OTU Only: A Funny Thing Happened on the Way from Collace

[mike wightman]

It was meant to allow fleets to jump into a system with a full Jump fuel load on arrival, so they could get back out again without having to calculate reduced Jump capability from drop tanks for each ship individually.

That is one use, but there is, as far as I can remember or find, no mention of this in a canonical source. It has been mentioned lots of time by the likes of us as a possible use for the technology.

Gazelle, TCS, HG '80, and the JTAS blurb came later.

Nope.
The JTAS blurb came out roughly the same time as LBB5 79 - which introduced drop tanks and the high capacity TL12 accumulator that allows for their use.
Your tactical explanation of a possible use for them wouldn't come up for several years after HG79/JTAS introduced drop tanks.

 

[mike wightman]

That was the intent as of Book 5. Weren't they imported from one of the fleet battle games? (Imperium or FFW)?

No.
Only Imperium predates HG79/JTAS 2 and refueling in that game makes no mention of drop tanks since it has a completely different jump paradigm (in fact the tanker units manufacture fuel from the outer layer of stars)

 

[Grav_Moped]

So they meant to allow Gazelle (and by extension, other short-fueled starships) from the get-go. Hmmn.

This canonized a TL-15(?) droptank 100Td J6 XBoat. (It'd be only 130Td or so at TL-15 under HG 80 without drop tanks -- so why bother making it less than 100? Just to save having a Navigator, or is it not TL-15?)

Did they notice at the time, or care, that also meant J6/6G* in 200Td with a 120Td drop tank at TL-12 by grandfathering in LBB2, though?


* you can have 6G. You probably don't need it.

 

[mike wightman]

The Gazelle is designed using a weird design system. It superficially resembles 79HG but there are element of HG80 and the description of how to use the particle accelerator barbettes for LBB2 combat mentions treating them as heavy lasers - shame there is no mention of a heavy laser in any edition of CT I have.

A jump 6 xboat as mentioned in JTAS2 would be buildable under 77LBB2 rules with the simple addition of drop tanks from the HG79 rules and so would be TL12 due to the necessary special capacitors.

As to did they notice did they care - nope. GDW didn't use their own rules to describe the setting, and didn't recognise the consequences of changing rules which are meant to be reflected in the setting.

It wouldn't be until MT that the rules and setting are totally unified, in that the rules describe the setting.

 

[AnotherDilbert]

The Gazelle is designed using a weird design system. It superficially resembles 79HG but there are element of HG80

Looks like a bog standard LBB5'79 ship, except the rating of the PA on the turret column, rather than bay?

CE-44444C2-900600-40400-0        MCr 351         240 Dton
bearing                                           Crew=12
batteries                                           TL=15
                               Cargo=12 Fuel=16 DropT=160

Dual Occupancy                                       12     350,9
                                     USP    #      Dton      Cost
Hull, Part Streaml  Custom             2            240          
Configuration       Close Structure    4                     14,4
Scoops              Partial                                   0,2
Armour              9                  9             15         6
                                                                 
Drop Tanks          160                                       0,2
Total tonnage       400                                          
                                                                 
Jump Drive                             4    1        20      80,5
Manoeuvre D                            4    1        48      28,8
Power Plant                            4    1        16        64
Fuel, #J, #weeks    J-4, 4 weeks            4        16          
Purifier                                    1        15       0,1
                                                                 
Bridge                                      1        20       1,2
Computer            m/3fib             C    1         6        27
Software                                                     34,4
Staterooms                                  8        32         4
                                                                 
Cargo                                                12          
                                                                 
Bay                 Particle           9    2        10        12
Turret-3 Beam       1 Turret           4    2         2         8
                                                                 
Nuclear Damper                         6    1         8        38
                                                                 
Launch              20 Dton                 1        20        32
                                                                 
Nominal Cost        MCr 350,88           Sum:        12     350,9
Class Cost          MCr  66,96          Valid        ≥0        ≥0
Ship Cost           MCr 287,1

and the description of how to use the particle accelerator barbettes for LBB2 combat mentions treating them as heavy lasers - shame there is no mention of a heavy laser in any edition of CT I have.

It's right there in JTAS:

They are a variant drawn from the material in High Guard, and grafted onto Book 2. Specifically, the barbettes are 5 tons each. The particle accelerators should be treated as heavy lasers as in Traveller Book 2, subject to an advantageous DM of +2 to hit. Damage from such hits should be skewed toward crew casualties, and electronic and computer damage if there is no fibre optic back-up present.

 

[mike wightman]

Please tell me the stats of a heavy laser in LBB2?

Every printing of CT I have mentions pulse lasers and beam lasers but no heavy laser.

 

[AnotherDilbert]

Only Imperium predates HG79/JTAS 2 and refueling in that game makes no mention of drop tanks since it has a completely different jump paradigm (in fact the tanker units manufacture fuel from the outer layer of stars)

Imperium sounds remarkably similar to Traveller:

Starships may, depending on specific capabilities, move through space at just below lightspeed using sublight movement, or may use hyperspace jumps along jump routes.
...
Hyperspace jumps involve movement directly between stellar hexes at faster than light speeds.
...
The ship making the jump does not actually enter the intervening hexes, and cannot be affected by forces in those hexes.

Refueling: All ships use hydrogen as fuel for their thermonuclear reactors. This may be supplied from the oceans of a habitable planet or from the atmosphere of a gas giant.

Tankers are only needed in a specific systems that lacks planets to refuel from.

It's even published in the same year, and developed by the same people, as Traveller...

 

[AnotherDilbert]

Please tell me the stats of a heavy laser in LBB2?

It's right there in JTAS:

..., subject to an advantageous DM of +2 to hit. Damage from such hits should be skewed toward crew casualties, and electronic and computer damage if there is no fibre optic back-up present.

 

[whartung]

I loathe drop tank threads.

I'm "pro" fuel shuttle as I see them as not much more than as a better built drop tank with a motor to get out of the way in time for jump.

 

[mike wightman]

It's right there in JTAS:

No, it's not.

JTAS says to treat it as a LBB2 heavy laser - which does not exist. I ask again, where are the stats of a LBB2 heavy laser?

You even quoted it:

treated as heavy lasers as in Traveller Book 2, subject to an advantageous DM of +2 to hit

Note the position of the comma.
They should be treated as heavy lasers - which do not exist - with a +2 to hit.

Is a heavy laser a beam laser which does one hit, is it a pulse laser that does two hits?

 

[mike wightman]

Imperium sounds remarkably similar to Traveller:

But not exactly the same, fleets can only follow jump routes, no empty hex jumps until Dark Nebula.

Tankers are only needed in a specific systems that lacks planets to refuel from.

Yup and you didn't quote the interesting bit:

Tankers are capable of manufacturing fuel directly
from stellar atmospheres.

It's even published in the same year, and developed by the same people, as Traveller...

Yup, but it was only later retconned into the OTU future history

 

[boomslang]

The internal tanks in the tanker are drop tanks that just happen to be shaped exactly like the inside of the fuel tank of the tanker*. Drop tanks can deliver their fuel to the Jump Drive in time, while internal demountable tanks cannot.

Well, the trick here is that you are only buying and installing the couplings, not the actual tanks themselves. Any hard tank would do, in practice.

HG2 tells us (p. 39) that is takes two turns to transfer fuel between ships using whatever the default piping may be. Using custom-fitted Drop Tank couplings -- which by definition are already up to the task -- is simply an expensive way to speed that transfer up to the point that the fuel is available immediately from one ship's hard tankage to another's. The cost of the fittings (on whichever ship has the smaller ones, if applicable) then determines the maximum volume of fuel that can be transferred quickly enough to support Jumping.

 

[Grav_Moped]

Two turns is enough -- a ship that can supply EP=2*Jn per 100Td can jump at the end of the first turn. "Can jump", not "must jump". And it's a rare LBB2 design that has Pn=2Jn.

Ok, that applies to max Jn only. J2 doing J1, J4 doing J2 or less, J6 doing J3 or less... yeah, they'd have to slow the jump fuel burn if they were transferring using stock fuel transfer fittings instead of drop tank fittings. They could still do it.


More to the point, is this counting 100% of donor vessel tankage transferred, or 100% of recipient vessel tankage? If the latter, it probably takes less a lot less time...



To be clear, I think your interpretation works fine. I was just trying to address the "only drop tanks work this way" argument (which, as you might have guessed, I don't strictly agree with).

 

[Grav_Moped]

Which brings up something weird.

Stock Scout Courier, Size A Jump Drive, takes 2 turns to Jump (J2) under HG.

Replace the powerplant with a TL-15 version that puts out 4EP (4Td, same as the Size A powerplant).*

It can now generate the 2EP*Jn*100Td for a J2 in 1 turn, and thus its jump fuel burn only takes 20 minutes.

What changed about the Size A Jump Drive to enable it to burn its 20 tons of fuel twice as fast?

Just observing an oddity, not really going anywhere with it.




* You'd do it so it could fire a double laser turret while keeping Agility 2. If anyone wants to argue fuel use, we can use drop tanks for this example if needed.

 

[boomslang]

Just observing an oddity, not really going anywhere with it.

It is worse than that.

Under LBB2, a Type S may mount 3 lasers, carry a Model/7 computer (if you make the room), and still Jump at the end of any turn in which is has a enough fuel available for the trip and has crunched the numbers. That is the equivalent of a whopping 14EP out of a level-A power plant right there. Then you add the fact that the full 2Gs of maneuver are concurrently available, and therefore the ship is fully agile, and you are now burning a grand total of 16EP. Per turn. For 28 days straight, if need be.

Maybe that's why the LBB2 power plant fuel requirement is so absurdly excessive in comparison to what Beltstrike gives us as an hourly/daily/weekly usage rate.

HG2 Agility and EPs are actually a step backwards from HG1, I tend to think.

Also, apropos of odd musings, why do exterior demountable tanks even exist?

 

[AnotherDilbert]

JTAS says to treat it as a LBB2 heavy laser - which does not exist. I ask again, where are the stats of a LBB2 heavy laser?

The language may not be perfect, but it is quite understandable with an ounce of good will.

I see "heavy" here as a quality, not a category; something like this:

The particle accelerators should be treated as heavylarge and powerful lasers as in Traveller Book 2, subject to an advantageous DM of +2 to hit. Damage from such hits should be skewed toward crew casualties, and electronic and computer damage if there is no fibre optic back-up present.

That would not make you look for a "large and powerful laser" in LBB2? (https://dictionary.cambridge.org/dictionary/english/heavy#cald4-1-4)

I agree the effects are not exactly defined, e.g. which laser is considered base, or how damage locations should be modified.

 

[AnotherDilbert]

But not exactly the same, fleets can only follow jump routes, no empty hex jumps until Dark Nebula.

Agreed, not exactly the same, but the basics are the same. Since IIRC all 2 parsec jumps are mapped out as jump routes, that is just a semantic difference, the effect is the same as all J-2 routes allowed.

Yup, but it was only later retconned into the OTU future history

Agreed, the original game says nothing about Traveller or Vilanis, just Terrans and the Imperium.

 

[AnotherDilbert]

Well, the trick here is that you are only buying and installing the couplings, not the actual tanks themselves. Any hard tank would do, in practice.

And the logical conclusion is that all normal jumps ship use fuel from the local Farport or tanker at the 100D limit, and no ships except explorers bother with jump fuel tanks.

You have left the OTU far behind...


You said IMTU before, so I guess that is how your game works, but this thread is marked "OTU Only" which is why I drone on about RAW.

 

[AnotherDilbert]

Two turns is enough -- a ship that can supply EP=2*Jn per 100Td can jump at the end of the first turn. "Can jump", not "must jump". And it's a rare LBB2 design that has Pn=2Jn.

Not "may", just jumps:

If it can do this in two turns, it jumps at the end of two turns. If it can do this in one turn or less, it jumps at the end of one turn (in the pursuit step). A ship which cannot summon the required energy in two turns may not jump at all.

"may jump" applies to black globes:

If a ship absorbs enough energy to make a jump, and is supplied with sufficient fuel, it may jump at the end of the turn.

 

[AnotherDilbert]

Ok, that applies to max Jn only. J2 doing J1, J4 doing J2 or less, J6 doing J3 or less... yeah, they'd have to slow the jump fuel burn if they were transferring using stock fuel transfer fittings instead of drop tank fittings. They could still do it.

According to JTAS#24 the jump fuel is burnt in a fraction of a turn, not several turns.