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Old 04-21-2018, 12:53 PM   #11
Rupert
 
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Default Re: 2300 ad tl

Quote:
Originally Posted by weby View Post
The rocket engines are actually called thrusters in 2300AD and produce super science results.

The thrusters allow you to go down and up a 1g planet by using approximately 14.3% if the mass as fuel. (Rule is add 1/6th of the mass as fuel for that, but do not count that fuel as part of the mass. See naval architects manual page 9)
That's less than I remembered.
Quote:
The fuel appears to be hydrogen-oxygen as it can be made in the fuel station by splitting water. The specfic impulse varies a bit depending things like the altitude but is normally below 400 at sea level on earth and below 500 in vacuum.
That's not what the rules say.
Quote:
Originally Posted by NAM
Thrusters may only be added to ships which have MHD tur-
bine power plants. The addition actually consists of adding a large
reinforced re-ignition chamber to the power plant and thrust nozzles
at the rear of the hull. The MHD turbine is thus modified to func-
tion as a thruster. When in thrust mode, large volumes of addi-
tional fuel are added to the re-ignition chamber, burned, and ejected
as reaction mass.
That looks like the fuel is being both burned and heated and it's some awful hybrid of an MHD turbine and rocket. That's super-science right there.
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Old 04-21-2018, 01:48 PM   #12
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Default Re: 2300 ad tl

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Originally Posted by Rupert View Post
That looks like the fuel is being both burned and heated and it's some awful hybrid of an MHD turbine and rocket. That's super-science right there.
Normal hydroox engines use use more hydrogen than is consumed in the burning and the remaining is ejected as reaction mass.

That is pretty much as described in the description "When in thrust mode, large volumes of additional fuel are added to the re-ignition chamber, burned, and ejected as reaction mass."

Also any actual thrust from the MHD part is likely miniscule.

As example take the ship closest to a normal shuttle the Yinma-class Lander from the ships of the french arm. It has only a 0.5MW MHD reactor, that is really not much when compared to the energy you get even by burning that 1/6th of the mass as fuel. It uses thus 0.3 tons fuel/hour in the MHD engine. The total weight seems to be 175 tons base+225 cargo=400 tons loaded without fuel +25 tons fuel. So it is using 66 2/3 tons fuel for the landing/takeoff out of the 25 toms it has.. or more likely it has 25 tons for long term operation and 66 2/3 tons for interface work. Either way MHD uses 0.5% of the fuel/hour that the thruster uses.

So most of the thrust comes from magic, the next highest component is the burned hydrox in the camber as a rocket engine and the last really small part from the MHD turbine exhaust.

In case of the Yunma it is about: 92.6% magic, 7.4% hydrox burning and maybe 0.01% from maybe 20 minutes of the MHD.
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Old 04-21-2018, 02:06 PM   #13
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Default Re: 2300 ad tl

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Originally Posted by RogerBW View Post
I think that several of us who remember the game felt that Earth/Cybertech was a bit of a false step – it was trying to hook into the cyberpunk gaming boom of the era, but wasn't really in keeping with the rest of the setting. So if you wanted to saw that off and pretend it didn't happen, I don't think it would break anything.
Ah but hindsight and many years of sci fi development and...
Look at it this way.
Combine the cybernetic stuff and biological enhancements of the provolutionists with the downloading of people's personalities and memories and what you have is not a cyberpunk game but a very early transhuman setting...
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Old 04-21-2018, 02:10 PM   #14
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Default Re: 2300 ad tl

Quote:
Originally Posted by weby View Post
The rocket engines are actually called thrusters in 2300AD and produce super science results.

The thrusters allow you to go down and up a 1g planet by using approximately 14.3% if the mass as fuel. (Rule is add 1/6th of the mass as fuel for that, but do not count that fuel as part of the mass. See naval architects manual page 9)

The fuel appears to be hydrogen-oxygen as it can be made in the fuel station by splitting water. The specfic impulse varies a bit depending things like the altitude but is normally below 400 at sea level on earth and below 500 in vacuum.

The full equations due to the changing pressure and the slight fraction of unburned hydrogen normally used you would be complex but using a value closer to vacuum than seal level gives good enough result as the ship will spend more time outside the densest atmosphere than inside it, so picking say 450 as average very generous ISP and putting it and the fuel fraction into the basic rocket equation:
delta-v=specific impulse*9.80665 m/s/s* Natural logarithm of(mass with fuel/mass without fuel).

We get a delta-v of 679 meters/second and you would need 9000+ m/second to get to low earth orbit, so there is a factor of 13 more needed.

Thus their thrusters must do some super science to get to orbit with that low fuel fraction.

You would need a fuel fraction of about 7.7 to 1 to get that speed with hydrogen-oxide, that is for each kilogram to orbit you need to add about 6.7 kilograms of hydrogen and oxygen combined. In reality you need more than that as your total mass is highest when your efficiency is lowest in the lower atmosphere, the efficiency used in the calculation was rounded heavily upwards, system loss and so on, but that is close enough for visualization purposes.
Consider them to be the 300 year hence development of the SABRE engine.
Serious answer I though you were implying thrusters were reactionless rather than superscience.
But then neither of us have mentioned the fusion power plants which are superscience and the MHD turbine red herring.
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Old 04-21-2018, 02:26 PM   #15
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Default Re: 2300 ad tl

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Originally Posted by Mike Wightman View Post
Consider them to be the 300 year hence development of the SABRE engine.
You still only get so much from 14% of the mass as fuel, when you burn hydrogen you only get so much energy. But as the game specifies that it is the same fuel as the MHD uses so you already have the oxygen and venting it does thus not help.

Quote:
Serious answer I though you were implying thrusters were reactionless rather than superscience.
Nothing I said was meant to imply reactionless thrusters as the game very clearly used just super science "extra energy from nothing" reaction engines.

The thrusters were listed by me as super science and named specifically thrusters because that is what they are called in game.

Quote:
But then neither of us have mentioned the fusion power plants which are superscience and the MHD turbine red herring.
Why would fusion plants be super science? Nothing about them seems overly strange to me, maybe I have missed something about them?
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Old 04-21-2018, 05:55 PM   #16
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Default Re: 2300 ad tl

The feel I got from 2300 was similar to Firefly...

...the Core has extremely high tech but the outworlds donít see much of it.

Cyberpunk probably exists onEarth but most of the adventures are taking place on th frontier.
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Old 04-22-2018, 07:13 PM   #17
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Default Re: 2300 ad tl

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Originally Posted by tanksoldier View Post
The feel I got from 2300 was similar to Firefly...

...the Core has extremely high tech but the outworlds don’t see much of it.

Cyberpunk probably exists on Earth but most of the adventures are taking place on the frontier.
Eh, kinda-sorta-maybe, as far as your description goes, anyway.

In the 2300 AD setting, multiple polities existed and the main coalitions had set out in different directions from Earth. Each of them controlled their own "arms," or paths to and from various colonies. The Earth-based polities governed some colonies, others had gained independence, and many planets had colonies created by either the the main colonizing power or by favored clients.

Friendly clients sometimes had their own colony worlds, corporations and NGOs had others, and sometimes paths ("fingers") branched off from the main polity's "arm" and led to those colonies.

In a few cases, planets had been settled by rival powers, which resulted in considerable inter-colony tension, and sometimes even nasty little localized proxy-wars.

So, yeah the core worlds (of which there were only two) had technological advantages, but the equipment available to the colonists partially depended on the initial investment made by the sponsor, as well as local conditions.

In many cases (and this makes it my favorite setting), the writers recognized the impracticality (or even impossibility) of installing at the colony, from the get-go, an industrial infrastructure. That means the equipment used on each planet varied a lot, and depended on available resources and distances from the colony hub.

So, yeah, I'd call the core planets TL10, with just enough super-science to have relatively inexpensive space travel and "slow" FTL speeds.

(Even an unmanned, light and fast messenger drone couldn't travel much faster than about 1 ly in 12-24 hours or so, IIRC, but it's been awhile and my books are packed in boxes.)

That said, I will note that, wholly unlike Firefly, privately-owned starships didn't really exist in vanilla 2300 AD. Most starships were owned by governments, NGOs (of which 2300AD had many) or large corporations.

A few billionaires owned private yachts with stutterwarp capabilities, but that's it. No independent merchants struggled to keep flyin' in their ramshackle ships. If the PCs needed to travel, they booked flights and bought tickets.

I'd agree that computers are retarded, by modern standards, and think the TL 7+1 suggestion is pretty good. Also, nobody had conceived of cell phones, at the time GDW created the setting, so radios were the best they could do.

Most colony hubs had TL 9 available to them, but that dropped off as distance increased. I remember the vehicles mostly used hydrogen fuel cells, buildings used solar panels, advanced colonies had central powerplants of some sort, and guns outside the Core mostly used chemical propellants.

I'd say a significant fraction of colony equipment qualified as the equivalent of TL8, but with far less integration of computer technology, and no information networking to speak of. The books noted that a lot of the small-arms used by the colonists were former military weapons that had been phased out in favor of more advanced replacements, and then dumped in the surplus market.

In some cases, if the environment supported it and allowed for more self-sufficiency, the outlying colony areas might even use TL7 equipment -- especially if it was simple, durable, and easily maintained and repaired with the resources on hand.
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Old 04-22-2018, 08:44 PM   #18
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Default Re: 2300 ad tl

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Originally Posted by tshiggins View Post
So, yeah, I'd call the core planets TL10, with just enough super-science to have relatively inexpensive space travel and "slow" FTL speeds.

(Even an unmanned, light and fast messenger drone couldn't travel much faster than about 1 ly in 12-24 hours or so, IIRC, but it's been awhile and my books are packed in boxes.)
Fast warships could manage 3-5LY/day. Most would do more like 1.5-2.5LY/day. A liner did about 1-1.5LY/day, as would an unladen freighter. A freighter loaded with ore would do about 0.5LY/day, and for some of them this would make their range limit the fuel for their power-plant when they were that heavily laden.
Quote:
That said, I will note that, wholly unlike Firefly, privately-owned starships didn't really exist in vanilla 2300 AD. Most starships were owned by governments, NGOs (of which 2300AD had many) or large corporations.

A few billionaires owned private yachts with stutterwarp capabilities, but that's it. No independent merchants who struggled to keep flyin' in their ramshackle ships. If the PCs needed to travel, they booked flights and bought tickets.
There were a few freighters that would be within reach of a small shipping company, especially if second-hand, and parts of the French Arm were just getting to the point where there might've been room for a few independent operators (though they'd still be running set routes and mainly carrying freight, not speculative cargo, IMO) when the Kafer War went all hot, which would've killed off that budding trade opportunity.

One thing about the tech that makes it seem primitive to us today is that most of what we see is stuff intended for explorers, wilderness colonists, and small military units operating with little logistics support, so it's rugged and doesn't depend on other pieces of gear to function. Massively networked, talks to all its friends, uses distributed processing over the whole unit, navigates by GPS and wi-fi hotspots, and so on stuff might exist in the core, but out in the frontier it's seen as unreliable, I think. People want self-contained equipment that works when the GPS sats are down, the comm sats are unreachable because of solar activity, and you're on your own and thus have no network.
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Old 04-22-2018, 09:18 PM   #19
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Default Re: 2300 ad tl

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Originally Posted by Rupert View Post
One thing about the tech that makes it seem primitive to us today is that most of what we see is stuff intended for explorers, wilderness colonists, and small military units operating with little logistics support, so it's rugged and doesn't depend on other pieces of gear to function. Massively networked, talks to all its friends, uses distributed processing over the whole unit, navigates by GPS and wi-fi hotspots, and so on stuff might exist in the core, but out in the frontier it's seen as unreliable, I think. People want self-contained equipment that works when the GPS sats are down, the comm sats are unreachable because of solar activity, and you're on your own and thus have no network.
Still is there anything about the tech that shows it hasn't advanced beyond the 1980s or whatever? For the rugged exploration stuff I mean.
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Old 04-22-2018, 09:56 PM   #20
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Still is there anything about the tech that shows it hasn't advanced beyond the 1980s or whatever? For the rugged exploration stuff I mean.
I think it has - there are flight packs and HUD systems for your helmets that work for more than just really expensive aerospace fighters, so that's better than today in those areas. Hovercraft are common, and some blimps are used for cheap transport on colonies where the weather is agreeable and roading is limited, but these are more a slightly alternate tech line than higher tech. The aircraft are batter than ours - semi-functional hypersonic stealth, and useful SVTOL attack planes. Battery power density and robotics are good enough to allow combat walkers in the ~3m tall range that have enough armour that you need a plasma gun or AT system to kill them and not merely a 25mm cannon.
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