StarDestroyer.Net BBS

Does anyone know the logistics of a Star Destroyer? How long can it go without resupplying?

I'm just wondering, to supply ~35,000 crew members, service their vehicles and weaponary.. I would imagine the SD would need to be a lot bigger than it already is to go for some time without resupplying. Also, how long does it take to resupply a SD? The bays can only hold and process so many at a time.

I wondered the same thing. I have a exploded cross-section of an ISD and it seems to have very little space for spare parts for its volume.

According to Dark Fleet Rising, resupply takes just under a week(Four to six days) and it can run on its stores for many months before Resupplying agian, Two months is the minium its expected to be able to surive on its own with one year being the max.

SDs are fast enough to not need in-space repleneshing, i'd think. need food? hyper back to the nearest outpost and pick up food, then hyper back, in a few hours.

kojikun wrote:SDs are fast enough to not need in-space repleneshing, i'd think. need food? hyper back to the nearest outpost and pick up food, then hyper back, in a few hours.

While they technically could do that, I'm sure it would be much more economical to simply carry food and supplies on board. Hyperspace isn't free, after all...

Dark Force Rising, Bean...

It should have been the Dark Fleet! Not the Dark Force. NEVER will I say any diffrent!

kojikun wrote:SDs are fast enough to not need in-space repleneshing, i'd think. need food? hyper back to the nearest outpost and pick up food, then hyper back, in a few hours.

That seems time and economically inefficient. Maybe their support ships carry cargo like in modern day task forces? I mean, have you seen the consumption rates for modern supercarriers? Good god, it's amazing they can even make it across the oceans with 5,000 mouths to feed.

Someone here was also talking about supllying a Death Star well given its sioze they could use droids to farm all there food for em and use the plants or whatnot to clean the sewage and air to a degree

Why would it be so inefficient for a Star Destroyer just to hyper to the nearest supply depot? AFAIK, a Star Destoyer is not on exploration duty but patrol. Surely their routes are in accordance with the supply depot locations. Besides which, it's doubtful that a ISD would wait until they are completely out of food, etc... to restock. There is probably some kind of safety margin in place.

XPViking

XPViking wrote:Why would it be so inefficient for a Star Destroyer just to hyper to the nearest supply depot? AFAIK, a Star Destoyer is not on exploration duty but patrol. Surely their routes are in accordance with the supply depot locations. Besides which, it's doubtful that a ISD would wait until they are completely out of food, etc... to restock. There is probably some kind of safety margin in place.

XPViking

To paraphrase, it takes more energy for an ISD to make a jump than many planetary civilizations consume in their entire existences. That's a lot of energy, even by SW terms. While it is not impossible for them to jump every time they need something, I have a feeling it would be cheaper to stock up once, do whatever they need to do until they need to restock, and then resupply. If they reduce the number of jumps they need to make by only one, they will be saving enormous amounts of money.

I'm not saying that the ISD hypers to the nearest depot because somebody lost a wrench. I understand it as the ISD gets resupplied once, maybe twice a year. For the most part, the ISD is cruising around.

Of course hyperspace isn't free, but how often does an IDS hyper around? As well, depending on the circumstances, I suppose a supply depot can send a freighter out to an ISD if the ISD is lacking some critical components.

XPViking

XPViking wrote:I'm not saying that the ISD hypers to the nearest depot because somebody lost a wrench. I understand it as the ISD gets resupplied once, maybe twice a year. For the most part, the ISD is cruising around.
Of course hyperspace isn't free, but how often does an IDS hyper around? As well, depending on the circumstances, I suppose a supply depot can send a freighter out to an ISD if the ISD is lacking some critical components.

Well yeah, an ISD supplies by hypering to the nearest depot or having a resupply convoy rendezvous with them. But koji's original idea was "need food? hyper back to the nearest outpost and pick up food, then hyper back, in a few hours." That is what I was calling uneconomical.

I'd imagine that, yes, as you said, a few times a year, the ISD visits a supply depot and takes a few hours filling its stores. Any additional supplies could be provided by roving transport fleets.

I'd imagine that an ISD would also have animal nurseries onboard, as well as hydroponic farms. Not that I have a point, I just think that's interesting.

Mr Bean wrote:According to Dark Fleet Rising, resupply takes just under a week(Four to six days) and it can run on its stores for many months before Resupplying agian, Two months is the minium its expected to be able to surive on its own with one year being the max.

6 years according to RPG's

jaeger115 wrote:I wondered the same thing. I have a exploded cross-section of an ISD and it seems to have very little space for spare parts for its volume.

I wonder about those cross sections, I'm pretty sure they have machine shops and everything.

They do have dedicated cargo vessels like Star Galleons. I seem to recall at least 1 description saying resupply was part of their function

Most of you guys are all looking at this from the wrong direction. Given the mission requirements of an ISD, the optimum 'supply' methodology is not to carry huge quantities of end-use items, such as food, CO2 scrubbers, oxygen, and spare parts, but rather to use closed cycle life systems wherever possible and to make parts as needed.

Instead of carrying X months worth of food, carry a farm. In the end, it'll weigh less, use less space, and cost less than carrying around years worth of food.

That was my reference to machine shops anyway, with their observed molecular, possibly subatomic (effective)controll of matter they could make most spare parts themselves.

All the sources I've come across so far have specified that a standard ISD has a complement of 8 Lambda-class shuttles for cargo and personnel transfers. These shuttles have long range hyperspace capability, effectively being small starships in their own right, and in ROTJ it aroused no undue suspicion for a shuttle of that class to be on a supply run to provide a base with parts and personnel.

Obviously, even the entire complement of shuttles would not be enough to completely replenish and ISD in a reasonable period of time, but regular supply runs (maybe averaging four shuttles worth of supplies daily) would dramatically extend the endurance of the vessel. Only those supplies that a Lambda could not transport would pose a problem, things like particularly volatile substances or major mechanical components too large to possibly fit inside a shuttle.

A Lambda shuttle used purely for cargo can carry up to 80 tons of cargo. Thus, just four shuttle loads per day would provide an ISD with up to 320 tons of supplies. That should be enough for daily replenishiment, and it is probably more energy-efficient, not to mention tactically efficient, to have a few relatively small shuttles make a hyperspace hop to a resupply base or a Star Galleon rendezvous point than to have the entire ISD do so.

Water should be a relatively low priority in terms of resupply, for the simple reason that even on an ISD with sharply limited recycling facilities, recycling the majority of the waste water is a trivial operation. Each load of cargo would likely average a cubic meter or two of water nonetheless, to make up for inevitable losses and to provide wonderfully fresh water for the officers' mess. Unrecyclable liquid waste might well find itself used as reaction mass by the massive ion engines.

Similarly, oxygen and carbon dioxide processing, especially using high energy methods, would be such a trivial bit of engineering that producing an ISD without atmosphere recyclers would be abysmally stupid and impractical. That would limit the necessary atmosphere processing supplies to loss replacement and precision parts and materials that it is not practical to fabricate aboard the ISD.

As for the fabrication or repair of minor mechanical parts, that is what the machine shops of real-world naval vessels are there for, and extending that capability to an ISD is not unreasonable.

Small amounts of food might be produced aboard an ISD, in something like a captain's garden, but under most circumstances it would be much more practical to simply shuttle in a load of fresh food every few days to supplement the normal stores of rations.

So what is the duty cycle for a Star Destroyer? What percentage of its time is spent "in port" for repairs, refit and training? Even the US generally has less than 1/2 of the fleet actively deployed. And most modern navies don't achieve even that.

Here are the offical USN figures for today:
Ships Underway: 206 (67%)
On deployment: 163 (54%)
Submarines underway: 27 submarines (51%)
On deployment: 16 submarines (30%)

I can't imagine the personel on a Star Destroyer could take more than a six odd month cruise without needing to return to their home base for training and downtime. If that is the case they would probably stock sufficient supplies for a full cruise. They would suppliment that, as Patrick suggests, with some regular trips by Lambdas to pick up fresh produce for the officers and the occasional part that could not be worked up in the ISDs own machine shops.

Enlightenments comment is ill-placed: We've seen at least stabs at an ISD's internal spaces, and there's no farms there. There's apparantly widgets called 'Food Replicators', though, if that helps.

Ultimately, having dedicated cargo tenders hypering from the ISD to the supply base makes the supply train almost unassailable. Hell, they can be assigned to the supply bases and go out to any ship in a certain radius that needs resupply.

As for downtime and training, an ISD is, effectively, a city of 50,000 people, with a pop density probably close to that of an urban center. Since they can be on patrol for years, I find it impossible to believe there are not both entertainment facilities(Hell, one can easily imagine a 'Red Light' district slowly growing near the engineering space), and training facilities onboard.

I do believe I may have found the likeliest method of major resupply for an ISD.

The ISD and a medium bulk freighter, like the Corellian Action IV Transport, meet at a designated rendezvous point. The freighter, which is just a box 100 meters long, fits handily in the larger docking bay of the ISD. Then the designated cargo is transferred. The stated cargo capacity of the bulk freighter, at 30,000 cubic meters or 75,000 tons, whichever comes first (with various holds that can be partially or fully pressurized and climate-controlled), handily exceeds the ISD's stated cargo capacity of 36,000 tons.

One of the stated uses of converted bulk freighters, per "The Star Wars Sourcebook" of West End Games fame, is as a fleet resupplier.

That would leave minor or sensitive cargo transfers to the Lambdas.

I'm willing to bet that the only reason an SD would ever go to port is for major maint and when its crew is on leave. i also doubt that it would ever need to resupply with food, as they could produce plenty from hydroponics etc and minifarms. the metal supplies they would rarely need and if theyre nowhere need a civilised world they could hang around an asteroid field or hyper to one for extraction of metals (the farthest from an asteroid field theyre ever likely to be is ~3 LY). For officer training they would use training centers on the ship. Non-manufacturable materials or items would be hypered in by smaller vessels so the ship wouldnt need to leave its post.

So the only reason to leave patrol is when the ship needs massive work done to it or when the crew gets planet/station leave.

kojikun wrote:I'm willing to bet that the only reason an SD would ever go to port is for major maint and when its crew is on leave. i also doubt that it would ever need to resupply with food, as they could produce plenty from hydroponics etc and minifarms. the metal supplies they would rarely need and if theyre nowhere need a civilised world they could hang around an asteroid field or hyper to one for extraction of metals (the farthest from an asteroid field theyre ever likely to be is ~3 LY). For officer training they would use training centers on the ship. Non-manufacturable materials or items would be hypered in by smaller vessels so the ship wouldnt need to leave its post.

So the only reason to leave patrol is when the ship needs massive work done to it or when the crew gets planet/station leave.

It may not be economically practical, though, to work with extensive onboard fabrication and food production. We have canon evidence that an ISD will dump huge volumes of trash, including lots of massive machine parts sized similarly to tramp freighters. If the ships had extensive metals extraction and reprocessing facilities, it would not make sense to just dump that stuff. Basic waste and water reprocessing is almost certainly there, but apparently some official sources indicate that an ISD does not have extensive recycling facilities, leading to the practice of dumping damaged major items as garbage.

The economics of hyperspace transport make things a bit different than with modern navies. Even a bulk freighter with an anemic class 3 hyperdrive can move across the galaxy as quickly as Darth Spikypate did, and at sufficiently trivial expense that it is practical to support the population of Coruscant on food imported from around the galaxy. The Corporate Sector Authority maintains entire planets that serve as giant farms, with it apparently being economically lucrative to ship bulky, low-value goods like grain over interstellar distances in robot barges with hyperdrives.

In such an environment it would actually be wasteful to install extensive farming/hydroponics facilities on warships. Any wastes not easily recycled by automated systems should be dumped, for the simple reason that it would be much more expensive to recycle. Also, dumping the trash keeps the major contractors happy, as there is constant demand for resupply (and undoubtedly Palpatine and his cronies were among the backers of many of those contractors, or at least received massive bribes).

I seem to remember that in the Hand of Thrawn series, a character mentioned that there were over 100,000 flaws in the SD's design, so you have to count in repair time each time a ship comes into port. The war and tear on a SD are pretty bad, considering how long it takes to rearm and repair some of the systems.