[GZG] Not So Small thought re: Orbital Assault

4 posts ยท Nov 25 2005 to Nov 25 2005

From: Alan and Carmel Brain <aebrain@w...>

Date: Fri, 25 Nov 2005 18:37:54 +1100

Subject: Re: [GZG] Not So Small thought re: Orbital Assault

Orbital assaults:

I've been giving this a lot of thought, but from a rather different
perspective.

First, working out what would be a good game, utilising as much as possible
existing game mechanics, and only then coming up with the PSB to justify it,
rather than looking at authenticity first, or what
happened in Iraq, Normandy, Dnieperpetrovsk, Market/Garden, Gallipoli,
Iwo Jima, Klendathu and Hoth. Or how much Fire Support Falkenberg's 42nd

or Hammers Slammers could call on.

Where I did examine both real and fictional invasions, I tended to concentrate
on the more cinematic aspects: the "Commando" operations ideal for SGII, and
the base assault on Hoth.

I started out with a "top down" approach: what planetary defences could

do, what their likely limitations were, how they could be integrated into the
GZGverse for FT primarily.

The easiest method, and one with the least impact on the rules mechanics, is
to have planetary defence bases being merely motionless ships on a planet.
After all, if the Planetary Defence Unit (PDU) system

is on an airless asteroid, what difference is there between a PDU and a
cruiser that's moored to it?

But when you get to "objects of significant interest", ie habitable planets
with biospheres, hydrospheres, and atmospheres, the problem becomes different.
Then, you have to consider interactions of weapons with the atmosphere. For
this, taking FT only as canonical, we have
specialised Ortillery, which has limited if any Anti-ship (AS)
capability, but is vastly better at planetary attack.

To get a decent game, we need to have normal weaponry degraded a LOT to make
Ortillery useful. We also need to have PDUs cheap enough so they should exist,
but expensive enough so system ships (with no FTL) become useful if there are
multiple points in a system to be defended.

A reasonable break-even point is 2 : if only a single point (planet
etc), then use a PDU. If 2, then 2 PDUs or the same cost in System
Ships. If 3+, System ships would be better. A better break even point is

3, if tugs are available.

So let's say that a PDU costs 1/3 as much as the equivalent ship,
providing its built near an industrial base. This is not so much due to the
cost of lofting to orbit, but the use of cheaper construction
materials ( 100 metre thick Ferro-concrete vs 2cm of Unobtanium), the
use of oceans or underground rivers as heat exchangers, or whatever PSB you
like.

Now a reasonable "firing arc" for weapons is 1 arc, 60 degrees. Otherwise, I
dunno, the thickness of the atmosphere gets in the way, whatever. Firing arcs
SMs stay at 180 degrees, the things can "bunt" after a vertical launch.
Similarly, a PDU can only be fired at by things

in that arc.

The upshot is that a planetary invasion has 2 possibilities: to land
"outside the arc" of the defences, and face a month-long slog vs local
guerilla forces and counter-attack to get to the place of interest, or
to drop in the teeth of the defences and take its lumps on the way in,
hopefully having supressed them with ortillery.

A little jiggling of the fighter rules would allow fighters to be both useful
planetary defences, and useful planetary attackers, operating inside the
atmosphere and so with weapons not degraded. More jiggling,
and "commando launches" of fighter-size, but carrying sticks of special
forces, could land by stealth and conduct raids to take out the Beam-10s

of Navarone.

Well-settled planets, with population centres on multiple continents,
will have multiple PDUs, with no single "safe" landing site arc. But that
invites defeat in detail, if equally distributed, each 60 degree
arc has only 1/6 of the defences that it would have if it was all in one

place, to state the obvious.

A neat way of balancing costs is to make them proportional to the number

of sites being defended. An outer colony, with 1 continent settled, will

have 1 PDU per X points. An inner world, with 6 continents settled, will

have 6 PDU for the same price - simply because it has more industry
that's closer. So worlds can be considered in a strategic game as having

values of 1-6, indicating approximate population factors. A size 1 world

has ~10,000, size 2 ~100,000, size 6 ~1,000,000,000.

How much do PDU's cost? Let's say 1/3 of the equivalent ship, and they
also get unlimited single-row armour free ( and all but bypassed by
specialised Ortillery). Non-damagable Screens too, if the atmosphere is
thick (but targets get the same protection). Damage to this armour indicates
damage to the environment, civilian casualties etc. Cities could be
represented by "passenger spaces". Give the PDUs too much of a pasting, and
you'll kill megapeople in the bunkers. Use too many
non-specialised planetary attack weapons, like the dreaded KV "Mass
Drivers" or Beams, and you conquer a radioactive or dust-covered
hellhole. That's why you need ground forces, and have a reason for DS2 and SG2
games.

As to the exact mechanisms of landing troops, interface with tactical
rather than defence-suppression ortillery etc, I leave that to the
GroPos. This view is strictly that of the Sky Marshall, charged with getting
the troops dirtside. It covers the space battles where an

From: John Atkinson <johnmatkinson@y...>

Date: Fri, 25 Nov 2005 12:15:57 +0100

Subject: Re: [GZG] Not So Small thought re: Orbital Assault

> On 11/25/05, Zoe and Carmel Brain <aebrain@webone.com.au> wrote:

True. But the firing arc question assumes that PDUs are on smooth spheres. But
most planets are bumpy. Anywhere you put your PDU is going to involve
compromises and you will need secondary installations to cover air corridors
which may not have a good LOS to the PDU that would be defending that sector.
Furthermore, if you site it with LOS being a primary concern, you get to build
it on top of a mountain
(more expensive, more time-consuming) and then it is seperated from
the settlements. Perhaps enough to overcome the reluctance to just slam it
with a pair of tactical nukes launced from said fighters?

> How much do PDU's cost? Let's say 1/3 of the equivalent ship, and they

??? Only savages put bomb shelters for civillians in military installations.

I'd shy away from putting PDUs in actual valuable territory. I mean, what if
you win the battle? Then your colony is trashed and it's your own fault.
Furthermore, major population centers are in places which (typically) have
good agricultural production and easy transportation routes. River valleys are
a favorite, which is not always the best
place to stick a PDU, LOS-wise.

Even when coastal fortresses were an effective defense, they weren't
necessarily located downtown, but typically at the entrance to the harbor, or
on an island just off from the harbor which could control it with gunfire. A
castle would (usually) be situated on a hilltop near the town, not in middle
of the market square.

Personally, my inclination for a planetary defense scheme runs like this:

Massive phased-array antennas scattered out all over the place for
fire control.

Buried silos--SMRs--scattered randomly through the wilderness and
heavily camoflaged. They would have buried landline controls to launch them,
and the transmitters to control them after launch would also be in the boonies
and linked by hardline to the command center. Which would be buried under a
mountain.

Could also place batteries of beam weapons in places where they defend good
LZs, but that would be seriously secondary. Salvo Missles are going to be
better at shooting down stuff locked into an orbit.

Instead of a single big PDU, dozens of tiny installations scattered all over
the places, mostly in regions far, far away from anything valuable. And since
they are SMRs, after they launch, you can waste
time/ordnance shooting at empty silos.  Doesn't hurt my feelings.

The population centers get PDSs. Lots of them, locally controlled but linked
into the central command facility.

But that would be secondary. I'd rather fight the fight in orbit anyway. Less
people live there.

From: KH.Ranitzsch@t... (K.H.Ranitzsch)

Date: Fri, 25 Nov 2005 15:09:45 +0100

Subject: Re: [GZG] Not So Small thought re: Orbital Assault

[quoted original message omitted]

From: Alan and Carmel Brain <aebrain@w...>

Date: Sat, 26 Nov 2005 03:12:36 +1100

Subject: Re: [GZG] Not So Small thought re: Orbital Assault

> KH.Ranitzsch@t-online.de wrote:

> My impression was that Zoe was basically thinking in terms of FT scale