1g Ships and Size:7 worlds...

[Captain_Ahab]

probably easiest to just use the launch rules from 'Hard Times' 'One Small Step' rules after all

 

[Spinward Flow]

The fun part is when you look at the Travellermap and the Vilani Main.

The thing that sticks out like a sore thumb is ... Vland/Vland ... when it comes to 1G maneuver drives.
Vland is a Size: 9, Atmosphere: 6, Hydrographics: 7 world ... so a bit of a "super Terra" that is slightly higher gravity (because it's larger).

Out of all the "nearby" worlds on that part of the Vilani Main, only ONE can be seen as being Size: 8+ ... and that's Zhattar/Kasear (at Size: 8).

This means that in the "close abroad" around Vland, the classical J1/1G Free Trader makes perfect sense, since Size: 8+ worlds are most definitely the exception, not the rule. The only place that J1/1G Free Traders would be incapable of landing under their own power within "a decent range" of Vland itself would be at ... Vland itself. For an interstellar merchant ship, that works perfectly fine. You only need to rent orbital shuttle services at the homeworld ... which will have them.

So from a "historical archaeology" perspective, the J1/1G Free Trader is as "lean" an operator as was needed for the region of space within which it originated. It would have to have been constructed in orbit at a highport shipyard at Vland, but then once built such a J1/1G Free Trader would be able to land on and conduct business at 42 of the 44 worlds visible on the above map of just a portion of the Vilani Main, which sounds like a bargain to me!

By "outsourcing" the need to maneuver to a downport on Size: 8+ worlds, you keep the construction costs as low as possible while also keeping the revenue tonnage fraction as high as possible, putting the overall design on a glide path towards profitability that makes the whole venture viable for low end operators to enter the market.

Of course, the classical J1/1G Free Trader still has the pesky problem of needing to buy refined fuel (to avoid misjumps) and the risks of piracy when operating in such a "low drive performance" starship ... but in terms of minimal costs to enter the interstellar trading game, it's hard to do much better than the "ol' rusty bucket" of the J1/1G Free Trader.

So naturally I'm going to have to see if I can "one up" the classical Free Trader design with a "modernized" version that includes a fuel purification plant and a regenerative life support system setup, that also includes a collapsible fuel tank for optional range extension. Might even revise the cargo hold (Cr0 per ton) into being a hangar bay (Cr2000 per ton) so as to enable an option for small craft containerization to enable surface to orbit interface options that way.

 

[mike wightman]

I am of the opinion that the type A free trader is actually an insystem delivery van.

To move bulk goods, people, manufactured items and the like from a world with a population of a billion to other worlds with populations of hundreds of millions the 80t cargo hold of a type A is insignificant.

What it is good for is moving stuff quickly from main world to outsystem. It is an Amazon delivery van.

It would be built in sizable numbers, and makes for a good initial vessel for an ethically challenged Traveller posing as a merchant.

Any established merchant line is going to have its own fuel purification plants, teams of brokers to arrange for cargo and passengers, multiple crews for each ship to allow for crew downtime - what you do not want is your jump ship sitting around for a week. Jump, unload cargo and passengers, refuel, take on new crew, passengers and cargo, jump again.

A Traveller merchant in their free trader picks up what is left over, or passengers that want to avoid the usual traders, speculative trade goods. A free trader allows them to make enough money - if they are lucky - that they can eventually either found their own merchant line or build a better adventure class ship to seek their fortune.

 

[Condottiere]

1. You could set up a starport in an orbitting moon; I'm pretty sure that's in store for Luna.

2. And in the parking lot, filed with any number of freetraders, you can set up weekly swap meets.

 

[Spinward Flow]

One of the side benefits of standardizing on a J1/1G Free Trader that is "incapable of landing" on the homeworld (except by lithobraking, which is not recommended) is ... customs duties and enforcement. All of the interstellar trade infrastructure needs to flow through a highport (duh!) ... which then makes that highport the FIRST LINE OF DEFENSE against all kinds of knock on effects of interstellar trade (when you've got low technology levels and are just starting your interstellar expansion and colonization phase).

Smuggling and illicit goods
QUARANTINE against diseases, pathogens and "hitchhiker" biology brought back from off world(!)
Administration and Port Authority

If the Vilani Free Traders could land directly on Vland "no problem" ... there would have been no "buffer zone" between the population and economy on the world's surface from what was happening elsewhere beyond the planet's exosphere. The opportunities for an outbreak of plague from some unexplained/unrecognized source offworld would have been immense.

Essentially, the highport would become the "choke point" that ALL offworld commerce would need to pass through before interfacing with Vland, making it so much easier to regulate and police.



Just one of those things where if you start looking at the broader context, certain details of starship design can start to make more (retroactive) sense.

---

Any established merchant line is going to have its own fuel purification plants, teams of brokers to arrange for cargo and passengers, multiple crews for each ship to allow for crew downtime - what you do not want is your jump ship sitting around for a week. Jump, unload cargo and passengers, refuel, take on new crew, passengers and cargo, jump again.

Indeed.

One of the more "well duh, that should have been obvious from the start" realizations from doing all of my research into External Cargo Loading that culminated in the Five Sisters Clipper (Iderati evolution) is that having a ground support organization that does all the legwork locally to scare up cargo freight for transport IS THE WAY TO GO. Let the locals master the local market and then just use the starship(s) to move the goods around on what amounts to a moderately set schedule (because jump durations vary from 150-175 hours, per LBB5.80, so there's a limit to schedule precision). Having a "set route" that a starship runs that lets them berth, unload, fuel, load, launch in as little time as possible quickly becomes the most profitable way to do business.

When you're looking at the difference between 24-25 jumps per year and 31-35 jumps per year, that can make a fairly big difference to balance sheet revenues with minimal downsides to expenses (aside from consuming more fuel and paying more in berthing fees). Rapid turn around times so that starships spend more time in jump (earning money) and less time berthed at starports (losing money) helps the bottom line enough to justify the added expense of supporting local operations in each star system.

Even something as simple as "outsourcing" fuel purification to local company installations for shipping lines managing multiple starships makes a lot of sense. Why put fuel purification plants into every starship when you can just install them "at headquarters" and leave more tonnage aboard every starship available for cargo and passenger services (that earn revenue). You just need to have your own company ground support setup and personnel to make it happen. No need for type A or B starports to buy refined fuel from, your own company has ground support equipment and personnel to maintain it all in working order to supply refined fuel to MULTIPLE starships every week!



None of which helps the Tramp Freighter that goes around chasing speculative cargoes as a wildcat operator ... but that's a different market segment. That's the speculator, not the routine delivery, when it comes to operations and business models. The speculator needs to be more "selfishly sufficient" because they go wherever the Trade Winds (of commerce) are blowing. The Tramp Freighter has no set route or schedule of destinations (they can have habits, but they aren't presets determined well in advance).

Most Traveller campaigns view the Free Trader through the lens of the wildcat speculator Tramp Freighter perspective ... simply because the more complicated and involved "just a delivery van" for someone else business model is relatively unappealing to adventure minded Players, who don't want to be tied down to set routes and schedules they need to keep.

 

[Jame]

Or have a 1.25G drive and a bit of patience.
If the rules allow a 1.25G drive, which is part of the problem.

The rules also include contragravity at TL 9.
Any 1 ton or larger interstellar vessel has contragravity unless we're playing harder science than Traveller (or the GM states for their campaign).
Now, what this means, for those of us who actually have read this, is that the 1G acceleration ship can still enter any gravity well, land, do VTOL and then take off again. It might take longer on a higher gravity or larger size world - yes, even a gas giant, but it can still be done.
If you're concerned about realism, just say "yeah, it's fictional technology." It's what I'd do.

 

[Condottiere]

Seems to depend very much what the description of the manoeuvre drive says, which differs from edition to edition.

 

[AnotherDilbert]

The rules also include contragravity at TL 9.
Any 1 ton or larger interstellar vessel has contragravity unless we're playing harder science than Traveller (or the GM states for their campaign).

Yes, in TNE, T4, and T5 (if the ship is specified with it, it's a common option), but not in CT or commonly in MT.

So it depends on the edition we are talking about.

Now, what this means, for those of us who actually have read this, is that the 1G acceleration ship can still enter any gravity well, land, do VTOL and then take off again. It might take longer on a higher gravity or larger size world - yes, even a gas giant, but it can still be done.

That might be true in TNE, but not in T4, nor (I think) in T5.


Unless you want it work that way, then YTU works that way...

 

[Jame]

Yes, in TNE, T4, and T5 (if the ship is specified with it, it's a common option), but not in CT or commonly in MT.

So it depends on the edition we are talking about.

CT doesn't mention it, but it does have air/rafts and other contragravity vehicles. So it's a logical process to apply the tech to spacecraft, which aren't specified as not having them. And in this case they would have to have specified.

 

[AnotherDilbert]

CT doesn't mention it, but it does have air/rafts and other contragravity vehicles.

Agreed, CT/MT has anti-gravity. Anti-gravity works slightly differently than contragravity from TNE and beyond, but that doesn't matter to this discussion.

So it's a logical process to apply the tech to spacecraft, which aren't specified as not having them. And in this case they would have to have specified.

Agreed, it is a drive system that could be installed in spacecraft and MT has the rules for it, but it is not default or common in CT/MT. In CT we could homebrew the grav drives in Striker into spacecraft.

At least in MT a 1 G grav drive would cost roughly the same as a 1 G M-drive (but only works close to a planet), so you could have a 1 G M-drive + 1 G grav drive for roughly the same cost as a 2 G M-drive. I'd take the 2 G M-drive.

By the description in MT the M-drive is essentially an advanced version of the grav drive that works in open space.

 

[Condottiere]

On reflection, the only reason I'd care about one gee acceleration drives is because I'd be able to design technological level nine spacecraft, or more specifically, starships.

Sort of all in one.

Once you break that glass ceiling, manoeuvre drives can become factor one plus fraction.

 

[AnotherDilbert]

In CT we could homebrew the grav drives in Striker into spacecraft.

Hmm, let's see:

_ _ K. Grav Generators: A grav vehicle requires grav generators installed in its chassis. Each .02 m³ of grav generators produces 1 ton of thrust and requires .1 megawatts of power from the power plant. They weigh 2 tons and cost Cr100,000 per m³.

A 100 Dt would be about 1000 tonnes.
1000 tonnes of grav thrust (~10 MN) is 1000 × 0.02 m³ = 20 m³ ≈ 1.5 Dt.
Cost 20 m³ × MCr 0.1 = MCr 2.
Power 1000 × 0.1 MW = 100 MW ≈ 0.4 EP.

Well, that was cheap...

 

[Jame]

Agreed, CT/MT has anti-gravity. Anti-gravity works slightly differently than contragravity from TNE and beyond, but that doesn't matter to this discussion.



Agreed, it is a drive system that could be installed in spacecraft and MT has the rules for it, but it is not default or common in CT/MT. In CT we could homebrew the grav drives in Striker into spacecraft.

At least in MT a 1 G grav drive would cost roughly the same as a 1 G M-drive (but only works close to a planet), so you could have a 1 G M-drive + 1 G grav drive for roughly the same cost as a 2 G M-drive. I'd take the 2 G M-drive.

By the description in MT the M-drive is essentially an advanced version of the grav drive that works in open space.

Oh! You mean as a form of space propulsion.
No, they have contragrav lifters that function in the same way that an air/raft's do, in that while the contragrav lifters nullify the force of a location's gravity and therefore allow a 1-g thrust vessel to land and take off from a location that has greater than 1 gravity worth of gravity.

The contragrav lifters, since they are contragrav lifters and not a form of propulsion, otherwise do not provide propulsion, as they just nullify the gravity of a location that a 1-g thrust vessel is trying to take off from or land on. Thus functioning in the same way as an air/raft's.

If I'm hammering away at the point, well, I think that I have to be excessively detailed to communicate how Classic Traveller already has a way around the issue.

 

[kilemall]

Hmm, let's see:


A 100 Dt would be about 1000 tonnes.
1000 tonnes of grav thrust (~10 MN) is 1000 × 0.02 m³ = 20 m³ ≈ 1.5 Dt.
Cost 20 m³ × MCr 0.1 = MCr 2.
Power 1000 × 0.1 MW = 100 MW ≈ 0.4 EP.

Well, that was cheap...

Means the A mDrive is part that and the rest of it is 1.6 EP of thruster.

I thought the MT weight of a Type S was 600-700 tons.

 

[Baroun Tardis]

That might be true in TNE, but not in T4, nor (I think) in T5.

In T5, the hull comes with Z-Drive aka Lifters that allow the ship to ignore local gravity and move around at about 35kph tops (Nap of Planet). Lifters are able to take you to orbit in several hours per world size. It's slow
Lifters also cover intertial dampers and internal gravity for the ship.
You can have the lifters removed and get a credit cost back , but no volume savings. (it's 0.5mcr per 100 tons of hull, so maybe some Type-A's got a 1Mcr discount and don't have lifters? But then what do they do for internal grav and inertial dampers? Maybe tail-sitters that do constant accel?)


If you bought "wings" for your ship, you get an effective +1 G thrust while in decent atmo, as long as you're moving fast
Landing fast requires either landing gear with wheels or a flotation hull. The default landing gear is "skids" which are specially strengthened hull sections the ship is designed to sit on the tarmac on, and not reccommended for unpaved landings.

 

[Grav_Moped]

At least in MT a 1 G grav drive would cost roughly the same as a 1 G M-drive (but only works close to a planet), so you could have a 1 G M-drive + 1 G grav drive for roughly the same cost as a 2 G M-drive. I'd take the 2 G M-drive.

Except that, not being an additional rating point of M-Drive, it wouldn't need the associated additional power plant and fuel.

 

[AnotherDilbert]

Means the A mDrive is part that and the rest of it is 1.6 EP of thruster.

Sorry, no. By LBB2 and Striker ships are affected by gravity, so by default they don't have grav drives.

I thought the MT weight of a Type S was 600-700 tons.

10 tonne per Dt is a rough estimate:



Basically the more fuel, the lighter the ship.

 

[AnotherDilbert]

Except that, not being an additional rating point of M-Drive, it wouldn't need the associated additional power plant and fuel.

It's an additional drive that would need power concurrently. You would need a bigger PP.

 

[AnotherDilbert]

In T5, the hull comes with Z-Drive aka Lifters that allow the ship to ignore local gravity and move around at about 35kph tops (Nap of Planet). Lifters are able to take you to orbit in several hours per world size. It's slow

Yes, that is basically T4 contragrav: lift and slight propulsion.
TNE contragrav is just lift and no propulsion.

 

[AnotherDilbert]

Oh! You mean as a form of space propulsion.
No, they have contragrav lifters that function in the same way that an air/raft's do, in that while the contragrav lifters nullify the force of a location's gravity and therefore allow a 1-g thrust vessel to land and take off from a location that has greater than 1 gravity worth of gravity.

CT anti-gravity provides both lift and propulsion, it's just thrust (like a helicopter rotor). It has to be dimensioned for the amount of thrust it can provide, commonly measured in G of acceleration for the craft.
You are describing TNE contragrav, there is a difference.
There is no nullification, even in TNE, just counteracting, i.e. cancelling out with a counter-force.

The contragrav lifters, since they are contragrav lifters and not a form of propulsion, otherwise do not provide propulsion, as they just nullify the gravity of a location that a 1-g thrust vessel is trying to take off from or land on. Thus functioning in the same way as an air/raft's.

That is TNE contragrav. Even T4 and T5 contragrav provides some slight propulsion. T4 contragrav provides a specified amount of lift, and has to be dimensioned for the gravity it's supposed to counteract.

If I'm hammering away at the point, well, I think that I have to be excessively detailed to communicate how Classic Traveller already has a way around the issue.

CT does not have contragrav, but anti-grav. Anti-grav is just thrust, just like a M-drive.