mike wightman
SOC-14 10K
Anywhere within 4 light years, including where you jumped from.
Drop Tanks
- Thread starter Badenov
- Start date
mike wightman
SOC-14 10K
Which just proves the T4 authors didn't know the game as well as they thought they did.
Could you provide a reference to drop tanks being only TL15 in T4 FF&S because I can't find it.
HG79 makes drop tanks effectively a TL12 technology, while HG80 onwards doesn't have a TL restriction that I can find.
So T4 FF&S authors bring you TL15 drop tanks and a hydrogen filled jump bubble. Time to just ignore the book.
I tend to use the drop tanks for trade routes that need different volumes of goods or jump number. For merchants consicider the previously posted 100DT J-6 merchant that under FF&S 2 can carry all of it's jump fuel externally, and perform J-1 with 350 DT of cargo pods and another 50 DT of internal cargo. All for perhaps a 35 DT external drop tank and a 1DT internal fuel tank to accomodate for various different TL manufacture drop tank. cost: perhaps 30kCr.
Oh and the power plant fuel:
5) T4 FF&S Fusion power plants have such small fuel requirements that they are listed in volumes per year.
Oh and the power plant fuel:
5) T4 FF&S Fusion power plants have such small fuel requirements that they are listed in volumes per year.
Erratta for pp 16: "In the 3rd Imperium, jump drives capable of using drop tanks were not developed till 1090 and can only be manufactured on TL 15 worlds. However, Drop tanks can be manufactured on most worlds that can build hulls."
For the military use of drop tanks, you have the choice of procuring armored drop tanks that can be retained and carried into battle, or just getting the paper thin armor 5 ones. Another consideration: You can have drop tanks bigger than the ship, have the grappels fuel scoops, fuel refinery power plant and maneuver drive a pair of flt computers and a single workstation, and go do wilderness refuelling with your drop tank while your ship is docking and doing in port stuff. In short make the ship a jump tug bulk cargo carrier and the drop tank the manuver drive and fuel scooper.
So all those TL-14 Gazelles are in fact from TL-15 worlds, in contradiction of years of canon.
Condottiere
SOC-14 5K
AnotherDilbert
SOC-14 1K
Adding contradicting Canon in the footnotes of an errata? Yeah, I will disregard that...
Perhaps I could agree that T4 and Milieu 0 does not have drop tanks.
No, just the jump drives are imported from TL 15 yards. I used this in the islands campaign to give some better legs to the lower tech squadrons.
mike wightman
SOC-14 10K
I can easily ignore that particular error introduced by errata then.
That refers to civilian use of drop tanks and first appeared in JTAS 2 TAS News The military have been using them for much longer.
As has already been mentioned the Gazelle contradicts this bit of silliness.
Yes I know, I am currently writing up a merchant using a streamlined drop tank that stays attached for jump, then detaches for a speed run to the local gas giant to skim and refine fuel, meeting back up with the main ship and provides delta V for getting to 100 diameters. The main power and delta V sourse is the drop tank craft, the grappels are on the drop tank craft, not the main ship. Look for a posting soon in my T4 merchant design challenge thread.
Marcatlas
SOC-12
Maybe. They increase the tonnage on the way in reducing your Jn. It would really depend on how far you are jumping on that last jump into combat
Actually not necessarily so, you can resize the jump drive to jump the full JN with the drop tank attached. Edit, at least in rule systems that let you do that.
Marcatlas
SOC-12
I've never played a version where one can just change the JD size on the fly. Which Trav version is that?
Not on the fly, in the shipyard when you install a larger jump drive and an auxillary power plant and use the volume previously dedicated to the flag officer's private dining room and the crew's swimming pool. Example J4 scout intially has a jump drive of 5 DT and needs 40 DT of fuel to J-4 one time. Is retro fitted with a 70DT drop tank and the jump drive uprated to 8.5DT and the internal jump fuel reduced to 20DT to allow the space for the grappels expansion of the jump drive and power plant. It is now displacement 170DT does a J-4 jump with 68 DT of fuel, and can drop the tank and do a J-2 on internal fuel. EDIT: If you add a 2nd grappel for use with a 2nd drop tank with 68 DT of usable fuel, removing 10 more DT of the internal tankage you can then J-4, expend the 2nd drop tank, then J-4 back retaining the first tank with 12 tons fuel remaining. (assumming diverted 2 DT from the 70DT tank to top off the power plant fuel before dropping the remaining tanks and emergency J1 out.
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Marcatlas
SOC-12
Nope. Doesn't work that way. When the ship is designed and built the engineering part of the ship has tonnage allocated. You cannot later grab random areas of the ship to make bigger drives. No more thaan you could with a real warship.
So, my original concern/problem stands. "They [drop tanks] increase the tonnage on the way in, reducing your Jn. It would really depend on how far you are jumping on that last jump into combat"
And that is why I said depending on your ruleset, LBB5 user
Later editions did not have a specified engineering section.
Marcatlas
SOC-12
ALL editions have you account for the tonnage according to the drives you install.And that is why I said depending on your ruleset, LBB5 user
Spinward Flow
SOC-14 1K
If I can hazard a guess, this is about reverse engineering the displacement per jump number from the tonnage used for the jump drive.
For example ... using LBB5.80 custom drives:
- 1000 ton hull @ J1 = 20 tons of jump drives
- 1000 ton hull @ J2 = 30 tons of jump drives
- 1000 ton hull @ J3 = 40 tons of jump drives
- 1000 ton hull @ J4 = 50 tons of jump drives
- 1000 ton hull @ J5 = 60 tons of jump drives
- 1000 ton hull @ J6 = 70 tons of jump drives
- 1000 ton hull @ J3 = 40 tons of jump drives = 2000 ton hull @ J1
- 1000 ton hull @ J5 = 60 tons of jump drives = 2000 ton hull @ J2
It's then possible in the design spec phase to "overspec" a set of drives in excess of what you "need" for a particular drive performance integer in order to account for external loading by drop tanks (or whatever).
This is how the Gazelle-class manages its J5 @ 300 tons = J4 @ 400 tons displacement modulation.
- 300 ton hull @ J5 = 18 tons of jump drives required
- 400 ton hull @ J4 = 20 tons of jump drives required
Change your assmuptions from 100 ton drop tanks to 80 ton drop tanks and you get this result under LBB5.80:
- 320 ton hull @ J5 = 19.2 tons of jump drives required
- 400 ton hull @ J4 = 20 tons of jump drives required
LBB2.81 standard drives are "less messy" for this calculation, since it's a "straight multiplier" factor with them, rather than a "multiplier with an offset" like with LBB5.80 custom drives.
Which just supports and demonstrates the notion that LBB2.81 drives are "better for towing external loads" while LBB5.80 drives are "more finely custom tuned" to operate in the hulls they're installed into, enough so that external loads pretty quickly generate "adverse results" for LBB5.80 custom drive performance breakpoints (because they're just not meant for towing external loads).
