel
040 000 Jump Fuel
008 001 Staterooms ×2
004 030 Computer Model 4
011 000 Cargo
=== ===
100 075 Totals

now, if we want to have the claimed massive computer banks from the descriptions...
15 tons of computers and max model 7. We can only get to 14 tons by big....
a model 5 and a model 7.
But, per storage point?
Let's math...
Mod 1: 4 per ton (4s/1Td) TL5
Mod 2: 3 per ton (6s/2Td TL7
Mod 3: 3 per ton (9s/3Td) TL9
Mod 4: 3¾ per ton (15s/4Td) TLA
Mod 5: 5 per ton (25s/5Td) TLB
Mod 6: 5 per ton (35s/7Td) TLC
Mod 7: ~5½ per ton (50s/9Td=5.55555) TLD
Mod 8: 6.3636363 per ton (70s/11td) TLE
Mod 9: ~6.9230 per ton (90s/13Td)

So import that TL 14 Model 8 as a data computer. Perhaps houserule a data variant that's 1/2 cost, and has 0 CPU but adds twice the lost CPU to Storage... and can be accessed by any specified at construction other computer onboard?

But we probably should consider a variant computer line that's neither sensor nor jump enabling. For that, T20 is our friend... because it's canonical.

The computer can be a model 4111 at 1.3 Td, and MCr2, TL10.
Data computers are model 4001 at at 0.6 Td and MCr0.5 each, fitting in the 13.7 tons available. Which means 22 of them. This changes the costs by -28 (for the flight unit) and +11 for a net MCr -17... MCr58, 1 ton cargo, perfectly legal design, and really an odd duck. LOADS of bandwidth at short range.

(All HG-80 legal designs are in fact T20 legal designs, but not the reverse, due to the computer and airframe changes.)

Yes, it's simple in LBB5. It also makes LBB5 mandatory if you want to keep XBoats in CT post-'77, at least as they're described in canon.

That said, something like an XBoat is possible in LBB2 '81 if you use implied fuel burn rates and disregard the 4-week power plant fuel requirement.
Since the 4-week minimum is not dictated by operational constraints, it's undoubtedly dictated by a regulation.
The entity operating XBoats (the Imperium) is also the one making that regulation, and surely can exempt itself from it.

LBB2 '81 "XBoat"

Tons  MCr   Description
20    0.5   Bridge 
 4   30     Mod/4 Computer 
 2    0.5   Half-Stateroom  
15   20     Jump Drive B (J4)  
 7   16     Power Plant B (Pn=4)  
 0    0     No Maneuver Drive  
40    0     Jump Fuel (Jump-4) 
10    0     Fuel for 1 week Pn 4 
 0   20     Hull (minimum hull cost, custom nonstreamlined)
 2   TBD    Payload
Totals:    
100   88.0

The only item not explicitly described in LBB2 is the half-stateroom, but it's implied by the existence of double-occupancy and the Small Craft Cabin. (TCS authorizes it explicitly.)

If the possibility of Jump running "overtime" (the +/-10% duration variation) requires proportionate additional power plant fuel use, make 1Td of payload into 1Td fuel tankage.

The resulting small data bank could explain why XMail is so costly and must be in text form...

Also note that with the worst-case fuel requirement (+10% jump duration), it cannot have both 1Td payload and a maneuver drive; otherwise, some house-ruling becomes necessary to carve payload out of other components.

Now, take all that as a demonstration that the '81 rules didn't prohibit an operational equivalent to the '77 XBoat.
Then, use the +/-10-20% deckplan error rule to draw it oversized, and artistic license to fit the second stateroom and data banks into the deckplans.
Voila! '77 XBoat under '81 rules.

Yes, of COURSE it's cheating. But it's a different kind of cheating

Instead of violating the revised drive requirement rules in '81, it's just got a few extra tons of setting fluff stuffed into the hull.

 

[Spinward Flow]

The way I see it, following the black-letter rules lets you ignore power plant fuel use -- just refuel every 28 days and you can do whatever you want. Interplanetary trips, visiting asteroid belts, whatever, just so long as you can get to a refueling point by day 28.

The Type Y can do a normal interstellar flight with as little as two weeks of fuel on board, which implies that only two weeks fuel supply is necessary to do so.

Man, you are SO hung up on this point, aren't you?

You keep trying to imply/rule that the requirement is for 4 weeks of power plant operational reserve AFTER accounting for any time/weeks spent in jump space ... while the rest of us keep telling you it's the design requirement for operational reserve BEFORE accounting for any time/weeks spent in jump space. If the jump+4 MORE weeks interpretation were true, the basic requirement would be for 5+ weeks of power plant fuel for starships, not just merely 4.

1 week of jump + 4 weeks of operations = 5 weeks total
2 weeks of jump + 4 weeks of operations = 6 weeks total

I honestly cannot understand why this extremely simplistic concept eludes your interpretation. It's not like the power plant shuts down during jump weeks or anything.

You should be thinking about it like this.

• 4 weeks of required minimum power plant operations.
  During this time you can do any of the following:
  • Jump to other star systems (takes one week and sufficient fuel)
  • Interplanetary travel (time varies, covered by power plant fuel)
  • Conduct business (time varies)
  • Go sightseeing (time varies)
  • Etc.

You keep trying to ADD 4 weeks onto the time spent in jump ... when what you should be doing is starting at 4 weeks and SUBTRACTING the time spent in jump from those 4 weeks to calculate the remaining operational duration after having made those jumps.

4 weeks - 1 jump = 3 weeks of operations remaining before needing to refuel
4 weeks - 2 jumps = 2 weeks of operations remaining before needing to refuel

What you DO with those 2-3 weeks outside of jump space is an operational consideration for the crew to manage (as I've said before), not something the "naval architect" (who can only be a Scout who has gone to Technical School) has to manage for the crew at the blueprints stage. The designer only has to design in the required minimum reserve (4 weeks) for power plant fuel ... exactly HOW the crew uses that reserve to spend their time is THEIR business, not the ship designer's.

The 4 weeks of power plant operations is the minimum STARTING point ... not the minimum ENDING point like you keep asserting. Please recognize the implications of what you're repeatedly saying.
If you jump once or twice during those 4 weeks doesn't matter to the required minimum for power plant fuel, what matters is that you started with 4 weeks of power plant fuel ... after that, what you "do" during those 4 weeks of endurance is your own affair as a crew.

As a simple matter of Rule Of Thumb™ about these matters, I would argue that as a practical matter, the best way to think about this is that you *NEED* 1 week of power plant operations more than the number of jumps you make (so jump quantity +1), but with a minimum of 4 weeks of power plant operations as the minimum boundary. Here, I'll even do chart for you.

4 weeks power plant with 1 jump = 3 weeks of power plant operations remaining before needing to refuel
4 weeks power plant with 2 jumps = 2 weeks of power plant operations remaining before needing to refuel
4 weeks power plant with 3 jumps = 1 week of power plant operations remaining before needing to refuel
5 weeks power plant with 4 jumps = 1 week of power plant operations remaining before needing to refuel
6 weeks power plant with 5 jumps = 1 week of power plant operations remaining before needing to refuel

See the pattern?
See the 4 week basic requirement in its proper context as a minimum requirement?

Most ship designs only carry enough fuel to jump only once before needing to refuel in order to jump again ... but there's no "rule" either in the LBB or in practical terms which says you cannot carry more fuel than is needed to only jump once. The rules explicitly state minimums, not maximums. The allocation of fuel for 4 weeks (minimum!) of power plant operations is a "hard" requirement that starships, non-starships and small craft ALL must obey. That's the starting point. After that, for starships you need to add more fuel on top of this to be able to support jumps.

Of course, since fuel tankage is "fungible" between power plant and jump drives, you can get up to a few shenanigans sometimes, like I'm about to demonstrate.

Yes, it's simple in LBB5. It also makes LBB5 mandatory if you want to keep XBoats in CT post-'77, at least as they're described in canon.

That said, something like an XBoat is possible in LBB2 '81 if you use implied fuel burn rates and disregard the 4-week power plant fuel requirement.
Since the 4-week minimum is not dictated by operational constraints, it's undoubtedly dictated by a regulation.
The entity operating XBoats (the Imperium) is also the one making that regulation, and surely can exempt itself from it.

LBB2 '81 "XBoat"

Tons  MCr   Description
20    0.5   Bridge 
 4   30     Mod/4 Computer 
 2    0.5   Half-Stateroom  
15   20     Jump Drive B (J4)  
 7   16     Power Plant B (Pn=4)  
 0    0     No Maneuver Drive  
40    0     Jump Fuel (Jump-4) 
10    0     Fuel for 1 week Pn 4 
 0   20     Hull (minimum hull cost, custom nonstreamlined)
 2   TBD    Payload
Totals:    
100   88.0

The only item not explicitly described in LBB2 is the half-stateroom, but it's implied by the existence of double-occupancy and the Small Craft Cabin. (TCS authorizes it explicitly.)

In this specific instance I would simply "reverse" the power plant and jump fuel amounts. So you would have 40 tons for the power plant and only 10 tons for the jump drive (enough for a Jump-1, not a Jump-4, I know). Since fuel tankage is recorded as the total, you have 50 tons of fuel and can meet the minimum requirements for the power plant. The performance profile then becomes:

4 weeks of operations - jump1 week = 3 weeks of operations remaining
4 weeks of operations - jump2 week = 2 weeks of operations remaining
4 weeks of operations - jump3 week = 1 week of operations remaining
4 weeks of operations - jump4 week = 0 weeks of operations remaining (Rescue Me Express Tender!)

It's an edge case that relies on the Express Tender system to recover (rescue) XBoats after they Jump-4 and have exhausted their entire fuel reserve during that 1 week of jump. For any other type of ship, breakout after jump with no fuel reserves is a death sentence, since without a way to refuel (and thus maneuver), you're basically stranded ... adrift ... in deep (hopefully interplanetary!) space. However, if there's a "rescue" service nearby your breakout from jump point, they can get to you in time and replenish your ship so you don't actually, you know ... DIE in space. :toast:

Of course, with no maneuver drive, XBoats need to be rescued/recovered by Express Tenders anyway. It's just that there's more "margin" for those recoveries to happen when the XBoat has jumped 3 parsecs or less, since a single Tender can only be in one place at a time.

As for the Cabin plus 2 tons of cargo thing ... I would personally (house) rule in favor of a full stateroom and 0 tons of cargo, and simply stipulate that if vital/precious small lots of cargo need to be carried, up to a combined 1 ton (displacement) of it can be stored inside the 4 ton stateroom allowance, but the specific "modules" of the cargo needs to be something that can be hand carried in through a sliding door and stowed stacked on the floor, rather than being a "bulk" cargo container of 1 ton dimensions (it's not a "proper" cargo bay). So the "cargo capacity would be up to 1 ton (possible) provided the items that make up that cargo are less than 1 ton each (so a pair of 0.5 ton cargo items would fit into that 1 ton, for example). The crewman needs to give up 1/4 of their living space to do it though, so it's going to be a bit more cramped than usual for the week of that trip.

Likewise, you can transport 1 passenger (possible) using double occupancy for the stateroom during jump week (and until recovered by an Express Tender). Just realize that it's going to be VERY cramped living conditions if you try to transport 1 passenger AND 1 ton of (possible) cargo at the same time. It can be done if the need is that compelling, but would NOT be standard operating procedure. The habitable volume of the XBoat would be ... the bridge and the stateroom, plus any drive compartment space used for maintenance ... so not a lot of space to work with if a passenger gets unruly during jump week.

 

[AnotherDilbert]

HOWEVER:

For ALL of the games I've ever refereed, a starship built using ALMOST ANY rule system could be brought in line with the Traveller assumptions of my game.

Sure, if we only consider that ship. If we just have a deck plan we can make up stats.

But it tends to make all other ships silly inefficient, or the imported ship is silly inefficient.


I enjoy some internal consistency in my games.

 

[AnotherDilbert]

[FONT=arial,helvetica]
Now let's try fitting into a 300-ton economodel using LBB2. I am assuming rather the opposite of the rules lawyers, you exceed 200 tons you are rated on the 400-ton line.
[/FONT]

But as you may notice it is barely cheaper than the 400 Dt version since it uses the same drives, yet it has very little payload.

The 400 Dt version is a little bit more expensive, and much better capacity, making it generally a better buy.

 

[AnotherDilbert]

I'm ok with rules-as-implied, in addition to the rules-as-written.

The problem is that that is entirely subjective and indistinguishable from house-rules to some others.

Example: When we look at the fuel rules I see the implied rule "small ships are less efficient" and you see an implied rule about fuel reserves, and we both disagree with the other. Likely we are both wrong...

Pretty soon you are playing a different game.

When we then discuss the game with other gamers we have different understandings about what game we are playing, and often completely misunderstand each other.

Which is I prefer to declare anything questionable openly as house-rules, and preferably out of forums such as this.

 

[Grav_Moped]

Man, you are SO hung up on this point, aren't you?

You keep trying to imply/rule that the requirement is for 4 weeks of power plant operational reserve AFTER accounting for any time/weeks spent in jump space ... while the rest of us keep telling you it's the design requirement for operational reserve BEFORE accounting for any time/weeks spent in jump space. If the jump+4 MORE weeks interpretation were true, the basic requirement would be for 5+ weeks of power plant fuel for starships, not just merely 4.

1 week of jump + 4 weeks of operations = 5 weeks total
2 weeks of jump + 4 weeks of operations = 6 weeks total

I honestly cannot understand why this extremely simplistic concept eludes your interpretation. It's not like the power plant shuts down during jump weeks or anything.
...

The problem with that "extremely simplistic concept" is that the mandatory 4-week requirement is exactly the same amount for ships without jump drives. Non-starships don't get credit for an extra week of power plant fuel for not jumping. 0 weeks of jump + 4 weeks of operations = 4 weeks total. That only works out if the power plant really does shut down during jump.

As for the Cabin plus 2 tons of cargo thing ... I would personally (house) rule in favor of a full stateroom and 0 tons of cargo, and simply stipulate that if vital/precious small lots of cargo need to be carried, up to a combined 1 ton (displacement) of it can be stored inside the 4 ton stateroom allowance, but the specific "modules" of the cargo needs to be something that can be hand carried in through a sliding door and stowed stacked on the floor, rather than being a "bulk" cargo container of 1 ton dimensions (it's not a "proper" cargo bay). So the "cargo capacity would be up to 1 ton (possible) provided the items that make up that cargo are less than 1 ton each (so a pair of 0.5 ton cargo items would fit into that 1 ton, for example). The crewman needs to give up 1/4 of their living space to do it though, so it's going to be a bit more cramped than usual for the week of that trip.

The 2Td (Tons displacement) "payload" consists of the message data banks called for by the ship's design brief. Those data banks certainly could be carved out of the bridge tonnage allocation by house rule, if needed. I went with the half-stateroom instead because I'm keeping the "take it out of the bridge allocation" option in reserve -- it's arguable that up to 2 more Td of fuel might be called for*. Of course, if those 2Td of fuel aren't needed, you could use your house rule to free up the space to make it a full stateroom.

Likewise, you can transport 1 passenger (possible) using double occupancy for the stateroom during jump week (and until recovered by an Express Tender). Just realize that it's going to be VERY cramped living conditions if you try to transport 1 passenger AND 1 ton of (possible) cargo at the same time. It can be done if the need is that compelling, but would NOT be standard operating procedure. The habitable volume of the XBoat would be ... the bridge and the stateroom, plus any drive compartment space used for maintenance ... so not a lot of space to work with if a passenger gets unruly during jump week.

I'd even argue you could steal some lifesystem space from the drive bay outright. This ship doesn't need an engineer, so perhaps there aren't any user-serviceable parts to the drives and there's no internal access to them at all. Maintenance access is through exterior hatches and removable hull panels (like the engines on jetliners rather than the engines in steamships).


Footnote:
*Jumps can last up to 7.7 days (the +/-10 variation). If the power plant needs to run for 10% longer than the nominal one week, that's 1Td more fuel needed. If it can't run off batteries until the tender gets there and the power plant can't be idled down it needs another 1Td of fuel for 16 hours of operation -- yes, that's saying it uses a gigawatt of power just floating there in space with the lights and HVAC running (1 LBB5 EP is 250MW according to Striker rules).

I don't think either of these are the case.

IMTU the power plant stops feeding energy to the jump drive at the 90% time increment (6.3 days) and the jump field is allowed to decay on its own. This happens at some point between "immediately" and "1.4 days later" (the +/-10% interval) unless the ship has misjumped. Shutting power off early increases the odds of a mishap, while keeping the power on past the 90% mark makes no difference in when the jump field collapses. The power plant still uses 7 days worth of fuel, though.

Also IMTU (but backed by the example of the International Space Station), ships can run life support for quite a while on batteries if they shut off their artificial gravity. The ISS's power requirements per pressurized Td equivalent are basically a rounding error when measured in High Guard Energy Points.

 

[Grav_Moped]

The problem is that that is entirely subjective and indistinguishable from house-rules to some others.

Example: When we look at the fuel rules I see the implied rule "small ships are less efficient" and you see an implied rule about fuel reserves, and we both disagree with the other. Likely we are both wrong...

Pretty soon you are playing a different game.

When we then discuss the game with other gamers we have different understandings about what game we are playing, and often completely misunderstand each other.

Which is I prefer to declare anything questionable openly as house-rules, and preferably out of forums such as this.

Just to clarify a little:
The implied rule you're discussing is that power plants are less efficient in small hulls, not that small ships themselves are less efficient. Note that hull size does not affect Jump Drive fuel efficiency, and it only affects Maneuver Drives to the extent that they need power plants. It doesn't speak to fuel reserve requirements at all, until one brings in the JTAS#14/TCS power-down rule.

The one I'm arguing here with the Yacht and XBoat Loopholes is that the fuel allocation rules -- both in LBB2 and LBB5 -- describe both a minimum fuel requirement and a fuel consumption rate. The rate is presumably due to the engineering/physics of the power plant. The minimum requirement doesn't align with the rate and standard practices, so it's by definition arbitrary. (The LBB2 XBoat with 52 Td fuel is legal as a Jump-1 ship with a very oversized jump drive, illegal as a Jump-4 ship despite having enough fuel to complete a Jump-4 with a small safety margin. Arbitrary.)

In the first edition, it did align (if I remember right). Every jump regardless of distance used fuel based on the jump drive capability, not jump distance (no jump governor), and every trip used all of the power plant fuel. The Type S couldn't do a Jump-1 outbound then another Jump-1 to return without refueling in the first place, so the exact fuel burn didn't matter. It mattered when implicit jump governors (they were explicit, separate hardware in HG '77) became standard in LBB2 2nd Ed.

 

[whartung]

Sure, if we only consider that ship. If we just have a deck plan we can make up stats.

But it tends to make all other ships silly inefficient, or the imported ship is silly inefficient.

Inefficient at what? Compared to what? And in what way does any of this inefficiency actually manifest in the play environment of the actual game?

 

[AnotherDilbert]

Inefficient at what? Compared to what? And in what way does any of this inefficiency actually manifest in the play environment of the actual game?

If we import something vaguely like a Free Trader but it has J-3 and 150 Dt cargo space, it would be much more efficient than a Free Trader at being a Free Trader.

Having 150 Dt cargo instead of the default ~80 Dt it would be much more profitable, so not forcing the characters to take side missions to make ends meet, i.e affecting game play.

Given the opportunity to upgrade their "Free Trader" to a Subbie, they would scoff at it and ask why they would want such a bad ship, barely any more cargo and only J-1?

Yes, it is an extreme example, but it hopefully illustrates what I mean.

 

[AnotherDilbert]

Just to clarify a little:
The implied rule you're discussing is that power plants are less efficient in small hulls, not that small ships themselves are less efficient. Note that hull size does not affect Jump Drive fuel efficiency, and it only affects Maneuver Drives to the extent that they need power plants.

That is a distinction without a difference since all drives, hence all ships, need a power plant.