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The Compleat LBB2 Ship Design

Reaching waaay back:
A 5000 ton starship using the same fuel consumption (scaled up) as a 50 ton small craft would need 100 times as much fuel, or 100 kg fuel per minute = 1 ton per turn. With a power plant fuel allotment of 10 tons it would be able to accelerate at 1 G for 10 turns. It certainly would not have any "at least 288 accelerations" worth of reaction mass.
Except that in '77, they were using a ludicrously unrealistic "flat rate per G-turn" fuel burn rate that explicitly did not scale up by hull size. That 5KTd'er was literally using the same fuel consumption as a 50Td small craft of the same acceleration. A poorly-thought-out rule (bigger vessels are more fuel efficient) that turned into magic at the high end, though at the low-to-middle range of Adv-Class Ships it wasn't quite as implausible. It's probably worth noting that the fuel use rates from LBB2 and LBB5 match at 1KTd, while also noting that all of the ships in LBB2 are less than 1Ktd (and even Kinunir is only 1250Td).
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".
And it is effectively unlimited. At small craft burn rates (10kg/G-turn), 10Pn gives you a week of continuous full-power acceleration.

You don't need more than that, since if the trip would take longer than a week, you might as well jump. Go ahead and jump. (Youtube, and you're welcome)

And since you don't need more than that, just handwave the situations where the math would dictate that you would actually need more -- and then hide the actual fuel use by ruling that you write off the whole tankful every trip.

Worst case total trip time -- covered by the handwave -- is then two weeks (gas giant to gas giant), no power plant fuel burn during jump ('77). HG'79 says there's a power plant and it runs at full power during jump, so worst case trip time then becomes three weeks. Now, add in the normal-space runs from the mainworld to the gas giant on each end -- partially nerfing the handwave -- and you're up to four weeks. Works for HG, well enough that that it stays unchanged in HG'80.

Backport the 4 weeks to LBB2'81 and there you go. What was once 1 week of full power operation for the maneuver drive alone, had now become 4 weeks of power for the entire ship. Of course, the fuel requirement was still based on the original '77 rules that didn't scale fuel use by ship tonnage, but it looked like they'd fixed it because suddenly it did four times as much with the fuel as it did in the first edition.
 
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Reaching waaay back:

Except that in '77, they were using a ludicrously unrealistic "flat rate per G-turn" fuel burn rate that explicitly did not scale up by hull size. That 5KTd'er was literally using the same fuel consumption as a 50Td small craft of the same acceleration.
Flat rate for small craft.

Ships had no specified fuel burn rate.
 
Flat rate for small craft.

Ships had no specified fuel burn rate.
Of course they didn't. But if you apply the small craft burn rate to starships, the numbers come out close enough to handwave -- and they did handwave them with the "write all the power plant fuel off every trip" rule. I think it fits together, even if the rules didn't commit to it.

The key is that the starship power plant fuel was also flat rate.
 
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Flat rate for small craft.

Ships had no specified fuel burn rate.
Space ships do - it says so in the design rules, but again I do not have an electronic copy of 77 edition so I will leave it to others to find the quote in the n-n-starships section page 17.
(ok out with the magnifying glass and the torch)

"Space-going vessels that do not have jump drive are classed as non-starships...
other non-starships may be designed in accordance with the starship design rules, but leaving out the jump drive...
All non-starships {that includes your own bespoke designs in the 100 to 5000t range} consume fuel at the rate of 10 kilograms (1/100th of a ton {yet more evidence that one starship ton was originally 1000kg} for each g of acceleration for ten minutes, regardless of the mass or cargo carried."
the italics in parentheses are my thoughts
 
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Space ships do - it says so in the design rules, but again I do not have an electronic copy of 77 edition so I will leave it to others to find the quote in the n-n-starships section page 17.

LBB2'77, p5-6:
_ _ 1. Fuel. Starship fuel costs CR 500 per ton (refined) or CB 100 per ton (unrefined),
at most starports. Fuel consumption is based on formulae related to the size of the starship power plant and the jump drive.
_ _ A power plant, to provide power for one trip (internal power, maneuver drive power, and other necessities) requires fuel in accordance with the formula: 10Pn. Pn is the power plant size rating, determined from the maximum drive potential ta- ble by cross-referencing power plant letter and hull size. The formula indicates amount of fuel in tons, and all such fuel is consumed in the process of a normal trip. 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).
_ _ A jump drive requires fuel ...
_ _ Fuel is also used by the maneuver drives of non-starships. When used in such vessels displacing under 100 tons (ship's boats, shuttles, pinnaces, etc) 10 kilograms (1/100th of a ton) of fuel is sufficient for 1G of acceleration for 10 minutes.
Starships require power plant fuel.
Small craft require M-drive fuel.
Large non-starships not exactly specified.


LBB2'77, p17:
_ _ Shuttle: Access to planetary sur ... uum. Base price for a shuttle is CR 33,000,000.

_ _ 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 calcu- lated at 50% of the price for a similarly equipped starship.

_ _ All non-starships consume fuel at the rate of 10 kilograms (1/100th of a ton) for each G of acceleration for ten minutes, regardless of mass or cargo carried.
_ _ A non-starship described above can support its passengers for up to 30 days in space. Beyond that time, air, food and water begin to run out. The passenger capacity cannot be increased, due primarily to design constraints, and potential overload of life support equipment. At the end of 30 days, throw 9+ each day to prevent the recycling machinery from breaking down. If it does fail, it must be repaired on the same day (throw 9+ to repair; DM: +1 per level of mechanical expertise, once per day) or the air is exhausted and the passengers will suffocate.
At a guess that applies to the small craft described, not "all non-starships", despite the wording.


If all ships from 20 Dt to 5000 Dt use the same reaction mass, I'll discard that silly rule system immediately, but that is only my opinion of course.
 
If all ships from 20 Dt to 5000 Dt use the same reaction mass, I'll discard that silly rule system immediately, but that is only my opinion of course.
It looks like they did.
And that was officially discarded in HG1, so they're right along with you.
LBB2'80 kept the allocation rule for backward compatibility, but changed what it meant.
 
I'm not claiming it is, no more than Belter or Double Star, but it does show the evolution of ship to ship combat and the intent.

Triplanetary - LBB2 77 - HG 79 all reaction drive M-drive
As we've pointed out before, you're making a leap that isn't well supported.
Pulling non-canon as defense for a weak position is, fundamentally, dishonest. It's not even forbidden canon, a la DGP... it's not part of Traveller.

It is a direct parallel to trying to derive T2K setting information from Boots and Saddles and/or Johnny Reb... It's a denial of the intelligence and creative capability of the designers involved to reduce them to having a single intent across unrelated designs.
 
If all ships from 20 Dt to 5000 Dt use the same reaction mass, I'll discard that silly rule system immediately, but that is only my opinion of course.
I can see a justification for it... the fuel being funneled into a mass to energy high efficiency conversion and then generating a pulsinng KK drive (AD Foster's Humanx Commonweath setting, aka the Flinx series)...
And that's the kind of obscure handwavium that would seem to fit my experiences of Marc's sense of humor...
It's the same issue in Beltstrike, BTW.
 
It's the same issue in Beltstrike, BTW.
No, it's scaled:
Beltstrike, Belter's Handbook, p5:
The fuel consumption table on page 11 shows the raquirements of various types of maneuvering in terms of fuel use per hundred tons of ship. Basic power is used at at! times, including when maneuvering. Every maneuver matching course with an asteroid, for instance) uses at least one hour's fuel at the 1G rate.
 
You are done in this thread. Any further participation in it is, by your own statement, a waste of your and others time.
As we've pointed out before, you're making a leap that isn't well supported.
Pulling non-canon as defense for a weak position is, fundamentally, dishonest. It's not even forbidden canon, a la DGP... it's not part of Traveller.

It is a direct parallel to trying to derive T2K setting information from Boots and Saddles and/or Johnny Reb... It's a denial of the intelligence and creative capability of the designers involved to reduce them to having a single intent across unrelated designs.
You can point out as much as you like, I consider my interpretation and inferences to be true, you and others do not. You will not convince me, and I will not convince you.

As to using Triplanetary, it shows how Marcs thoughts developed over time, I'm not likely to use En Guarde to justify ship combat, but I may do to draw parallels with game developments in other areas of game evolution. As to similar intend, many GDW games are based on the same intent across unrelated designs. There are certain design elements that crop up in game after game that GDW produced, similar mechanics, and I am talking here beyond their RPG output and into their wargames.

The facts remain the facts - the game authors intended 77 LLB2 M-drives to be reaction drives.
 
Fuel use in Trplanetary is handled in a similar way to smallcraft in Mayday, mayday ships are the equivalent of torchships in Triplanetary.
Perhaps if golden age sci fi had been a little more scientifically rigorous in its description of magical ship drives we could have got a 'harder science' drive for Traveller, I have toyed with making the jump fuel requirement the M-drive fuel.
 
So 10kg per 1g per 600 seconds per 100,000kg of ship...

I wonder what the exhaust velocity would have to be...

For small craft I'd normalise to 50 tonnes, but OK.

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A cutter is 50 tonnes, 4 G, and 15 tonnes of fuel.
It consumes 0.04 tonnes of fuel per 10 min.
4 G for 15 / 0,04 = 375 turns so 375 × 10 × 60 = 225000 s.
Total ∆v is 40 m/s² × 225000 s = 9 000 000 m/s.

ve = ∆v / ln m0/mf = 9000000 / ln 50/35 ≈ 25 Mm/s = 25 000 km/s so almost relativistic.

Supposing all the fuel mass is reaction mass, and the energy for free.

Somewhere in that region?
 
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