Ship Design Philosophy

Discuss the Traveller RPG and its many settings
Condottiere
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Re: Ship Design Philosophy

Postby Condottiere » Sun Dec 18, 2016 7:35 am

Spaceships: Manoeuvre Drive and Weight Watchers

As someone pointed out a while ago, there are no minimums for manoeuvre drive tonnage, as opposed to power plants and jump drives.

Thumbing through Mongoose First, gravitational drives would be half a tone, while reaction ones are a quarter, but that got thrown out of the window with a revision of manoeuvre drive percentages, and doubling down on that for reaction drives.

Technically, the smallest default manoeuvre drive would be one tenth of a tonne for a ten tonne spacecraft, available at technological level nine at two hundred thousand schmuckers.

Manoeuvre drives are introduced at technological level nine, meaning that whatever zero factor drive is being introduced at technological seven can't be manipulating gravitational forces; the only thing you can do is ignore it, and install an underpowered manoeuvre drive, which at least gives some form of discernible and constant acceleration; it's also cheaper.
Condottiere
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Re: Ship Design Philosophy

Postby Condottiere » Sun Dec 18, 2016 2:32 pm

Spaceship: Shuttle Cock Class

Hull
. 10 tonnes
. 3 points
. technological level nine
. non-gravitated
. lightened hull
.. MCI 0.15
. sphere configuration
.. partially streamlined
. armour
.. none
Engineering
. manoeuvre
.. factor one
.. technological level nine
.. budgeted
... increased size
.. zero point one two five tonnes
.. MCI 0.15
. solar panels
.. four
... half-tonners
.. two tonnes
.. MCI 0.2
. power plant
.. early fusion
.. eight scotts
.. technological level eight
.. budgeted
... increased size
.. one tonne
.. MCI 0.3
.. energy requirements
... basic
.... 2
... manoeuvre
.... 1
... weapons
... systems
. bunkerage
.. one tonne
.. endurance
... one hundred sixty weeks
Bridge
. cockpit
.. one point five tonnes
.. MCI 0.01
. computer
.. bandwidth five
.. technological level seven
.. MCI 0.03
.. software
... library
... manoeuvre
. sensors
.. basic
... lidar
... radar
... dice modifier minus four
Armaments
. firmpoints
Craft
Systems
.
Accommodations
. staterooms
..
Cargo
. ship's locker
. dry
.. two and three eights tonnes
Acess
. airlocks
.. one free

MCI 0.81


I like the basic concept and price, but as a civilian spacecraft, the four solar panelling are taking up too much space, and the fusion reactor is producing more power than you need, especially for an orbital runabout.

I don't think the tetrahedron concept will work at this level; probably have to upscale it.
Condottiere
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Re: Ship Design Philosophy

Postby Condottiere » Mon Dec 19, 2016 3:59 am

Spaceships: Engineering, Not Enough Power, Cap’n!, and Hardened Systems

Selected ship systems get priority, which the bridge can allocate energy to as they prefer, whenever there's not enough energy to power all the currently operating gadgets.

You can operate a ship by only allocating one scott per ten tonnes, but that leaves it subject to power fluctuations, hence lights dimming, and impromptu levitation, though you could set up an uninterruptible power supply via a battery to smooth that out.
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Re: Ship Design Philosophy

Postby Condottiere » Tue Dec 20, 2016 1:29 am

Spaceships: Engineering, Sunbathing and It's Not Easy Being Green


Image

If the panels are fitted to a ship without a power plant, then assume the (non–existent) power plant is sized to the ship’s basic systems and a Thrust one manoeuvre drive.

If the panels are fitted to a ship without a power plant, then assume the (non–existent) main power plant is sized to deliver a performance rating of one.


Can you spot the difference?

The top sentence comes from the revised edition, and for our purposes, that for every ten tonnes, you have an appropriate rated solar panel that will deliver three scotts, in lieu of an a shipboard generator).

Though, which generator?

Let's go with my favourite technological level, nine, since that's when you introduce manoeuvre drive technology.

Let's take an early fusion power plant, with a default setting of ten scotts per tonne output.

Let's see how all this fits on a thousand tonne hull (mostly to get over the half tonne panelling minimum).

So a one kay hull has a basic power requirement of two hundred scotts, and can needs another hundred scotts to input into the impulse drives.

That means I need thirty tonnes of early fusion power plant to generate three hundred scotts.

Solar panelling is sized to ten percent of the matching power plant, that would mean that I only need three tonnes of solar panelling to generate three hundred scotts at technological level eight.

If we assume that actually any solar panelling can only deliver three quarters of the advertised output, we have four tonnes of technological level eight solar panelling delivering a net output of three hundred scotts, which works out to seventy five scotts per tonne of solar panelling, which is just seventy percent as efficient per tonne as a technological level twenty anti matter power plant; and greener.
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Re: Ship Design Philosophy

Postby Condottiere » Tue Dec 20, 2016 3:27 pm

Spaceships: Engineering, Power Corrupts and Then And Now

When I came up for designs for the Rocket Sled and Ultralite fighters way back when, as I recall, you could skip installing a power plant by pairing batteries and fusion rockets, because the spacecraft wasn't constantly sucking energy; well, at least within a twenty four hour period, since a cockpit rather than a bridge was a requirement to keep within the bounds of space available.

At best, you can start prioritizing which components get juiced, like the bridge and any engineering spaces, but in no way would you get the same pay off as just having a normal power plant, over an extended stretch of time.

Unless you pair up the batteries with solar panelling, the down side is you're probably stuck at one gee constant acceleration, unless you embed the panels into the hull itself, but the upside is that as long as you aren't eclipsed, you have an infinite amount of energy, needing only a tiny bit of tonnage for all your power requirements.

While you might think that the rules put a stop to that by mentioning minimal manoeuvring, powering the manoeuvre drives from the battery pack bypasses this caveat, which of course then get constantly recharged from the solar cells.
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Re: Ship Design Philosophy

Postby Condottiere » Wed Dec 21, 2016 6:57 am

Spaceships: Accommodations and Ambiance

https://www.youtube.com/watch?v=imzDk6dfP54

And that's why you drill portholes through the hull.

While it might seem rather cynical to sort of ignore cattle class in what seems like an infomercial, for us cattle class is very close to just a chair/extendable couch.

The other extreme would be:

Image

Image
Condottiere
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Re: Ship Design Philosophy

Postby Condottiere » Wed Dec 21, 2016 6:50 pm

Spaceship: Space/Raft

Hull
. 10 tonnes
. 3 points
. technological level nine
. non-gravitated
. lightened hull
.. MCI 0.3
. streamlined configuration
.. completely streamlined
. armour
.. none
Engineering
. manoeuvre
.. factor one
.. technological level nine
.. budgeted
... increased size
.. zero point one two five tonnes
.. MCI 0.15
. solar panels
.. none
. power plant
.. early fusion
.. eight scotts
.. technological level eight
.. budgeted
... increased size
.. one tonne
.. MCI 0.3
.. energy requirements
... basic
.... 2
... manoeuvre
.... 1
... weapons
... systems
. bunkerage
.. one tonne
.. endurance
... forty weeks
Bridge
. cockpit
.. one point five tonnes
.. MCI 0.01
. computer
.. bandwidth five
.. technological level seven
.. MCI 0.03
.. software
... library
... manoeuvre
. sensors
.. basic
... lidar
... radar
... dice modifier minus four
Armaments
. firmpoints
Craft
. none
Systems
. none
Accommodations
. staterooms
..
Cargo
. ship's locker
. dry
.. six and five eighths tonnes
Access
. airlocks
.. one free

MCI 0.79


Notes:
1. Basic model costs more than three times a default air/raft, but probably can carry five times more payload, and range out to the edges of the solar system.
2. One gee constant is like thirty six thousand kilometres per hour.
3. Default airlock, though, even free, still occupies two tonnes; could just have a cargo hatch out back.
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Re: Ship Design Philosophy

Postby Condottiere » Thu Dec 22, 2016 4:34 pm

Spaceship: Space/Board

Hull
. 10 tonnes
. 3 points
. technological level nine
. non-gravitated
. lightened hull
.. MCI 0.3
. streamlined configuration
.. completely streamlined
. armour
.. none
Engineering
. manoeuvre
.. factor three
.. technological level ten
.. budgeted
... increased size
.. zero point three seven five tonnes
.. MCI 0.45
. solar panels
.. none
. power plant
.. early fusion
.. eight scotts
.. technological level eight
.. budgeted
... increased size
.. one tonne
.. MCI 0.3
.. energy requirements
... basic
.... 2
... manoeuvre
.... 3
... weapons
.... none
... systems
.... none
. bunkerage
.. one tonne
.. endurance
... forty weeks
Bridge
. cockpit
.. one point five tonnes
.. MCI 0.01
. computer
.. bandwidth five
.. technological level seven
.. MCI 0.03
.. software
... library
... manoeuvre
. sensors
.. basic
... lidar
... radar
... dice modifier minus four
Armaments
. firmpoints
Craft
. none
Systems
. none
Accommodations
. staterooms
..
Cargo
. ship's locker
. dry
.. six and three eighths tonnes
Access
. airlocks
.. one free

MCI 1.09

Notes:
1. It's a technological level ten upgrade from a space/raft, using the excess power output to install a larger manoeuvre engine.
2. Acceleration is now three gee constant, probably about as fast as you'd want to expose your crew and passengers to uncompensated travel, and only for a short duration.
Last edited by Condottiere on Sat Dec 24, 2016 11:49 am, edited 1 time in total.
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Re: Ship Design Philosophy

Postby Subzero001 » Fri Dec 23, 2016 12:56 am

Couldn't something like this be used in "Staterooms" https://www.wallbedsbywilding.com/murphy-bunk-beds/ :shock:

Then you could have a Sleeping cabin or convert it to a working / relaxing cabin? you could even put at least two per cabin converting to a sofa or computer desk etc... when not in use. from my understandings they have something of the like on trains now. 8)
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Re: Ship Design Philosophy

Postby Condottiere » Fri Dec 23, 2016 1:49 am

Image

Fittings isn't really an issue, more exactly how much do we want to pay for per tonne of accommodations, since we even have the above option.



Speaking of which:


Happy Holidays to One and All
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Re: Ship Design Philosophy

Postby Condottiere » Sun Dec 25, 2016 4:37 pm

Spaceships: Engineering and Maximum Atmospheric Speed

As I like pointing out, I'm not an engineer.

As I understand it, the maximum speed a craft can travel within our atmosphere is a tad over twenty eight thousand kilometres per hour, about eighty percent of acceleration factor one. At least, not without some catastrophic structural failure.

Then there's meteoric re-entry; how fast can a spacecraft go without really burning up, or being able to disgorge it's assault troop complement, within a reasonable period of time?

Why does this matter?

I thought it was time to see if it's worth resurrecting gliders for planetary assaults.
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Re: Ship Design Philosophy

Postby AnotherDilbert » Sun Dec 25, 2016 5:12 pm

Condottiere wrote:As I understand it, the maximum speed a craft can travel within our atmosphere is a tad over twenty eight thousand kilometres per hour, about eighty percent of acceleration factor one. At least, not without some catastrophic structural failure.
I do not understand what you mean.

Acceleration is not speed. Acceleration is rate of change of speed. "kilometres per hour, about eighty percent of acceleration" makes no sense to me.

Max speed (without burning up) would depend on the density of the atmosphere which depends on height. Max speed at sea level would be much less than max speed at 100 km. Where did 28000 km/h come from?
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Re: Ship Design Philosophy

Postby AndrewW » Sun Dec 25, 2016 7:30 pm

Condottiere wrote:I thought it was time to see if it's worth resurrecting gliders for planetary assaults.
There's Re-entry Capsule and Re-entry Pod.
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Re: Ship Design Philosophy

Postby Condottiere » Mon Dec 26, 2016 1:19 am

The encapsulated are paratroopers.

As regards twenty eight thousand kilometres per hour, that figure came from the re-entry speed of the space shuttle.

I always thought how neat it's to fly through the atmosphere at full speed, whatever full speed is for the assault shuttles, forgetting the barrier of an unforgiving atmosphere, which meant there would be limits to the exact speed you could getaway with at sea level, though well within how fast our spacecraft can actually go.

At some point I came to the conclusion that it would be rather dumb, except in the case of an unexpected commando raid, to actually use a starship in the direct assault role, so I wondered which real life analogue to try and flesh out, a Huey, an Osprey, or a Chinook?

Then I considered the attraction of a cheap, expendable delivery vehicle that could land ground forces and their equipment, without the (immediate) necessity of trying to get it to fly back.

Hence, a (powered) glider.
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Re: Ship Design Philosophy

Postby Condottiere » Mon Dec 26, 2016 5:28 pm

Spaceships: Hulls and Technological Levels Seven Eight Nine

Any real spaceship design has to default to technological level nine, because that when all hulls become self-sealing.

Normally, I'd try to go for the lowest viable technological level, if we ignore steampunk, would be technological level five, or the realm of Space Nazis; after all, hulls would still cost twenty five thousand schmuckers per non-gravitated schmuckers, and fifty thousand per. gravitated tonne, probably out of ordinary steel. Wait, that can't be right.

So when did we invent artificial gravity? Can't be seven, because we'd have it now; might be eight, because we're still haven't got fusion right. Likely nine, though it would appear to me that the design sequence fails to mention it.

Lower technological level hulls aren't cheaper higher up the production food chain, so nine becomes the logical starting point, or higher, since there's no price difference. Certainly seven is an unworthwhile technological level.

That's why nine eight seven.
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Re: Ship Design Philosophy

Postby AnotherDilbert » Mon Dec 26, 2016 8:46 pm

Condottiere wrote:So when did we invent artificial gravity? Can't be seven, because we'd have it now; might be eight, because we're still haven't got fusion right. Likely nine, though it would appear to me that the design sequence fails to mention it.
MT makes starship artificial gravity and inertial compensators available at TL 10.
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Re: Ship Design Philosophy

Postby Sigtrygg » Mon Dec 26, 2016 10:53 pm

1980 CT HG2e
TL7 maneuver drive is limited to 2
TL8 maneuver drive is limited to 5 max (this is the TL the air/raft and fusion power show up on the CT TL tables)
TL9 maneuver drive is now the full 6.
CT also states that it was Terran research into gravitics in the latter part of the twenty first century that lead to their discovery of jump drive, so TL9.
Last edited by Sigtrygg on Mon Dec 26, 2016 10:54 pm, edited 1 time in total.
Condottiere
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Re: Ship Design Philosophy

Postby Condottiere » Mon Dec 26, 2016 10:53 pm

Spaceship: Modular Lighter

Hull
. 35 tonnes
. 12 points
. technological level nine
. non-gravitated
. lightened hull
.. MCI 0.7875
.. modular
. streamlined configuration
.. completely streamlined
. armour
.. none
Engineering
. manoeuvre
.. factor one
.. technological level nine
.. budgeted
... increased size
.. zero point four three seven five tonnes
.. MCI 0.63
. solar panels
.. none
. power plant
.. early fusion
.. eight scotts
.. technological level eight
.. budgeted
... increased size
.. one tonne
.. MCI 0.3
.. energy requirements
... basic
.... 7
... manoeuvre
.... 3.5
... weapons
.... none
... systems
.... none
. bunkerage
.. one tonne
.. endurance
... forty weeks
Bridge
. cockpit
.. one point five tonnes
.. MCI 0.01
. computer
.. bandwidth five
.. technological level seven
.. MCI 0.03
.. software
... library
... manoeuvre
. sensors
.. basic
... lidar
... radar
... dice modifier minus four
Armaments
. firmpoints
.. none
Craft
. none
Systems
. none
Accommodations
. staterooms
.. none
Cargo
. module
.. twenty five tonnes
.. MCI 0.5625
. ship's locker
.. none
. dry
.. 4.0625 tonnes
Access
. airlocks
.. one
.. two tonnes
.. free

MCI 1.7575 (2.32 with module)

Notes:
1. While total energy requirement is ten and a half scotts, the lighter can function at seven scotts, with one scott in reserve.
2. While I'm not that keen on the thirty tonne module, at least not for the Confederation Navy, I thought that Solomani commercial entities might not be that finicky; imagine my surprise when I suddenly found myself stonewalled at twenty six plus tonnes: you need at least a forty tonne spaceship to do that, and it's possible if you squash the components a bit.
3. Lighters are really only meant for short range transfers, and if it's orbit to planetary surface, one gee constant is more than enough; also the reason they're streamlined.
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Re: Ship Design Philosophy

Postby Condottiere » Tue Dec 27, 2016 10:00 pm

Spaceships: Engineering, Inertial Compensators and I Feel The Need, The Need For Speed

One issue with accelerating in Einstein's backyard and Traveller design is, why we can't just fill up half the spaceship with manoeuvre drives and/or rockets.

Inertial compensators of the right type was always the elephant in the room, though that wouldn't stop someone at technological level ten just devoting nine percent of the spaceship to the manoeuvre drive modules creating factor nine thrust, compensated by factor three inertial compensators, switching off artificial gravity, taking bath, and gritting your teeth for the remaining three or four uncompensated gees.

Or just send in a droid to pilot it.

And even if compensators would be a requirement for manoeuvre drives, you can always install rockets, of which you can install twelve factors without violating the rules, or even bending them.

So inertial compensators aren't the limiting factor, except in the sense as the crew can't function under heavy uncompensated thrust.

So, there's no satisfactory answer or solution to this. So far.
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Re: Ship Design Philosophy

Postby Condottiere » Thu Dec 29, 2016 11:10 am

Spaceships: Orbital Range

This manoeuvre drive only functions when the ship is within short range (up to one thousand two hundred and fifty kilometres) of a planetary body ... requires two
disadvantages.


Earth's diameter is 12'742 kilometres.

Orbital range should be one tenth of a planetary, or celestial object's diameter; possibly adjusted by standard gravity.

That would mean for the Moon, the spacecraft couldn't go further than 3'474 kilometres divided by six, therefore 579 kilometres.

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