Planets & Meson gun sites

[Shayde01]

I thought I might draw on the experience & knowledge of some of the members here in seeking an answer to a few questions.

In my campaign, the players will soon need to covertly insert themselves into a system and land on a planet to infiltrate a research base. The relevant planet is actually a (tidally locked) satellite ("S") in orbit 9 of the mainworld ("MW") itself in orbit 11 around its star.

I'm thinking of putting a number of meson gun sites on the MW which would cover S. This might give the players some strategic possibilities of using the farside of S to avoid detection. It might also be fun to rain down near miss meson shots on them later. In any case, I suppose I'm looking for input on 1) whether meson guns have a feasible range to reach S if they are based on the MW, 2) what is the effective range of meson guns, 3) the gameplay difference between taking a standard (low), high or geo-sync orbit, and finally 4) rules or considerations for targetting/detection of ships when in orbit around a planet.

All brainstorming welcomed and appreciated.

 

[veltyen]

1) Depends what you mean by orbit 9. Probably.

2) Under T20 the maximum range for a meson spinal (and you might assume that a ground installation may have a longer range since smaller meson weapons have a reduced range) is about 4 light seconds/1 million km. For most planetary systems that would encompass all but the most distant satellites. With adequate detection and rangefinding most of that range should be useable.

3) Not quite sure what you mean. Which aspect of gameplay?

4) Especially for meson weaponry there shouldn't be a whole lot of difference.

 

[mike wightman]

In the hybrid rules of Mayday/High Guard a meson gun has an effective range of 5 light seconds, and a maximum range of 15 light seconds.

A standard low orbit allows a ship to hide from other ships' sensors, while a ship in geo-sync would be easily detected - LBB2 interpretation.

Detecting and targeting a ship from the planet would depend on the planet's TL...

 

[RainOfSteel]

Originally posted by veltyen:

2) Under T20 the maximum range for a meson spinal (and you might assume that a ground installation may have a longer range since smaller meson weapons have a reduced range) is about 4 light seconds/1 million km.

Was there errata? T20 p.275 says 75,000 km is the maximum range for a meson spinal mount. A 50-ton bay has a 30,000 km range and a 100-ton bay has a 45,000 km range.

Oh, and I will agree completely about larger systems having a greater range, though that point has been argued against me with substantial vigor in the past (see Invading Star Systems/Defending Them).

 

[mike wightman]

Those are the ranges:

this weapon may engage a target without penalty

75,000km is the range increment of the spinal meson gun. It may fire at longer ranges but takes a penalty to do so. See page 154.

 

[far-trader]

Nope, those aren't the maximum ranges in the tables RoS, they are the 1st range band. Pg. 154 explains range rules. Spinal meson weapons at up to 4.8 million kilometers are only -8 to hit and -4 damage dice, and the rules seem to suggest that they are only -10 to hit and -5 damage dice for anything beyond that (to infinity and beyond ).

Seems like a little more playtest or errata could have been done to make that bit clearer and more sensible.

I have cooked up some house rules that seem more sensible to me, but that's a topic for another time and thread

 

[far-trader]

Aw Sigg beat me to it

I go offline to compose and get distracted and come back to find the question answered. Oh well, good for a post pad

 

[veltyen]

Was there errata? T20 p.275 says 75,000 km is the maximum range for a meson spinal mount. A 50-ton bay has a 30,000 km range and a 100-ton bay has a 45,000 km range.

Range increment as mentioned above.

Doh. Having looked at the rules, yeah, it has a range of 4.8 million km. I forgot that I use a house rule heavy variant of space combat (which uses a more linear scale) that uses the 15 increments from the vehicle scale instead. 15x75,000 is the 4 light second/1 million km mentioned above.

 

[mike wightman]

Originally posted by far-trader:
I have cooked up some house rules that seem more sensible to me, but that's a topic for another time and thread

Well, come on then, get them posted...

 

[RainOfSteel]

Originally posted by Sigg Oddra:
75,000km is the range increment of the spinal meson gun. It may fire at longer ranges but takes a penalty to do so. See page 154.

D'oh!

Range increments . . . of course.

 

[marvo]

Here's something that has always bugged me about the whole meson gun site thing...
If a starship has to manuever to aim it's spinal mount, how does a planetary deep meson gun site aim?

 

[Gruffty]

I've always thought the MG would be suspended from a cradle that can rotate 360 degrees in any direction.

 

[far-trader]

I always picture (and build) them as big ships inside a large hollow subterranean cave (or deep ocean trench). They just hover there on antigrav and spin to target. Power is usually a direct thermal tap into the subcrust magma.

 

[aramis]

I've always pictured them as equitorial-mounts in huge spheroid caverns. The excess space is for the power systems. Usually either closed cycle geothermal or fusion powered.

 

[Border Reiver]

I build them as ships in FF&S or MT, with an open frame, multiple redundant power sources, crew quarters, meson and hardwired comms and more. Place it all in a deep spherical cavern and use gravitics to aim.

Immune to everything except meson fire or commando raids, the only way normally available to knock them out is to wipe out their eyes. A difficult enough job that I decided to make harder IMTU by adding FOO SDB's, highly manouevrable, low signature 200 ton vessels packed with comms and sensors. Set up a firing solution, pass to the gun emplacement and "boom". An invading fleet now has more to worry about than a bit of laser and missile fire from those SDB's that went to ground, their capital ships are now vulnerable until the actual gun is taken out.

 

[mike wightman]

Originally posted by Border Reiver:
I decided to make harder IMTU by adding FOO SDB's, highly manouevrable, low signature 200 ton vessels packed with comms and sensors. Set up a firing solution, pass to the gun emplacement and "boom". An invading fleet now has more to worry about than a bit of laser and missile fire from those SDB's that went to ground, their capital ships are now vulnerable until the actual gun is taken out.

Very sneaky

- consider it borrowed for MTU

 

[veltyen]

Spotting shouldn't actually be that hard.

Neutrino sensors. Just fire at any working reactors that you know aren't yours. Might not work all the way through planets, but should be fine through a mere 5 km of rock and dirt.

Speaking of detector ships, I got so far as doing a deckplan (and a 3d model, and an animation of the boom unfolding, amazing what you dig up looking through old files) for a 90 dTon passive detection vessel.

Big Ear
Type: Listening Post
Hull: 90 dTon Cylinder (partially streamlined)
Tech Level: 15 (F)
Armor: AR8
Computer: 9 (Avionics 1/Sensor 9/Communication 9)

Engineering
Maneveur Drive: 1 G
Agility: 1
Power Plant: 16 EP
Fuel Tanks: 24 dTon (12 weeks duration)

Weapons
1 x Beam Laser (USP2)
1 x Missile Launcher (USP2)
1 x Sandcaster (USP3)
20 x Sancaster Ammo
Missile Magazine 1 dTon (20 rounds)

Fittings
4x Staterooms
4x Low Berths
1x Fresher
1x Autodoc
1x Supplies Locker (184 person weeks)
18 crew maximum life support capacity

Crew
1x Pilot
1x Gunner/Marine
1x Engineer
4x Sensor Operator

Description
A long cylinder (30m long with an approximate 5 m radius) with 4 enormous booms, more then five times the length of the vessel, holding an enormous antenna. When deployed the vessel sits as the collector cone for the antenna much like a satellite dish. The booms fold not so much for going into atmosphere (the vessel is never intended to go near a planet) but for storage onboard carrier vessels.

This type of listening post is considered the poor companion of the asteroid based listening post, which for the same cost offers longer endurance, more resilience, a larger crew and greater weaponry. The one advantage is the ability to transport the vessel more easily (the rock post is 200 dTon for the same cost) and sometimes you just don't have the rocks.

Cost: 111 MCr (mostly from the computer and the power to run it)

Variants
The already mentioned rock post is the most common variant. For the same cost you can equip a 200 dTon similarily equiped buffered panetoid with maximum armor, and its even more likely to be mistaken for junk if spotted while passive. For this reason, where possible, a rock post should be used for static defences. The asteroidal listening post ("rock post") could be considered the smallest in the chain eventually leading into defensive asteroidal weapon platforms that carry fleet destroying firepower.

The images are still pretty rough. I'll post them if people are interested.

 

[mike wightman]

Originally posted by veltyen:
Spotting shouldn't actually be that hard.

Neutrino sensors. Just fire at any working reactors that you know aren't yours. Might not work all the way through planets, but should be fine through a mere 5 km of rock and dirt.

What if it isn't powered by a fusion reactor? Geothermal was mentioned earlier...

Speaking of detector ships, I got so far as doing
{snip}

Nice one

The already mentioned rock post is the most common variant. For the same cost you can equip a 200 dTon similarily equiped buffered panetoid with maximum armor, and its even more likely to be mistaken for junk if spotted while passive. For this reason, where possible, a rock post should be used for static defences. The asteroidal listening post ("rock post") could be considered the smallest in the chain eventually leading into defensive asteroidal weapon platforms that carry fleet destroying firepower.

I'm borrowing this as well

The images are still pretty rough. I'll post them if people are interested.

Yes, please post them.

 

[veltyen]

What if it isn't powered by a fusion reactor? Geothermal was mentioned earlier... [Wink]

Um. I was actually thinking for the buried meson weapons to target vessels (even fusion powered grav tanks) on the surface and near the planet.

IMTU a deep meson installation consists of several extremely large fusion reactors, seperated by kilometres, connected to an array of (again dispersed) meson spinal weapon equivalents. Takes several hits to take out the power, the meson weapons cannot be seen until they fire (and might be hard to target even then), and all this is buried 5-10 km deep under the toughest rock you can find with enough fuel and supplies to hold out for multiple years with no external contact.

No planet could consider itself well defended without several of these installations. An opponent without counter meson fire is ... toast.

*NOTE*
This is from guesswork and memory, as I hadn't labelled it at the point that it went on the shelf.

1- Gunnery and weapons station. To the right and left are the launching tubes and ammo storage for the sandcaster and missile tube.
2- Bridge. 4 Sensors stations that can also be used for more general duties.
3- Bridge head.
4- [optional] The free "cabin equivalent" that comes with a small craft bridge. In this case converted to an actual small cabin.
5- Single Staterooms
6- Double Staterooms
7- Mess/Communal area
8- Life support supplies storage
9- Low berths and autodoc
10- Air lock mechanism
11- Air lock chamber
12- Powerplant
13- Maneveur drive
14- Engineering station
15- Fuel

And the partially complete 3d model with the arms at 20% extended.