Why X-Boat tenders

[phavoc]

A few reasons why tenders might make more sense than a station:

1) Jump accuracy is never really defined in the books. If you can be a few hundred thousand Km off your entry mark, your arrival locations can vary a bit. Not so much a tug couldn't pick up an X-boat though, but a tender would do a better job overall (but at a higher cost).

2) While the game doesn't model it at all, we know a jump is a straight line from entry to exit. To get places those straight lines will intersect with objects large enough to pull them out of jump space (i.e. a planet, gas giant, star or otherwise large asteroid). A tender will be able to drop off an X-boat in the correct location to make a jump outsystem that doesn't intersect with one of the aforementioned objects. A station's location MIGHT, but over time it would need to move as planets move. And some paths may not be possible due to stellar alignment of different systems (and their planetary objects).

3) An X-boat is defenseless and unable to move. Enterprising pirates or enemies would be able to capture it whole and jump out with it. Probably not likely, but if you see some of the things PC's do in their games, it's not entirely far-fetched! A mobile tender will be able to quickly acquire the helpless craft and also the departing craft would be not helpless. I don't recall if tenders normally mounted armaments, but they are large enough to not be pushovers if you put some guns on them.

4) X-boat arrival times are random, and departing X-boats can't go until they have the information necessary for the next leg of the journey. It could be that direct-connect of the data from arriving to departing X-boat is fastest and most secure (though data transfer speed probably isn't the whole reason). Maybe there are secure data wafers onboard that can only be moved physically, so you need to dock with the arriving unit, take them onboard and transfer to the departing one and then drop it off for departure.

Those are the biggest reasons why mobile tenders might make better recover vehicles than a station. There are pro's and con's to each type of idea. Without a truly well-thought out model that explains all the mechanics and reasoning, we are just left with the basic explanations and have to fill in the blanks with speculations.

 

[Nelphine]

2 i disagree with. You simply cant reliably get a straight line given the existence of stars unless you regularly are jumping in 5+ days at M2 from your target. While its often alluded to, it makes less sense than the alternative.

 

[Arkathan]

I specifically do away with that particular problem. Its not specified in the rules as written that you have to avoid large chunks of any given solar system when jumping in - or out, depending on your destination. Indeed, that would make many adventures not function properly, and completely destroy most trade rules as written.

Nothing wrong with house ruling an inconvenience out of existence. In practice, I don't calculate where the start and end point are in relation to each other either.
But this is a theoretical pondering on how things could work, so using house rules that ignore the problem is not relevant to solving the problem. It DOES make it convenient, and there is nothing wrong with that.

 

[Arkathan]

2 i disagree with. You simply cant reliably get a straight line given the existence of stars unless you regularly are jumping in 5+ days at M2 from your target. While its often alluded to, it makes less sense than the alternative.

No, that is rules as written.
Again, you can house rule the problem out of existence, but you cannot use a house rule as a basis for declaring someone else wrong.
As always, you do you and enjoy your game.

 

[Nelphine]

Sorry, where does it say its a straight line?

And, even if it does, im willing to call the house rule canon, because otherwise the trade rules dont work in the core rulebook for mgt2e; and adventures such as pirates of drinax no longer work. Given the assumption that trade, and major published adventures, work as written, not going in a straight line is accepted in the otu, which IS good enough for the discussion at hand.

While i accept there will be games it doesnt work, those will be the exception, not the standard, and therefore our discussion of what works in standard, will still allow it to work.

 

[Arkathan]

Since you have no access to the real universe, and your trajectory is determined upon entering jumpspace and now your jump drive is only active during the entry transit, it is a straight line. It cannot be anything else.
Hyperspace, a non-"Charted Space" concept, is more conducive to your line of thought. I have no problem using hyperspace reasoning with Traveller travel, but again, that is a house rule, and not relevant to the conversation at hand. You do you and have fun with it, but no amount of "but my house rule" will change the imaginary rules set by the OTU.

GM's should not have to worry about line of sight and stellar/planetary occlusion in-game. Theorists and novelists DO need to consider such things.
No sane person is going to calculate the position of imaginary planets, many of them not defined in canon, each time a player jumps. But for THIS discussion, such considerations are relevant.

 

[ottarrus]

To build on Ark's point, jump-space astrogation is NOT an exact science! Nobody can predict the exact point in real-space that a ship will emerge from jump, nor can they predict the exact time. As MM's novel Agent of the Imperium points out, even with highly tuned drives and expert astrogators, each using the best military grade computers and software, the narrowest predictive window for emergence is multiple hours and thousands of kilometers from the astrogated time and location.
And even then, how is the receiving station supposed to know when a given X-boat jumped out of its last station? With latitudes this wide, you can only predict the day a given X-boat might arrive and have a tug in the general vicinity.

 

[Nelphine]

The otu DOES assume we dont have to worry about it. Thats how mortgages of ships, trade, and everything thats related (like cost pf passengers) are calculated. If the otu had to worry about it, every trip would be assumed to be 5-10 days longer, making the average jump routine 3 weeks, not 2 weeks.

That messes up ALL the math in the core rulebook. Since the core rulebook is THE thing the otu is based on, we can assume for discussions like this one, or for novels and published adventures, that this 'house rule' is actually standard in the otu, regardless of what might be suggested.

Nowhere does it say jump space follows a linear line within real space. I completely agree that my extension (where you can change the jump path while within jump space) is a house rule. Thats why i made it a seperate post. But having a jump path that circles round gravity wells, does not break otu assumptions. And my extension isnt needed for this discussion.


Ottarus, the random emergence point is only thousands of kilomers - maybe even tens of thousands of kilometers. Tugs, and tenders, both can get there in a matter of hours, not days. Which means, both tugs and tenders, also dont need to predict the time. They simply react to the emergence, and head over.

Hell, TENDERS dont work if you have emergence points on different sides of a solar system. Youd need 3 or 4 tenders in the smallest backwaters if you dont allow for non linear jump space. The entire xboat system would collapse.

 

[phavoc]

Sorry, where does it say its a straight line?

And, even if it does, im willing to call the house rule canon, because otherwise the trade rules dont work in the core rulebook for mgt2e; and adventures such as pirates of drinax no longer work. Given the assumption that trade, and major published adventures, work as written, not going in a straight line is accepted in the otu, which IS good enough for the discussion at hand.

While i accept there will be games it doesnt work, those will be the exception, not the standard, and therefore our discussion of what works in standard, will still allow it to work.

Miller wrote about jumpspace in JTAS 24, and it's stated in many other editions - Entering (and exiting jump space) occurs at least 100D outside a planetary body or star (some editions speak to significant gravitational masses as well). Jumping OUT within the 100D results in a ships destruction or a misjump. Jumping INTO a 100D gravity well is impossible as your ship will be forced out of jump at the 100D limit.

The passage of "The perturbing effects of gravity preclude a ship from exiting jump space within the same distance", which is directly below the passage about jumping at the 100D limitation.

If one is forced out of jump coming within 100D of a planet or a start, then one cannot jump through them, but must go around them. And if that's the case then, logically speaking, jump travel is a linear line.

GURPS Traveller (probably the best attempt at filling in a lot of the game universe potholes) says "JUMP-POINT MASKING Jump-point masking occurs when the 100D limit of another astronomical body blocks (masks) the jump point of the main world. Since a ship trying to jump in through the100D limit would be precipitated out of jumps pace well short of its destination (see p. GT120), and since jumping ou tfrom within that radius runs the risk of misjump, astrogators must plot a course that just skims the 100D limit and begins or ends as close to the main world as possible (see illustration). Masking occurs about 78% of the time at either origin or destination, making completely free (unmasked) jumps less than 5% of the total. This adds 30 hours to the average voyage length" GT: Starships, pg 102. There is an illustration of this on pg 103 that clearly shows how jump masking by a planet or star works.

Like many things in Traveller this is never fully defined in the original editions And without mapping software and mapping planets and systems fully in 3D with all major bodies having their X,Y, and Z axis known, it's simply impractical to incorporate this into the game. Oddly enough the original 1977 LBB does give the mathematical models for vector movement and gravity wells affecting movement and combat.

Can one argue that jump space is curved? Sure. Can one argue that you just need to do 100D and then you can jump through a star? Sure. Traveller's foundation is built upon an incomplete model of the gaming universe.

 

[phavoc]

The otu DOES assume we dont have to worry about it. Thats how mortgages of ships, trade, and everything thats related (like cost pf passengers) are calculated. If the otu had to worry about it, every trip would be assumed to be 5-10 days longer, making the average jump routine 3 weeks, not 2 weeks.

That messes up ALL the math in the core rulebook. Since the core rulebook is THE thing the otu is based on, we can assume for discussions like this one, or for novels and published adventures, that this 'house rule' is actually standard in the otu, regardless of what might be suggested.

Nowhere does it say jump space follows a linear line within real space. I completely agree that my extension (where you can change the jump path while within jump space) is a house rule. Thats why i made it a seperate post. But having a jump path that circles round gravity wells, does not break otu assumptions. And my extension isnt needed for this discussion.


Ottarus, the random emergence point is only thousands of kilomers - maybe even tens of thousands of kilometers. Tugs, and tenders, both can get there in a matter of hours, not days. Which means, both tugs and tenders, also dont need to predict the time. They simply react to the emergence, and head over.

Hell, TENDERS dont work if you have emergence points on different sides of a solar system. Youd need 3 or 4 tenders in the smallest backwaters if you dont allow for non linear jump space. The entire xboat system would collapse.

CT (LBB version) assumes many things, sometimes contradictory. Technically, CT is CT-77, or CT-81. Then you get to further muddy the waters by referring to the supplements, modules and JTAS - all of which are considered canonical from a CT perspective. CT-77 rules state that you need 10kg of fuel for a100tons or less ship to move at 1G for 10m. That doesn't match the larger ship fuel consumption, even though both types use similar M-drives and fusion power plants.

CT-71 also states there is a "normal" limit of one person per stateroom, with couples taking adjoining staterooms, and crew members get their own staterooms. Military or chartered ships "may" use double occupancy rooms.

There are many more examples, but most people are rather used to these sorts of things. Some people still play by CT rules as they are probably the most stripped down/basic of all Traveller. As for the potholes in the rules, I think most have just figured out how to either fill them in or just disregard that which they don't like - the classic "IMTU" argument. The many versions of conversations between Traveller players via the web are a prime example!

 

[CordwainerFish]

It's not a logical necessity for what happens to a ship in jump to meaningfully correspond to any sort of path at all - nor for that path, if it exists, to elegantly map to a path in normal space, nor for that path to be a geodesic. (There is no such thing as a straight line in normal space, though on a small scale geodesics approximate straight lines.)

I'm perfectly happy for jump to consist of "your ship goes away at this point, and comes back at that point, and if you want to even understand the basics of arguments physicists have about what happens in between you need Science (Mathematics)-2 at least". I'm also not a fan of jump masking.

 

[Geir]

I'm also not a fan of jump masking.

Just stepping randomly into this thread because something made my neuron (yes singular - it gets lonely at times) fire.
Two things on jump masking:
Is Traveller a simulation or a game? As a game, the concept of jump masking adds little unless it is a specific plot point. Since the majority of stars in the OTU are M-class dwarfs (except, because someone at some time did the generation way wrong, there a tremendously large surplus of F class stars - but that is neither here nor there - or out there) it would be an issue in most systems, but it is inherently ignored by the rules and by every adventure I can think of.

Second: Let's pretend we're in the Solar System and jumping somewhere else: Good news, Earth is more than 100D away from the sun, so we can ignore that. And the sun is only half a degree wide, so ignoring complicated math, only a 50 degree circle of the 360 degree sky is blocked by the sun's 100D at any one time - this can potentially block some destinations some of the time and will never blank destinations far to the north or south of the ecliptic - and Traveller's universe is only 2-demsinsional so... you don't have the tools to even accurately consider masking without a 3D interstellar map. (And about that 50 degree cut of the sky that is blocked? I am lazy today, so I asked ChatGPT what percent of the sky it would block. Four times I asked, and the answers were: 25%, nonsense, 3.183%, and then nonsense again - I love AI )

 

[phavoc]

It's not a logical necessity for what happens to a ship in jump to meaningfully correspond to any sort of path at all - nor for that path, if it exists, to elegantly map to a path in normal space, nor for that path to be a geodesic. (There is no such thing as a straight line in normal space, though on a small scale geodesics approximate straight lines.)

I'm perfectly happy for jump to consist of "your ship goes away at this point, and comes back at that point, and if you want to even understand the basics of arguments physicists have about what happens in between you need Science (Mathematics)-2 at least". I'm also not a fan of jump masking.

I very much agree - not a requirement to play the game or have fun adventures. It's one of those things Al Gore calls and Inconvenient Truth. GURPS handles it by explaining what it is, and then saying how long it would take to jump out. The assumption is that you'll always find a straight line to your destination - it just may take a few more hours here or there. Which, if you think about it, makes piracy and such much more likely. Personally I prefer the explanation of the how, and then the explanation of how the game mechanics easily deal with it. I buy stuff just because authors take the time to think through their background material and make it sound interesting (even the etheric controls for X-wings that allow them to fly like planes in space. Silly, but someone took the idea of how to explain the silly away for the setting). Oh, and art. I buy things just for the cool art, too.

You are correct in that from a simplicity standpoint going to 100D and pushing the button to jump is easy for records and gaming. Jump space, conceptually, exists today in science. It's all theoretical and unproven. No need to worry about the maths unless you are arguing with a bunch of physicists. Gamers just toss the dice and move on to the pew-pew.

 

[CordwainerFish]

Inconvenient Truth

If I think something in the books is bad I gleefully ignore it. Let me rant at you sometime about how the jump limit being a function of size is ridiculous and how I replace it.

 

[Condottiere]

Assuming it's gravitational based, then local gravity well divided by Terran norm times 12’742 kilometres times one hundred.

 

[Sigtrygg]

Here is the most important single sentence with regards to jump masking etc.

When ships are directed to exit jump space within a gravity field, they are
precipitated out of jump space at the edge of the field instead.

So being within 100D only matters as you are trying to leave jump space. It does not mater what is between the two jump points in our universe, because jump space is a hyperspace beyond our universe (I can dig out references to jump space being described as a hyperspace in canon). This is what the GT crowd failed to take into account and as a result we got fanon made canon.

Later on Marc says:

On the other hand, there is a built-in safety feature for ships trying to leave
jump space within 100 diameters of a world. Ships naturally precipitate
out of jump as they near the 100 diameter limit.

Twice it is stated the ship must be trying to leave jump space, nowhere does it mention in the article that ships can be pulled out of jump space by objects in our universe.

 

[Condottiere]

Has anyone tried to jump through the middle of a star?

 

[Sigtrygg]

There are no stars in jump space...

 

[Condottiere]

Or more simply, Earth to Mars, while Mars is exactly opposite Earth on the other side of the Sun, in a straight line.

 

[MongooseMatt]

There are no stars in jump space...

That we know of...