Variant: Reintroducing CT:Book 2 (v.'81) Jump Drives into the OTU

[whulorigan]

In another thread, the following posts were made:

CT'77 limited the drive performance to 1-6 for all drives depending on the size of hull it was put in.
TL allowed you to build certain drives, eg TL9 drives A-G (TL10 is required for a type H drive) and those drives could achieve performance 6 in smaller hull sizes. Oh and there was a rule that you couldn't have drive performance over 6 with these drives...
Point - a TL 9 culture can build ships with jump 1-6 (there was no computer restriction back then either, you just had to be able to run the jump 6 program which takes up 2 spaces)
The OTU setting has adopted the HG derived drive TL paradigm where you don't access higher jump numbers until higher TLs - so there is a rules/setting disconnect right there.

CT 81 is similar, but not quite the same.
You have to have a computer model at least as high as the jump, so TL 9 is J3, TL A is J4, TL B is J5, TL C is J6, TL D+ are theoretically higher, but you can't build higher than J6 (and J7 won't fit with fuel and bridge anyway).
Also TL 9 is A-D, TL10 is E-H, 11 is J-K, 12 L-N, 13 P-Q, 14 R-U, 15 V-Z...

I also like the Book 2 (and Old Mongoose) drive tables and the Book 2/Book 3 drive TLs rather than the Book 5 (and all later Traveller) ones. This makes ship "mass" (volume technically, but presumably corresponding with mass) matter - the heavier the ship, the harder it is to accelerate it to high speeds or to throw it into distant jumps. Also, Book 3 drive TLs are much more nuanced, as you can have faster ships earlier, though they are much smaller and on the other hand on lower TLs ship size is limited; I prefer this over the linear drive progression introduced by Book 5 (which is now canonical).

I agree. And (as an aside) it probably explains why DGP noted that the Vilani of the First Imperium had a "faulty theory of jump drive", that did not allow them to produce drives greater than J-2 performance (if they were using the CT '77 / CT '81 ruleset as their basis for MT); otherwise, the Vilani should easily have been able to make J-4 by TL11 under CT '77 / CT '81 , which would break the canon-history of the Interstellar Wars period.

As an OTU-variant, I was curious as to what people's insights would be concerning the idea of reintroducing the CT '81 version of Jump Drives into the otherwise "canon" universe of the OTU (i.e. Jump-rating is NOT limited by TL, but only by TL of Drive Letter and Computer type).

What problems would it introduce with the back story or how the canon-universe functions? Could the Book 5 design system be modified to fit the paradigm, or would the hassle be significant enough to relegate it to a strictly a small-ship universe?

(Note: The idea here is Jump distance, not whether or not the Jump Drive is self-powered or powered by the Power Plant. Assume it is powered by the Power Plant for the sake of the discussion).

 

[Condottiere]

You tie the jump factor to tech level in order not to question the limitation of six or the inability of the Vilani to go beyond two.

If it's open at nine, or earlier, than some other limitation would apply.

 

[whulorigan]

You tie the jump factor to tech level in order not to question the limitation of six or the inability of the Vilani to go beyond two.

If it's open at nine, or earlier, than some other limitation would apply.

Let's assume the limitation has to do with the nature of the Jump Drive itself (similar to the T5 ruleset: You can't go beyond J6 (or J9 ?) because that would require a higher-order Jump Drive [like a Hop-Drive at TL-17]). The computer limitation and other general design constraints will still practically limit J4 at TL10, J5 at TL13, and J6 at TL15 (IIRC - Aramis once worked this out in another thread-post somewhere).

Let's keep the DGP reference that the ancient Vilani had a faulty theory of Jump Drive, limiting the First Imperium to J2 performance. And let's make a presupposition that since the Terran's had just invented the Jump Drive at TL9 by their own research, that their development curve was a little slower and it took them a TL or so before they had viable non-prototype J2 or J3.

What other issues would there be?

 

[aramis]

Let's assume the limitation has to do with the nature of the Jump Drive itself (similar to the T5 ruleset: You can't go beyond J6 (or J9 ?) because that would require a higher-order Jump Drive [like a Hop-Drive at TL-17]). The computer limitation and other general design constraints will still practically limit J4 at TL10, J5 at TL13, and J6 at TL15 (IIRC - Aramis once worked this out in another thread-post somewhere).

Let's keep the DGP reference that the ancient Vilani had a faulty theory of Jump Drive, limiting the First Imperium to J2 performance. And let's make a presupposition that since the Terran's had just invented the Jump Drive at TL9 by their own research, that their development curve was a little slower and it took them a TL or so before they had viable non-prototype J2 or J3.

What other issues would there be?

J9 in T5. Actually, until one has drop tanks (a separate discovery, tho' one quite obvious in retrospect... J8 and j9 are out of reach simply due to fuel requirements...
_2% bridge
_7% PP
_8% JD
70% JFuel
_7% PFuel
=== =====
94% Total for J7 before MD, Crew, and Payload

That said...

In a Bk2 universe without Bk5...
hull sizes are limited severely by drives available.
Hull sizes are further limited by fuel carriage capability (more so in 81 than 77)

the cheapest merchant shipping is "big" ships - 800-2000Td - check my moot blog.


In a mixed universe, the cost difference cannot be made up between Bk2-81 and bk5-80 until well over 20KTd.

This is a pricing table worked with the same 3/8 profit margin as J1... it's from my moot blog.
Rounding to next 50 Cr...
Price for Cargo per Ton per jump
Ship__ Jump Done
Doing_ __J1__ __J2__ __J3__ __J4__ __J5__ __J6__
Cargo_ _1,000 _1,000 _1,350 _1,650 _3,200 _7,300
LowPsg _1,000 _1,000 _1,100 _1,320 _2,150 _4,150 1.6
MidPsg _8,000 _7,750 _8,500 10,250 15,850 30,400
HiPsg_ 10,000 10,000 10,650 13,100 20,800 40,950

J2 under Bk2 is actually cheaper in certain hulls than J1; J3 is only slightly more.

 

[mike wightman]

Let's assume the limitation has to do with the nature of the Jump Drive itself (similar to the T5 ruleset: You can't go beyond J6 (or J9 ?) because that would require a higher-order Jump Drive [like a Hop-Drive at TL-17]). The computer limitation and other general design constraints will still practically limit J4 at TL10, J5 at TL13, and J6 at TL15 (IIRC - Aramis once worked this out in another thread-post somewhere).

Let's keep the DGP reference that the ancient Vilani had a faulty theory of Jump Drive, limiting the First Imperium to J2 performance. And let's make a presupposition that since the Terran's had just invented the Jump Drive at TL9 by their own research, that their development curve was a little slower and it took them a TL or so before they had viable non-prototype J2 or J3.

What other issues would there be?

The first thing that springs to mind is computer and max drive TL found in LBB3 - in 81 you needed a model number equal to the jump rating and drive size is limited, applying those parameters to the LBB2 drive table you find:
model 3 TL 9 drive max D - a jump 3 200t ship is doable
model 4 TL10 drive max H - a jump 4 400t ship is doable
model 5 TL11 drive max K - a jump 5 400t ship is doable
model 6 TL12 drive max N - a jump 6 ship is only doable with drop tanks (which are TL12 according to HG1 )

 

[whulorigan]

The first thing that springs to mind is computer and max drive TL found in LBB3 - in 81 you needed a model number equal to the jump rating and drive size is limited, applying those parameters to the LBB2 drive table you find:
model 3 TL 9 drive max D - a jump 3 200t ship is doable
model 4 TL10 drive max H - a jump 4 400t ship is doable
model 5 TL11 drive max K - a jump 5 400t ship is doable
model 6 TL12 drive max N - a jump 6 ship is only doable with drop tanks (which are TL12 according to HG1 )

That would also help rectify the issue of how the Aslan crossed the J-5 route across the Great Rift so long ago.

 

[Condottiere]

Maybe overclocking the drive.

 

[AnotherDilbert]

Note that GDW apparently allowed the use of Z drives at TL C.
JTAS#10: Trillion Credit Squadron Winners: Wasp class.
Perhaps only an accident?

 

[aramis]

Note that GDW apparently allowed the use of Z drives at TL C.
JTAS#10: Trillion Credit Squadron Winners: Wasp class.
Perhaps only an accident?

Judge oversight, most likely. Many fans of Bk5 are completely ignorant of the TL limits on drives in Bk 2 & 3.

 

[AnotherDilbert]

That would also help rectify the issue of how the Aslan crossed the J-5 route across the Great Rift so long ago.

Sub Merchant or Liner can cross a J-5 reft if you fill them with fuel. Just give them time...

 

[AnotherDilbert]

What problems would it introduce with the back story or how the canon-universe functions?

You'd need a bit more Referee fiat on the Terran vs. Vilani story, thats about it? Doesn't seriously affect anything in the last millennium.

Could the Book 5 design system be modified to fit the paradigm, or would the hassle be significant enough to relegate it to a strictly a small-ship universe?

The Drive Potential Table on p23 would need to be replaced with a matrix (like the LBB2 Drive Potential table p22) that indicated the minimum TL to achieve the desired performance for a given hull size.



I do not see much reason to do it in a 1105 setting, but not much of a problem either. In a TL10 - 11 setting it would certainly be interesting. Small couriers would be faster than warships, and much faster than big lumbering freighters. Fighters would come back in style. A bit of Honorverse.

 

[Condottiere]

The best way to do that would be tinkering on the temporal plane, smaller volumes move faster through the hyper ocean.

 

[AnotherDilbert]

The best way to do that would be tinkering on the temporal plane, smaller volumes move faster through the hyper ocean.

I think that would be a major change in the setting. The "one week per jump" rule is rather basic.

But if you want a different setting that would be one way of differentiating it.

 

[whulorigan]

That would also help rectify the issue of how the Aslan crossed the J-5 route across the Great Rift so long ago.

Sub Merchant or Liner can cross a J-5 reft if you fill them with fuel. Just give them time...

Oh, I am aware that it can be done (with some difficulty) using the standard drive rules with additional internal fuel capacity. I just find it interesting to speculate that perhaps when the J-5 Route was first conceived by GDW, the drive paradigm in their minds was still the earlier CT'77 or CT'81 w/o Jump-distance limitations by TL. It makes the J-5 crossing of the Rift at such an early date a little bit more practical (and economical) if it can be done at TL11-13 in single jumps.

 

[whulorigan]

You'd need a bit more Referee fiat on the Terran vs. Vilani story, thats about it? Doesn't seriously affect anything in the last millennium.
.
.
.
I do not see much reason to do it in a 1105 setting, but not much of a problem either. In a TL10 - 11 setting it would certainly be interesting. Small couriers would be faster than warships, and much faster than big lumbering freighters. Fighters would come back in style. ...

It would mean that exploration in Imperial history could have proceeded at a faster pace (theoretically - fewer small rifts as impediments), and would also mean that past and current colonial navies of lower TL worlds would have the ability to build faster and longer-ranged ships (at least in the smaller ship-size ranges typical in such fleets, unless I have overlooked something).

J1-Mains might also be less significant in trade.

 

[AnotherDilbert]

Exploration would certainly be faster, but I think colonisation and trade would still be slow. It takes fairly large ships to transport large amounts of people with equipment for colonisation. E.g. You can make a 200 dT ship with J-4 at TL9 but it would be a scout, it would have no cargo capacity.

 

[kilemall]

I apply all limits TL wise as IMTU the LBB2 engineering are standardized designs, and the oddities in fuel use are just 'design tradeoffs' between them and the custom HG2 engineering.

HG2 computers for size, general TL LBB2 for LBB2 drives.

 

[Timerover51]

Exploration would certainly be faster, but I think colonisation and trade would still be slow. It takes fairly large ships to transport large amounts of people with equipment for colonisation. E.g. You can make a 200 dT ship with J-4 at TL9 but it would be a scout, it would have no cargo capacity.

The Vikings successfully colonized Iceland and Greenland using the knorr, with a capacity of maybe 30 people and 30 to 40 tons of cargo. The New World was successfully colonized by nautical ships with a water displacement of under 1000 tons, or under 100 Traveller Displacement Tons. Colonizing requirements would be dependent on the habitability of the world being colonized, the distance to the colonizing planet, and the degree to which the colony would be expected to "boot strap" itself, by producing its own materials.

As for ship size beyond those types of vessels, the World War 2 Liberty ship was rated at 7,100 Gross Register Tons of volume, which equates to 1420 Traveller dTons of volume. Her cargo capacity was assessed at 10,800 deadweight tons of cargo, i.e. mass tons, or 11,886 measurement tons of 100 cubic feet cargo capacity. Even using Classic rules, the Liberty would not be considered a large ship, but it would deliver a lot of cargo. A WW2-era Attack Transport, Haskell-class, roughly the size of a Liberty, could carry 1,565 troops plus about 500 crew. This data comes from the FM101-10 STAFF OFFICERS' FIELD MANUAL: ORGANIZATION,TECHNICAL AND LOGISTICAL DATA PART 1 UNCLASSIFIED DATA, 1959 edition.

I would have to do some experimenting, but as a first cut, I suspect that with a 2000 to 2500 Traveller dTon hull, I could come close to approximating the cargo capacity of a Liberty and the passenger capacity of the Haskell-class. The transport would require a big boost in life-support capacity and the relaxation of the stateroom limitation. One Traveller dTon of food storage space would contain enough food to feed about 1500 people for one day, and that is quite conservative in terms of food.

Edit Note: One metric ton of WW2 5-in-1 rations, with each ration supplying about 4100 calories for one person, would feed 385 people for one day, and occupy 85 cubic feet of space. A Traveller displacement ton of 13.5 cubic meters volume would easily hold 5 metric tons of 5-in-1 rations, occupying 425 cubic feet or slightly over 12 cubic meters. The 5-in-1 ration was intended to feed 5 troops for one day using non-perishable foods. If you give me 365 Traveller displacement tons of cargo space, I will guarantee feeding 1500 people for one year, and unless they are working very hard, at the end of the year, they will be a bit heavier than when they landed. That does assume a non-Arctic climate of temperate to tropical temperatures. Arctic climates take a bit more food.

 

[Timerover51]

When making my previous comments on food, I was basing them on the US Army Ration for WW2 in terms of volume requirements and weight. The following comment comes from the Quartermaster Corps report: COMMITTEE ON FOOD RESEARCH: CONFERENCE ON FOOD ACCEPTANCE RESEARCH, convened in Chicago in December of 1945, and published in August of 1946. The quote is on page 59.

The American soldier is allowed five and one-fourth pounds of food a day or about 4500 calories. He is the best fed soldier in the world.

That is the end of war ration standard, which is what my 1959 Logistics Data is based on. Take a good hard look at the calorie figure and then look at the requirements for a sedentary adult of the present.

The early war standard was 4100 calories. As a side note, the German Army ration in 1944 was only 2800 calories, which does explain why the German PoWs thought that C-Rations were great.