Re: Ships in closed airspace

A thread of 4 messages, 23 August 1990 to 28 August 1990, in the order they were sent.

#1488 Re: Ships in closed airspace

Bertil Jonell · 23 August 1990

> Date: Tue, 21 Aug 90 11:25:00 BST
> From: [email removed]
> Subject: (1479) Peformance of Starships/Shipsboats in Close Airspace
>
> Hi List,
>
> I'm currently writing a mercenary scenario, and I was thinking about the
> situation where fighter aircraft, jets and helicopters came against
> ships boats or even starships armed with lasers and missile racks.

  All common air to air missiles and guns have penetrations that is way below
40. (I think this is the case for the missiles, since they in fact don't have
any penetration listed! I assume that they have the same penetration as they
do damage.)

  On the other hand, if the spaceship is relatively slow and lacks excessive
agility, it might work to lob some anti-tank missiles and the heavier types
of command guided missiles at it. Those with HEAP warheads have penetrations
above 40, and since the only way to resolve this, presently at least, is to use
the vehicle hits, there is at least a small chance that one will hit at vital
component. The drive, for example :-)

  (Using command-guided weapons against flying objects actually work. One of
the main weapons of the Swedish fighter J35 Draken (Dragon) during the 50's
was a big ugly command-guided air-to-air missile. The idea was to use it
against big lumbering high-altitude strategic bombers. The warhead was about
one ton of high-explosives, so even a close miss would tear the bomber to
pieces.
  The US equivalent was the 'Blivet'. a dumb nuke missile that flew in a
straight line towards the formation of bombers and detonated. Blivet equivalents
would certainly be usable against starships in Traveller.)

> Are the spacecraft going to be like whales in sky, easily shot down or
> are they flying fortresses, impervious to the weapons of, say, earths
> current tech level.

  Largely impervious, unless the weapons are exceptional.

> ie who would win, a group of tornados or the modula cutter?

  If the tornados could carry mavericks, I'd put my money on them, otherwise
they couldn't harm the cutter.

> Any ideas? What is the generally accepted performance and normally space-
> bound vehicles inside close airspace?

  If you cought the ship on the ground, on the other hand, it would be a sitting
duck to any B52 or B1 equivalent with a bombbay full of laserguided 1000kg
iron bombs and with a forward observer on the ground to point a laser at the
ship.

  The onetonners have pen49 and damage60, which mean that they will do 30
unmodifyed. But since hitting a target with laser guided bombs is simple, they
will have their damage multiplied in most cases.
  (Is this correct? COACC says in essence 'apply damage according to the players
manual, and I think that includes the exceptional success multiplyers.)
  I think that the COACC B1 equivalent had a 34ton bomb bay. That would make it
capable of dishing out about 3000 damage points (modified for multiplication and
armor) which is enough to totally wreck a scoutship (remember the *10 for damage
points, a scoutship has 900/2250, not 90/225) and give inoperable to a ship of
300 tons.


  However, if one combines the ship design rules and the COACC weapons, things
get *really* nasty. It is easy to build a realtively fast and agile smallcraft
of 50t that could take 420 tonnes of bombs (if one cuts endurance to about
4 days)
  So, what could you do with 420 tons of bombs? Well, according the COACC rules
for dropping bombs in big numbers, one is to multiply the dangerspace with the
number of bombs which is totally unrealistic.
  The 'beaten zone' table in the referees companion gives a much smaller area
which is more realistic, and according to that, the 50ton ship could cover
3.9 square kilometers with 1000kg bombs.
  If it was loaded with HEAP cluster, effective against battledress clad troops,
it could cover 24 square kilometers! (The manhattan island is about 60 square
kilometers)
  That kind of ground attack craft would be bad news for anyone.

  And think about dumping the load of a 30000 ton naval transport down at a
world from orbit....

- -bertil-
- --
"Greetings, Nuke Dorris!..... eh... Duke Norris!"
Anonymous player.

#1494 Re: Ships in closed airspace

Dan Corrin · 24 August 1990 · reply to #1488

> Date: Thu, 23 Aug 90 11:14:02 MET DST
> From: [email removed]
> Subject: (1488) Re: Ships in closed airspace
>
> > Date: Tue, 21 Aug 90 11:25:00 BST
> > From: [email removed]
> > Subject: (1479) Peformance of Starships/Shipsboats in Close Airspace
> >
> > Hi List,
> >
> > I'm currently writing a mercenary scenario, and I was thinking about the
> > situation where fighter aircraft, jets and helicopters came against
> > ships boats or even starships armed with lasers and missile racks.
> > Are the spacecraft going to be like whales in sky, easily shot down or
> > are they flying fortresses, impervious to the weapons of, say, earths
> > current tech level.
>
>   Largely impervious, unless the weapons are exceptional.

Most combat vessels have more than the standard armour, thus even more
impervious and if its a starship with a nuclear damper...

>
> > ie who would win, a group of tornados or the modula cutter?
>
>   If the tornados could carry mavericks, I'd put my money on them, otherwise
> they couldn't harm the cutter.

Highly dependant on the armament (on both sides)
>
> > Any ideas? What is the generally accepted performance and normally space-
> > bound vehicles inside close airspace?
>
Speed and agility aren't the entire point. The streamlining is. If the
ship is streamlined its max atmospheric speed is 1000 kph, it will be a
whale in the sky. If however the stremlining is airframe the top speed is
90% of its vaccuum movement. a 6-G fighter/ship would go .9*4800 (I think
this figure is accurate) 4320 kph. As this is 1200 m/s (Mach 3.5) and the
ship's acceleration is 59 m/s/s (in any direction) and of course unlimited
ceiling it would be a nasty opponent for an aircraft especailly a modern
(earth) aircraft. Note that a 500000Ton battleship with 6G and airframe hull
would perform almost identically (probably a larger turning radius unless its
agility was higher) an impressive sight.

The ships lasers are essentially 250Mw beam or pulse lasers. I thought that
there was a (space) fighter described in the CoACC book?

>   If you cought the ship on the ground, on the other hand, it would be a sitting
> duck to any B52 or B1 equivalent with a bombbay full of laserguided 1000kg
> iron bombs and with a forward observer on the ground to point a laser at the
> ship.

Don't forget there is also point defense weapons. I don't know if the lasers
can act as point defense. Repulsors and possibly the lasers as they can fire
at incoming missiles, the usual bombing height of a B52/B1 plus the nice
lasers (assuming laser detectors) make the tracking of the bombs easy and/or
destruction of the FO.

Instead of attacking all these civilian-type cutters and ships, try a
military target, things will not be as easy. Think of the effect of an
EM pluse from an air-burst nuke from a military ship on the local
(air) fighters/bombers. (assuming fib computer on the ship).

					-Dan

Dan Corrin, System Manager, Mechanical Engineering, UWO, London, Ontario
TML FTP site coordinator:  [email removed]    ...!watmath!julian!engrg!dan

#1499 Re: Ships in close airspace

Adrian Hurt · 27 August 1990 · reply to #1494

Dan Corrin [email removed] writes:
> > From: [email removed]
> > > From: [email removed]
> > > Hi List,
> > >
> > > I'm currently writing a mercenary scenario, and I was thinking about the
> > > situation where fighter aircraft, jets and helicopters came against
> > > ships boats or even starships armed with lasers and missile racks.
> > > Are the spacecraft going to be like whales in sky, easily shot down or
> > > are they flying fortresses, impervious to the weapons of, say, earths
> > > current tech level.
> >
> >   Largely impervious, unless the weapons are exceptional.
>
> Most combat vessels have more than the standard armour, thus even more
> impervious and if its a starship with a nuclear damper...

Even a plain simple 100 ton scout/courier can seriously unbalance a battle.
It can outrun most things it can't destroy.  (Except other spaceships! :-)

> > > ie who would win, a group of tornados or the modula cutter?
> >
> >   If the tornados could carry mavericks, I'd put my money on them,
> >  otherwise they couldn't harm the cutter.
>
> Highly dependant on the armament (on both sides)

He said Mavericks, the USAF's standard anti-tank missile.  If they can destroy
modern heavy tanks, they should be able to damage an "unarmoured" spaceship.
Of course, even the cutter is big compared to tanks, which is why I said
"damage" rather than "destroy".  It also depends on what is in the cutter's
module.  I had one filled with every piece of ECM, ECCM and sensor gear I
could find in the Striker books, plus a laser turret, a computer, and an
extra power supply to drive all this.  In a mercenary scenario, it did what
an AWACS plane does nowadays, plus it could defend itself very well!

I did some calculations for ship's weapons once, based on the Striker rules
(which aren't that far off the MegaTraveller ones for this purpose).  It
said a ship's laser had a 250MW input; so did a ship's plasma gun; a ship's
fusion gun had a 500MW input.  Here are the results:

Weapon	Input	Effective range/pen.	Long range/pen.	Extreme range/pen.
Beam	250	125000 (73)		250000 (65)	1250000 (55)
Laser

Pulse	250	166667 (79)		333333 (71)	1666667 (63)
Laser

Plasma	250	7070 (83)		14140 (71)	28280 (44)
Gun

Fusion	500	17700 (99)		35500 (87)	70100 (64)
Gun

These are the figures for the introductory tech levels; I also have the
figures for the guns which got + DM's in High Guard due to higher tech
levels, and also the blast radius and penetration for the plasma and
fusion guns.  Put it like this; a near miss from a fusion gun will
wipe out a heavy tank!  For comparison, the Imperial Grav APC in the
Striker Book 3 has an armour factor of 73 at best.  The ranges above
are in metres, by the way.

Now to answer the question, what happens if a modern jet with Maverick
missiles tries to attack a cutter?  Answer; unless its missiles are longer
range than I think they are, or unless the jet can get close without being
detected, the jet gets fried the moment the cutter sees it.

> >   If you cought the ship on the ground, on the other hand, it would be a sitting
> > duck to any B52 or B1 equivalent with a bombbay full of laserguided 1000kg
> > iron bombs and with a forward observer on the ground to point a laser at the
> > ship.
>
> Don't forget there is also point defense weapons. I don't know if the lasers
> can act as point defense. Repulsors and possibly the lasers as they can fire
> at incoming missiles, the usual bombing height of a B52/B1 plus the nice
> lasers (assuming laser detectors) make the tracking of the bombs easy and/or
> destruction of the FO.

What do you mean by "the usual bombing height of a B52/B1"?  The B-52 goes
high, the B-1 goes low.

Lasers and fusion guns, as well as sandcasters, can be used against missiles.
So says High Guard, anyway.  Sandcasters can also be used as giant shotguns,
and would make a nice mess of aircraft.

Finally take note, the biggest penetration for explosives is around 60, and
that's with HEAP.  Against an armoured spaceship, those bombs would do
nothing - unless they're nukes.  Also, if the ship can use its lasers in
point defence, it can use them to zap the bombers long before they get to
drop their bombs.

- --
 "Keyboard?  How quaint!" - M. Scott

 Adrian Hurt			     |	JANET:  [email removed]
 UUCP: ..!ukc!cs.hw.ac.uk!adrian     |  ARPA:   [email removed]

#1503 Re: Ships in closed airspace.

Bertil Jonell · 28 August 1990 · reply to #1499

Adrian Hurt [email removed] writes:
> Now to answer the question, what happens if a modern jet with Maverick
> missiles tries to attack a cutter?  Answer; unless its missiles are longer
> range than I think they are, or unless the jet can get close without being
> detected, the jet gets fried the moment the cutter sees it.

  If the ship is relatively low (1000 to 10,000 meters) the COACC could spring
some nasty surprises by scrambling aircrafts from bases under it and firing
almost directly after launch. VTOLs would be ideal since they can hide in
large garages etc. and just roll out and pop up.
  (If the COACC were sensible, they'd wouldn't have spent their money on a/c's
but on big SAM's :-)

> Finally take note, the biggest penetration for explosives is around 60, and
> that's with HEAP.  Against an armoured spaceship, those bombs would do
> nothing - unless they're nukes.  Also, if the ship can use its lasers in
> point defence, it can use them to zap the bombers long before they get to
> drop their bombs.

  There is always flying low and hugging the landscape. And if the ship isn't
on general quarters, it would take some time from detection to start the power
plant and man the lasers.

  (I have actually considered starting a campaign that way:
  The party is in a scoutship on Ruie (balcanized tech7 or 8) when news of
Strephons death is released, and the anti-imperial nations of Ruie goes into
full scale attack against the neutral and pro-imperial ones.
  What the players notice is that there suddely begins raining 1000kg bombs
on the starport :-)

- -bertil-
- --