The Compleat LBB2 Ship Design

[AnotherDilbert]

No, you stated that I am wedded to the idea that the LBB2 drive is a fusion rocket, which I am not.

Not quite, I said "... I grasp that you really want": It's a statement about my mind, not your mind.

It is most likely some sort of super advanced ion/plasma engine that also makes use of null grav technology

Ok, that that is your position is more than I have grasped before.

It is stated it is a reaction drive, and it therefore must use reaction mass, ...

Not quite, it must fulfil Newton's Third, i.e. create "an equal and opposite reaction". Expelling propellant is the simplest case, but a drive accelerating a nearby planet through the gravity field is also a reaction drive.

... and since there is only liquid hydrogen or fusion products available to be that reaction mass you have to take your pick between those two. Since there is no mention of venting fusion products or having them stored and then dealt with at a starport it is a safe assumption that it is the fusion plasma products that provide the reaction mass.

I would not go so far as that. LBB2 does not mention fusion at all. It's an easy guess when hydrogen is the only fuel, but still a guess.

Fusion would consume minute amounts of matter, and produce minute amounts of fusion products. Venting them wouldn't be very noticeable, or worth remarking on.

As you state the fuel used is not enough to give a ship the performance stated -

Not quite, it's not remotely enough fuel for a chemical rocket, but if we accelerate any expelled propellant to high enough speed (ludicrous speed, but SciFi...) it might be enough. Hence I have suggested it might be some sort of ion drive.

A larger ship would of course consume proportionally more propellant, unlike the power plant fuel requirement.

but since this is 77/79 a ship ton is still the equivalent to 1000kg of mass.

Agreed, as used in my calculations in the last post.
Edit: Agreed for LBB2'77, not LBB5'79:

LBB5'79, p33:
3. Volume: When referring to starship tonnage, one ton equals 14 cubic meters; the volume of one ton of liquid hydrogen. Two 1.5 meter squares, from deck to ceiling, occupy approximately one ton.

Either the plasma reaction mass has to be ejected at near c, or the mass of the ship has to be reduced by null grav tech.

Expelling propellant at ludicrous speed is a lot more likely than changing mass, something that would be out there with jump drives as impossible with current understanding of physics. There is no hint that I can see that normal Traveller tech can achieve that miraculous feat.

Military ships obviously use much larger m-drives (look at the size difference between LBB2 and HG) so they can use the plasma/fusion exhaust as a weapon.

LBB5'79 does not limit that to LBB5 designs, LBB2 ships are equally capable of doing that.

LBB5 is not just for military ships, it's for large ships, small ships, and even small craft.

 

[robject]

LBB5 is not just for military ships, it's for large ships, small ships, and even small craft.

While true, its primary purpose is for Big Ship design and operations, and specifically defers to Book 2 as the standard for small starships.

Regardless, it was generally more convenient in the 80s to just use HG -- not just with large ships, but also what with the new components that come with HG that CAN be used with Book 2, but aren't IN Book 2.

Hence, this thread.

 

[aramis]

So we are back to what you read and infer is right, and when others read and infer they are wrong.

You're inferring from things absent...
Bk2-77 doesn't specify maneuver fuel for standard drives on starships. At least not in any of the 3 printings I've seen of it. (One of which is the electronic from FFE.)
B2-77 p. 5-6 only requires PP fuel & Jump fuel, but only maneuver fuel for small craft; p. 17 contradicts p. 5-6 slightly, noting non-starship burn 10kg per 10 G×Minutes.so standard jump drives can and should be presumed to negate a fuel need to maneuver... as the distinction of a "non-starship" is use of maneuver fuel... but note as well, no standard designs are large craft non-starships. So we can't establish for certain which is intended... it's a quantum superposition.

CT Beltstrike Belter's Handbook p. 11, upper left: fuel use rate for maneuver contradicts both...0.002 tonnes per hour which is 30× more efficient than Bk 2-77 - and lists basic power as 0.05 tonnes per week... so, given the LS limit of 4 weeks, any Bk2 ship is using 0.2 tonnes per month for PP, and leaving the rest of the 10Pn for maneuver fuel. 0.002*24=0.048+0.0096=0.0576/day so an M1 merchant is able to get 9.8/0.0576=176.x days of maneuver...
The numbers don't make much sense... But they're canonical.

So, given the beltstrike numbers... a ships LS good for 4 weeks, but maneuver for 24.5 weeks... emergency low berths now make a lot more sense to me... set an inbound course, lock the autopilot, and have the computer wake you when someone's within an hour of intercept or you're an hour out... To be honest, I think the numbers in Beltstrike are actually quite compelling if used as a rate per 100 Td of hull, but that's seriously houseruled turf.

And Bk2-77 notes on p. 17 that large non-starships cost half but require maneuver fuel, and cannot be modified for a jump drive later. So, it's a pretty clear indicator that a jump drive has some mitigating effect on maneuver fuel and require a different and more expensive system overall.

It's not the game I learned (as I started with CT 3LBB-81 and TTB), but it also doesn't read as the game you seem to remember.

Then again, Beltstrike is J. Andrew Kieth & John Harshman, while 3LBB-77 is Marc edited by Loren with input from Frank and the playtesters - but the only credit is "Game Designer's Workshop"...

Likewise, in CT-81, Non-starships don't get that 50% discount, and don't require maneuver fuel.
Until Beltstrike, at least. (1984)...

CT is a bit of a mess... because there are so many different PoVs in canon.

 

[whartung]

And none of this suggests a rocket of any kind. Rather it simply suggests that when you use power it consumes fuel and that, all things considered, the M-Drive consumes a lot of power.

"Better" would a be DTon/MW (or MW hour) conversion rate for the plant, and then a MW consumption for the devices (Jump, Maneuver, microwave in the lounge). But that's way, way, way to fiddly to keep track of at play, so wisely tossed in the bin.

I haven't played Beltstrike, but it seems to me that fuel is introduced there as it must have some discernible impact on play. Perhaps keeping detailed fuel records (and thus costs) are important to the hard scrabble life of a Belter.

So, given the beltstrike numbers... a ships LS good for 4 weeks, but maneuver for 24.5 weeks... emergency low berths now make a lot more sense to me... set an inbound course, lock the autopilot, and have the computer wake you when someone's within an hour of intercept or you're an hour out... To be honest, I think the numbers in Beltstrike are actually quite compelling if used as a rate per 100 Td of hull, but that's seriously houseruled turf.

If going in to low berths and shutting down the ship save you enough money to be able to pay your Air Tax when you dock at the space station, then its a viable mechanic indeed. I just don't know how tight the budgets are in the game.

Otherwise the mechanic is just a flavor thing.

Later, this is all pretty resolved as M-Drives were little different from light bulbs and fusion power produces silly amount of energy at effectively no cost in the big picture of things.

 

[mike wightman]

The CT M-drive is a reaction drive. That means you are dumping stuff out the back.
It consumes fuel, 288 turns worth before it can no longer accelerate. It is a logical assumption that the reaction mass is hydrogen, which is why your accelerations are limited.
Also note you have to pay for your pp fuel for every trip, not every four weeks, every trip.
Beltstrike backs up fuel being used as reaction mass
HG79 flat out states the M-drive can function as a fusion weapon at close range thus it is dumping fusion products out the back at high velocity.

I stand by my interpretation - that and the authors flat out stated that the M-drive was intended to be a reaction drive when HEPlaR was introduced for TNE.

 

[Silverhawk]

But does it go through the power plant first? If so, it would likely be Helium and other fusion reaction products.

 

[Grav_Moped]

The CT M-drive is a reaction drive. That means you are dumping stuff out the back.
It consumes fuel, 288 turns worth before it can no longer accelerate. It is a logical assumption that the reaction mass is hydrogen, which is why your accelerations are limited.
Also note you have to pay for your pp fuel for every trip, not every four weeks, every trip.
Beltstrike backs up fuel being used as reaction mass
HG79 flat out states the M-drive can function as a fusion weapon at close range thus it is dumping fusion products out the back at high velocity.

I stand by my interpretation - that and the authors flat out stated that the M-drive was intended to be a reaction drive when HEPlaR was introduced for TNE.

My interpretation of the "at least 288 turns" of fuel is that they meant it as a statement that on a normal interstellar flight (between two size-eight worlds, full-stop before jump), engaging in combat wouldn't run a starship out of fuel, period. Small craft were an entirely different matter, of course.

B2-77 p. 5-6 only requires PP fuel & Jump fuel, but only maneuver fuel for small craft; p. 17 contradicts p. 5-6 slightly, noting non-starship burn 10kg per 10 G×Minutes.so standard jump drives can and should be presumed to negate a fuel need to maneuver... as the distinction of a "non-starship" is use of maneuver fuel...

If you carry forward the small craft fuel burn rates, the 10Td per Pn allocation provides for just about 7 days of constant maximum acceleration.
(16.67g*hours/ton)*10 tons=166.7 hours or 6.94 days. I don't think that's a coincidental result; rather, that "7 days of full maneuver" was considered enough for whatever you'd be doing with a starship -- and the exact endurance was swept under the rug by saying it was all used each trip regardless of actual manuvering, as with Jump fuel and jump distance.

Yeah, not scaling it to tonnage is a fatal flaw in the system, but it's what they used back then.

 

[aramis]

The CT M-drive is a reaction drive. That means you are dumping stuff out the back.
It consumes fuel, 288 turns worth before it can no longer accelerate. It is a logical assumption that the reaction mass is hydrogen, which is why your accelerations are limited.
Also note you have to pay for your pp fuel for every trip, not every four weeks, every trip.
Beltstrike backs up fuel being used as reaction mass
HG79 flat out states the M-drive can function as a fusion weapon at close range thus it is dumping fusion products out the back at high velocity.

I stand by my interpretation - that and the authors flat out stated that the M-drive was intended to be a reaction drive when HEPlaR was introduced for TNE.

Frank, Loren, and Dave did. I don't recall Marc saying so.

 

[aramis]

My interpretation of the "at least 288 turns" of fuel is that they meant it as a statement that on a normal interstellar flight (between two size-eight worlds, full-stop before jump), engaging in combat wouldn't run a starship out of fuel, period. Small craft were an entirely different matter, of course.

If you carry forward the small craft fuel burn rates, the 10Td per Pn allocation provides for just about 7 days of constant maximum acceleration.
(16.67g*hours/ton)*10 tons=166.7 hours or 6.94 days.

But it only requires it for non-starships. Starships have no B2-77 fuel need for MD. Which very strongly says J-drive makes M-drive different. As does the half-cost for large craft non-starships. Starships do not need maneuver fuel; non-starships do. Black letter B2-77.

 

[Grav_Moped]

But it only requires it for non-starships. Starships have no B2-77 fuel need for MD. Which very strongly says J-drive makes M-drive different. As does the half-cost for large craft non-starships. Starships do not need maneuver fuel; non-starships do. Black letter B2-77.

You're overthinking this.

There's no need for a starship to have a power plant, except if it has a maneuver drive. If it does have a maneuver drive, it has to have a power plant; that power plant has to have fuel, that -- just coincidentally, mind you -- works out to a solid week of maneuver fuel as described elsewhere in the rules.

Flavor text might not make it explicit, but the underlying mechanics do.

EDIT TO ADD: the higher cost of starship hulls likely includes embedded jump grids (or equivalent technobabble).
It also suggests that non-starships (with their non-starship hulls) can't be carried externally on starships. Or drop tanks, either, for that matter.

 

[Grav_Moped]

You're overthinking this.

There's no need for a starship to have a power plant, except if it has a maneuver drive. If it does have a maneuver drive, it has to have a power plant; that power plant has to have fuel, that -- just coincidentally, mind you -- works out to a solid week of maneuver fuel as described elsewhere in the rules.

Flavor text might not make it explicit, but the underlying mechanics do.

EDIT TO ADD: the higher cost of starship hulls likely includes embedded jump grids (or equivalent technobabble).
It also suggests that non-starships (with their non-starship hulls) can't be carried externally on starships. Or drop tanks, either, for that matter.

(replying to self rather than deleting since, it's already posted)

Let me re-word that :
A starship only needs a power plant if it has a maneuver drive. That power plant requires fuel that, coincidentally, works out to be a solid week of maneuver fuel as described elsewhere in the rules.
Nonstarships need power plants and maneuver drives. The nonstarship fuel allocation is identical to that of that for starships with equivalent maneuver capability.

 

[robject]

Frank, Loren, and Dave did. I don't recall Marc saying so.

I think Frank is the source of the reaction-y elements of e.g. 1977 and HG1.

 

[aramis]

I think Frank is the source of the reaction-y elements of e.g. 1977 and HG1.

I strongly suspect so.

(replying to self rather than deleting since, it's already posted)

Let me re-word that :
A starship only needs a power plant if it has a maneuver drive. That power plant requires fuel that, coincidentally, works out to be a solid week of maneuver fuel as described elsewhere in the rules.
Nonstarships need power plants and maneuver drives. The nonstarship fuel allocation is identical to that of that for starships with equivalent maneuver capability.

Non-Starships require PP, MD, PPFuel, and MDFuel.
Sharships require a PP, MD, JD, PPFuel, and JDFuel.

And, by extension, since the non-starship costs half overall (not just hull, not just hull and drives), that means special PP, MD, SR, Weapons, Computers, and bridge, as well as the hull.
You''re not taking into account all the evidence.

REQUIRED STARSHIP COMPONENTS
Most starships are constructed using one of the six basic standard hulls, and into this hull is then fitted the other required components, including drives and power plants, life support equipment, hardpoints for armaments, computers and other
items.

The Engineering Section: Each starship is fitted with a power plant (to provide internal power and power for the maneuver drive), a maneuver drive (for interplanetary travel), and a jump drive (for interstellar jumps).

There is no in-rules provision for no MD installed.
The X-boat doesn't exist in the Bk2 rules to provide counterpoint until the '81 version, which is different in MANY ways more than I thought this time 2 days ago...

 

[Grav_Moped]

I strongly suspect so.

Non-Starships require PP, MD, PPFuel, and MDFuel.
Sharships require a PP, MD, JD, PPFuel, and JDFuel.

What is the MD fuel allocation for a non-starship, over and above that required for the power plant?

And, by extension, since the non-starship costs half overall (not just hull, not just hull and drives), that means special PP, MD, SR, Weapons, Computers, and bridge, as well as the hull.
You''re not taking into account all the evidence.

Half overall? I'll believe it, but it seems a bit extreme.

There is no in-rules provision for no MD installed.
The X-boat doesn't exist in the Bk2 rules to provide counterpoint until the '81 version, which is different in MANY ways more than I thought this time 2 days ago...

It existed in S9. Was S9 published at a point in 1981 prior to the release of LBB2'81? Was it introduced in S9, or did it appear earlier?

Because it's an illegal build, RAW, in '81. It's technically legal (if you disregard the description of required components that you quoted), as described, only under '77. (Or as a different ship built at TL-13 under LBB5, or possible as a different rules-breaking but functional J4/0G with 51Td fuel under '81.)

 

[AnotherDilbert]

The CT M-drive is a reaction drive. That means you are dumping stuff out the back.

If you want it that way, that is the way your game works, absolutely.

But why go out of your way to say that the book says so, when it's questionable at best?

 

[AnotherDilbert]

I haven't played Beltstrike, but it seems to me that fuel is introduced there as it must have some discernible impact on play. Perhaps keeping detailed fuel records (and thus costs) are important to the hard scrabble life of a Belter.

It's not about the money, it's about mission duration. You spend months out in the belt looking for and inspecting asteroids.

Interesting idea, but about as much fun as watching paint dry...

 

[AnotherDilbert]

Non-Starships require PP, MD, PPFuel, and MDFuel.
Sharships require a PP, MD, JD, PPFuel, and JDFuel.

Starships require PP fuel, small craft require MD fuel. Nothing requires both.

Large non-starships are a grey area, I would assume they use the same drives and fuel requirements as starships, despite the cost reduction.

 

[AnotherDilbert]

Half overall? I'll believe it, but it seems a bit extreme.

Yep.

LBB2'77, p17:
The above are standard designs; other non-starships may be designed in accordance with the starship design rules, but leaving out the jump drive. Such vessels may not be converted to take a jump drive at a later time. Construction cost is calculated at 50% of the price for a similarly equipped starship.

That was of course removed from all later editions...

 

[AnotherDilbert]

It consumes fuel, 288 turns worth before it can no longer accelerate.

That's a step too far. It says:

LBB2'77, p5-6:
A fully fuelled power plant will enable a starship an effectively unlimited number of accelerations (at least 288) if necessary to use the maneuver drive during the trip (as when miniatures combat is used to resolve a ship to ship encounter).

Not exactly 288, at least 288, meaning more than 287. It does not say 288 turns and you're out of luck. There might be a limit, but it's not exact.

The rest of the book sticks with "effectively unlimited".


If we look at irrelevant outside sources:

Starships use hyperspace jumps to move along jump routes, or travel just below light speed to move using the map hex grid (at one hex per turn). Fighters and missile boats (due to their small size and lack of endurance) may not use sublight movement.

Boardgame Imperium, p4.
Starships seem to be able to accelerate and keep the PP running for years...

 

[aramis]

What is the MD fuel allocation for a non-starship, over and above that required for the power plant?

10 kg per gee per 10 min.

As for Sup 9... ©1981.
But it's also in Sup 7, ©1980. It's an illegal design either way...
Under 1981, it's lacking the PP. So it's an not a starship. it's lacking the MD of a Non-Starship (aka Big Craft), and it's too big to be a small craft...
Under 1977, it's lacking the MD. So it's neither a starship nor a non-starship.
It can be argued to be, under CT rules, "A plot device masquerading as a starship designed to create engagement amongst afficionados."

The Engineering Section: Drives are installed in the engineering section. A non-starship must have a maneuver drive and a power plant. A starship must have a a jump drive and a power plant; a maneuver drive may also be installed, but is not required.

Sup 7 notes that it's JD subsumes PP function.

But in 1979 we have HG-79...

HG79 Td		HG-80 Td
20	Bridge	20
1	PP 1 (79) or 4 (80)	8
2	MD 1	2
5	JD 4 (TL D)	5
1	PP FUel	4
40	JD Fuel	40
5	Model 7 (TL D)	9
8	2×Stateroom	8
18	Data Banks?	4

From a "Bk 5 doesn't depracate Bk 2" perspective, there's zero reason to have the X-boat be a Bk2 broken design, when a much more capable machine is generatable by the timeframe available Bk 5 (either edition, tho' 79 is much more forgiving.