The perils of 100D

[kaladorn]

Reading about Pearl Harbour, and thinking about such a thing in a Traveller context, it occurs to me that the conversation we've had here about the building of transfer stations at 100D near the 'Jump Percipitation Threshold' were strictly economic, having no security (or a minimal one) considerations.

Consider this:

The Highport, at the world, 100D from the JPT, gets at least 100D with of warning of an enemy jump emergence. They get some time to get people to battle/emergency stations, bring dampers and point defence online, launch screening craft, mobilize interceptors, etc. Now, put the port (or a transfer station) at 100D. Suddenly it has little or no warning of hostile emergence! If the hostile nav-O is good at his job, they arrive on top of you and blammo! Pearl Harbour and then some.

That may be one good non-economic reason for locating your Highports deeper into the 100D field or having to have them constantly at a high alert status (problematic for many reasons). Of course, one could argue that deeper towards Core regions, this is less necessary and that's where we'd see these kinds of 'trucking'. But even there, planetary conflicts loom and if one pirate/raider can appear and pop big holes into your starport with a few missiles then jump out.... (because he isn't inside 100D, he can just go 'blip' and be gone again).... then you have a big security issue.

Just another thought on this interesting thread.

 

[EvilDrGanymede]

Yeah, but 100D isn't a point, it's a radius around a star or planet. All ships do not arrive at exactly the same point, so it'd make it rather fortuitous (or unlucky, depending on your perspective) for the enemy fleet to arrive at the Highport station.

 

[Whipsnade]

Evil Dr Ganymede:

"Yeah, but 100D isn't a point, it's a radius around a star or planet. All ships do not arrive at exactly the same point, so it'd make it rather fortuitous (or unlucky, depending on your perspective) for the enemy fleet to arrive at the Highport station."


Dr. Thomas,

Yes, the 100D limit is a shell and not a point. However, the physical accuracy of jump drives; 3000 km per parsec jumped, makes a near pin-point arrival at a 100D highport easy. Your fleet or squadron can arrive close enough to the station to be within weapon's range immediately.

It's the temporal accuracy of jump drive that makes multi-vessel 'Pearl Harbor' style attacks improbable. Vessels will normally arrive across a 33.2 hour window. Even with MT's squadron synch jump rules, the arrival window will be measured in hours; single digit hours yes, but still multiple combat 'turns'.

Single vessel strikes on 100D facilities; such as those proposed as part of Project Blackheart (the Nemesis-class cruisers), will be very nasty to deal with or prevent.


Sincerely,
Larsen

 

[Hecateus]

I would have placed High ports at a 'natural' Geosynchronous orbit 'above' the Downport if possible.

 

[EvilDrGanymede]

Originally posted by Larsen E. Whipsnade:
Yes, the 100D limit is a shell and not a point. However, the physical accuracy of jump drives; 3000 km per parsec jumped, makes a near pin-point arrival at a 100D highport easy. Your fleet or squadron can arrive close enough to the station to be within weapon's range immediately.

Despite that big discussion on JTAS a while ago about whether or not you need a mass to jump into or out of realspace, I can't remember what canon said off the top of my head now... does an incoming ship HAVE to precipitate out of jumpspace at the 100D limit, or can it come out at any point beyond that?

 

[Andrew Boulton]

I would have placed High ports at a 'natural' Geosynchronous orbit 'above' the Downport if possible.

Same here.

There's also a safety problem with putting the 'port at 100d - most ships will try to arrive as close as possible, so increasing the risk of collisions.

 

[Whipsnade]

Evil Dr Ganymede wrote:

"Despite that big discussion on JTAS a while ago about whether or not you need a mass to jump into or out of realspace, I can't remember what canon said off the top of my head now... does an incoming ship HAVE to precipitate out of jumpspace at the 100D limit, or can it come out at any point beyond that?"


Dr. Thomas,

Any point beyond that. You need not 'hit' the 100D limit to precipitate. You can 'hit' your exit point with an accuracy of 3000 km per parsec jumped; within 3K km for a 1 parsec hop, 6K km for 2 parsecs, etc.

Of course, the real answer is whatever you as the GM choose for YTU!


Sincerely,
Larsen

 

[Rupert Boleyn]

Originally posted by Larsen E. Whipsnade:

Single vessel strikes on 100D facilities; such as those proposed as part of Project Blackheart (the Nemesis-class cruisers), will be very nasty to deal with or prevent.

It certainly makes a Lucan-style black war more attractive, though by the time the Rebellion's Black War came along I suspect any 100D ports would've been long since pulled back deeper into thier planet's or star's gravity well.

 

[Rupert Boleyn]

Originally posted by Larsen E. Whipsnade:

Any point beyond that. You need not 'hit' the 100D limit to precipitate. You can 'hit' your exit point with an accuracy of 3000 km per parsec jumped; within 3K km for a 1 parsec hop, 6K km for 2 parsecs, etc.

Of course, the real answer is whatever you as the GM choose for YTU!

I prefer 30,000km per parsec for normal jumps, and 3,000km for outstanding successes - this way a normal jump scatters one _Brilliant Lances_ hex per parsec.

A carefully plotted jump (one that gets the tighter time seperation as well) is ten times as accurate, so a really good astrogator with good charts and plenty of time has about a 50% chance (TNE rules) of getting 'pinpoint' accuracy and putting the ship within a few hundred kilometres of its intended emergence point.

 

[kaladorn]

I saw a comment from MWM that at one point indicated that ship's must in fact precipitate at 100D from any large mass. He indicated it wasn't a gravity well thing, but some property of mass.

Now, a good Nav should be able to help set you down near one of the transfer stations.

The best attack would be a carrier or battle rider or battle tug that brought a whack of ships in to attack at the same time (or one darn big ship).

Now, we have the competing aspects of economy and security - I think some systems in more secure territories would see such 100D ports. Others in less secure might set ports at 50D, others less secure yet, right over the downport (or offset

.

And once conflict broke out, some of these big ports might need moved in, to be safer, but all the shippers would be screaming.

If anything this added layer of concern/balance makes the issue even more interesting. Lots of adventure possibilities.

 

[Whipsnade]

Rupert wrote:

"It certainly makes a Lucan-style black war more attractive, though by the time the Rebellion's Black War came along I suspect any 100D ports would've been long since pulled back deeper into thier planet's or star's gravity well."


Mr. Boleyn,

Yes, that's a very good point. By the time the Black War kicked off, most 100D facilities would have either been pulled in or were already lost.

If GT:FT is any guide (and it should be), most megacorp frieght operations are of a LASH nature. That in turn provides a great emphasis for 100D facilities. Systems in the long settled regions of the Imperial Core may have had many 100D facilities each and many facilities means many targets!

Imagine, just what form did all those commerce raiding campaigns mentioned in the 'Rebellion Sourcebook' take? You know, all those dots speckling the regions between Dulinor and Lucan? Were they warships flitting from system to system trying to hunt down lone frieghters or merchant convoys? Or were they warships appearing off the 100D limit a few thousand kilometers from a LASH facility and quickly slagging everything present? Which tactic would be easier to begin with? Given the perversity of the human mind; i.e. it can't happen here, how long do you think shipping companies will try to make LASH operations work? After all, the ship are designed for LASH, right?


Sincerely,
Larsen

 

[Rupert Boleyn]

Originally posted by Larsen E. Whipsnade:

Imagine, just what form did all those commerce raiding campaigns mentioned in the 'Rebellion Sourcebook' take? You know, all those dots speckling the regions between Dulinor and Lucan? Were they warships flitting from system to system trying to hunt down lone frieghters or merchant convoys? Or were they warships appearing off the 100D limit a few thousand kilometers from a LASH facility and quickly slagging everything present? Which tactic would be easier to begin with? Given the perversity of the human mind; i.e. it can't happen here, how long do you think shipping companies will try to make LASH operations work? After all, the ship are designed for LASH, right?

I think it likely - IIRC the TNS articles mention insuarance permiums becoming astronomically high over the course of the Rebellion, which would suggest more than just the odd raid and the extra costs of convoying (either from having to hire private esocrts or from factions transferring convoying costs to ship owners).

 

[TheDS]

Originally posted by kaladorn:
I saw a comment from MWM that at one point indicated that ship's must in fact precipitate at 100D from any large mass. He indicated it wasn't a gravity well thing, but some property of mass.

This means that a ship can jump no closer than this limit, not that a mass must be present. IYRC (if you recall correctly), the Terrans jumped to deep space and set up a fueling station, in order to get to the star they were after, Barnard. Even AC requires J2.

As long as the ship has the fuel, or can refuel, it can make jumps into deep space and jump back out. No calibration points required. This makes jump a powerful tool, and eliminates the concept of a front line; you can attack from anywhere that you can set a tanker.

 

[daryen]

Originally posted by Evil Dr Ganymede:
Despite that big discussion on JTAS a while ago about whether or not you need a mass to jump into or out of realspace, I can't remember what canon said off the top of my head now... does an incoming ship HAVE to precipitate out of jumpspace at the 100D limit, or can it come out at any point beyond that?

Canon has (to me, anyway) always been very unambiguous:
- You may enter jumpspace at any point. You can do it from the middle of a deep cave on a size "A" world, you may do it from deep space in an "empty" hex, or you may do it from any point in between. Obviously, if you enter jump from any point within 100D of something more massive than your ship, you increase your chances of a misjump, but you can do it.
- You can try to exit jumpspace at any point. However, if you exit point is within 100D of a massive object, you will precipitate out at that 100D limit. (I.e. exiting jump is always "safe".)