Beth wondered:
> why can't mines use it too?
They could. I think the first time I ran across this idea was in the
mid 80's, in Donad Kingsbury's novel The Moon Goddess and the Son--one
character designs landmines which communicate with each other to more
efficiently attack a column of enenmy vehicles. You'd want to specify the
triigering conditions: "Only attack if 3 or more targets are in the field" or
"only attack ships of greater than 50 mass" or whatever conditions you like.
If the conditions require much discrimination ("50 mass"), you may need to
roll to see if the mines make an accurate
determination--they might get spoofed.
When you talk about minefields are you talking about the mines as something
like the mines from Galaxy Quest? Or something else?
For the mines to be effective they would have to have a reasonably large
engagement range to attack the enemy ship otherwise you would need millions of
the things to cover any decent kind of area with any density.
I could imagine a planetary defence grid of something like the Centauri
blockade mines from B5. Those looked like they could move to engage the
targets and had a reasonable engagement range.
I could also imagine a stealthy hunter killer robotic vessel that sits plugged
into a widespread sensor net, possibly even in hyper space and when an
intruder is detected it powers up and attacks. This kind of thing would be
much more cost effective than millions of mines.
If the enemy can detect the sensor net emissions then you could use this to
your advantage steering the prey further into the field before attacking. This
would depend on how smart the defence grid programming would be.
The effectiveness of static defences depends on things that are not described
in the FT universe. For example if the hyperspace emergence points are
restricted to specific points, say above or below the poles of the star then
those points could be defended by mines. If you could emerge from hyperspace
anywhere then how do you try and defend and area the size of the Solar system
with mines.
For battery power why would you not look to make the mines able to absorb
solar radiation or cosmic rays or tap into hyperspace or something so that
they don't need large batteries?
John
[quoted original message omitted]
I would tend to think that a mine could do a passive sensor shot, and if it
detects something that doesn't match IFF it simply blows up with a bomb pumped
laser directed towards the target or perhaps fires off as an autonomous
missile in a wait mode. It would only need to draw enough power to run a
computer core and the passive sensor array, which probably could be done with
a small enough power source that masking the emissions from enemy sensors
wouldn't be nearly as difficult as doing so for a full scale interstellar
vessel.
If it had even a small drive on it, it would probably be a lot more effective,
yes, but it would also be a lot easier to detect while it's moving, so it'd
probably have to do small bursts of thrust.
E
[quoted original message omitted]
> John Tailby wrote:
> For the mines to be effective they would have to have a reasonably
Bingo.
> I could imagine a planetary defence grid of something like the Centauri
> blockade mines from B5. Those looked like they could move to engage the
> targets and had a reasonable engagement range.
But note that those blockade mines were intended to stop ships that tried
to *leave* the blockaded planet - ie., ships that had no choice but to
pass close by the mines if they wanted to reach deep space. When attacked from
deep space OTOH, the Centauri mines were quickly destroyed.
> I could also imagine a stealthy hunter killer robotic vessel that sits
It would - but it would be a robotic combat vessel rather than a space
mine. Heck, if you have this kind of sensor net there's no reason why you
couldn't plug your crewed warships into it as well!
Regards,
[quoted original message omitted]
> John Tailby wrote:
> I could also imagine a stealthy hunter killer robotic vessel that
Very nice idea! Yeah, much more cost effective to have one attack platform and
a zillion sensors.
cheers,
> John Tailby wrote:
> I would tend to think that a mine could do a passive sensor shot, and
What house rules do you use that restrict the maximum range of passive sensors
to 24"?
According to the published Full Thrust rules, the maximum *identification*
range of Full Thrust passive sensors is 36" (FT2 p. 21). Passive
*detection* range is longer still - any unit on the table will have its
presence detected unless it is Cloaked (even though it might not be positively
identified).
'Course, the mines' *sensor* range isn't particularly imortant as long as
it exceeds the mines' *weapons* range (or combined single-turn movement
and weapons range, if you treat the mines as dormant missile salvoes or
somesuch).
> An effective defence platform could be to have swarms of automated
What would be the game difference between these "automated ships" and normal
ships crewed by living people?
Regards,
> An effective defence platform could be to have swarms of automated
OA said:
> What would be the game difference between these "automated ships" and
Normal ships, or IF ships?
Modern Mines are floating (or anchored on bottom) torpedo tubes with a sensor
package. When a target meeting parameters is detected, the torp is launched.
No reason that a Futuristic "mine" could not detect and not launch at an
friendly IFF response. No reason to assume that a mine doesn't have the same
range that any torp from any ship has. This gives the minefield an
incredible reach - as it would today if sea control mines were ever
deployed.
[quoted original message omitted]
[quoted original message omitted]
[quoted original message omitted]
John Tailbey wrote -
> A modern torpedo has a range of a few kilometres and without the wire
A few kilometres is understating it a bit. Even 20 yrs ago ranges in the
30-50km bracket were not unusual. Torpedoes can also use passive systems
for final targeting to reduce the chances of detection.
//snip//
> In game terms it also comes down to detection range. If mines
There seems to be a general fuzziness about passive sensors. A passive sensor
system should always detect a target at longer ranges than a system using an
active system of the same technology level. To describe in terms of
radar, the reason is this - for an active sensor to detect a target
there has to be sufficient power reflected from the target to be detected by
the scanning array of the active sensor. The passive system is catching the
original pulse, without the power loss of the pulses return journey to its
transmitter. Therefore, it should be able to see the target first.
Therefore, assuming they have the same weapons, and that weapon ranges exceed
the range at which active sweeps will see them, mines will be able to engage
at longer ranges than the ship. Depending on what they're armed with the mine
may even be able to avoid detection when firing. If they were armed with a
number of torpedoes they could be built to give them a manual shove off at a
random vector, with the torpedo only activating its drive after a certain
period.
CJ
> Richard CJ wrote:
Actual ranges are classified. (well Duh...)
A torpedo has X kilometres of wire inside, and the launching sub has another Y
kilometres in the tube, to allow it to depart the firing point
after launch. The wire remains stationary once it's payed out.
The torpedo can be guided by the sub to distance X, and steered to
re-attack if it misses the first (or second or third...) attacks, but
after that the wire can be cut, and it can proceed autonomously.
They normally have at least 2 speeds. Often they'll use the fast speed
to reach the target area, slow down to reduce self-noise to acquire the
target (better sonar performance and reduced chance of target detecting them),
then speed up again for the attack. Sometimes they'll cruise at a
slow speed at long ranges.
Sorry, this is one of the occasions where those who know don't say, and those
who say don't know.
Source http://www.fas.org/man/dod-101/sys/ship/weaps/mk-48.htm
Range Officially "Greater than 5 miles (8 km)"
Claimed 40 kt 55 kt
MK-48 44,550 yd 34,430 yd
MK-48 ADCAP 54,685 yd 42,530 yd
I cannot say whether these figures are accurate or not, merely that FAS
figures are often wrong, sometimes right, but generally (not always) in the
right ballpark.
Having worked with the Mk 48, I can't even say if the two speeds listed are
correct, nor whether the figures above are under wire guidance, or "extreme
range" before the fuel runs out.
I can say that the shorter the range, the bigger the bang, as the Otto
monopropellant is a pretty decent explosive in its own right, and at short
range there's a lot of it.
I've also worked with the SST-4 SEEL, SUT and DM2 A-3 SEEHECHT torpedos.
From http://www.navweaps.com/Weapons/WTGER_PostWWII.htm
DM2 A-3: 22,000 yards (20,000 m) / 35 knots
Also a lower speed setting for increased range.
DM2 A-4: 55,000 yards (~50,000 m)/ 50 knots maximum speed, different
speed settings
SUT 24,000 yards (22,000 m) / 35 knots
56,000 yards (51,200 m) / 23 knots
SST-4 12,000 yards (11,000 m) / 35 knots
22,000 yards (20,000 m) / 28 knots
40,000 yards (37,000 m) / 23 knots
Same remarks about reliability of figures apply, these figures may be wildly
out, or exactly right, or anywhere in between. These are all battery torpedos,
rather than Otto fueled ones.
Passive guidance is only useful at slow speeds, self-noise is a problem.
Active guidance is useful when torpedos are fired in staggered pairs. The
first torpedo pings and finds the exact position of the target (often quite
different from where you thought it was), even if the geometry is wrong for
interception, then the second going slow and
passive can be steered from the sub till its at point-blank range before
Passive sensors are pretty straight-up 36 MU range. If your mines
aren't giving off a real energy signature that seperates them from a rock in
deep space, there's not much that would say you'd detect them.
This reminds me of a concept I came up with a while back that I thought was a
bit cute (although perhaps a bit implausible). We were doing a storyline that
didn't allow for cloaking fields, so instead of those we came up with a ship
concept where the ship would use ECM with minimum emissions while it trailed
behind a comet and let its sensor signature get broken up by the
comet's tail, perhaps using gentle nudges of thrust with several of the ships
on the comet itself so that you didn't have to wait a literally
astronomical amount of time to get in-system. We were playing this
primarily in an intra-system warfare scenario so the FTL jumps weren't a
factor, otherwise the FTL into the system might give them warning that
something was out there depending on whether your PSB allows for detecting
jumps into the system no matter how far away. But the general idea was that
the "comet chasers" would nudge the comet fast enough and then just float in
behind it, invisible to a defender's sensors in the mass and tail of the
comet, and then come out in the open only when they were close enough to the
target planet that the majority of the defenders would probably be powered
down and/or asleep.
Probably not the most plausible of things, but I thought it was original, at
least.
E
[quoted original message omitted]
Seems quite resonable as long as you picked an unknown cometary body. The
system defenders might get a little suspicious if, say, Halley's Comet turned
up 3 years early.
Brendan 'Neath Southern Skies
http://home.pacific.net.au/~southernsk/
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And what about the torps of the far future? What is the range of torps from
any ship in the GZG universe? Indeed, any sensor package on a mine needs to do
is to put the torpedo on a general course to the target, using the torpedo's
sensors for final acquisition and guidance.
No one needs to defend space itself. The big black isn't where you put mines.
Same is true in the ocean. You put it near places ships must go. Ports,
strategic targets, channels, etc. No difference in space.
In fact, just a couple of sea control mines could shut down the passages
around the Kamchatka Peninsula. Big ships and tiny channels are always a
problem.
> John Tailby wrote:
> What house rules do you use that restrict the maximum range of passive
> sensors to 24"?
IOW, you're using Noam's house rules. OK. (Note that those rules don't
actually make *detection* any harder though - if a "stealthed" unit is
on the table the enemy knows roughly where it is, though they might not know
its location accurately enough to shoot at it.)
Regards,
> John Tailby wrote:
> It would - but it would be a robotic combat vessel rather than a space
> mine. Heck, if you have this kind of sensor net there's no reason why
Sure, but these sensor-relay issues apply just as much to robotic combat
vessels as to live-crewed ones.
> Alternatively for this to work you have to have a fleet of crewed ships
> could wait patiently for years without a drop off in efficiency.
As long as no bugs develop in its programming... let's pray they don't use
MicroSoft software :-/ (IIRC the USN had certain problems with MS
software a few years ago...)
> One of the worst things about automated weapon systems is they can
If they're poorly designed (and yes, many older types of land mines are IMO
criminally poorly designed in that respect!). Well-designed automated
weapons OTOH are equipped with shut-down timers, specifically to prevent
them from persisting after they're meant to.
> In space, decay rates would be much lower
Hm... I'm not entirely sure that all of the astronomer members of this list
would agree with that. Space can be an extremely harsh environment.
> If you built your defences with say a factory on a nearby asteroid then
As long as there's also some sort of mechanism for deploying the mines,
sure... preferrably one that is as stealthy as the mines themselves. (If
the mines can't deploy away from the factory you'll eventually end up with a
*very* concentrated minefield; and if they can't deploy stealthily the
enemy will fairly soon learn not just where the mines are but also where
the factory is.)
Regards,
> Oerjan Ariander wrote:
That does raise the possibility of some interesting scenarios. One region of
the map could be infested with hundred year old automatic weapons left over
from some ancient battle. Such weapons could be unreliable, both in activation
and in weapons strength.
So a ship captain