What is this ship for? (2KTd Collector-1, hamster-wheel hull)

[Grav_Moped]

I started with this:

...
An easily-tolerated 1G from 2RPM needs a 224m radius. You're going to need to do this with a tethered pod, because even a 3m x 4.5m cross-section makes for a 1400Td ring at that radius.
...

And came up with what I think is a really interesting design at 2000 tons.

Roughly, it's that 450m diameter spun ring hull for 1400Td of living quarters and a 600Td non-rotating "axle" with part of the bridge tonnage, the Jump-1 Drive, a battery bank, plus a shuttle dock and cargo bay. It has a Collector-1. The minimal life-support and sensor/comms power requirements are supplied by thermal generators using the Jump Drive heat sinks (or waste heat from the collector when it's charging) as a heat source. (Yes, it's a house rule, but there's nothing on it that needs power in 250MW Energy Point increments except the jump drive, and the collector covers that.)

The interesting thing is that the Collector Canopy is entirely inside the spun ring, remaining stationary so it doesn't get centrifugal loading. There are elevator spokes alongside it to provide for access to the center hull (as well as a short-cut across the ring). There are also tram cars that run along both edges of the ring for fast point-to-point transit.

The canopy does not need to retract for Jump, as it's contained within the Jump field generated by the ring hull (this is a house rule, but it feels plausible).

The ship has [or may have] what MgT calls "Maneuver-0" (station-keeping or very slow transit); when under (small-fractional-G) thrust, the canopy is held in place by low-power grav generators on the ring and the elevator struts. It has a small power plant for this purpose, but it's offline unless maneuver is required. Using T5 collectors rather than Double Adventure 1 collectors means it doesn't really need any maneuver capability since the collector doesn't have to be pointed at a star to gather energy.

I don't think it's armed. If so, it'd need a [bigger] power plant to support weapons.

Haven't run any numbers on it other than to note that the canopy area can be proportionately 150% larger than the one on ANNIC NOVA in terms of Jn X Td before it reaches the inner surface of the ring hull.

Crew is going to be about 20, mostly engineers. It will be able to carry more than 300 passengers. Might have a couple of hundred tons free for shuttles and cargo.

Since it gets nearly all of its power from the Collector (either directly, or indirectly from the jump drive heat sinks), it can keep going as long as the food supplies last. It's just not going very fast -- one Jump-1 every other week

Here's my problem: it's nifty and all, but... what's it for?

It's kind of slow for a passenger liner, and inconveniently laid out as well. Not a great troop ship, either. If it's just for rift crossings, a conventional ship using drop tanks or fuel caches would be more effective.

Maybe swap a bunch of the staterooms for hydroponics and carniculture vats for extended life support capacity?

Any suggestions for why someone would build this thing?

 

[Matt123]

My first thought was it sounds like a modern day airship. Quirky and likely to be a boon to mankind, if only mankind was not in such a rush to get places.

Following this logic, it would never be a mass produced or even slightly popular vehicle. It would however feature in designs that harken back to the days many people long for, when life was slower and simpler. The generic principles of the design will be fairly well known, but not researched well enough to convince enthusiasts that there is not still magic to be found in the concept.

Keep in mind that I'm a CT guy, so I may have a couple of the underlying T5 concepts wrong.

Failed (or maybe successful) commercial concepts might include;

• using robotics to cut down the crew complement to a handful of people,
• a modular cutter holding (assuming I "get" what the collector does) a large battery bank that can be charged at local ports speeding turnaround,
• differing ideas around optimum diameter, with optimising relating to
  • cargo or passenger capacity
  • fuel or energy efficiency
  • energy signature hiding
  • hydroponic support needed for desired community size
  • comfortable Gs vs spin rate
  • size and efficiency of the catcher
  • size of the inner hub
• luxury month long holiday cruises to the next system offering two weeks of spaceport visits with grav limo or grav tour bus services to exotic sights - with no need to ever change hotel room or risk local food,
• budget cargo haulers with dangerously low crew numbers that get serviced by system based engineers during the two week turnaround
• sublight interstellar travellers that choose the purity of sublight travel in the knowledge their descendants on arrival will not have been exposed to the terrors and evils that lurk in jump space
• small hermit or retirement communities in deep space that use jump rarely and only to reach advanced medical facilities if needed.
• deep space family or cult mausoleums that only need jump for crew emergencies (funerals go to them)
• hmmm, more on the deep space theme
  • deep space research
  • deep space fuel depot (eg. allowing J1 merchants to cross a J2 gap)
  • deep space early warning (year long deployment, jump home if you see million ton Fleet Tankers and warships enter your location)
  • deep space rare gas, minerals or isotope miners
  • deep space mis-jump rescue facilities (for low tech systems with low regulatory maintenance requirements)
  • deep space prison colonies (no small craft on board, the entire prison auto-jumps if the crew loses control)
  • deep space arks holding seeds, culture, information to rebuild society and eminent citizens on 10 year duty "on ice"
• entrepreneurs exploring the latest ideas

Just some random thoughts. I like where you are going even if it is slowly

 

[AnotherDilbert]

The interesting thing is that the Collector Canopy is entirely inside the spun ring, remaining stationary so it doesn't get centrifugal loading.

Even the much smaller Annic Nova canopy isn't that small.

... outside will note that the canopy is unfolding. After about an hour, the process will be completed, revealing a skeleton framework and a circular thin black radiation-absorbent film about 1 kilometer in diameter.

Note that even a solar panel of that size would not produce more than ~800 MW in habitable orbit, or about 3 EP, too little to even produce basic power for a ship of that size.

Magical indeed.

 

[chipla]

Deep space black-site.

You can use it for research too sensitive or dangerous (or illegal) to be done in civilised space. Or you can start in civilised space and jump into deep space when the nanites or zombies get loose.

Can also be space gitmo. Assuming most of the great powers of your setting are opposed to enhanced interrogation techniques (either morally or practically) all those pesky non-lawful combatants (Ine Gvar, Zhodani infiltrators, terrorists, jaywalkers, etc) you find can be dealt with off in deep space away from prying eyes.

Can also be used by those who have a lot of time and don’t need to rush about. Think 1920s grand tour - take a few months Holliday and get to your destination in style with casinos and pools etc. Of course while you’re in that deep space casino looking at that nebula some one will get murdered and it’s four days till you can collect enough matter to jump…

 

[robject]

It sounds like a neat variation on the laboratory ship.

I'd love to see this written up. I would've put it in Xboat.

Heck, I could put it in Xboat No. 5.

 

[MThompson016]

It sounds most useful as a labship. A small powerplant maybe useful for more intensive energy consumption, though.

 

[willtron3030]

If the collector was *one* side, the other could be tiled with individually steerable reflectors, to emulate a 450m reflector dish with variable radius of curvature.

 

[whulorigan]

A very general comment: don't overlook the angle that it could be an alien design for a non-humanoid sophont species. I didn't have a particular race in mind, but perhaps some of the needs and/or sensibilities of some hypothetical race (perhaps from outside Charted Space even) are different than ours.

 

[Grav_Moped]

It's too small, as AD noted. Minimum viable size is about 1Km diameter, 3000Td with about 2500Td in the ring and 500Td in the hub*. Requires a 1.33RPM spin for 1G, tangential velocity is about 70m/sec.

Even the much smaller Annic Nova canopy isn't that small.

Responses hidden for clarity.

Spoiler:

ANNIC NOVA has a ~1km diameter canopy, which (as written) supports a 5-parsec range as J3 + J2 since DA1 didn't include the self-discharge in 24 hours. As such, it supports 3000Td X Jn. This one [Note: smaller first-attempt, not the viable 1km diameter version] is 220m diameter, and has 1/5.16 the area. Ok, I undersized it... expand the diameter and drop the RPM to keep it at 1G. I'll get to the math later, but area goes up as square of diameter while tonnage (circumference, with a constant cross-section ring) only goes up linearly by diameter. At a large enough diameter, the concept is viable.*

For a 1km diameter collector at 100% efficiency on a 3000Td hull, it intercepts the equivalent of Pn-0.87.

Note that even a solar panel of that size would not produce more than ~800 MW in habitable orbit, or about 3 EP, too little to even produce basic power for a ship of that size.

Magical indeed.

At 100% efficiency, the ANNIC NOVA's 1km diameter collector intercepts the equivalent of about Pn-4.3 for its 600Td hull (at 1AU from Sol). This is enough power for AN if you're using 1st Ed. LBB2, which AN did. It kinda works for MgT if you assume that baseline power without artificial gravity is "emergency power" level (and I think MgT implies that "emergency power" includes artificial gravity). T5 allows even lower power levels. Extracting that much energy from the waste heat of the jump drive and accumulator should cover it without much more magic than the drives themeselves use...

The place where it all breaks is the 2nd Ed (and up) requirement for Pn=Jn and the baseline power requirements that implies.

* 1km diameter with a 10.6m² cross section for the habitation ring (3m x 4.5m ellipse), for a 3KTd ship. Ring is about 2467Td (3142m circumference x 10.6m cross-section), remaining tonnage is 523Td. Of that, drives are about 360-400Td depending on whether you're using T5 with stage effects, or LBB2 '81. Part of the 40-80Td of the Jump Drive can be in the ring. The rest can be cargo or carried craft. Consider "choking down" some parts of the ring to a 3m circular cross section from the 3m x 4.5m ellipse; this cuts the cross section in those parts of the ring from 10.6m² to 7m², allowing 26.67Td to be shifted to the hub section (or elevator shafts) for each 100m of smaller cross-section.

It needs to spin at 1.33RPM to provide 1G.

Docking small craft to the ring itself while it's rotating would be difficult, but not impossible (tangential velocity is 70m/sec; it takes good timing...). Lifeboats ought to be included in the ring tonnage, but seldom used (and maybe only launched in pairs to avoid unbalancing the ring).

 

[Grav_Moped]

My first thought was it sounds like a modern day airship. Quirky and likely to be a boon to mankind, if only mankind was not in such a rush to get places.

Following this logic, it would never be a mass produced or even slightly popular vehicle. It would however feature in designs that harken back to the days many people long for, when life was slower and simpler. The generic principles of the design will be fairly well known, but not researched well enough to convince enthusiasts that there is not still magic to be found in the concept.

Keep in mind that I'm a CT guy, so I may have a couple of the underlying T5 concepts wrong.

Failed (or maybe successful) commercial concepts might include;

Spoiler:

• using robotics to cut down the crew complement to a handful of people,
• a modular cutter holding (assuming I "get" what the collector does) a large battery bank that can be charged at local ports speeding turnaround,
• differing ideas around optimum diameter, with optimising relating to
  • cargo or passenger capacity
  • fuel or energy efficiency
  • energy signature hiding
  • hydroponic support needed for desired community size
  • comfortable Gs vs spin rate
  • size and efficiency of the catcher
  • size of the inner hub
• luxury month long holiday cruises to the next system offering two weeks of spaceport visits with grav limo or grav tour bus services to exotic sights - with no need to ever change hotel room or risk local food,
• budget cargo haulers with dangerously low crew numbers that get serviced by system based engineers during the two week turnaround
• sublight interstellar travellers that choose the purity of sublight travel in the knowledge their descendants on arrival will not have been exposed to the terrors and evils that lurk in jump space
• small hermit or retirement communities in deep space that use jump rarely and only to reach advanced medical facilities if needed.
• deep space family or cult mausoleums that only need jump for crew emergencies (funerals go to them)
• hmmm, more on the deep space theme
  • deep space research
  • deep space fuel depot (eg. allowing J1 merchants to cross a J2 gap)
  • deep space early warning (year long deployment, jump home if you see million ton Fleet Tankers and warships enter your location)
  • deep space rare gas, minerals or isotope miners
  • deep space mis-jump rescue facilities (for low tech systems with low regulatory maintenance requirements)
  • deep space prison colonies (no small craft on board, the entire prison auto-jumps if the crew loses control)
  • deep space arks holding seeds, culture, information to rebuild society and eminent citizens on 10 year duty "on ice"
• entrepreneurs exploring the latest ideas

Just some random thoughts. I like where you are going even if it is slowly

Good ideas, and lots of them!

A few quick responses:
- This thing doesn't need a small crew. The spun section has room for everybody! (That's actually a problem I'm trying to resolve here: who could use this much living space?)
- Making the accumulator component of the Collector detachable and modular really screws up gameplay balance -- it's too effective as a Jump power source. (It's not allowed in any version of the rules.)
- I really like the "embrace the slowness" aspect of your responses.

 

[Grav_Moped]

Deep space black-site.

Spoiler:

You can use it for research too sensitive or dangerous (or illegal) to be done in civilised space. Or you can start in civilised space and jump into deep space when the nanites or zombies get loose.

Can also be space gitmo. Assuming most of the great powers of your setting are opposed to enhanced interrogation techniques (either morally or practically) all those pesky non-lawful combatants (Ine Gvar, Zhodani infiltrators, terrorists, jaywalkers, etc) you find can be dealt with off in deep space away from prying eyes.

Can also be used by those who have a lot of time and don’t need to rush about. Think 1920s grand tour - take a few months Holliday and get to your destination in style with casinos and pools etc. Of course while you’re in that deep space casino looking at that nebula some one will get murdered and it’s four days till you can collect enough matter to jump…

Good suggestions. A few of these can be done with more conventional starships as well.

 

[Grav_Moped]

It sounds like a neat variation on the laboratory ship.

I'd love to see this written up. I would've put it in Xboat.

Heck, I could put it in Xboat No. 5.

Once I get the kinks worked out, I'll probably do a full writeup. It's weird enough to be interesting.

Basically, it started with "you need a really large diameter ring for comfortable spin gravity", bumping into "hey, wait -- that ring is almost as big as the collector canopy!", and here we are. Give or take a math error... LOL.

As a side note, having the spun ring on the perimeter of the Canopy spoils one of the nifty Collector ship tactics: hiding most of the hull behind the more-than-perfectly-energy-absorptive canopy for effective invisiblity in a large arc (not quite 180^o) aside from your shadow on the starfield.

 

[Grav_Moped]

It sounds most useful as a labship. A small powerplant maybe useful for more intensive energy consumption, though.

Yeah, it'd make a decent lab ship, but it's starting to approach the size of a Research Station after I dealt with my math error.

No problem, now it's a self-propelled Research Station!

 

[Grav_Moped]

If the collector was *one* side, the other could be tiled with individually steerable reflectors, to emulate a 450m reflector dish with variable radius of curvature.

The original ANNIC NOVA could probably handle that (it needs to be near a star). T5 and MgT collectors don't (they work in deep space too, and probably collect energy from both surfaces of the canopy).

I'd briefly considered fixing my original concept by using two (T5/MgT) canopies, spaced a few meters apart, in the middle of the ring. Then I stopped to consider how the canopies function and realized that the space in between the two would probably be subject to some really weird effects, even if the canopies didn't interfere with each other.

 

[Grav_Moped]

A very general comment: don't overlook the angle that it could be an alien design for a non-humanoid sophont species. I didn't have a particular race in mind, but perhaps some of the needs and/or sensibilities of some hypothetical race (perhaps from outside Charted Space even) are different than ours.

Good point! Maybe there are aliens who don't react well to canonical artificial gravity and need to use spin-gravity instead. We already have some canonical self-replicating machines that can't handle jump space, so it's not impossible.

 

[Grav_Moped]

Some comments on the design:

- Really, a conventional collector-driven ship would be better for nearly all purposes. The point behind using spin-gravity is to save enough energy by not using artificial gravity fields so that the basic life support can be run off thermocouples from the jump drive heat sinks or those of the collector's accumulator. This would enable operation for as long as food and life-support expendables last (which if there's a large hydroponics/carniculture-vat section, could be quite a while). If that's not a critical matter, save yourself the trouble and just build an ordinary collector-driven ship with an auxiliary fusion power plant and a decent-sized fuel tank.

- It's more of a self-propelled deep space station than a starship meant to go between points, though it can do that too. The main thing it can do is go for months -- perhaps years -- without needing to encounter another ship or world. (Yes, this feature isn't helpful if you're trying to have adventures, unless you want an endless succession of locked-room mystery scenarios.)

- The main operational advantage this configuration has is that it can jump immediately at any time after the collector gathers a full charge, because it doesn't have to fold the canopy. I'll admit that a jump bubble that's 1km across and just a few meters thick stretches the concept a bit, but I'll cite the Lab Ship as precedent.

- As I mentioned in a previous response, having the spun ring on the canopy's perimeter spoils one of the few tactical advantages of a collector-driven ship: the ability to hide most of the hull behind the canopy. The canopy not only absorbs any energy that encounters it (radar, etc.)* but also absorbs energy that isn't even there**. It's only effective from one side (somewhat less than a 180^o hemisphere), but on that side it's at least as good as a black globe for cloaking purposes. And, no, this version can't do it since the ring is outside the canopy.

- The ring is essentially a 3-deckplan-square-wide loop that's over 3km long. Not terribly convenient, but having people-movers running along the outside edge helps some.

- My original idea was that all carried craft would dock at the hub. I now think there should be lifeboats/launches in (or attached to) the ring section. They'll only be launched in opposing pairs, for balance. If only one is needed for a given mission, the other will recover to the docking point at the hub until the deployed craft returns. Docking to the ring isn't a trivial task, but it could be automated. (The maneuver won't be standard in most small-craft autopilots, but a programming team with Computer-1 and Small Craft Pilot-1 can define it for the autopilot in under an hour.)

- Here's a good online calculator for spin-induced artificial gravity math: SpinCalc ( ht tp://www.artificial-gravity.com/sw/SpinCalc/ )


*Annic Nova from DA 1 didn't need more energy than the canopy would intercept in Earth-orbit-equivalent because of how the 1977 rules worked.
**T5 and MgT rules imply that the canopy produces more energy than it would intercept, and no longer require a nearby star to operate. So, they're now pulling energy out of nowhere...

 

[AnotherDilbert]

Historical reenactment ship?

 

[Grav_Moped]

Historical reenactment ship?

Spoiler:

RACING YACHT!!!!

No, seriously. This configuration saves two hours per recharge by not having to fold or deploy the canopy! And you really could have a race between Collector-powered ships where maintenance and skill would make a difference. (How fast do you dare deploy and fold the canopy? Does a brand new canopy give you a charge-rate advantage?)

I posted more on collector-drive yacht racing in the General Collector Discussion Thread.

Historical reenactment might work for cultures that got Collector tech before fusion tech. (Hey, it could happen...) But this sort of goes back to the IMTU idea that Collectors are niche and deprecated technology in the OTU, rather than being completely unknown until the discovery of the derelict ANNIC NOVA. Probably tried at earlier TLs and the Experimental/Prototype/Early versions were so ineffective that the idea was discarded.

Unless the tech has been deliberately suppressed. OTU history says this kind of thing happens.

 

[Grav_Moped]

I've found a use for it.

It's a Zhodani Discotheque.
Spoiler for Agent of Empire follows:

Spoiler:

There's a Zhodani world with a collective of psionic reality warpers whose dancing changes timelines. They have no need to put them on a starship that can hide indefinitely in deep space, but other cultures might have to do this.

Background for a possible scenario:
It's a Sindalian Empire platform for/of a small battalion of weaponized psionics; initially as reality warpers, then for direct telepathic and telekinetic attack. Most of them are developmentally disabled, as with the AotI example. Some are children.

And then there came the paradox.

(You could build something like it at TL 13 -- the Sindalians' max TL -- using a Prototype Collector-2 that amounts to a 25% oversized Collector-1: 559m radius canopy, 562m spun ring for 2770Td spun.)

The reason it's still there to be found in the early 1100s is that the lead psionic used the massed power of her psionic minions to wish the ship out of existence, thereby creating a paradox: if it doesn't exist, then there's nothing to have made it cease to exist -- so it exists and can make itself not-exist. And then it can't. And so on...

It's been frozen in this loop for 2500 years.



Why did she do this? You see, reality warping is a relatively bloodless enterprise. Change some odds, things that wouldn't have happened do happen. Your allies get lucky, a lot. There's no direct involvement in your adversaries' doom -- it just happens.

The problem she faced is that when you alter timelines, nobody notices because the (changed) outcome seems inevitable in hindsight. Her superiors demanded more obvious interventions: telekinetic and telepathic attacks.

The army of psychics on board hadn't been conditioned to cope with that, though. They managed a few small practice attacks with only some backlash, but during their first real assault the horror of directly dealing death killed two dozen of the minions and traumatized hundreds more, and appalled the lead psionic. Unfortunately, it was visibly effective, and her superiors demanded an encore.

After weeks of psionic work with her team leads to bring the minions back into alignment, they were ready. So was she. And she knew that it was better that they'd never existed in the first place than for them to go through that again.

She tried to make it so -- but didn't quite succeed.


The effects of this half-existence on sophonts interacting with the derelict are what would make the scenario interesting. Honestly, I'm not sure how that would work... (suggestions?)

And if the PCs somehow manage to break the ship and its crew out of the loop, what then? Their Empire is two and a half millennia gone, the Third Imperium would nuke them in orbit if they found out about them, and the lead psionic is a traitor to the ship's crew (but the psionic army on board understands why, to the extent they understand anything).

 

[robject]

It's a Zhodani Discotheque.

Great. Now I've got the Bee Gees in my head.