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The Fleet Ship designs, strategies, and tactics.

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  #51  
Old September 26th, 2020, 08:12 PM
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Does T5 say what the propulsion system is for standard ship missiles?
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  #52  
Old September 27th, 2020, 04:29 AM
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Originally Posted by kilemall View Post
Another option I considered is using the capacitor in HG associated with BG energy absorption but which is noted as available at TL9. 36 EPs per ton of capacitor. Assuming we are going with a 'handwave' of a largely gravitic M-drive, then most of the power plant and fuel that my theoretical missile build would be instead capacitor.
Ok...


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Originally Posted by kilemall View Post
Assuming a 'normal' density of 1000kg per ton and ...
Way off base. A Displacement ton is ~14 m3. 14 m3 of water is about 14 tonnes and 14 m3 of steel is about 140 tonnes.

Machinery is generally several times heavier than water, but of course lighter than a sold block of steel.

Let's call it about 50 tonnes per Dton capacitor?


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Originally Posted by kilemall View Post
... civilian missiles are 50kg total/25-35 kg 'fuel' and military/bay missiles are 750kg with a 3/5 fuel 'budget' of 450 kg, that leaves us with about 1.08 EP for the small missiles and 16.2 EP for the bay missiles.
That would make 30 kg about 30/5000036 = 0.02 EP, and that is of course completely insignificant...

450 kg capacitor in the "bay missile" would be about 0.3 EP and still insignificant.





Note that 1 EP = 250 MW 20 min 60 s/min = 300 000 MWs = 300 GWs = 300 GJ.

0.02 EP is 6 GJ, enough to accelerate a 50 kg missile to v = √( 2 6 GJ / 50 kg ) ≈ 15.5 km/s at 100% efficiency.

A ship can reach 12 km/s by accelerating at 1 G for 1 turn (20 min [HG]).

A missile with a max velocity of 15.5 km/s would be overtaken by the launching ship in the second round, and never catch up to a fleeing ship.

OK, Traveller grav drives don't work that way, but the morale of the story is that even Traveller energy densities and capacitors are not magic wands conjuring infinite acceleration...
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  #53  
Old September 27th, 2020, 06:21 AM
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This may be a stupid question, but where did the 50kg per missile standard come from?

I can see (per Mongoose) that you can store 20 missiles per dTon volume...so 1/20th of a dTon=625kg at density of 1. So probably nearer 1500kg to 2000kg

TNE missiles were 7 tonnes each.
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  #54  
Old September 27th, 2020, 06:39 AM
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On the bit about the 50kg missile, I'm just working within the confines of the missile design sequence as written and trying to make it consistent with the Striker widths and the 1 bay missile per dTon bit of the bay weapons.

As such it's more like the liter/volume design aspects of the robots, which are also highly dense mobile pieces of tech.

I don't worry about the weight bits too much on the ships of heavy equipment vs. volume, figuring there is a lot of open access space surrounding fhe gravitic/fusiony/maneuver things. I'm well aware that Traveller dTons are relatively light densities, and I handwave the 1000kg/1dTon thing as being more about not having excessive shifting weight in flight or exceeding lift capacities even for the magic M-drives.


Bit odd pillorying missiles for unrealistic power profiles when you're quoting a ship blowing past them using 'ship-magic'. Might as well be consistent and say the missiles are on the same tech with limitations for game purposes and a reason for limited accel that sounds good.


Speaking of jacked-up conversions, there is that whole business about what does an EP mean.

Yes Striker says 250MW, but 250MW WHAT? 250MW constant generation and constant use? 250MW-seconds constant, power backed up into batteries per second of use so 1000 seconds of 250MW power needs 250GW of capacitor/battery?

Depending on how you slice it, a scout ship charging capacitors for a jump requires two turns of full juice, 2EP x 2= 4EP. Which works out to a minuscule bit of capacitor readily subsumed into the Jump drive tonnage.

But if it means 2EP x 2000 seconds, that's 4000 EP, which requires 223 tons of capacitor, not possible unless Jump drives come with an extra-dimensional bag of holding capacitor.



This isn't casual for crazy people like me who wants to get a power allocation thing going, or really figure out what that ortillery fire rate is integrated into Striker time/phasing.

Speaking of ortillery, wait until we go over those. It's hair-raising being a fire support ship against an unsuppressed planet with hidden PD/starship weapons, because they have to come in REAL CLOSE to drop those little eggs in fast enough to only have a few seconds of fire against missiles or blaze away with laser/fusion, cause atmo. But you don't get the full flavor of it unless you vector move everything around.
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  #55  
Old September 27th, 2020, 06:56 AM
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Quote:
Originally Posted by BackworldTraveller View Post
This may be a stupid question, but where did the 50kg per missile standard come from?

I can see (per Mongoose) that you can store 20 missiles per dTon volume...so 1/20th of a dTon=625kg at density of 1. So probably nearer 1500kg to 2000kg

TNE missiles were 7 tonnes each.

Not stupid, just obscure.


I'm talking about the standards from the Missiles In Traveller supplement, which got published as an add-on to a JTAS issue.

https://wiki.travellerrpg.com/Missiles_in_Traveller

This tacked on a design sequence in the manner of Striker vehicles except for our little turret missiles.

It postulated an almost modular standards system, so you could fiddle with your missiles, upgrade them, have different effects so you could have generic missile or something really special and expensive on the rack waiting for a key situation. I like the fiddling modular stereo component aspect of the system, really gives the ship's gunner something to do to earn their keep other then constant sim battle gaming.

50Kg was the defined limit of the missile, but almost more like a volume design thing, although the speeds could go up a bit if you designed below 50kg with the same power package.

The way the components are described, it sounds VERY reaction-chemical fuel. But for so many reasons as described here and for decades of discussion, it doesn't work by any stretch of the imagination for pure reaction rocketry.


Which is part of the reason why you have later versions with more 'realistic' missile sizes, I suspect to 'stop the mockery'.




I'm just crossing that boundary to get a working build process so they assume their proper build costing and therefore player choice, but you really have to suss out the details to make it an alternative that is not automatically 'the way to win' or ignored as a bad weapon.

Bit nuts as I'm patching together all sorts of standards from multiple CT iterations which were designed to be separate games, with numbers that 'sounded good' to somebody at the time with 1980s publishing deadlines and less physics wonk QA or foresight to see the endless nitpicking the internet would enable.
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  #56  
Old September 27th, 2020, 10:32 AM
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"where did the 50kg per missile standard come from?"

Book 2 '81
page 17
weaponry

I'm assuming more or less arbitrarily chosen to be
a round number
light enough for a single gunner to reload in one turn
and heavy enough to seem plausible
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  #57  
Old September 27th, 2020, 01:25 PM
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Quote:
Originally Posted by kilemall View Post
Yes Striker says 250MW, but 250MW WHAT? 250MW constant generation and constant use?
Yes, 250 MW is a power.


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Originally Posted by kilemall View Post
250MW-seconds constant, power backed up into batteries per second of use so 1000 seconds of 250MW power needs 250GW of capacitor/battery?
Power multiplied by time is energy.

250 MW (power) for 1000 s is 250 GWs = 250 GJ (energy). Note that the units multiply just as the numbers do.


You might think of energy as the amount of water in a swimming pool and power as the flow of water in a hose. If a hose lets 2 litres per second (think power) into the pool, after 1000 s we will have 2 l/s 1000 s = 2000 litres (think energy) in the pool.



Quote:
Originally Posted by kilemall View Post
Depending on how you slice it, a scout ship charging capacitors for a jump requires two turns of full juice, 2EP x 2= 4EP. Which works out to a minuscule bit of capacitor readily subsumed into the Jump drive tonnage.
You forget the jump fuel that is turned into energy and buffered in the jump drive capacitors. The scout has 100 2 0.5% = 1 dTon capacitor that can contain 36 EP.


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Originally Posted by kilemall View Post
But if it means 2EP x 2000 seconds, that's 4000 EP, which requires 223 tons of capacitor, ...
No, the time is already built into the EPs. Energy = Powerconstant time. 1 EP is 250 MW for 1 turn (1200 s in HG), so 250 MW 1200 s = 300 GJ. An EP is a measure of energy generally measured in Joule [J], not a power (flow of energy) measured in Watt [W] (=J/s).

A capacitor stores energy, power is how fast that energy flows into or out of the capacitor.
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  #58  
Old September 27th, 2020, 03:25 PM
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Quote:
Originally Posted by AnotherDilbert View Post
Ok...

. . .

OK, Traveller grav drives don't work that way, but the morale of the story is that even Traveller energy densities and capacitors are not magic wands conjuring infinite acceleration...
You sure about that?
You need better handwavium.
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