Jump Drive C impossible in a 100-ton ship?

[BP]

Oh, I got your meaning now!

Quite true - the rules' use of a code to derive a rating based on tons when the rating is also tied to TL is also as clear as mud.

I think of the 'codes' (i.e. drive letters) as simply a metagame method to relate one table to another (an unnecessary complication, especial if formulas had been used). But, if used like a 'product model #' for off the rack components, in game, then the lack of explicit addressing of the compound relationship with TL is even more apparent.

Seemingly taking a 200 ton Jump Drive C rated for J3, which can be TL 12, and putting it in a 100 ton ship and, voila, it becomes a J6 capable drive, a TL 15 accomplishment, at the lower TL.

A drive code can really only be part of the specification of an exact model. TL must be incorporated. So, its really a Jump Drive C/TL 12 as opposed to a Jump Drive C/TL 15. Regardless of what tonnage ship the C/TL 12 is placed in, it can't normally exceed the rating its TL was capable of - J3 in this case.

Of course, this isn't spelled out anywhere - and probably wasn't even thought through by the writers (the same wisdom that uses hand made tables as opposed to formulas). :roll:

 

[DFW]

Seemingly taking a 200 ton Jump Drive C rated for J3, which can be TL 12, and putting it in a 100 ton ship and, voila, it becomes a J6 capable drive, a TL 15 accomplishment, at the lower TL.

ALSO, the smallest J-Drive available is J-2 capable, not J-1. So, at TL 9? how do you make a J-1 only drive? 8)

 

[rust]

They used hyperdrives at TL 9, the much less efficient jump drive was
only invented later, but became the standard drive because the corpo-
ration which produced it was owned by Bill Gates. 8)

 

[DFW]

They used hyperdrives at TL 9, the much less efficient jump drive was
only invented later, but became the standard drive because the corpo-
ration which produced it was owned by Bill Gates. 8)

Ya can't buy a 100 ton or > hull without an MS J-drive pre-installed. :lol:

 

[hdan]

Seemingly taking a 200 ton Jump Drive C rated for J3, which can be TL 12, and putting it in a 100 ton ship and, voila, it becomes a J6 capable drive, a TL 15 accomplishment, at the lower TL.

ALSO, the smallest J-Drive available is J-2 capable, not J-1. So, at TL 9? how do you make a J-1 only drive? 8)

Definitely a place where the rules sacrifice reason for simplicity. I assume that (like many things in Traveller) it's up to the GM to decide how to proceed.

I do wish that MgT had included the "what Jump/Hull Size is available at what tech level" table from CT.

IMHO, the drive letter doesn't tell the whole story, and is really just a rough categorization of how powerful the drive is, like a modern ICE's displacement. Sure, you can make a "Jump A" drive at TL 9, but that TL-9 Jump A drive won't have the control circuitry to handle a J-2, even though it's technically capable of generating the energy or whatever.

You might also just decide that if the ship has TL-10+ control circuitry (bridge/computer) that you can coax a J-2 out of a TL-9 drive, even if the people who built that drive don't have the tech to understand the math involved.

In an OTU setting, I'd assume that you would just import whatever extra mechanisms you need if you couldn't build high enough tech stuff on-world. In a setting with a TL-12 cap, I'd just clamp Jump numbers at 3.

 

[BP]

Seemingly taking a 200 ton Jump Drive C rated for J3, which can be TL 12, and putting it in a 100 ton ship and, voila, it becomes a J6 capable drive, a TL 15 accomplishment, at the lower TL.

ALSO, the smallest J-Drive available is J-2 capable, not J-1. So, at TL 9? how do you make a J-1 only drive? 8)

Easy - any TL 9 drive is limited to J1. So just dumb down your designers and fabricators! :lol:

(Hint: start with engineers who were previously rulebook editors...)

...IMHO, the drive letter doesn't tell the whole story,...

...
A drive code can really only be part of the specification of an exact model. TL must be incorporated. So, its really a Jump Drive C/TL 12 as opposed to a Jump Drive C/TL 15. Regardless of what tonnage ship the C/TL 12 is placed in, it can't normally exceed the rating its TL was capable of - J3 in this case.

Of course, this isn't spelled out anywhere - and probably wasn't even thought through by the writers (the same wisdom that uses hand made tables as opposed to formulas).

 

[Reynard]

I took a stab and built as tight as possible: Type C jump (20) with 60 tons fuel, Type C Power Plant - TL15 (7.5) with two weeks fuel (6), Compact Bridge with Standard Electronics and Computer M5bis included (7.5) for a total of 101 tons. Not even room for a low berth at 0.5 tons and we have to leave the airlock open for the bridge. Ain't happening.

Check my math just in case.

I know the exercise was specifically for a 100 tonner but try 200 tons: Type F Jump (35) with 120 tons fuel, Type F Power plant-TL 15 with two weeks fuel (18), Compact Bridge with Standad Electronics and Computer M5bis (7.5) and a Stateroom (4) for 184.5 tons. Jump 6 with 5.5 tons for cargo.

You need a bridge no matter how few crew. The Bridge is the brain center of the ship. You need crew to monitor and perform routine and emergency operations. Though there are 'bots flying starships in Traveller I notice they suppliment crews and even the Scouts don't let them fly X-boats. It seems they're not trusted enough to be left alone. Even a single trained crewperson can do the operations of multiple robots for a lot less.

 

[BFalcon]

Reynard: I agree - I was unable to shoehorn the parts in at all... even though I did miss the compact bridge, it only saves 2.5 tons...

The only hope, as mentioned before, is to use external drop tanks (and those, I later learned need fittings, so aren't as good a saving as they initially seem).

Also - 184.5 tons - wouldn't that be 15.5 tons left over for cargo?

200 tons is a lot more doable, so I can only surmise that a 100dt jump-6 ship is supposed to use the drop tanks to achieve maximum range and, instead, rely on jump-4 or less when using internal fuel tanks.

 

[billclo]

I took a stab and built as tight as possible: Type C jump (20) with 60 tons fuel, Type C Power Plant - TL15 (7.5) with two weeks fuel (6), Compact Bridge with Standard Electronics and Computer M5bis included (7.5) for a total of 101 tons. Not even room for a low berth at 0.5 tons and we have to leave the airlock open for the bridge. Ain't happening.

Check my math just in case.

The powerplant fuel at 6 tons is high. According to High Guard, 2 weeks of powerplant fuel requires 2/3rds (.66) the tonnage of the powerplant. So that 6-ton powerplant needs 3.96 tons of fuel, not 6.

 

[Reynard]

> Reynard: I agree - I was unable to shoehorn the parts in at all... even though I did miss the compact bridge, it only saves 2.5 tons...

Every ton is a ton less and closer to your goal.

> The only hope, as mentioned before, is to use external drop tanks (and those, I later learned need fittings, so aren't as good a saving as they initially seem).

Since there is no manuever drive and the drop tanks are inherently dangerous for jumping they wouldn't be used on a regular basis. There would be tenders to retrieve, refuel and deposit the ship for rejump.

>Also - 184.5 tons - wouldn't that be 15.5 tons left over for cargo?

Is that where that one disappeared?! Sorry, yes. That's a lot for other things.

 

[BFalcon]

> Reynard: I agree - I was unable to shoehorn the parts in at all... even though I did miss the compact bridge, it only saves 2.5 tons...

Every ton is a ton less and closer to your goal.

> The only hope, as mentioned before, is to use external drop tanks (and those, I later learned need fittings, so aren't as good a saving as they initially seem).

Since there is no manuever drive and the drop tanks are inherently dangerous for jumping they wouldn't be used on a regular basis. There would be tenders to retrieve, refuel and deposit the ship for rejump.

>Also - 184.5 tons - wouldn't that be 15.5 tons left over for cargo?

Is that where that one disappeared?! Sorry, yes. That's a lot for other things.

Yep, every ton saved is, it's true, closer... but then I was a way off...

Drop tanks = perfectly safe at TL15... and someone said something about the navy being TL 15 a while back I think...

Either way, you only need a few TL-15-capable members of the crew to fit them and the tools and then they can save you LOTS of headaches...

Also, I'd be tempted to fit at least a Maneuver 1 drive... just to stop it being stranded after a misjump, even if there's fuel in the same system...

But yeah, the maneuver-less ship and the drop-pod ships are two ways you CAN fit a Jump-6 drive into a 100dt ship... and your saved 10 tons would allow you to fit a stateroom or two.

 

[Reynard]

> The powerplant fuel at 6 tons is high. According to High Guard, 2 weeks of powerplant fuel requires 2/3rds (.66) the tonnage of the powerplant. So that 6-ton powerplant needs 3.96 tons of fuel, not 6.

Oh... Okay, I just saw that. I was using the core book. I avoided the Capital design section thinking it wasn't relevant.

Am I reading that right, 7% of the ship's tonnage for a J6 drive? That means a 100 tonner needs only 7 tons rather than 20 tons while a Power Plant is 5.6 tons rather than 7.5.

 

[barnest2]

It's only for cap ships though.
Starships are different.

 

[atpollard]

Strictly my personal opinion, but the inability to build a 100 ton J6/M1 ship feels a whole lot more like a "bug" than a "feature".

 

[DFW]

Strictly my personal opinion, but the inability to build a 100 ton J6/M1 ship feels a whole lot more like a "bug" than a "feature".

Yes, it is a bug in the rules.

 

[atpollard]

FYI,
from the T5 group at COTI:

atpollard:
Can T5 design a TL 15, 100 ton ship with Jump 6 and Maneuver 1?
(Yes or No will suffice).

MgT cannot using the core rules, can almost under the High Guard rules (101-200 tons) and ‘can’ under the Capital Ship rules (which do not apply to 100 ton ships).

So where does the allegedly compatible T5 fall in the spectrum?

morfydd:
Yes it can be done just barley .. but the single person that comprises the crew better not be claustrophobic .. and the ship will be running unarmed with minimal sensors

 

[DFW]

So where does the allegedly compatible T5 fall in the spectrum?

morfydd:
Yes it can be done just barley .. but the single person that comprises the crew better not be claustrophobic .. and the ship will be running unarmed with minimal sensors

Thanks. I'll revisit MT and see if it can be done there.

 

[GypsyComet]

MegaTraveller uses a different calculation for jump fuel, so yes, it can be done under those rules.

MegaTraveller uses (J+1)x 5% instead of J x10%, so jump fuel for a J6 is only 35% of the hull's volume unstead of 60%.

 

[DFW]

MegaTraveller uses a different calculation for jump fuel, so yes, it can be done under those rules.

MegaTraveller uses (J+1)x 5% instead of J x10%, so jump fuel for a J6 is only 35% of the hull's volume unstead of 60%.

Now I remember. Thanks for saving me the time and effort!

 

[GypsyComet]

Note that MegaTraveller's (and TNE's) lower jump fuel requirements were compensation for the vastly higher power (in MT) or maneuver (in TNE) fuel requirements, resulting in very different design balances than found in CT and MGT. Using the lower jump fuel requirement of MT and the reactionless Maneuver of MGT together without adding in something else throws out the traditional Traveller balances, and with them ALL of the existing ship designs.

As long as you're good with that, go for it.

One of the alternatives I've considered is to allow both Jx10 and (J+1)x5 drives to exist with different operational characteristics, maintenance cycles, and "rides". The upshot is that civilian ships will almost always opt for the J10 drives on the basis of comfort, as subjecting a High Passage to the vertiginous ride of the J+5 is a good way to lose business. The vast majority of civilian ships are Jump 1 anyway, so there is no benefit to switching.
Engineers on a J+5 ship rarely see the light of day, as maintenance is not merely a fact of life, but a way of life. J+5 ships are also more sensitive to unrefined fuel than J10s.

Go ahead and install one. You know you want to...