OTU Only: Gypsy Queen Class Fast Merchant, LBB2, 199Td, J26GP7

[Spinward Flow]

Then it isn't following a formula.

The TL=15 drives, rather egregiously, break the established pattern used throughout the rest of the table.

And THIS is rather obviously a TYPO error ... but some people would rather not admit it as a possibility.

If there is a formula being used to produce the results in the table, it works consistently for drives A-V and tonnages 100-4000 just fine.

Drive-V = 20 * 200 = 4000
4000 / 600 = 6.66666667 ... drop fractions to yield an integer result = 6
4000 / 800 = 5
4000 / 1000 = 4
4000 / 2000 = 2
4000 / 3000 = 1.5 ... drop fractions to yield an integer result = 1
4000 / 4000 = 1

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Try doing it for the W-Z drives and the answers just go ... WACKY.

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Drive-W = 21 * 200? = 4200?
4200 / 600 = 7 ... therefore, code: -
4200 / 800 = 5.25 ... drop fractions to yield an integer result = 5
4200 / 1000 = 4.2 ... drop fractions to yield an integer result = 4 ... but the table has an entry of 5

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So the only way that the Drive-W "works" as shown in the table is if Drive-W is code: 1 @ 5000 tons ... a +1000 tons increment step from the prior Drive-V.
Except, even THAT fudge doesn't work correctly!

Drive-W = 5000
5000 / 600 = 8.33333333 ... therefore, code: -
5000 / 800 = 6.25 ... drop fractions to yield an integer result = 6 ... but the table has an entry of 5
5000 / 1000 = 5
5000 / 2000 = 2
5000 / 3000 = 1.66666667 ... drop fractions to yield an integer result = 1
5000 / 4000 = 1.25 ... drop fractions to yield an integer result = 1
5000 / 5000 = 1

---

If the drive formula changes from +200 per letter from A-V to being +1000 per letter from V-Z ...

• Drive-W (code: 1 @ 5000 tons) has one table error entry @ 800 tons (should be 6, but it's only 5)
• Drive-X (code: 1 @ 6000 tons) has one table error entry @ 800 tons (should be - instead of 6, because 6000/800=7.5)
• Drive-Y doesn't work as code: 1 @ 7000 tons, but it does work as code: 1 @ 8000 tons ... except ...
  • Drive-Y (code: 1 @ 8000 tons) creates TWO table entry errors!
  • @ 800 tons (should be - instead of 6, because 8000/800=10)
  • @ 1000 tons (should be - instead of 6, because 8000/1000=8)
• Drive-Z can only work as code: 1 @ 12,000 tons(!) ... except ...
  • Drive-Z (code: 1 @ 12,000 tons) creates TWO table entry errors!
  • @ 800 tons (should be - instead of 6, because 12,000/800=15)
  • @ 1000 tons (should be - instead of 6, because 12,000/1000=10)

See if you can spot the pattern break in this progression (@ TL=15, of course ):

1. A = 200 ... TL=9
2. B = 400 ... TL=9
3. C = 600 ... TL=9
4. D = 800 ... TL=9
5. E = 1000 ... TL=A
6. F = 1200 ... TL=A
7. G = 1400 ... TL=A
8. H = 1600 ... TL=A
9. J = 1800 ... TL=B
10. K = 2000 ... TL=B
11. L = 2200 ... TL=C
12. M = 2400 ... TL=C
13. N = 2600 ... TL=C
14. P = 2800 ... TL=D
15. Q = 3000 ... TL=D
16. R = 3200 ... TL=E
17. S = 3400 ... TL=E
18. T = 3600 ... TL=E
19. U = 3800 ... TL=E
20. V = 4000 ... TL=F
21. W = 5000 ... TL=F
22. X = 6000 ... TL=F
23. Y = 8000 ... TL=F
24. Z = 12,000 ... TL=F

No wonder the "magical Drive-Z" is SO MAGICAL!
It's 3x the performance of the Drive-V (the last "sane" drive that "respects" the rest of the table) for only +4 increments on the drive tonnage and cost table!

In other words ... the "magical Drive-Z" ... CHEATS LIKE A MOFO to produce its performance yield ... according to a table that can't even "play by its own rules" consistently. It's pure munchkinism, plain and simple ... and it's been sitting there this entire time, since 1977/1981 ... unquestioned, because it is RAW.

 

[Grav_Moped]

And THIS is rather obviously a TYPO error ... but some people would rather not admit it as a possibility

Not necessarily a typo. As I noted above, it's rounded up by 10% to the next integer instead of rounded down as with the rest of the (internally-consistent part of the) table. After piling all the bonus performance onto the TL-15 drives, that's a trivial "gimmie" by comparison.

In other words ... the "magical Drive-Z" ... CHEATS LIKE A MOFO to produce its performance yield ... according to a table that can't even "play by its own rules" consistently. It's pure munchkinism, plain and simple ... and it's been sitting there this entire time, since 1977/1981 ... unquestioned, because it is RAW.

It's like that because it's the only way to get more-than-token performance out of the largest hulls on the table, without the table itself either spilling onto the next page, or turning it sideways on a page.

 

[Grav_Moped]

It's like that because it's the only way to get more-than-token performance out of the largest hulls on the table, without the table itself either spilling onto the next page, or turning it sideways on a page.

Here's what that corner of the table would look like if the TL-15 drives were "normal":
(This is the lower right corner of the table with the X and Y axes swapped.)

Note that Drives V are TL-14, not 15. [Edit: V is also TL-15.]
I mean, at that point the only drive bigger than V that matters is Z in an 800Td hull. Everything else yields the same performance as the V drives.

Drive/Tons	800	1000	2000	3000	4000	5000
V	5	4	2	1	1	-
W	5	4	2	1	1	-
X	5	4	2	1	1	-
Y	5	4	2	1	1	-
Z	6	4	2	1	1	-

 

[Spinward Flow]

Note that Drives V are TL-14, not 15.

Not according to LBB3.81, p15 ...

Also, if you count the letters for each tech level, an interesting pattern emerges.

TL=9 ... 4
TL=A ... 4
TL=B ... 2
TL=C ... 3
TL=D ... 2
TL=E ... 4
TL=F ... 4

I'm thinking that the pattern of 4.4.2.3.2.4.4 being a palindrome is not a coincidence.

 

[Grav_Moped]

Not according to LBB3.81, p15 ...

Right. Doesn't change much but it's a fair catch. I'd actually had it correct in my spreadsheet but un-did it because it didn't seem right. Guess it was.

There's a performance step between the U (TL-14) and V (TL-15) drives, but as noted, all the drives V-Z have the same performance in each hull increment 800+ except that Z will yield 6 in 800Td where the others only yield 5.

I'm thinking that the pattern of 4.4.2.3.2.4.4 being a palindrome is not a coincidence.

"Able was I ere I saw tech levels"? Nah, that's not right...

 

[Grav_Moped]

There's a performance step between the U (TL-14) and V (TL-15) drives, but as noted, all the drives V-Z have the same performance in each hull increment 800+ except that Z will yield 6 in 800Td where the others only yield 5.

I think (but am not really motivated to try to sort it out) that it's an artifact of the scale changing from 200Td increments to 1000Td increments. There'd be a bit more variety in ratings in the "un-bonused V-Z range" if they'd kept to the 200Td intervals -- at the cost of adding over a dozen rows that nobody would ever use. (Need a 1400Td ship, anyone? 3200Td? No? Didn't think so.)

 

[Grav_Moped]

I'm just going to note that I now understand why they felt they could and should stuff bonus performance into the last 4 columns of the drive performance table: if you don't, you're pretty much wasting them because they exactly duplicate the V drive column (except for drive Z, which has 6 instead of 5 in 800Td).

For consistency, those drives ought to be sized and priced at the level of their performance (like a double-sized un-bonused Z drive or whatever instead of just following the trend up from drives A-U). But that's well outside the scope of this...

 

[AnotherDilbert]

Here's what that corner of the table would look like if the TL-15 drives were "normal":
(This is the lower right corner of the table with the X and Y axes swapped.)

Don't just look at the drives, look at the total ship.

The drives, the drive table, the 20 Dt bridge, and the PP fuel requirement all work together to make small (= low tech) ships less efficient and large ships (=high tech) ships more efficient.

Take J-2 (&M-2) ship:

Free usable space "Payload" as a percentage of the ship increases as the size and TL increases, and the cost of the ship per Dt payload decreases.
The 5000 Dt ship is IIRC the only J-2 ship that is profitable at standard freight rates.

It's much the same at J-4:

The negative payload indicates that we can't really make effective ships under 400 Dt with J-4.
We can make a J-4 ships with TL-10 drives, but we need TL-12 drives and 600 Dt to be marginally effective.


And finally at J-6 we can only make usable ships with TL-15 drives:

The only really useful J-6 ship is the 2000 Dt Z drive ship, essentially the Type TJ.

 

[AnotherDilbert]

I'm just going to note that I now understand why they felt they could and should stuff bonus performance into the last 4 columns of the drive performance table: if you don't, you're pretty much wasting them because they exactly duplicate the V drive column (except for drive Z, which has 6 instead of 5 in 800Td).

It just mirrors the larger steps in hull sizes. The drive potential table is compressed on both axles.

 

[atpollard]

I'm just going to note that I now understand why they felt they could and should stuff bonus performance into the last 4 columns of the drive performance table: if you don't, you're pretty much wasting them because they exactly duplicate the V drive column (except for drive Z, which has 6 instead of 5 in 800Td).

For consistency, those drives ought to be sized and priced at the level of their performance (like a double-sized un-bonused Z drive or whatever instead of just following the trend up from drives A-U). But that's well outside the scope of this...

Funny, the instant I looked at the progression, I thought each letter should produce J1 in a 100 dTon increment hull (A = J1 in a 100 dT hull, B = J1 in a 200 dT hull, etc) until you reach K = J1 in a 1000 dT hull, then step 1000 dTon increments to U = J1 in a 10,000 dT hull, then step 10,000 dT increments until Z = J1 in a 60,000 dT hull.
Filling in the rest of the table (same number of A-Z drives) would now allow up to J6 in a 10,000 dT hull with a Z drive!

However, I didn’t come along until The Traveller Book (1982) … so the damage was already done. I just moved on the High Guard for ship design.

 

[AnotherDilbert]

And THIS is rather obviously a TYPO error ... but some people would rather not admit it as a possibility.

Or perhaps someone thought the table looked neater this way, or someone had a favourite design, or something...
Either way that is the way it was printed (& reprinted) and used for decades.

In other words ... the "magical Drive-Z" ... CHEATS LIKE A MOFO to produce its performance yield ... according to a table that can't even "play by its own rules" consistently.

Quite, so why do you think nothing else in the system can be inconsistent?

 

[atpollard]

Either way that is the way it was printed (& reprinted) and used for decades.

Only maybe. I asked about an actual ship design that used that drive in that hull and nobody knew of any.

So intended or errata may have little actual consequence. If nobody ever placed that drive in that hull … then these pages of debate on “errata” vs “RAW” is really closer to “How many angels can dance on the head of a pin?” in importance.

 

[AnotherDilbert]

Only maybe. I asked about an actual ship design that used that drive in that hull and nobody knew of any.

Published, official design...

So intended or errata may have little actual consequence. If nobody ever placed that drive in that hull …

Of course someone somewhere made a 2000 Dt J-1 ship...

IIRC GravMoped made one a few years ago because it was slightly more efficient than other J-1 ships?

 

[Grav_Moped]

Don't just look at the drives, look at the total ship.

My point was that if the TL-15 drives don't get that performace boost, there's no point to any drive larger than V, except for Z in an 800Td hull. Otherwise, V drives yield the maximum available performance and the others merely match them at greater size and cost (and 5000 ton ships aren't possible).

It just mirrors the larger steps in hull sizes. The drive potential table is compressed on both axles.

It's only compressed by rating, not by drive cost/tonnage. That is, the ratings by letter get compressed (with boosted ratings shoved into those columns) but the drives themselves aren't.

There's a jump from 200Td increments to 1000Td increments, but no corresponding jump from, say, a 40EP power plant to an 80EP power plant in the next letter step (nor, if it's direct compression, from 61Td and MCR160 -- size V -- to the 121Td and MCr320 that a "W that's actually a Double-V"* power plant should have).


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* dual-language pun not intended but I'll go with it.