Spin-Hab Transition Areas

[SpaceBadger]

For those of you designing ships w habitats that spin for simulated gravity (ie, 2300AD or hard-sf Traveller games without gravitics), what kind of transistions do you use between the spin-habs and the non-spinning core of the ship?

Of course, one answer is to either spin the core or de-spin the habitat so that they are stationary relative to each other, and then simply move between them (or climb or use an elevator if the spin-hab is separated from the core by spokes). Seems to me you might not want to have to do that for every shift-change or other time someone needs to pass from one to the other.

Also, what if you want/need to keep the habitat spinning (as for example a long haul passenger liner whose passengers won't do well in zero-G) but need to have crew move from one portion to another?

One thought I had was to have a spinnable collar between the non-spinning core and the spinning habitat. You match the collar up to which ever part of the ship you are moving from, then enter the collar, then spin or de-spin the collar to match up with the part you are moving into, then move on. I'm pretty sure that would work, but it seems inefficient and a potential point of failure that would isolate one part of the ship from the other.

Anybody else have some better ideas as to how you do it in your designs?

 

[Vladika]

You really wouldn't need to spin/de-spin the collar in question. Assume the collar is on the "axle" of the spin module (habitat). The collar itself is "split". The portion from the "ship" doesn't spin but the second half does (we are assuming zero g at this location).

Move from the non-spinning end to the spinning end. It will be a relative slow spin. Reach for a grab bar and move DOWN the "spoke" to the rim. Gravity then goes from zero to whatever it will be at the point on the rim you reach at the end of your climb.

You will be climbing down backwards or taking an elevator/lift.

 

[McPerth]

I envision more like a non-spinning axis with some portions (the entrances) that may spin to match the spinning zones. You climb a ladder (or an elevator, if large enough) to the entrance, with simulated gravity being lower the closer you are to the axis.

When you arrive close to the axis (with simulated gravity near to zero), it spins to match your habitat, so you can enter it. when doors are closed, it matches the rest of the axis ans stops spinning, until you reach another door and order it open. then that axis section begins to spin to match the hábitat you're now in and door is open to another ladder/elevator for the new habitat.

Of course, as diferent habitats are spinning in oposite directions (to keep the balance of the ship), no direct habitat to habitat comunication is posible without stoping the spinnings (only on emergency situations).

 

[Vladika]

I envision more like a non-spinning axis with some portions (the entrances) that may spin to match the spinning zones. You climb a ladder (or an elevator, if large enough) to the entrance, with simulated gravity being lower the closer you are to the axis.

When you arrive close to the axis (with simulated gravity near to zero), it spins to match your habitat, so you can enter it. when doors are closed, it matches the rest of the axis ans stops spinning, until you reach another door and order it open. then that axis section begins to spin to match the hábitat you're now in and door is open to another ladder/elevator for the new habitat.

Of course, as diferent habitats are spinning in oposite directions (to keep the balance of the ship), no direct habitat to habitat comunication is posible without stoping the spinnings (only on emergency situations).

I think we are on the same thought process, with only slight differences. Either would work fine.

 

[Carlobrand]

For those of you designing ships w habitats that spin for simulated gravity (ie, 2300AD or hard-sf Traveller games without gravitics), what kind of transistions do you use between the spin-habs and the non-spinning core of the ship?

Of course, one answer is to either spin the core or de-spin the habitat so that they are stationary relative to each other, and then simply move between them (or climb or use an elevator if the spin-hab is separated from the core by spokes). Seems to me you might not want to have to do that for every shift-change or other time someone needs to pass from one to the other.

Also, what if you want/need to keep the habitat spinning (as for example a long haul passenger liner whose passengers won't do well in zero-G) but need to have crew move from one portion to another?

One thought I had was to have a spinnable collar between the non-spinning core and the spinning habitat. You match the collar up to which ever part of the ship you are moving from, then enter the collar, then spin or de-spin the collar to match up with the part you are moving into, then move on. I'm pretty sure that would work, but it seems inefficient and a potential point of failure that would isolate one part of the ship from the other.

Anybody else have some better ideas as to how you do it in your designs?

I travel quite a bit in my job, mostly by car but occasionally by plane - ergo airports. In some of the larger airports, they have these moving tracks that people step on and it takes them from one end of a long walkway to the other, so they can stand and rest (or walk along it and get there faster).

Now I imagine that I'm in a ship with a rotating section. In essence, I'm standing on the inner surface of a drum - I'm on a hamster wheel, held to the bottom by the rotation of the wheel. I exit the section onto a floor that rotates with the drum section. Depending on the speed of rotation, I may be able to step directly from that floor to a section of floor that's not rotating, or I may step from that floor to a series of tracks rotating at slower speeds until I'm slow enough to step onto the nonrotating section.

Alternately, I could use an "elevator"-like section that runs the perimeter of the circle (not up and down) to bring me to matching speed: step in one door, it gradually slows down or speeds up until it matches speed with the other section, then step out the other door into the other section.

 

[SpaceBadger]

Now I imagine that I'm in a ship with a rotating section. In essence, I'm standing on the inner surface of a drum - I'm on a hamster wheel, held to the bottom by the rotation of the wheel. I exit the section onto a floor that rotates with the drum section. Depending on the speed of rotation, I may be able to step directly from that floor to a section of floor that's not rotating, or I may step from that floor to a series of tracks rotating at slower speeds until I'm slow enough to step onto the nonrotating section.

I really like this, at least for designs that have room to include it. No need to start and stop, just continuous motion at different speeds for transition, so no bottleneck if you need to get from one portion to the other quickly.

Thanks!

 

[McPerth]

Now I imagine that I'm in a ship with a rotating section. In essence, I'm standing on the inner surface of a drum - I'm on a hamster wheel, held to the bottom by the rotation of the wheel. I exit the section onto a floor that rotates with the drum section. Depending on the speed of rotation, I may be able to step directly from that floor to a section of floor that's not rotating, or I may step from that floor to a series of tracks rotating at slower speeds until I'm slow enough to step onto the nonrotating section.

I'm afraid the speed should be too high for this if the desired effect (simulated gravity to the point it makes the habitat confortable) is to be attained.

Alternately, I could use an "elevator"-like section that runs the perimeter of the circle (not up and down) to bring me to matching speed: step in one door, it gradually slows down or speeds up until it matches speed with the other section, then step out the other door into the other section.

That whould need a double drum, one rotating inside one that does not rotate, so that the non rotating ones (where the "elevator" would be) may match in different sections of the hull, with counter-spinning habitats each.

 

[SanDragon]

Bah!

A long inward spiraling ramp, walking, then, when you're near the center, you'd probably be lightly bouncing from handhold to handhold, and your angular momentum should be minimal and transferring to the non-spinning sections would be easy.

 

[Carlobrand]

I'm afraid the speed should be too high for this if the desired effect (simulated gravity to the point it makes the habitat confortable) is to be attained.

Because ...

If there's room for it, there shouldn't be a problem with it.

F=mac=mv^2/r

ac=v^2/r
v=sqrt(ar)

Let's build around the lab ship. Say for some reason you're slapping the ring on another drum structure, one section to remain in 1G while the other is in 0 G:

r=21.65*1.5=~32.5 meters
desired ac is 10
v=sqrt(325)=18 meters per second

Comfortable walking speed's about 1.4 meters per second, more or less.
A series of 12 belts moves you from 1G rotation to 0 (you might need velcro or something on your shoesies) at just over the speed of a confortable walk, which is about what those airport belts did. If r is larger, v goes down and you need fewer belts. Imagine the lab ship as a 400,000 dTon structure: r is ten times larger, v drops by the square root of 10 to roughly 6 meters per second, four tracks do it comfortably.

That whould need a double drum, one rotating inside one that does not rotate, so that the non rotating ones (where the "elevator" would be) may match in different sections of the hull, with counter-spinning habitats each.

I'm not seeing this. Mount the elevator on a track running the circumference of the nonrotating structure. Get in, push the button, it accelerates slowly on the track to the speed of the rotating structure, then moves to match the doorway on that side. Once it's lined itself up, the doors on that side open and you exit.

You're seeing the elevator as moving up and down. I'm applying the word badly, but I don't have a word for a kind of elevator that moves only laterally. Circumfralator?

 

[SpaceBadger]

A long inward spiraling ramp, walking, then, when you're near the center, you'd probably be lightly bouncing from handhold to handhold, and your angular momentum should be minimal and transferring to the non-spinning sections would be easy.

Nice! And I like having several different solutions available for this problem, so all of the ships don't end up the same.

IMTU, humans don't have gravitic tech, so most ships require some kind of spin-hab to have simulated gravity for living quarters or at least for exercise areas to avoid zero-G degeneration. I am contemplating letting the very newest cutting-edge-tech ships have internal grav/inertial-compensator systems based on tech purchased from someone more advanced, just so I can use some traditional Traveller deckplans.

 

[SpaceBadger]

You really wouldn't need to spin/de-spin the collar in question. Assume the collar is on the "axle" of the spin module (habitat). The collar itself is "split". The portion from the "ship" doesn't spin but the second half does (we are assuming zero g at this location).

Move from the non-spinning end to the spinning end. It will be a relative slow spin. Reach for a grab bar and move DOWN the "spoke" to the rim. Gravity then goes from zero to whatever it will be at the point on the rim you reach at the end of your climb.

You will be climbing down backwards or taking an elevator/lift.

Ah, just re-reading this and now it clicks - so yet another good workable option for transition. Thanks, Vladika!


Edit: This sounds somewhat like what is used in the space station in Allen Steele's "Orbital Decay", which I have been meaning to re-read. I remember descriptions of jumping up into a tube from the zero-G central area, pulling along the ladder, then needing to flip over and climb "down" upon nearing the outer part of the ring with simulated gravity.

 

[shadowdragon]

Because ...

If there's room for it, there shouldn't be a problem with it.

F=mac=mv^2/r

ac=v^2/r
v=sqrt(ar)

Let's build around the lab ship. Say for some reason you're slapping the ring on another drum structure, one section to remain in 1G while the other is in 0 G:

r=21.65*1.5=~32.5 meters
desired ac is 10
v=sqrt(325)=18 meters per second

Comfortable walking speed's about 1.4 meters per second, more or less.
A series of 12 belts moves you from 1G rotation to 0 (you might need velcro or something on your shoesies) at just over the speed of a confortable walk, which is about what those airport belts did. If r is larger, v goes down and you need fewer belts. Imagine the lab ship as a 400,000 dTon structure: r is ten times larger, v drops by the square root of 10 to roughly 6 meters per second, four tracks do it comfortably.

FYI you are looking at about 5.25 RPM to generate 1g at this size (32.5m radius) and that will mess with the inner ear rather strongly. Even 0.5g is going to be the upper limit of comfortable at 3.75 rpm. You are also looking at about a 7.2% difference in gravity between the head and the feet. Install extra air scrubbers mate, gonna need 'em if you go this route.

Try to keep rotations below 3rpm for comfort, and cleanliness, and radii of g-compartments large.

 

[Carlobrand]

FYI you are looking at about 5.25 RPM to generate 1g at this size (32.5m radius) and that will mess with the inner ear rather strongly. Even 0.5g is going to be the upper limit of comfortable at 3.75 rpm. You are also looking at about a 7.2% difference in gravity between the head and the feet. Install extra air scrubbers mate, gonna need 'em if you go this route...

It's a lab ship - maybe they were on a tight budget.

 

[McPerth]

One thing I didn't realized until read in on MgT2300AD about moving by the spin axis is how the coriolis forces would affect there if they're spinning too. I'm not sure about the effect, but I guess it could be quite dizzying.