Wednesday, October 3, 2012

Rocketship Polaris, Mongoose Traveller Style


Just for fun, a while ago I put together a Mongoose Traveller version of the classic spaceship "Polaris" from "Tom Corbett, Space Cadet". If you don't know what I'm talking about, get off my lawn! :)

The picture below is originally from the Spaceship Handbook and is included without express permission. I'm not sure where I got this actual image from, though Project Rho has a similar picture and draws some different conclusions about the ship's volume and other attributes.

Polaris: 60m long, fission power plant, reaction drive
Laid out as a cigar shaped "tail sitter" with circular decks and aerodynamic fins.

scale picture: 375px long, 48px wide
Assuming the 60m is the hull and not the fins, then we have a diameter of 7.5 meters

The ship is layed out in cylindrical sections, with the widest part being centered on the power plant/engineering deck

Conveniently, the decks are about standard Traveller deck height.

The widest deck (9) is roughly 9dt
The whole ship comes out to about 100dt



Now on to the stats:

Hull: 100t small-craft, streamlined + aerofins(5t)

Decks:
1 - Radar/Avionics (sensors) 1dt
2 - Sensors/Radar Deck (sensors, cockpit) 2dt
3 - Bridge/Command Deck (sensors, cockpit) 3.5dt
6.5 dt total
These three decks make up the control and electronics center
Military Sensors DM+0 (2dt)
Radar Operator Cockpit (1.5dt)
Commander Cabin (3dt)

The engineer's "cockpit" controls are down on the Power deck.

4 - Hydroponics 5dt
common area, "luxuries", galley and food storage, all rolled in to one.
The hydroponics allows lifesupport to keep up to 2 prisoners in the brig

5 - Crew Quarters 6dt
Barracks for 3 - 6t

6 - Arms magazine 8dt (missiles, weapon tonnage)
The actual tonnage for the ship's weaponry is on this deck, as well as storage for missiles and probes.  There's not a lot of details available online, so whatever weapons you can squeeze into 8dt should be ok. I imagine this space is somewhat modular, and armament could vary from ship to ship or even mission to mission.

The hull can support up to 5 "ship" weapons and 10 anti-personel weapons The power plant can handle up to 2 energy weapons.

7 - Stores/Storm Cellar 9dt
Ship's locker(1dt)
2dt cargo space, convertable to a brig.
Vault (6dt) +4 Hull, +4 Structure containing barracks
Vault can also be used for general storage

8 - Boat Deck 10dt
A 10dt Hangar, suitable for a G-Carrier or pair of air/rafts
The entire deck can be depressurized to allow space access.

9 - Power Deck 9dt(+1.5) (p-plant 3, sL )
1.5dt for the engineer's control room "cockpit"
Fission plant sL is the largest that will fit, giving a P-3 rating This rating is necessary to power up to 2 beam weapons, but otherwise we could get away with a much smaller power plant.

I'm cheating a little and letting this deck be too "Deep". I feel justified though, because the plans give a thick radiation shield between this deck and the fuel.  In Traveller, fission plants are twice the size of a fusion plant, so I've decided to allow an extra 1.5dt "for free" so we can fit a 9dt power plant in here.

10 - Fuel Tankage (about 5 deck's worth) 33 dt
The power plant is a fission plant and doesn't need fuel, but the engines are reaction drives, and these tanks hold enough for 13.2 G-hours, which in normal operations should be enough.

NOTE: this should be more like 40dt by the map, but the aerofins and other options take us over 100dt.  It might be worth it to scale back on some stuff, like dropping the hydroponics and reducing the arm magazine deck, but that would definitely change the layout some.

11 - Engine Deck (about 2 deck's worth) 7dt
sX drive M6
The Polaris is a hotshot rocket, so it gets 6G engines.
However, given the TL, they are reaction drives not gravity drives.
(Which is odd, considering that the ship has artificial gravity....)

So there you go. Now you can chase down robot rockets, save asteroid miners and rescue maidens from the dinosaur infested jungles of Venus. Just don't think too hard about why a trio of teenagers would be given command of such a vehicle in the first place.

7 comments:

  1. I'm not so sure this is actually 100 tons. I haven't actually looked at the rule books in a while, but my recollection is that 1 ton is supposed to be the volume of 1000kg of liquid hydrogen, which takes up about 14 cubic meters. Even pushing up the volume to 60m times 7.5m for the full length, that gives us 450 cubic meters, or about 32 tons.

    It's possible I'm confusing Book 1-3 rules with High Guard rules, but this also seems to jive with the deck plans for the old scout ship as well as the Far Seeker deck plans.

    Man... I miss playing Traveler.

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  2. Working on the idea that the rocked is roughly two cones and a cylinder with a radius of 3.75m, and then dividing by 14m^3, I get just over 100 tons. Since the small craft rules don't go above 100t, I capped it there. It's a big boat, but it's still a boat.

    But as Mrs. Apsey my old Algebra II teacher can attest, solid geometry math is not my strong suit. :)

    Oh wait - I see where your "sanity check" calcs differ from mine - you're not squaring the radius, so you're calculating m^2, not m^3.

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  3. Huh, looks like my picture is from the Project Rho website, where there is another take on the Polaris. Their version is closer to 40t, but doesn't follow the "book dimensions", but rather the "show dimensions".

    Maybe I'll do a Pinnace version some day, but I think this one feels like a useful ship as it is. And the books do describe Polaris as being a huge ship.

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  4. Oh dear, I completely messed up the volume calculation in exactly that way, not squaring the radius.

    I officially yield my math geek credentials, but I ask mercy for the fact that this was WAAAAY early in the morning.

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  5. The image comes from the Spaceship Handbook.

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  6. Thanks Shawn, I'll edit to include that information.

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