Lifeboats

[kaladorn]

Excellent designs (both the larger lifeboat and the smaller cannister, though I perfer pod as a name... cannister always calls to mind an artillery round....).

Permission to use and perhaps modify the designs and post it on my site (with due attribution, though I only have board handles, noted in the description)?

Comments:

Life Cannister:

Really nice. Just like in the 5th element. Sweet!

With an Enhanced Position Indicating Radio Beacon (and perhaps, on fancy ships, the EPIMB - Meson version), this would be just enough to get you off and out.

Of course, there is some argument for staying in the area of the abandon ship in some cases. 150kph 24 hours x 40 days (endurance without counting the solar cells) is 144,000 km. That could make for quite a wide search area....

It might be nice to have the ability to slow or stop the pod once you're clear of the immediate battle area (say clear by about 100 km).

 

[The Oz]

If you want to use my PEP design, go ahead; that's why I posted it. Just say where you got it, OK?

Having some way to decelerate the PEP after it's cleared the danger zone is a thought, but these pods are only intended for short durations, despite the long endurance provided. It's expected that they would be used in battle, and that someone would be around to do search and rescue immediately after the battle.

And even a search volume with a 150,000 km radius isn't that big, compared to both TRAVELLER sensor ranges and the Planetary range (50,000km) of the built-in radio communicator.

 

[kaladorn]

You make a good point about the range of the radio (beacon), though I'd have been tempted to make it System range.

The user might be knocked out or pass out from other injuries, so depending on them to trigger/control comms might not be a good idea. So a beacon that transmits on standard imperial channel wouldn't be a bad idea.

As to deceleration, SAR would be facilitated if it was not necessary to 'chase down' the pods. Having to chase 150 pods that might eject in varying directions could be... more fun than anyone should have.

If OTOH, they stop about 100km or 1000km out from the ejection point, getting to them sitting still in space might not be too hard.

If you want to drop me an e-mail (kaladorn at magma dot ca) and provide some particulars to how you'd prefer to be cited (other than "from The Oz on CotI"), I will make every attempt to give due attribution. (probably the *who* is more important than the *where*....)

 

[The Oz]

Originally posted by kaladorn:
You make a good point about the range of the radio (beacon), though I'd have been tempted to make it System range.

The user might be knocked out or pass out from other injuries, so depending on them to trigger/control comms might not be a good idea. So a beacon that transmits on standard imperial channel wouldn't be a bad idea.

As to deceleration, SAR would be facilitated if it was not necessary to 'chase down' the pods. Having to chase 150 pods that might eject in varying directions could be... more fun than anyone should have.

If OTOH, they stop about 100km or 1000km out from the ejection point, getting to them sitting still in space might not be too hard.

I didn't make the communicator System range since:

1) That costs more, takes up more space, and uses more power which cuts the duration.
2) It require more Control Points, which winds up taking more space, costing more money, and requiring more power, also cutting duration.
3) While the communicator might only be able to communicate over Planetary ranges, I imagine that military EMS sensors could detect it's transmissions over a longer distance.

While I didn't state it, I assume that the operation of these PEP would be mostly automatic. It does have a computer, after all. First, there's have to be a declared "Abandon Ship" condition, something that'd be authorized by the bridge or the ship's main computer (depending on damage, etc). The PEP computer would not launch without having this authorization. Then the passenger gets in, and punches the "Escape" button, which triggers an automatic sequence of events to launch the pod (once the launch tube is clear) and activate the communicator acting as a continuous rescue beacon. If a declared emergency exists, and someone gets in the pod, and other pods in the ship are ejecting, that pod will eject even if the passenger (who might be unconcious) does not punch the "Escape" button. Other people could even (under a declared emergency) put an unconcious person into a PEP, push the "escape" button and get out of the way as the hatch closes and the pod is launched.

As for putting in a deceleration rocket, it'd take up all the space given for the cargo hold/survival stores. I'd rather give someone the chance (however slim) of being found a few hundred thousand km away after a week or so.

 

[kaladorn]

It is possible that an EMS could detect a radio further away than it could be intelligible, but I doubt it. By high TL, if you can distinguish it from the stellar background, you'll be able to fetch the intelligence (message) from it. If you can't get the intelligence out of it, that means it is indistinguishable from background, ergo your EMS gives you no extra benefit, re: range.

IMO, anyway.

And as to reducing duration, if you aren't running the comms all the time (a blip every ten minutes), you hardly have a reduced duration. The stupidity of the system calculating everything as if it was running 24 hours a day is laughable (though I know default MT does this... Ship's For Windows at least lets you specify these items should not be reckoned into 'extended endurance' which is more realistic).

Lastly, my point about unconcious was in the context of using the radio as a comms device and calling for help. If it is a 'beacon' (which should use less power), then unconscious or not does not matter.

As to decel, I'd have allocated 2/3rds of your rocket to 'escape' and 1/3rd to 'decelerate'. This will still get you out of the ship at 200 mps (65 kph) and will let you, after 1000 km, decelerate to 150 mps. Altogether, that would cut your 40 day distance to about 20,000 km. A significantly smaller sphere than 150 K km.

 

[signless]

How about this...?
A friction drum-cable could be housed in either the ship launching the pod (I agree with Kaladorn on the name...although being "stuck in the can" for a while has some definite bar-story appeal...), or in the pod itself.
Once the escape pod has been ejected, the cable spools out, with gently-increasing tension that's been programmed into its tiny electronic brain. You could even have a simple tri-colored switching system for it...Red means get me the hell as far away from here as possible...Yellow means just give me a nudge thataway....and green means kill just about all of my velocity before disconnecting from the hull. You could include a small rocket package with enough fuel for small attitude adjustments over time, or for a continuous burn that would help, not eliminate, some delta-v.
I also agree the radio should be automatically activated when the pod is launched. It'll give players attempting to make a discrete getaway something else they have to fiddle with before being found out.

 

[The Oz]

Without a doubt the radio beacon starts transmitting as soon as the pod leaves the ship. That's just common sense.

As far as braking the pod's escape after it leaves the ship, that's up to the ref in his TU. I don't like it, myself, but that's me. I see this pod being used only by badly damaged ships in battle; the ship is doomed, enemy weapons are homing in on the cripple, and you expect many large explosions in the immediate vicinity of the ship real soon. In that case I'd want to get as far away as fast as possible. I would have made the escape rocket bigger, but I did want to leave some room for survival supplies.

If you want to have the pod brake itself, then allocate some of the escape rocket for decel, or add more rocket for that purpose; it's YTU.

The cable-brake system is ok, I can only think of a couple of quibbles, but it would work. If you want it that way, say it works that way.

 

[kaladorn]

I don't have any issue with getting away from the immediate vicinity of the ship before slowing to a stop or slow speed. I think 1000km is more than far enough, however. Getting to that 1000km should be quick. But after that, you'd be out of stray fire danger and you'd probably want to make search and rescue easier.

Imagine this:

Your side has 3 SAR shuttles available to recover 30 pods ejected from a damaged ship. They're good shuttles with 4G performance. But the rescue didn't occur till the battle was well and truly over, so say a day after the engagement that destroyed the target vessel. So, now they have to chase 30 pods which each took a different direction in 3D, rescue them, then go to the next pod. That's a lot harder if they're all headed off at full tilt.... than if they had all moved to a radius of 1000km or so and slowed down or stopped.

 

[Drakon]

This does point out a need for proper escape proceedures being in place. After the escape pods jettison and get clear, I would think it would be advisable for them to start gathering together, link up so that it makes it easier for them to be found.

Of course this depends on how manuverable you make the pods.

 

[kaladorn]

Yes. If you could mate in a 0.1G drive and the power to run it for a bit (or 0.25G) - something small but sufficient, given a bit of time, then you've got the ability to do just what you say. I think the original (still laudible) design was just 'get out!' as the priority - so a chem rocket. Getting together later isn't a factor, in that design.

But perhaps it should be.

Or perhaps one larger lifeboat (as opposed to pod) is present for every N pods, and that pod can be used to wrangle pods into groups. That's another approach to the problem.

This would certainly make recovery easier. In modern day, they try to keep lifeboats together.

 

[The Oz]

The more you add to the escape pod the bigger and more expensive it becomes. One of my major design criteria was to keep it as cheap and simple as possible so more could be packed into less space.

However, keeping the pods together after they eject is a good thing. In the actual circumstances of this thing being used, the ships' boats will be launching, there'll be pods punching out all over, and people bailing out the airlocks in vacc suits with thruster packs (maybe even without thruster packs). I suspect that keeping all these people together will be the job of the ships' boats. They have drives, sensors, crews, airlocks, and might even have extra space aboard. Even if the ships' boats may not be able to physically herd the suits and pods together, they can at least keep track of where they are.

One guy I know designed a purpose-built rescue pinnace intended to run into the line of fire and pick up stranded spacers, then deliver them back to the pinnace's mother ship, which was usually the Fleet Hospital Ship. He gave the pinnace a bigger computer than usual (to account for special rescue sensors) and allocated tonnage for mechanisms to pick up unconcious spacers, rescue balls, escape pods, etc, and bring them into the pinnace cargo bay. He even put a small sickbay/trauma room on the pinnace, with a medic team. The pinnace was armored to withstand accidental near-misses with nukes, but normally would be broadcasting the equivalent of the "Red Cross" so it would not be intentionally fired on (in battles between civilized opponents). It was unarmed, needless to say.

I always liked that rescue pinnace.

 

[far-trader]

Originally posted by The Oz:
<snip>

I always liked that rescue pinnace.

Sounds like a great idea and design, I may have to play with building one myself. I always liked the RL sea rescue plane that would fly low over a downed aviator and snag a harness line flown on a ballon for quick rescues. Sounds like the inspiration for the Pinnace design.