Missile and Fighter Coil Discharge

[rgrove0172]

I brought this over from part of a discussion on another forum.

Stutterwarp technology includes the accumualtion of a charge on the coils which must be discharged in a gravity well after 7.7 light years of performance. The coils acquire the charge even if they drive is offline. This prohibits ships from carrying spare drives and replacing them to artifically extend the canon 7.7 light year barrier which is integral to the setting.

This brings up the question though about warships having to continually discharge their fighter compliment and missiles in storage. An attack craft like the Kennedy would find itself unarmed after a long haul and have to spend hours not only to get its drive discharged but its main armament too. If we assume this process requires an engineer team, there would have to be scads of them on hand to work on the 20 missiles on the racks.

How do you guys see this situation?

One solution Im proposing is that missiles specifically dont utilize tantalum but some other less stable and problematic element. (Hafnium perhaps) These drives dont accumulate a charge when offline but do so at 10,000x the contamination level of a normal drive once they are on. Perhaps they also emit a nasty form of nasty radiation once cued up that is of no consequence on launched ordinance on its way to a few minutes of life, but is deadly as a drive element for longer periods on manned vessels.

Thoughts?

 

[F33D]

I think that you'll get more replies in the Traveller 2000 AD RPG forum...

 

[barnest2]

That's a forum for stront dog and Judge Dredd. 2000 AD as in the comic not the year.
Grove, you're in the right place, don't worry.

 

[Lord High Munchkin]

2300AD is a 'Traveller' engine RPG... so yes, you are in the right forum. "2000AD" is for the comic-based games.

As to the drives, I have always assumed that the discharge period is for all the carried stutterwarp drives, perhaps hooked up in series to combined devices that can dissipate the charges (there is an old 'Challenge' Magazine that goes into a lot of detail about shipboard engineering).

I tend to envision a brief, but busy shift for the engineering crew, but pretty routine.

 

[Captain Jonah]

I would break this down into two parts.

Missiles with detonation laser warheads are suicide units and the drive is lost when the warhead goes up. These would be carried shut down and would be quickly bought on line when the ship arms the missiles. So under normal operations the missile drives would not pick up a charge and once activated will probably get used soon after.

Missiles armed and then not used would probably take a while to safely shut down again but that would be post battle after you either won or escaped.

Fighters would see more use since they would be running patrols and missions while the carrier remained on station or on a mission. Given the 7.7 light year range it would take a fair number of flight hours for a fighter drive to build up its charge.

Take a typical fighter, the Martel. This has a loaded stutter warp rating of 1.8, if we allow that it is going to be operating on the shelf this gives it a speed of 1.161 AU/day or roughly 174,000,000Km per day. Given that the 7.7Ly range of a Stutter warp before discharge is 72.38 x 10 to the 15th Km your fighter is going to be obsolete before the drive needs a discharge from purely sub FTL use.

Now if the fighters are active and ready for use they will pick up the charge from the carrier. However given the tiny distance a fighter covers each day even if its drive is 99.9% charged from the carriers jump it would still be able to operate for days without risk. When the carrier discharges the fighters would also discharge. This means a carrier can jump into a system and have its fighters ready for launch at once with no concerns about the drives needing a discharge.

I would say that aside from routinely monitoring the fighter charge level engineers would not be overly concerned about fighter discharge.

 

[Colin]

Within the "Shelf" stutterwarp vessels discharge as fast as they charge, so there is no buildup. In orbit, they discharge at a faster rate than they build up charge.

Due to the need to keep them combat ready, missiles and fighters are carried in an "on-line" state, ready to go at a moment's notice. This means that they acquire a charge when the carrier is moving at ftl. As long as the carrier did not crowd dangerously close to the 7.7 ly limit, they will be fine. If they go over the line, then the missile drives can overload.

For this reason, most heavy missile-carrying starships do not use the "delaying discharge" rule. An Aconit, with only 2 missiles, might be able to get away with it. A Kennedy? Not so much.

 

[rgrove0172]

You brought up the "delaying discharge rule" Colin. This is a pretty major deviation from the maximum 7.7LY run rule isnt it? I mean, an additional day for a swift vessel could top them out at 11 or more light years. This seriously impacts the star arms development doesnt it?

I ruled that the delay only works "within the threshold" for emergency STL measures to reach a discharge point.

You mention that within the shelf discharge is as fast as the charge they are earning. I wasnt aware a ship could discharge and use its stutterwarp. I guess I assumed it was kind of a maintenance cycle of some kind. With the very very limited effect STL maneuvering has on the charge, I dont see the reason for all the hype in various articles about commanders coming into a system with their "drives screaming" and having to risk discharge if they could just get into a threshold orbit and discharge while in regular operations.

 

[kermit]

@rgrove0172 - Discharging a drive ASAP is important for several reasons. Within the threshold the discharge rate is a break even process. If a ship enters the threshold with his drive 95% "filled" and close to the need for discharge it can maneuver through threshold space without acquiring further charge. But it is not discharging that 95% charge that it has already accumulated. To do that it must enter a 0.1 gravity well and initiate the discharge process. For a merchant or some other civilian ship that is not too big of deal

But for a military ship carrying a high charge around can be a very dangerous proposition. Entering battle with a drive close to its limit greatly limits both strategic and tactical maneuverability. Any attempt to make use of the FTL shelf risks a drive over load and endangers the vessel. This is why during wartime military ships often enter a star system in a stealthy manner and immediately seek the most unobtrusive planetary body large enough to discharge from. Once they discharge their drives they regain the ability to move as doctrine dictates.

Benjamin

 

[rgrove0172]

Hmm, discharge within the .0001G threshold? Where did that come from?

Im fairly certain its always been a requirement for the vessle to be within the .1G shelf (Page 265 MgT2300 book and page 66 Director's Guide classic 2300AD) Thats pretty darn close to most worlds and within the orbit of most inner planets around a sun.

Zooming around the orbits of the outer and inner planets doesnt accumulate much of a charge at the STL rate but it doesnt discharge the current coil charge at all. Or so Ive always thought. If you want to discharge you have to come in pretty close, something like 12,000km above an earth-sized world and about 1 Au from the Sun.

 

[Captain Jonah]

I think, hope, that Colin is mistaken in his comment above. Stutterwarps do not discharge until the 0.1G limit.

The Stutterwarp shelf is the point where a ship drops below FTL speed, the 0.0001G zone. Ships flying in this zone are capable of moving at significant STL speeds but in terms of adding to an existing drive charge it’s not going to happen. A ship that comes onto the shelf at 99.9% of a drive charge can fly around for months and not reach drive overload.

Obviously it’s better to discharge as soon as possible but a carrier or warship that jumps in after a 7.6999LY jump can launch its fighters and the fighters or warship can operate for weeks without gaining anything noticeable in terms of a charge increase. 7.7Ly is a tiny distance at FTL speed, at STL speed on the shelf it is decades of travel.

The only limit a high charge level imposes to a warship is the inability to FTL if it needs to escape. If you have scouted a system and are certain you can defeat the enemy there you can jump in and attack straight away then discharge later. This only applies when you are certain you have scouted the system or must risk the attack.

Stutterwarp discharge does not happen till you reach an area of 0.1G which is also the stutterwarp wall where speed drops way down. If stutterwarp discharge happens on the shelf can we please have the discharge rate for that because that is not something that has ever been in 2300 and being a math type Gerd/Neek I would love to have some figures to play with.

 

[Colin]

They build up no additional charge. The mechanics of charge/discharge are dependent on the local gravitational regime. In unstressed space, charge is built up rapidly over time, and there can be no discharge. In stressed space (the shelf) the rate of charge build-up declines dramatically, but efficiency drops. Discharge occurs, sort of, only at a rate sufficient to deal with the small charge being acquired. Could a ship discharge a drive this way? Sure, in about 1000 weeks. In highly stressed space, efficiency drops yet again, but charge build up is minuscule. A drive can discharge. Note that is a drive is shutdown, it will still bleed out its charge, an the drive can be worked on, but it does not have I be shut down to discharge.

 

[rgrove0172]

Wow Colin, no disrespect intended but thats the first time Ive heard anything like a gradual discharge mechanic. Ive read every 2300 rulebook and Challenge Article in existance and its always been a hard .1G requirement and 40 hours or so. The idea that discharge is always in effect, just at different rates scaled to the current gravity is a new concept for me. Ive always seen it as a certain gravimetric force was required to trigger the effect, not a gradual thing at all.

Honestly, I think your version kind of complicates the issue and with no real advantage to fuction or storyline. The "outside .1G" rates are so slow as to not be worth tracking in a game. I suppose it could come in hand though if stuck out there with a hot drive and nowhere near a planet.

Still, I gotta ask, where did you see this explanation? Is this something your extrapolated at some point or is it something I missed somewhere?

 

[Colin]

It's simply how I see it. Gamewise, the effect is the same. Regardless, this explanation appears in no official product, neither the original 2300 nor in the Mongoose version. It is not official in any capacity yet, its just how I've always thought of it.

 

[rgrove0172]

Oh ok, well cool, it is an interesting variation. I did notice howwever that part of it did sneak into the Mongoose 2300 book where discharge is based on the accumulated light years of charge rather than a fixed 40 hour period. Is that part of the same approach or did that come from somewhere else?

 

[Colin]

That was an attempt to link the discharge to the distance covered, rather an a seemingly-arbitrary number.

 

[Colin]

Delaying discharge is part of the original rules, and remains canonical. It is seldom used, since the consequences of a failed roll are "everyone dies". Since the roll is Formidable (-4), even a ship with a decent Engineer (total DM +3) and a model 3 computer still has a nearly 50% chance of being destroyed (6 or higher on 2d6). No one in their right mind (except players) would accept those sort of odds. Commercial and military vessels would never take that risk except under extreme circumstances. An average commercial ship would need to roll 9+ on 2d6 to avoid being destroyed.

.

 

[rgrove0172]

Gotcha, thanks!

Again, I think where I apparently differ from a number of those here is the impression that discharge is an active, not a passive process. Its doesnt just occur when the situation permits it, its a physical task by the crew. It requires various mechanical operations, dissasembly of equipment, various processes be performed and maybe even some incidental replacement of minior componants. This was the reason for the original 40 hour time slot, or at least it is in my mind. It can be shortened, or extended a bit by the performance of the crew. Its also possible to discharge at any point up to your max 7.7 cap but doesnt benefit you as far as time or complexity is concerned.

I suppose I see it as serviceing a combustion engine in a way (filters, plugs, hoses, belts etc.) if you could place a strict point (lets say 10,000 miles for fun) when failure to do so would ensure a breakdown. Its going to take you x-number of hours to perform the maintenance regardless of how long you have driven since the last one. A green mechanic might take a little longer, a really ace hand might shave a little time off but thats about it. You could also do the maintenance a bit early, preventing you from having to take care of it for another 10,000 miles but its still takes x-hours.

 

[silburnl]

Again, I think where I apparently differ from a number of those here is the impression that discharge is an active, not a passive process ....This was the reason for the original 40 hour time slot, or at least it is in my mind.

Yeah - I see where you're coming from there, but I always went with a visualisation that matches Colin's perspective, that is that the drive coil charge/discharge behaviours were an automatic consequence of the move between different regimes of gravitationally stressed space. Furthermore I not only linked discharge time to distance covered (ie charge accumulated) but I thought that a flat-rate discharge just didn't feel right, so I faked up an exponential decay function for figuring discharge times.

Regards
Luke