External collapsible tanks

[aramis]

I didn't find any reference to them in LBB2 (nor in any CT book), what's not to say it des not exist...

Adventure 5: Trillion Credit Squadron. Page 13.

Collapsible Tanks: Large fuel bladders can be used to hold additional fuel; the collapsible tanks are filled with fuel and take up space in the ship's main cargo hold. It must have a hold equal to, or greater than, the tonnage required for the collapsible tanks, and the tanks displace tonnage in the cargo hold when in use.
When not in use, collapsible tanks collapse and are'stored in the cargo hold; they take up 1% of their filled tonnage.
Fuel from collapsible tanks must be pumped into the normal fuel tanks before it
can be used; thus a jump made using collapsible tanks may not use more fuel than the capacity of the normal interior fuel tanks. Pumping fuel before a jump takes about three hours.​

 

[McPerth]

Adventure 5: Trillion Credit Squadron. Page 13.

Collapsible Tanks: Large fuel bladders can be used to hold additional fuel; the collapsible tanks are filled with fuel and take up space in the ship's main cargo hold. It must have a hold equal to, or greater than, the tonnage required for the collapsible tanks, and the tanks displace tonnage in the cargo hold when in use.
When not in use, collapsible tanks collapse and are'stored in the cargo hold; they take up 1% of their filled tonnage.
Fuel from collapsible tanks must be pumped into the normal fuel tanks before it
can be used; thus a jump made using collapsible tanks may not use more fuel than the capacity of the normal interior fuel tanks. Pumping fuel before a jump takes about three hours.​

TY. Let me repeat:

Good once more for inter-version coherence :devil:...

 

[mike wightman]

So can you fire up your jump drive, use the main fuel tanks, charge the capacitors ready to jump....

and than wait 3 hours while you pump the fuel from the bladder back into the main fuel tank, or longer if it has to go through the purifier first

Yours is a new idea, a collapsible drop tank which you then carry through jump. Ignore the old rules and make up new stuff.

I would suggest that the collapsing machinery and storage for the tanks does take up some tonnage though.

 

[McPerth]

So can you fire up your jump drive, use the main fuel tanks, charge the capacitors ready to jump....

and than wait 3 hours while you pump the fuel from the bladder back into the main fuel tank, or longer if it has to go through the purifier first

Yours is a new idea, a collapsible drop tank which you then carry through jump. Ignore the old rules and make up new stuff.

I would suggest that the collapsing machinery and storage for the tanks does take up some tonnage though.

I thought about the pumping from the bladder to the main tanks to last less than 3 hours, and it can be purified once already in the tanks...

I don't want to ignore old rules, just to add a piece of equipment, and this 0.5% I sugesed as empty volumen (that can be altered, I abased it in the MT premise that they usually don't use any) was thought as this collapsing machinery and the storage of the bladder...

 

[Condottiere]

Considering the pressure caused by the rapid expulsion of fuel during transition, the bladder might burst, which would explain the need to transfer the fuel to a braced permanent tank.

 

[whartung]

Unfortunately, there is no consensus about the time it takes tu consume jump fuel, whether it is even consumed before or during the jump entry, or during the jump trip. No consensus on whether you can jump solely from capacitors, how long capacitors hold their charge, etc.

If there were, then all of the issues around drop tanks and fuel tenders and alternate methods to charge the capacitors would have been resolved long ago.

 

[aramis]

Unfortunately, there is no consensus about the time it takes tu consume jump fuel, whether it is even consumed before or during the jump entry, or during the jump trip. No consensus on whether you can jump solely from capacitors, how long capacitors hold their charge, etc.

If there were, then all of the issues around drop tanks and fuel tenders and alternate methods to charge the capacitors would have been resolved long ago.

There is a small amount of rules material on it, material that makes strong implications.

To wit: Annic Nova - it can jump with no fuel at all.
Also: T5 includes rules for collector only jumps. In other words, T5 allows you to validly build the Annic Nova.

Also, in HG-80, if you don't have the full fuel at start, you cannot make the jump. Same in MT, TNE, and T4. It's not a misjump - it's a can't jump. Which EXTREMELY strongly implies it's all used at the initiation.

How it's used is a different matter.

 

[mike wightman]

If the rule in HG about using energy absorbed via the black globe to power a jump did not end with 'and has sufficient fuel'
Get rid of that bit and black globe absorption of energy into the jump capacitors ties in with MWM's original Jump Drive article describing the operation of the jump engine.

It also ties in with the descriptive text of drop tanks in HG1 requiring special capacitors/accumulators and the Annic Nova.

 

[Patron Zero]

Perhaps a sideways thought but here goes all the same.

Could not external-mount collapsible fuel tanks be configured much like an inflatable aero-shell to allow non-streamlined ships to fuel-skim gas giants ?

Essentially 'deploying' an atmospheric brake styled 'envelope', likely several that configure into said aero-shell, then performing fuel-collection maneuvers to fill such.

A given it's likely to be time-consuming but if such might allow an otherwise unstreamlined ship to be free of fuel charges from more traditional venues, such might be considered an investment.

 

[warwizard]

Most everybody here has an image of a ship dipping down *just * low enough to get into the very top of the gas giant atmosphere while maintaining orbital velocity, perhaps starting with a orbit that is not circular and just losing the height on the apogee. This is beyond hypersonic, it's Apollo capsule style reentry speeds, with temperatures in thousands of degrees and a nearly pure hydrogen atmosphere. This method of skimming would take quite a feat of material engineering to stand up to such conditions with a balloon.

An alternative would be to have a ship equipped with sufficient anti-grav or just plain raw rocket thrust (Thinking HEPLAR here as you can get more h2 to feed the HEPLAR) to pull out of the 2.2 to 2.6 gravity encountered at the upper atmosphere of a gas giant, and just slow down and make a cold entry into the upper atmosphere and float there while compressors and chillers suck in the H2 gas and turn it into liquid H2 and send it to the purifier, once the tanks are topped off , float back out of the atmosphere then get back up to orbital velocity and on to wherever you are heading to next.

I would have no issues with balloon streamlining with scenario B, as your flight profile could be kept to about 200 kph relative to the wind speeds encountered.

 

[Matt123]

Not a fan of the idea, in part because it attempts to break existing constraints on jump capable vessels. In effect it breaks the economic system already in place. Traders no longer have to allocate space to tankage, they all use collapsible exterior tankage and install J6 drives that do not have to move rigid empty fuel tanks.

A few years back there was a similarly interesting discussion on using fuel stations at the 100D point with large hoses pumping fuel direct to the jump drives. On jump the hose would get severed by the jump field and quickly prepared for the next vessel. IIRC the conversation also discussed the same economic implications on the OTU.

 

[Condottiere]

If you take account of drop tanks, the starship sucks up an enormous amount of fuel within a very short time window from them, which I doubt your generic fuel hose can handle.

What I would say, is that the fuel bladders could refill the primary fuel tanks just as they are being emptied, allowing a subsequent jump after the first transition without requiring a fueling stop.

 

[McPerth]

Not a fan of the idea, in part because it attempts to break existing constraints on jump capable vessels. In effect it breaks the economic system already in place. Traders no longer have to allocate space to tankage, they all use collapsible exterior tankage and install J6 drives that do not have to move rigid empty fuel tanks.

A few years back there was a similarly interesting discussion on using fuel stations at the 100D point with large hoses pumping fuel direct to the jump drives. On jump the hose would get severed by the jump field and quickly prepared for the next vessel. IIRC the conversation also discussed the same economic implications on the OTU.

As the fuel must be pumped to the fuel tanks to be used, the ship still needs them. Those bladders will allow for a second jump without refuelling, they will not allow for tankless ships.

 

[mike wightman]

Drop tanks - which do allow fuel tank-less ships are:
a] canonical
b]canonically used by merchants in the Imperial core worlds
c]do not affect the trade system one little bit.

The trade system in the LBBs models the trials and tribulations of an ethically challenged merchant going from world to world. It does not model the LASH set up that GT went with, it does not model the bulk shipping the megacorporations engage in, it does not model the trade conducted between world governments in the OTU.

Drop tanks, collabsible fuel bladders, LASH trade model - all beyond a LBB1-3 merchant

 

[CliffBates]

Most everybody here has an image of a ship dipping down *just * low enough to get into the very top of the gas giant atmosphere while maintaining orbital velocity, perhaps starting with a orbit that is not circular and just losing the height on the apogee. This is beyond hypersonic, it's Apollo capsule style reentry speeds, with temperatures in thousands of degrees and a nearly pure hydrogen atmosphere. This method of skimming would take quite a feat of material engineering to stand up to such conditions with a balloon.

An alternative would be to have a ship equipped with sufficient anti-grav or just plain raw rocket thrust (Thinking HEPLAR here as you can get more h2 to feed the HEPLAR) to pull out of the 2.2 to 2.6 gravity encountered at the upper atmosphere of a gas giant, and just slow down and make a cold entry into the upper atmosphere and float there while compressors and chillers suck in the H2 gas and turn it into liquid H2 and send it to the purifier, once the tanks are topped off , float back out of the atmosphere then get back up to orbital velocity and on to wherever you are heading to next.

I would have no issues with balloon streamlining with scenario B, as your flight profile could be kept to about 200 kph relative to the wind speeds encountered.

Interesting idea. Workable too. See in the rules for Orbital (a Traveller mod game on pre Interstellar wars pre jump Terra) about the Venus flyer.

 

[aramis]

If you take account of drop tanks, the starship sucks up an enormous amount of fuel within a very short time window from them, which I doubt your generic fuel hose can handle.

What I would say, is that the fuel bladders could refill the primary fuel tanks just as they are being emptied, allowing a subsequent jump after the first transition without requiring a fueling stop.

It takes 3 hours to empty collapsibles into the main tanks. (A5:TCS p. 13)

 

[Selandia]

It takes 3 hours to empty collapsibles into the main tanks. (A5:TCS p. 13)

T5 master text p.339
Transfer Pump MCr1 / ton, tl10, Moves Drop Tank fuel to P-Plant in seconds. 1 ton for Tank up to 100 Tons

Reasonnable extrapolation: it could be done between collapsible and main, but not a free lunch

have fun

Selandia

 

[Condottiere]

That's assuming you don't burst your bladder from the pressure.

 

[Selandia]

That's assuming you don't burst your bladder from the pressure.

If you pay your collapsible "bladders" the same price you pay your drop tanks there is no reason to believe (that might not be strictly true fron an engineering stand point, but is workable from a play balance stand point) that they would not stand to a similar working stress.

have fun

Selandia

 

[Patron Zero]

..... A few years back there was a similarly interesting discussion on using fuel stations at the 100D point with large hoses pumping fuel direct to the jump drives. .....

Fuel stations operated near jump-points is a reasonable expectation and very likely a profitable venture. For ships making multiple jump runs needing to be 'topped-off' before the next leg the turnaround time saved could be crucial to small owner-operators.

That said, whether it being drop-tanks or collapsible fuel bladders, the convenience and availability of fuel right off the 'jump-ramp' would bring much trade and other benefits to any systems whom have such.