Fleet Jumping

[shadowcat20]

OK, I have a question has been bothering me for a while and I can not find it in the LBBs anywhere.

What happens when a battle fleet jumps to a system?

Due to the varibles in jump drives, course setting, and fuel differences, how could they all come out anywhere near each other or close to the same time?

As the rules now sit they should pop out all within 100 Dia of somewhere in the system but could be scattered by days and distance. That would make it too easy for the defenders to pick them off piece meal and get lots of advanced warning. It would make battle riders more useful though as large chunks of ships could all arrive at once.

Also if that many ships were close together and jumped all at once it should screw up the jumps of the smaller ships due to mass nearby. So they would have to disperse before jumping then once they got to the target, spend days collecting together the straggelers and refueling before going deeper insystem for the attack.

What are some other takes on this?

 

[sfchbryan]

There isn't anything in CT

It was addressed in MT however, Calculate the jump as a cautious task, & tie all of the ships together with the nav info from the ship making the calculations. Everybody pops in within 2 hours

In CT, I just treated it as using the Fleet Tactics skill. 8+, everybody arrives within 1 hour.

The LBB will never address every situation. That's why the GM exists.

 

[shadowcat20]

Interesting idea on tactics.

 

[Icosahedron]

Yeah, using fleet tactics is a good idea.
In CT I always figured it should be possible to synchronise the ships, network the computers and take account of the combined mass, jumping as one ship. You still wouldn't know exactly when and where you would arrive, but all the ships would arrive together - but that's just MTU.

 

[TashaG]

yeah Jump Synchronization is mentioned in more than one Traveller books. Most recently in Grand Fleet (currently published by Mongoose). I seem to remember seeing it elsewhere in an earlier book like Brilliant Lances or something similar.

I have just been reading though so many versions of Traveller lately, it's hard to keep them straight.

 

[rancke]

As the rules now sit they should pop out all within 100 Dia of somewhere in the system but could be scattered by days and distance. That would make it too easy for the defenders to pick them off piece meal and get lots of advanced warning. It would make battle riders more useful though as large chunks of ships could all arrive at once.

So it would, if the attackers jumped in near a defended part of the system. So they wouldn't do that. They'd jump in somewhere sufficiently far from the beaten track to have time to form up before moving to attack.


Hans

 

[BillDowns]

shadowcat, you did not say what ruleset you were using.

To me with CT where there is no rule regarding variable jump time, jump is always, forever and ever, 7 x 24 = 168 hours exactly to the microsecond.

Just in my mind, a week long jump that varies unpredictably a few hours either way blocks my suspension of belief. So I don't use it. Never have. Never will.

 

[BlackBat242]

In my opinion, most Refs that use the variable jump timing mis-apply it as being a constantly-varying factor... even on the same run.

To me, the variable jump time reflects the fact that very few stars are located in the exact center of their hex, therefore the actual distances covered vary... thus varying the exact jump time.

Considered this way, it should be plain that once a ship jumps between two systems, the exact jump time for THAT run is known precisely... and subsequent ships jumping from/to the same systems will have the same jump time, whatever it is.

The variable jump time between a given pair of stars is rolled once, with that number being recorded for future reference on later trips between that star pair.

This time would be part of the standard navigational data available at any starport, for all nearby stars... and for most commonly-travelled runs within about a sector's distance.

 

[Dragoner]

So it would, if the attackers jumped in near a defended part of the system. So they wouldn't do that. They'd jump in somewhere sufficiently far from the beaten track to have time to form up before moving to attack.


Hans

Agreed, it's called staging and has been done since ancient times because various columns would have to form up after traveling. Strategic movement versus Tactical movement.

 

[whartung]

Agreed, it's called staging and has been done since ancient times because various columns would have to form up after traveling. Strategic movement versus Tactical movement.

Staging is all well and good as long as circumstances exist to allow you to stage.

Never been a big fan of "surprise in space", it's too big and ships simply stand out too much, and there's just a bazillion other factors (like the 100d limit) to make surprise even available as an option.

There's always the great fun of the Black Globe, but the neat part of the Black Globe is not only do your opponents not know you're there, you don't know you're there either. You can't see out, you can't see anything, you have know idea where you are. You have a vector (that can't be changed) and a clock, that's about it. No idea what's waiting for you when you drop the globe. Good times for sure.

 

[dean]

In my opinion, most Refs that use the variable jump timing mis-apply it as being a constantly-varying factor... even on the same run.

To me, the variable jump time reflects the fact that very few stars are located in the exact center of their hex, therefore the actual distances covered vary... thus varying the exact jump time.

Considered this way, it should be plain that once a ship jumps between two systems, the exact jump time for THAT run is known precisely... and subsequent ships jumping from/to the same systems will have the same jump time, whatever it is.

The variable jump time between a given pair of stars is rolled once, with that number being recorded for future reference on later trips between that star pair.

This time would be part of the standard navigational data available at any starport, for all nearby stars... and for most commonly-travelled runs within about a sector's distance.

Well... stars are in motion just as the planets are in motion around them, so there is the potential for a lot of variability, around a limited range.

Consider a planet of the outer orbits; it travels a tremendous distance to complete one planetary year. If two stars in adjacent "hexes" have planets as close to each other as they can be (interstellarly speaking), then alternately at one point, they are at their closest points, that can be many millions of miles.

On the other hand, when one considers J6 takes as long as J1, distances really become irrelevant within the time referent...

I forget the Canon reason why this is so. Maybe some one can refresh my memory.

 

[Dragoner]

Staging is all well and good as long as circumstances exist to allow you to stage.

Never been a big fan of "surprise in space", it's too big and ships simply stand out too much, and there's just a bazillion other factors (like the 100d limit) to make surprise even available as an option.

There's always the great fun of the Black Globe, but the neat part of the Black Globe is not only do your opponents not know you're there, you don't know you're there either. You can't see out, you can't see anything, you have know idea where you are. You have a vector (that can't be changed) and a clock, that's about it. No idea what's waiting for you when you drop the globe. Good times for sure.

With gigantic fleets attacking each other, there will be a lot of intel work limiting suprise. The decisive battle is the prime operational strategy, if you can catch the other guys fleet piecemeal and destroy it, so much the better, but I wouldn't count on it.

Black Globes flicker.

 

[Captain Midnight]

As I recall (and I'm sure someone else can correct me), there was a JTAS article about jumps and jumpspace that gave some of Marc Miller's thoughts on the subject. I'm thinking specifically of the variability in picking a location -- you can be reasonably precise, although the fluctuation is less than 10,000 miles, if I remember correctly. (If you go with your own rulings, obviously that will change.) Given typical warship accelerations, it won't take days to assemble, once everyone has arrived; you're looking at a few hours, tops. If ships can travel in something less than groups very close to each other with matching vectors, they can initiate a little faster, too.

The time fluctuation is a major problem. There's a plus/minus window of around 8 hours for 95% of arrivals, I think, but that's just my recollection. It could be very different for small numbers of trials, too; if you only have eight battleships, you can't really look at that in a statistical fashion. You're also going to have to deal with the issues raised by the absence of command personnel; what happens if the flagship is the last ship to arrive?

I generally presume that major elements would arrive someplace where they expected to have some breathing room between the arrival point and any points of interest, or likely gathering places for defenders -- maybe someplace like "50,000,000 miles outward from Terra' orbit, 25 degrees ahead of its current position, at rest WRT Terra". (Polar coordinates work well for this.) This does mean that you can't count on having enough forces on hand to make a quick attack, especially into a defended world, but that's just part of why it's hard to be an attacker, IMO.

 

[shadowcat20]

A 100 D limit also means a big fleet is going to be scattered all over the place and you can forget any type of formations at first. If you stage too far out you can plain forget any type of surprise, and refueling takes AHL cruisers a week so other big ships may take just as long or risk damage skiming. So you pop in a ways out, reorginize while heading for a gas giant, taking days or a week to refuel, then attack. Or go right in with little orginization and dry tanks. Unless you refill in deep space 1 jump out, but that takes a lot more planning and resources to do.

I was using Classic Traveller rules for my info But I remember reading somewhere that times alway are varible for jumps. The better the navigator the closer he gets to the 100D limit and the better time.

 

[Andrew Boulton]

To me with CT where there is no rule regarding variable jump time

Nope.

Bk2: "about a week"

Bk5: "150 to 175 hours"

JTAS#24: "168 hours (+/-10%)"

 

[Dragoner]

One has to consider what constitutes suprise, min response would be 2 weeks for a ship to leave a system and alert a fleet that was waiting to jump in (eg one week out and one week in). If the responding fleet is even more distant, it would not be unreasonable to suppose 3 weeks to months or more for a response, by this time the invading fleet may have well moved to another system.

 

[dean]

One has to consider what constitutes suprise, min response would be 2 weeks for a ship to leave a system and alert a fleet that was waiting to jump in (eg one week out and one week in). If the responding fleet is even more distant, it would not be unreasonable to suppose 3 weeks to months or more for a response, by this time the invading fleet may have well moved to another system.

Unless your fleet has black globes installed throughout, Tactical Surprise is very difficult to achieve in space.

Strategic Surprise is easy to achieve (just be where your enemy doesn't expect you to be with your fleet), but since both sides have this ability, it evens out.

It's a lot like age of sail: You go somewhere on orders of the Queen, not knowing what to expect when you get there because your last intelligence is weeks to months old, you don't who/what you'll encounter on the way, and once you get there it takes a long to sent report and get new orders. Finally, you have to be strong enough to take what supplies you need once you get there, because it's hard to go on or back without them.

 

[Dragoner]

Unless your fleet has black globes installed throughout, Tactical Surprise is very difficult to achieve in space.

Strategic Surprise is easy to achieve (just be where your enemy doesn't expect you to be with your fleet), but since both sides have this ability, it evens out.

It's a lot like age of sail: You go somewhere on orders of the Queen, not knowing what to expect when you get there because your last intelligence is weeks to months old, you don't who/what you'll encounter on the way, and once you get there it takes a long to sent report and get new orders. Finally, you have to be strong enough to take what supplies you need once you get there, because it's hard to go on or back without them.

Initiative will count for a great deal, as will operational planning. Tactical suprise will be of less value as smaller fleets will not have the chance of making much of a difference. However, the caveat is of TL's, a smaller, yet higher TL fleet will be more effective.

 

[BillDowns]

Nope.

Bk2: "about a week"

Pretty vague for a rule.

Bk5: "150 to 175 hours"

Still pretty vague.

JTAS#24: "168 hours (+/-10%)"

JTAS is helpful, but not rules, im my book.

I just have a very large problem with jump requiring a week regardless of distance, and then verying that for whatever reason. Breaks my belief way too much, especially for two ships leaving from the same place at the same time to the same destination.

 

[BlackBat242]

Well... stars are in motion just as the planets are in motion around them, so there is the potential for a lot of variability, around a limited range.

Consider a planet of the outer orbits; it travels a tremendous distance to complete one planetary year. If two stars in adjacent "hexes" have planets as close to each other as they can be (interstellarly speaking), then alternately at one point, they are at their closest points, that can be many millions of miles.

On the other hand, when one considers J6 takes as long as J1, distances really become irrelevant within the time referent...

I forget the Canon reason why this is so. Maybe some one can refresh my memory.

All of which are exactly known for surveyed systems, and thus should be part of the pre-jump calculations, and thus are known quantities.

So for a group of ships jumping from the same point in one system to the same point in another system, there should be no variation between jump times.