Ship Design Philosophy

[Condottiere]

Spaceships: The Unbearable Lightness of Being and Putting the Fish to Bed

Most system navies will be happy with a point defence fighter that's cheap to operate and easy to fly.

A twenty four hour life support limit is well within tolerances, since they won't want the bird to stray far from the nest, so you base it around the one and a half tonne cockpit.

An interesting question is what weapon system to arm it with, or if you double down with two; which means that you either start off from a ten tonne template, or a thirty five tonne one. Since we want to skate on cheap ice, it will have to be one weapon system within a ten tonne limit. Less, but let's not go there now.

A mounted fixture takes up no volume, which is bovine fecal matter, so that's one eight of a tonne.

A one tonne power plant would either produce ten or fifteen scotts; a ten tonner needs two scotts for basics; a one tonne manoeuvre drive will create hundred tonnes of thrust for ten scotts of input, which would put you at factor ten acceleration, if you had a tech level sixteen drive.

Which we don't.

We could go to Tesco, and get a budget version off the shelf version that produces eight factors of acceleration for seventy five percent of the price.

Is this fast enough?

Generally speaking, interception tends to involve people flying towards you, and possibly a chase.

However, you're still going to need a tech level thirteen engine, so we should consider rocket power, even though that's double the size, but way cheaper, and available at a lower tech level. The odds are, that you're not going to encounter a spacecraft faster than nine gees, so a one point eight tonne reaction rocket available at tech level nine should be enough.

So at this point, we've consumed four point four two five tonnes, and have eight scotts to spare.

A pulse laser only needs three scotts, so that's five scotts in excess; a budget tech level eight fusion plant will be twenty five percent cheaper and produce a quarter less power, so that leaves two and a half scotts beyond requirement.

So that leaves fifty five odd percent for fuel, or twenty two thrust hours; or, two hours and twenty six minutes at full thrust.

 

[AnotherDilbert]

A single pulse laser is highly unlikely to penetrate hitech warship armour. Barbettes are needed if the enemy is armoured.

M-Drives and rockets are cumulative, it's probably a better idea to have a small M-drive and a small rocket for the last edge.

Since fighter weapons have very short range you need to get in close to do damage, the faster you are the faster you can get into range.

 

[Condottiere]

While you could squeeze out the energy for a factor one manoeuvre drive, the minimum size is still one tonne.

A low tech short range interceptor doesn't require continuous operation, and wouldn't be expected to go up against cutting edge fightercraft; it's more of a demonstration as to who owns this space, and to discourage opportunistic raiding.

 

[AnotherDilbert]

No minimum size for drives, only for fuel.

If you only want to herd civilians pulse lasers are of course enough. You might want to armour the fighter, making them very resistant to opportunistic sniping from civilians with the odd pulse laser.

 

[Condottiere]

I'm fairly sure that in another thread it was answered that engineering is minimum one tonne.

I offered the Striker formula as a compromise.

 

[AnotherDilbert]

I can't see any minimum in the rules? Several small craft in HG has drives smaller that 1 dT.

 

[fusor]

Spaceships: Engineering, and I Feel The Need

You'd think that with a big enough motor, you'd be able to pretty much go as fast you want.

So the question is, why at tech level nine, you can only accelerate one gee? Because if the answer is inertial compensators, why can we go with reaction rockets at nine gees?

And if we can go at sixteen gees for an extended period, aren't our crews and passengers going to turn to mush?

The speed limit in space is the speed of light. That's not the same as acceleration though. Acceleration depends on the mass of the ship and the thrust of the drive, but the way it's "calculated" in Traveller (except in TNE) has no relation to reality. What you need is something that says how much thrust (in tons) that each unit (cubic metre or dt of drive, megawatt of power or whatever) of the drive produces, and you need to know the mass of the ship components (you can fudge it by assuming that the contents of each dt of ship volume has a given mass (say, 10 tons)), or you can calculate it specifically for each component.

Otherwise, acceleration is whatever you can manage given the mass and thrust. There's no reason whatsoever for it to be limited to 1G at TL 9.

 

[Condottiere]

We tend to turn to mush under constant overpressure, rather than enduring a sudden acrobatic turn to get a better firing position, or get out of the enemy's.

So that usually seemed the reason for capping acceleration in Traveller.

Now we're up to nine or fifteen, or twenty four, so how does that work if the crew aren't all drones?

 

[Condottiere]

One option I considered was using a Half ton reactor. Nowhere in the rules does it say that have to be installed in one-ton increments.

We are going to leave the text 'as is' on this. We are unlikely to do any half ton reactors in 'official' designs, but we would be happy to consider this a viable 'hack' if ship designers want to do it in their games/supplements!

I knew I liked you guys for some reason...thanks for the feedback. That makes it a lot easier to make a few of the low power use small craft.

Though in the previous edition, you have a contradiction: reaction rockets are supposedly half the size, with the smallest sA at a quarter of a tonne, and the corresponding grav thruster at half a tonne, with a twenty tonne thrust.

 

[fusor]

So that usually seemed the reason for capping acceleration in Traveller.

Now we're up to nine or fifteen, or twenty four, so how does that work if the crew aren't all drones?

At pretty much anything above 1 or 2 G if you want people to be able to do anything on the ship then you're talking StarTrek-like "inertial compensators" or some other magitech that cancels out the force of acceleration inside a ship. Without that, I think being submerged in water in acceleration couches could protect against accelerations up to about 10G? But you'd basically need to be stuck in the couch, not able to do much else beyond praying you don't get killed by the G-force.

 

[AnotherDilbert]

One option I considered was using a Half ton reactor. Nowhere in the rules does it say that have to be installed in one-ton increments.

We are going to leave the text 'as is' on this. We are unlikely to do any half ton reactors in 'official' designs, but we would be happy to consider this a viable 'hack' if ship designers want to do it in their games/supplements!

Thanks, I had already forgotten that.

I would go with the written rules, and not apply scaling from older editions. The power output and fuel consumption of power plants vary wildly between editions. So I can't see that small power plants should be disallowed or disadvantaged in this edition.

 

[Condottiere]

Mobile scooters, like in the CoDominium.

I've always been fond of mermaids, though not if they look like Flipper.

As regards to power output, you'd have to assume there's an efficiency scale.

 

[Condottiere]

Spaceships: TIEs that Bind and the Umpire Strikes Back

In order to design a TIE fighter, you first have to know how much power it consumes.

On a ten tonne frame, that would two for basics, nine for ninety tonnes of thrust, and three for pulse laser; fourteen.

A tech level twelve one tonne fusion plant will get you fifteen scotts, well within that energy budget. However ...

TIE fighters are energized by solar panels, which without an actual deflector screen, seems an awfully vulnerable point of failure, considering how fragile they are.

Still, the minimum size for a solar panel is half a tonne, which generates the equivalent of seventy five percent of the output of a five tonne motor, in our case, let's take a tech level eight fusion plant, which would be thirty seven and half scotts, plus one scott for the factor one ten tonne thrust manoeuvre drive.

So thirty eight and a half scotts is really impressive, and you could operate a battery of turrets for that, and in theory, with only a one tonne manoeuvre drive and a one and a half tonne cockpit, you'd still have seventy percent of your fish bowl to fill, probably with armour and advanced sensors.

 

[Condottiere]

Starships: Engineering and Debt Collection

Having witnessed the amazing amount of power that the universe just lets stream outside your bridge windscreen and collecting in the solar panels of your craft, I bet you're wondering if you could use this to power your rather larger starship.

This isn't really recommended, but let's see what we can do for a two hundred tonne Freetrader.

In realspace, you need about forty for basics, twenty for manoeuvring, and possibly one for sensors; sixty one.

Let's assume thirty eight and a half scotts for every half tonne of solar panelling, which means a one tonne installation pretty much covers that, plus a surplus of sixteen scotts.

A one parsec jump needs only twenty scotts, you could easily allow the ship to drift for a turn, while diverting power.

Now comes the complicated part, because there is no sunlight in hyperspace as far as we know, so how can you power life support long enough, so that when the ship emerges at the other end of the rabbit hole, the crew are still alive and sane?

There's the artificial popsicle solution, though this doesn't seem a popular option; though it would allow the ship to run on fumes until the light at the end of the tunnel re-energizes the ship.

You can cheat and sneak onboard an auxiliary motor, to power the inhabited parts of the ship; a one tonne tech level eight fusion plant could do that for a quarter of the ship.

The other choice would be batteries, but it seems a very expensive solution, though while in realspace, recharging them is relatively easy.

 

[Condottiere]

Spaceships: Engineering and Bad Chemical Trip

However you try and slice it, chemical power plant doesn't cut it at one tech level below an introductory fusion plant, half the price and half the power, at incredible fuel consumption.

Arguably, you eventually get more out of paying a thousand times more for a prototype, or double that for an early prototype.

 

[fusor]

wtf is a "scott" that you keep going on about?

 

[wbnc]

wtf is a "scott" that you keep going on about?

Scott: Noun: ( Slang, or jargon) fictional term of power generated by a standard Fast cycle fusion reactor. Named for an equally fictional character from ancient earth mythology....just a guess.

 

[Condottiere]

After all, the actual amount of power produced is only defined vaguely as a point, so might as well honour someone who defined one of the the engineer archetypes.

 

[fusor]

After all, the actual amount of power produced is only defined vaguely as a point, so might as well honour someone who defined one of the the engineer archetypes.

OK, so 1 scott = 1 PP?

 

[Condottiere]

Spaceships: Engineering, the Radiant Bride and the Pharmaceutical Bridesmaid

While I'm not a fan of sitting in front, or standing over a fission reactor, in comparison to the alternatives, it can't be easily dismissed as an option, especially since using a fusion plant is no longer a requisite for entering the rabbit hole.

The chemical plant drinks too much, and no one seriously would want a relationship, with that, especially since the booze runs out too soon.

The fission plant is base tech level six, which means you could kick start it off at tech level four, if you plan to go for a steampunkish ambiance, though I'd have my doubts on completely being able to contain the radiation. With a ratio of twenty scotts per million schmuckers, that comparable to the next two alternatives, and certainly better than the later tech fusion plants, not counting the actual price of fuel, which I believe unprocessed is a million schmuckers per tonne.

It would seem to me that the fuel lasts longer than ten percent of motor size per four weeks. If I interpret Tee Five correctly, fuel rods last for a decade, there are two hundred rods per tonne (safely stored), and each costs forty kay schmuckers per rod.

That would be eight million schmuckers per tonne of two hundred rods.

So, how many rods per tonne of fission plant? Possibly, fifty rods.

That would be two million schmuckers over ten years, or five hundred twenty plus weeks, or 3'846.16 per week; which is expensive, but you aren't going to need to refuel for quite a while.

Another bonus is that while the price of the fission reactor may increase by fifty percent at tech level nine, fuel consumption would drop forty percent.


And yes, in the context of Traveller, one scott is one power point.