Merchant Drop Tanks

[mike wightman]

Ahh, but the Brilliance failure may have been due to sabotage that the authorities are choosing to keep quiet
Where did you get the figure of four drop tanks from? The TAS article mentions four survivors, but I can't find any mention of the number of drop tanks

By the way, here is the full text for drop tanks from High Guard first edition:

L-Hyd Tanks: Disposable fuel tanks which are fitted outside the ship, and drop away before jump Thae result is more interior space available for cargo and passengers. Cost Cr 10 000 plus Cr1000 per ton of fuel. Usable only with jump drives if a special high capacity accumulator is installed (tech level 12; Cr500,000).

 

[robject]

Yes Sigg, you're right, and sabotage is a much juicier plot hook than simple failure.

Four tanks is barely hinted at. The TML deduced it by noting that the TAS entry claimed the problem was "a failure of the port inboard L-Hyd drop tank". Port... inboard... two descriptors, therefore at least two tanks, probably four, and maybe more. Four 80 ton drop tanks seems reasonable.

 

[Valarian]

Instead of drop tanks, what about having traders use attachable fuel modules. The rules for external attachments to the hull would cover this. If the modules were the same size as the fuel modules used by the modular cutter, you could have a ready made tanker fleet for refueling in-system. The trader would just have to detach the empty fuel modules and attach full ones to be able to jump again.

 

[BetterThanLife]

Originally posted by Sigg Oddra:
Ahh, but the Brilliance failure may have been due to sabotage that the authorities are choosing to keep quiet
Where did you get the figure of four drop tanks from? The TAS article mentions four survivors, but I can't find any mention of the number of drop tanks

By the way, here is the full text for drop tanks from High Guard first edition:
</font><blockquote>quote:</font><hr />L-Hyd Tanks: Disposable fuel tanks which are fitted outside the ship, and drop away before jump Thae result is more interior space available for cargo and passengers. Cost Cr 10 000 plus Cr1000 per ton of fuel. Usable only with jump drives if a special high capacity accumulator is installed (tech level 12; Cr500,000).

</font>[/QUOTE]Lose last line and it is the same information in LBB5 Second Ed, which was carried over to MT, though the cost changes the description is the same.

I also notice that the complete CT canon source CD from FFE doesn't list both editions of LBB5.

 

[BetterThanLife]

Originally posted by robject:
BTL, I have two grades of drop tanks: one is the HG disposable cheapies, and the others are like Shere's, which are essentially small hulls, but are reusable. But good points nonetheless.

Ptah, while forming my opinions of droptanks this week, I also considered the dangerousness of droptanks (1 in 128 chance of jump failure, and half of those are fatal to people), but for the time being decided to not push the issue. I note you have a precedent there in the spectacular failure of the Brilliance.

The big question becomes, exactly at what point are the tanks dropped? If it is as the portal is opened, regardless of how you interpret Jumpspace (Bubble, Grid, cooling, whatever), no matter what you pay for them, they are unlikely to survive. As they will be in the jump space entrance as they are blasted free. (Otherwise Jump Gates would work, and be extremely efficient, compared to carrying your own jump fuel.)

T20 adds 10% to the chance of a misjump for using Drop Tanks. (The same as using unrefined fuel.) For other versions this sounds reasonable. So for your chance to misjump, use the Unrefined fuel modifier for chance of misjump with drop tanks.

 

[BetterThanLife]

Originally posted by Valarian:
Instead of drop tanks, what about having traders use attachable fuel modules. The rules for external attachments to the hull would cover this. If the modules were the same size as the fuel modules used by the modular cutter, you could have a ready made tanker fleet for refueling in-system. The trader would just have to detach the empty fuel modules and attach full ones to be able to jump again.

They are called External Demountable tanks and are legal, however they also add to the tonnage of the ship and reduce the jump number of the ship. For regular operation the external tanks are a dubious addition.

 

[robject]

Originally posted by BetterThanLife:
The big question becomes, exactly at what point are the tanks dropped? If it is as the portal is opened, regardless of how you interpret Jumpspace (Bubble, Grid, cooling, whatever), no matter what you pay for them, they are unlikely to survive. As they will be in the jump space entrance as they are blasted free. (Otherwise Jump Gates would work, and be extremely efficient, compared to carrying your own jump fuel.)

The TML debated this, and the consensus seemed to be that the jumpfield was generated with a link to the ship, the tanks were then blown away, and the ship could then enter jumpspace through the created portal. There were opinions on every side.

Most who took this stance decided that drop tanks ought to be reusable. Most folks also reasoned that the volume which entered jumpspace determined jump performance, but there's no canon text on this.

And, finally, jump gates do work, albeit at TL17.

 

[mike wightman]

Originally posted by robject:
Four tanks is barely hinted at. The TML deduced it by noting that the TAS entry claimed the problem was "a failure of the port inboard L-Hyd drop tank". Port... inboard... two descriptors, therefore at least two tanks, probably four, and maybe more. Four 80 ton drop tanks seems reasonable.

Clever detective work - I like it.

 

[mike wightman]

Originally posted by BetterThanLife:
I also notice that the complete CT canon source CD from FFE doesn't list both editions of LBB5.

Unfortunately not, nor does it appear to have first edition CT or Starter Edition. Both of the latter sets have rules that aren't in the LBB0-8 reprint or The Traveller Book.

Originally posted by BetterThanLife:
So for your chance to misjump, use the Unrefined fuel modifier for chance of misjump with drop tanks.

Consider that one borrowed

 

[mike wightman]

Originally posted by robject:
</font><blockquote>quote:</font><hr />Originally posted by BetterThanLife:
The big question becomes, exactly at what point are the tanks dropped? If it is as the portal is opened, regardless of how you interpret Jumpspace (Bubble, Grid, cooling, whatever), no matter what you pay for them, they are unlikely to survive. As they will be in the jump space entrance as they are blasted free. (Otherwise Jump Gates would work, and be extremely efficient, compared to carrying your own jump fuel.)

The TML debated this, and the consensus seemed to be that the jumpfield was generated with a link to the ship, the tanks were then blown away, and the ship could then enter jumpspace through the created portal. There were opinions on every side.</font>[/QUOTE]Going from MWM's Jumpspace article I'd go with jump fuel is used to charge the capacitors, the capacitor energy is then sent to the various jump drive components.
Drop tanks would be released while the capacitors are fully charged, but before the energy is fed through to the rest of the jump machinery.

Most who took this stance decided that drop tanks ought to be reusable. Most folks also reasoned that the volume which entered jumpspace determined jump performance, but there's no canon text on this.

The performance of the Gazelle with drop tanks attached and dropped prior to jump clarifies this.

And, finally, jump gates do work, albeit at TL17.

Are they jump gates though?
The expanded DGP/MT TL chart (which I have issues with ) mentions starship sized portals - are they the same thing?

 

[mike wightman]

What if the drop tank is fitted with a maneuver drive, bridge, and robot pilot?

 

[robject]

Originally posted by Sigg Oddra:
</font><blockquote>quote:</font><hr />Originally posted by robject:
</font><blockquote>quote:</font><hr />Originally posted by BetterThanLife:
The big question becomes, exactly at what point are the tanks dropped? If it is as the portal is opened, regardless of how you interpret Jumpspace (Bubble, Grid, cooling, whatever), no matter what you pay for them, they are unlikely to survive. As they will be in the jump space entrance as they are blasted free. (Otherwise Jump Gates would work, and be extremely efficient, compared to carrying your own jump fuel.)

The TML debated this, and the consensus seemed to be that the jumpfield was generated with a link to the ship, the tanks were then blown away, and the ship could then enter jumpspace through the created portal. There were opinions on every side.</font>[/QUOTE]Going from MWM's Jumpspace article I'd go with jump fuel is used to charge the capacitors, the capacitor energy is then sent to the various jump drive components.
Drop tanks would be released while the capacitors are fully charged, but before the energy is fed through to the rest of the jump machinery.
</font>[/QUOTE]Yep, that was one possibility, one that I liked ... until this week. Several gearheads (including Scott) have a serious problem with it. First, the energy stored in the capacitors, according to High Guard, comes from the power plant. Second, the amount of energy stored in the capacitors is rather piddling. Third, the amount of energy gained from fusing all that jump fuel is something like a million trillion megawatts.

In other words, you should be able to hook a weapon up to it and obliterate worlds, but you definitely can't store more than a percentage of it in the capacitors.

</font><blockquote>quote:</font><hr />And, finally, jump gates do work, albeit at TL17.

Are they jump gates though?
The expanded DGP/MT TL chart (which I have issues with ) mentions starship sized portals - are they the same thing? </font>[/QUOTE]Good point, and you're right, no, they're not the same thing (matter portals are at what TL?). Maybe that was a house rule.

What if the drop tank is fitted with a maneuver drive, bridge, and robot pilot?

The TML talked about this type of thing as well. It essentially becomes more like a tanker than anything else, which seems valid to me.

 

[BetterThanLife]

Originally posted by Sigg Oddra:
</font><blockquote>quote:</font><hr />Originally posted by robject:
</font><blockquote>quote:</font><hr />Originally posted by BetterThanLife:
The big question becomes, exactly at what point are the tanks dropped? If it is as the portal is opened, regardless of how you interpret Jumpspace (Bubble, Grid, cooling, whatever), no matter what you pay for them, they are unlikely to survive. As they will be in the jump space entrance as they are blasted free. (Otherwise Jump Gates would work, and be extremely efficient, compared to carrying your own jump fuel.)

The TML debated this, and the consensus seemed to be that the jumpfield was generated with a link to the ship, the tanks were then blown away, and the ship could then enter jumpspace through the created portal. There were opinions on every side.</font>[/QUOTE]Going from MWM's Jumpspace article I'd go with jump fuel is used to charge the capacitors, the capacitor energy is then sent to the various jump drive components.
Drop tanks would be released while the capacitors are fully charged, but before the energy is fed through to the rest of the jump machinery.</font>[/QUOTE]But the question is still at what point in the jump sequence this is. And how tight the hole in the fabric of space entering Jump is. Your tanks are still likely to fall into the hole and entering Jumpspace without a functioning Jump Drive and a Plot is instant destruction.

</font><blockquote>quote:</font><hr />Most who took this stance decided that drop tanks ought to be reusable. Most folks also reasoned that the volume which entered jumpspace determined jump performance, but there's no canon text on this.

The performance of the Gazelle with drop tanks attached and dropped prior to jump clarifies this.</font>[/QUOTE]However the Gazelle is broken in other ways. (4 hardpoints on a 300 ton ship being the most obvious.

) But even with this taken into account there isn't anything about recovery or reuse of drop tanks. And I haven't found anything to contradict the CT and MT description of Drop tanks which classifies them as disposable.
They may be destroyed by the jump field, or the explosive ejection of them. In either case they are clearly listed as disposable.

</font><blockquote>quote:</font><hr />And, finally, jump gates do work, albeit at TL17.

Are they jump gates though?
The expanded DGP/MT TL chart (which I have issues with ) mentions starship sized portals - are they the same thing? </font>[/QUOTE]I always took them as the gates described in Secret of The Ancients. Based on teleport not jump drive technology.

 

[BetterThanLife]

Originally posted by Sigg Oddra:
What if the drop tank is fitted with a maneuver drive, bridge, and robot pilot?

If they didn't interact with the jump field, or potentially interact with the jump field then there would be no increase in the possibility of a misjump. Now as I recall this is only a function of hte rules in later versions of Traveller.

One other point, if this was a nice leisurely proceedure, why bother with drop tanks in the first place? Every major system would have one or more fuel stations, for traditional, asthetic reasons shaped like a big arc, ships would hook up, get their fuel dump and proceed into Jump space without all that jump fuel tankage. Making a Jump 6 ship about as efficient as a Jump 1 ship.

Unfortunately it isn't a leisurely proceedure and the fact that the tanks are disposable helps imply that it all happens rather quickly.

 

[robject]

Right, the key issue seemed to have been whether or not the jump capacitors can hold their charge long enough to allow fuel transfer.

Apparently the "capacitors" aren't really capacitors, either, since you can't just keep them charged up indefinitely -- it's a one-shot deal.

 

[mike wightman]

I think they are charged up to a critical energy density and then they discharge through the jump engine/machinery - charging Imperial capacitors has to be done quickly to reach the charge density for some reason. Keeping them charged for too long runs the risk of damage or explosion.

Did we lose all the posts about charging capacitors using solar power or fission plants in the server move?

I suggested solar powered accumulators take 1d6 weeks, fission powered measured in days, and fusion powered measured in tens of minutes

The Annic Nova capacitors appear to function a bit diffrently to Imperial standard capacitors.

 

[mike wightman]

I still think revised CT and High Guard made a mistake in linking the power plant required with the jump engine size, I prefer the original jump drive is separate from the power plant/maneuver drive rule.

Which begs the question, could you install a fusion power plant in the Annic Nova to charge its jump drive faster?

I would have liked to have seen the Annic Nova's jump accumulator system design specs, a lot could have been added to the setting if different races had different ways to power their ships and jump drives IMHO.

 

[BetterThanLife]

The question isn't the capacitors but the fuel.

After all you can charge the capacitors using a Black Globe Generator. But that energy doesn't negate the requirement for a full load of fuel for the jump. (Pg 43, LBB5) So the fuel is apparently not a major factor in terms of charging the jump capacitors but is apparently used after that point. Implying that the drop tanks are dropped after that point.

 

[robject]

Exactly the problem. What does the Annic Nova use for fuel anyway? Someone suggested a TL25 portal to a gas giant-sized pocket universe...

 

[rhoneycutt]

It seems to me that its not important with reactionless thrusters anyways.......
Fuel is basicly used for jumps....not really much for manuvering. But I use reaction drives IMTU, so carrying extra fuel is more important than in the OTU.

combat can suck when you have to forego manuvering, evading or aiming spinal mounts because of running out of g-turns...