Refueling question

[bz249]

AFAIK an ISD is expected to carry supplies for years of continuous operations, on the other hand their range is shorter than 100.000ly

Since any such limitations of the hyperdrive is unknown and unexpected it could only be a fuel issue. With the known speed of the ISD it means that it can burn all of her fuel reserves in less than a week time.

Carrying food supplies, spare parts, tibanna... for years and have fuel for a week is only sensible when the refueling is much easier than the other parts of the replenishment.

So the question is how the ships of the Imperial Navy refueled? Are they using the civilian infrastructure? Or there is a fleet of tankers following the task forces? or there are dedicated naval refueling facilities (which are far less complex than the bases)? Or whatever other method... (note that returning to the home port is since why to carry useless staff for years when you return in a week time)

[TK-984]

I would assume that supplies and fuel are ferried around on bulk freighters or something to that effect. I don't know if stationary fueling stations have been mentioned in any EU sources. (Actually, now that I think of it, didn't Wedge's parents operate an independent fueling station?)

[VT-16]

Bannistar Station was one such place. It got totalled in a recent issue of Rebellion. I think the Cardan-class military stations spread around the galaxy also help out when they're far from home port.

[evillejedi]

I was under the impression that each sector had a mobile deepdock deployed to it to support all operations of the sector command (repair, refuel) the stations were modular so they could reconfigure to support different sized vessels. one example is given in the imperial source book another would be in the xwing games (the yevetha yards could be considered a combination etc)

[The Original Nex]

Also keep in mind that the vast majority of Imperial Navy warships are not going to be zipping all over the galaxy with much frequency. An (arguably) large portion of the fleet is tied up in the colonial sector fleet organization and as such would be more or less sedentary. The reserve fleets are for the most part kept in the Core and we don't know how often they are used. A relatively small number of roving ships and fleets are the only ones who are regularly traversing the galaxy and burning fuel for hyperdrive at fast rates. There are likely refuel/resupply stations in every sector or perhaps every major system, it is also likely that roving fleets have dedicated fleet tenders that can keep the fleet operational until a proper port can be reached.

[Saxtonite]

I was under the impression that each sector had a mobile deepdock deployed to it

Mobile? I thought each sector had a decent-sized shipyard that was the main place for the fleets; but didn't know it was mobile.

to support all operations of the sector command (repair, refuel) the stations were modular so they could reconfigure to support different sized vessels.

correct; the Rebellion era Sourcebook says that.

[Darth Ruinus]

Mobile? I thought each sector had a decent-sized shipyard that was the main place for the fleets; but didn't know it was mobile.

Yup, Type-IIs are mobile orbital repair yards.

[Andras]

Each sector has a Deepdock Fleet, which contains 2 deepdock complexes, an Engineering Corps, 2 Force Technical Services, and a Force Escort, averaging 280 support ships and 108 combatants.

The smallest deepdock has 3 bays, one of which is large enough to handle a VSD, and the other 2 able to handle 500m Escort Carriers.

The largest known deepdock complexhas 125 bays each of which can handle a Strike. Multiple bays can be reconfigured to handle larger ships, 4 for a VSD, 15 for a ISD.

All deepdocks are hyperspace capable, but are less efficient then the fixed shipyards of the major manufacturers. If not repairing a ship, each bay can construct an appropriate sized ship.

Imperial Sourcebook, page109

[bz249]

My problem was why to load years of supplies if they return to their home port let's say monthly to refuel, so I expected a more efficient way to refuel than going to the deepdocks.

So Galactic, Oversector and Sector level reserves are likely to sit most of the time, but ships on normal patrol routes can easily traverse more than 100.000ly (with lots of jump in and out) in a few month. Anyway is there a more economical 'cruising speed' for SW ship or there is no connection between fuel consumption and speed.

[PainRack]

My problem was why to load years of supplies if they return to their home port let's say monthly to refuel, so I expected a more efficient way to refuel than going to the deepdocks.

So Galactic, Oversector and Sector level reserves are likely to sit most of the time, but ships on normal patrol routes can easily traverse more than 100.000ly (with lots of jump in and out) in a few month. Anyway is there a more economical 'cruising speed' for SW ship or there is no connection between fuel consumption and speed.

Paradise Snare states that hyperdrive freighters travel slowly in order to conserve costs, thus causing the young Han Solo some difficulties.

[evillejedi]

think of how long it takes to stop at the gas station vs how long it takes to pack for a vacation, I'd think the logistics would be highly automated, but if I was a captain I wouldn't want to stop to load food every week when I have the cargo space.

consider this though

an ISD chews down at least 150,000 tons of fuel a second in full sub light burn, heavy combat operations or when initiating a jump. In a battle like endor or other fleet enegagments the vessels must be capable of operating at this capacity for a minimum of 30 minutes (if not hours in seiges or defensive operations), and then be able to make a few jumps and possibly accelerate to near C (very approximately two and a half hours at 1500G to reach .75 C) so even if we say a full fuel burn operation time is 5 hours on a full tank of gas we have gone through 2.7 billion tons of fuel.... and the density of that fuel is a minimum of 270 tons per meter^3

if we say that when initiating a hyper jump the vessel needs 15 seconds to dump fuel into the reactor to warm up to jump and no other separate fuel quantities are used (this charge time would also suggest that the hyper jump is much more energetic than the 1e25 W output) you would still be able to make 1200 hyperjumps on the same amount of fuel. A 100,000 ly maximum range for fuel would mean that the vessel could only go 83 LY in a jump (complete nonsense) THe other alternatives would be that hyperjumps exceed the maximum reactor capacity (nonsense) or that the limiting factor for hyperjumps is a secondary fuel source (plausible)

I believe the range represents the largest distance the vessel can achieve in one jump before it needs to make a second jump. We know that the energy needed to stay in Hyperspace is orders of magnitude less than the energy needed to initiate the jump so the limitation must be of the hyperdrive itself or of some other subsystem. Interpreted this way the vessel could make 1200 jumps in lets say 2 years if it was on non-combat patrol duty which would allow it to make around 2 jumps per day.

[Ender]

think of how long it takes to stop at the gas station vs how long it takes to pack for a vacation, I'd think the logistics would be highly automated, but if I was a captain I wouldn't want to stop to load food every week when I have the cargo space.

consider this though

Given that the Empire controls damn near everything and the enormous space presence the civilization must have (when you have a 10^27 population and most of your planets have a pop of 10^7 you have to have most people in space colonies), it is likely that they go from nearby system to nearby system with a minimal expenditure or resources and plenty of time on "shore leave"

an ISD chews down at least 150,000 tons of fuel a second in full sub light burn, heavy combat operations or when initiating a jump.

120,000 tons by my figures, what are you working with?

In a battle like endor or other fleet enegagments the vessels must be capable of operating at this capacity for a minimum of 30 minutes (if not hours in seiges or defensive operations), and then be able to make a few jumps and possibly accelerate to near C (very approximately two and a half hours at 1500G to reach .75 C) so even if we say a full fuel burn operation time is 5 hours on a full tank of gas we have gone through 2.7 billion tons of fuel.... and the density of that fuel is a minimum of 270 tons per meter^3

I don't follow your numbers. For a mass ratio of 4, an ISD can run at peak power for 4.56 hours before exhausting its propellant. Using that as a base time, and at 120,000 tons/s the ISD needs ~1.82*10^12 kgs of fuel. Now the complex nature of hypermatter does, I think, let us handwave around paying the mass penalties for this, but I am far from sure - I don't have the math to tell. But that can fit in 10% of the ISD volume at an order of magnitude less density then you came up with. A bigger concern is how they deal with that much stuff moving around (the gyroscopic effects) and hwo they keep it from reacting with itself. With regular fuel stasis fields can keep it from fusing under that much pressure, I doubt that tachyonic material will play that game.

if we say that when initiating a hyper jump the vessel needs 15 seconds to dump fuel into the reactor to warm up to jump and no other separate fuel quantities are used (this charge time would also suggest that the hyper jump is much more energetic than the 1e25 W output) you would still be able to make 1200 hyperjumps on the same amount of fuel. A 100,000 ly maximum range for fuel would mean that the vessel could only go 83 LY in a jump (complete nonsense)

Star Wars Technical Journal V. 2 gives the Lambda a range of 17 parsecs (55 light years) per jump. It doesn't make any sense for the reasons you state and conflicts with canon, but it isn't wholly out of the blue. Also, where does the 100k lightyear range come from?

I believe the range represents the largest distance the vessel can achieve in one jump before it needs to make a second jump. We know that the energy needed to stay in Hyperspace is orders of magnitude less than the energy needed to initiate the jump so the limitation must be of the hyperdrive itself or of some other subsystem. Interpreted this way the vessel could make 1200 jumps in lets say 2 years if it was on non-combat patrol duty which would allow it to make around 2 jumps per day.

That is one interpretation, and potentially valid, but it runs into problems with AOTC:ICS pointing out that the large range of the Acclamator marks the return of transgalactic warships, which would contradict or at least be a puzzling statement with your interpretation. Also, there would be no need to stipulate its 250k ly range was "fully fueled". Further, why would N-1s need to attach to the H-type space barge if they could just make more jumps every 1000 light years?

I don't disagree with the idea that fuel to stay in hyperspace and travel there should be far less then to enter it - Newton's laws of motion would hold then (always a plus) and it would mesh with statements in Rogue Squadron and Shield of Lies. However some other published stuff contradicts that, the aforementioned ICS books and this chart from the SWTJ would indicate that for some reason you need more and more energy to keep moving through hyperspace. I really wish Dr. Saxton would either resume updating or put up his incomplete notes on his site.

[Illuminatus Primus]

Hey Ender, where'd you get your 10^27 estimate? You really need to write a Publius-style essay so we can see what all your stuff is laid out, concise. These crumbs from the table are a tease.

[Ender]

Hey Ender, where'd you get your 10^27 estimate? You really need to write a Publius-style essay so we can see what all your stuff is laid out, concise. These crumbs from the table are a tease.

Typo. Should be 10^26. SWRPG 2nd ed, p.126 states a population of 100 quadrillion, so it is either 10^17 or 10^26. We have other sources stating a population of quintillions (of engineers and scientists alone in the AOTC ICS), so treating the metric value as correct allows all to be true. Plus that way the Confederate Droid Army doesn't outnumber the entire living population of the galaxy.

[evillejedi]

my mistake, should have written 2.7e9 tons total at 150,000 tons/sec

I used 10e6 m^3 for the volume in fuel silos in a 129e6 m^3 vessel, so less than 10% (about 7.7%) I also was extrapolating from practical run time rather than mass for this.

The 100K ly was in the OP, I was addressing that regardless if it was well sourced.

I haven't seen a quantification of fuel burn in HS vs realspace(would like to) other than it is less energy than the jump itself consumes (thus less than maximum output/s), but it would make sense if the hyperdrive function in hyperspace was partly of regulation rather than persistence (the hyperdrive prevents the vessel from superluminally accelerating when it impacts the realspace minute parts of the interstellar medium, which goes a long way towards explaining hyperspace lanes and routes for commercial traffic)

now about that 150,000 tons/s This one I really need an explaination on to nail down(to be honest I think it is more like 300,000). If you go by pure reactor volume the venstar is an utter piece of retarded shit, at best it has multiple reactors totaling to 1e6 m^3 (and maybe as low as .6 e6) so any direct reactor volume scaling to an ISD is a joke to begin with. The maximum reactor an ISD could support with subsidiaries is 10e6 so right away it could be nearly 10-20x more powerful (which could come up to a max of around 750,000 tons/s if directly multiplied)

now this is where I need some guidance, is surface area of a reactor more important than volume? (I haven't seen anything specific on SWTC that would indicate that volume isn't important, but also nothing that explicitly rules out internal surface area, which given that thermal dissipation in the hull uses neutrino radiators it is pretty easy to imagine the same tech being used in reverse to capture neutrinos) The reason I say this is that when you make surface area the important energy capture dimension almost all of the physical dimensional ratios work out to stated capabilities of vessels. In the venstar vs ISD case, the ISD comes out to around 5x more powerful, mon cals are 67% output of an ISD, dreadnaughts would be about 1/6th the output of an ISD, even all the way down to smaller frigates etc, it's almost uncanny how it works out... in fact it even explains why star cruisers and star dreadnaughts mount cylindrical reactors (and is backed up by the Hoth generator shape)

for the acclamator that makes a good point, the N-1's could simply be fuel limited (Afaik HS capable combat fighters only carry a few hours worth of fuel) To get anything useful out of the range would require a much better number for fuel burn in HS.

I would really like to see an explaination for that chart in more ways than one...

[Illuminatus Primus]

I'm pretty sure the AOTC numbers/Saxton's notes require a volume relationship.

[JGregory32]

Question, is that chart a chart of increasing velocity vs fuel consumption or is it differing Hyperdrive types versus consumption?

It's pointed out in various places that the Falcon has a .25 hyperdrive engine. Other sources I cannot remember off hand place most military vessals at .5 and civilian transportships at .75.
Though could some one please explain why faster speeds are indicated by smaller fractions of c?

[evillejedi]

Comparing to the 'warships of the empire notes' on SWTC and the AOTC notes it works out fine to be surface area, in fact it may be necessary for the reactors of larger vessels to be cylindrical to fit in the physical dimensions of the vessels.
if there was more accuracy on the outputs other than order of magnitude it would make a difference for getting ratios of 1x thru 10x. the split between e23 and e24 vessels is the same, between a carrack and a vindicator cruiser, the e24 to e25 split occurs between a victory and some of the new republic star destroyer redesigns, the e26 is home to both home one and giel's battle ship and the eclipse and executor remain e27 (though the executor is very low e27 in area based measurements and high e27 in volume based. (however lacking any great knowledge of the SSD internals its a guess anyway as to what type and count of reactors it has)[/list]

[Illuminatus Primus]

What about the Death Stars? The function should go all the way up.

[evillejedi]

if I scale from the venator reactor volume to the ISD. I get an ISD that is 760,000 tons/s, and e25 at a 135 m radius. calculating volume for a radius of 8km in the DSI I get barely e31 (which the SWTC power commentary puts the DSI at e33 and it is strongly suggested by superluminally scattering alderaan that the number may be higher.) SWTC says that 'The superlaser has a power source that is denser than ordinary matter or antimatter, or else it has a physical basis or energy source which is beyond mass-annihilation energy.' so I am willing to concede that an area reactor would be insufficient by far, but also point out that a volume based reactor would not be sufficient either using pure mass-energy conversion.

[Illuminatus Primus]

Link, I'm pretty sure that DS and other ships are modeled on basic mass-to-energy hypermatter annhiliation.

[evillejedi]

http://www.theforce.net/swtc/power.html#comparisons

http://www.theforce.net/swtc/ds/index.html#internal

Unless I am missing some data points or am misinterpreting things on SWTC, what I am trying to show is that there is a non-linearity of the scaling between small vessels and large battlestations using 4/3*PI*r^3 at equivalent fuel density, annihilation efficiency and energy capture efficiency.

All of saxtons work seems to be based on orders of magnitude which is not precise enough to be meaningful on comparisons involving vessels that are inside the same magnitude. Even he posits that the deathstar is of greater efficiency than normal annihilation. Add to this the fact that the Venator is about the worst yard stick in existence due to its wankery, saxton should have given us the reactor output of the ISD which is a yard stick for so many other calculations (which if it was 120,000 tons would still be insufficient to scale to the dimensional limits of the DSI at 160km, the ratio even with an ISD at 9.99999 e25 with a reactor volume minimized as much as possible and a maximum visually determined size for the DSI reactor would still yield high e31 very very low e32, you'd be min maxing beyond evidence to barely get e33 as a absolute maximum)

the reason I still support the argument for surface area scaling on normal vessels is two fold.

The physical dimensioning of the vessels to maximum contained sphere or cylindrical reactor (in some cases multiple spheres, but you lose too much volume to fit the fuel this way so cylindrical is optimal in most cases)

A scaling on surface area would allow for the same efficiency of energy capture per square meter which would be consistent with other neutrino manipulation devices. If the surface area was not the scaling factor for normal vessels then large vessels with their higher volume to surface area ratios would have to be significantly less efficient at capturing the energy and smaller vessels would have to be more efficient(unless you can convert the raw energy to usable energy in open space somehow). if you argue that neutrino capture of the material is 100% regardless of dimension, then you only need to base the calculations off of fuel density because the reactor dimensions drop out of the equation and you could develop nonsense uberships by just making denser fuel (which we are well under the limit for theoretical fuel density in SW technology)

[Illuminatus Primus]

He's not saying that E=mc^2 is fundamentally unworkable. What he's saying is it must be stored in a degenerate state or something similarly hypercompressed. I know Ender's numbers fit them both to a curve (what makes you think the relationship is linear?).

[Darth Wong]

It is not known how mass is converted to energy in the hypermatter scheme. If the hypermatter is tachyonic and maintained at an extremely high energy level, it is possible for its kinetic energy to actually exceed the energy you would get from annihilating its rest-mass. In theory, you could have an arbitrary amount of energy in a 1 gram piece of fuel, by accelerating it to the necessary velocity.

[Illuminatus Primus]

But relativistic effects means that 1 gram isn't 1 gram anymore for the purposes of mass penalties, is it? I suppose that the relativistic effects DON'T effect the density issues though.

You just "spin-up" the hypermatter to close to c and then let it accelerate to infinity to release all its energy.