Ortillery options

[PsiTraveller]

Am I reading this wrong or are missiles better for bombarding targets from space?

Ortillery missiles TL 7 300 000 Credits for 12 of them (25 000 each) and 1DD damage. (HG pg 30)
So a triple turret could fire three of them and do 3DD damage total to the target for 75000 credits. but are vulnerable to point defence. (And can ground targets have point defence?)
Takes 1 ton of space on ship. Ammo is 12 per ton. Cost of a triple turret, 1 million credits

Torpedo based Ortillery: Barbette based minimum. 3 torpedoes per ton 1 MCr for 3, so 333 000 Cr per torpedo. Does 3DD damage. (HG 32)
Point defence Effect is halved against torpedoes, so they may get through defenses.
Takes 5 tons of space on ship, 3 torpedoes per ton. barbette costs 3 million

Mass Driver: Small Bay: 40 million credits, 50 tons of space. 20 000 Credits per attack and doing 1DD of damage.

Is it just me or is it cheaper to just loft a lot of missiles at a target?
What are the advantages of a barbette or a small bay?

 

[AnotherDilbert]

If you launch a few missiles at a defended target, they will be shot down by Point Defence. You have to launch a lot of missiles.

The big metal slug from the Ortillery Bay will hit.

 

[Condottiere]

On the plus side, you can have a lot of birds in the air, whereas there's only one ball bearing down.

 

[PsiTraveller]

If you had 2 triple turrets and launched 6 missiles would they follow the missile rules on pg 162? +6 to the attack roll for all the missiles in the salvo (assuming all 6 survive the journey in bound), and then multiply the damage by the Effect of the Roll?

And can you make a higher TL Ortillery missile? the base TL is 7, you can use the TL of the attacking ship, or improve the missile TL somehow to get a better attack bonus.

What is the defense tech level of a building? assuming a TL 12 attacking ship, what TL of the building to adjust the attack roll as per pg 162.

Getting a good Effect roll could really improve the damage of an Ortillery missile barrage if the missiles rules do apply, far more damage than a mass driver missile that only sends one missile.

 

[AnotherDilbert]

If you had 2 triple turrets and launched 6 missiles would they follow the missile rules on pg 162? +6 to the attack roll for all the missiles in the salvo (assuming all 6 survive the journey in bound), and then multiply the damage by the Effect of the Roll?

Yes, I assume so.

And can you make a higher TL Ortillery missile? the base TL is 7, you can use the TL of the attacking ship, or improve the missile TL somehow to get a better attack bonus.

A missile basically has the TL of the manufacturer. You can make a missile of any TL you desire from TL7 and up, just like a current Tomahawk missile is better than a Tomahawk from the 70s while still having the same general shape and size.

What is the defense tech level of a building? assuming a TL 12 attacking ship, what TL of the building to adjust the attack roll as per pg 162.

A regular building should have a low TL for the Smart trait. It has no camouflage or ECM, nor can it dodge attacks.

A defended bunker would probably have the TL of the society that built it.

Getting a good Effect roll could really improve the damage of an Ortillery missile barrage if the missiles rules do apply, far more damage than a mass driver missile that only sends one missile.

Yes, missiles are better against soft, undefended targets. They can also be used against any target, not just infrastructure, and has superior range.

Ortillery bays are better against defended, armoured targets.

Note that the Effect is not really an advantage for the missiles. The Effect of the salvo attack roll simulates the number of missiles that hit. The damage of all missiles are then simplified to a single roll used for all missiles that hit. The Effect is not added to the missile attack, nor is it added to Destructive Ortillery bay attacks.

 

[PsiTraveller]

I have to disagree with your assessment of the Effect number in missile combat Another DIlbert. The Effect number is the single most destructive element of missile combat.

from pg 162
Impact
If an attack roll for a missile salvo is successful, the target
will sustain damage. Roll for damage as if for a single
missile and deduct the target’s armour as normal but do
not apply the Effect of the attack roll. Instead, any damage
is then multiplied by the Effect of the attack roll (the
Effect cannot exceed the number of missiles in the salvo).

So the +1 per missile for the attack roll, plus any Tech advantage, so the +6 to the attack roll for the 6 missiles in the salvo really changes the damage. Assume an average 7 for the attack roll, +6 is 13, -8 is Effect 5 +/- TL difference, but let's assume 0 DM. The Effect of 5 is the multiplier for the 1DD damage roll-armour * 5. That is a 5 DD damage to target number.

Torpedoes get the same benefits for salvo numbers.

Do mass drivers get a multiplier to damage? The Tons/Attack chart on HG pg 27 says a small mass driver uses 2 tons/attack, a medium uses 4 and a large uses 20. If these numbers add to the damage in some way then Mass Drivers are great for planetary bombardment. But if (IMO) the damage multiplier for missiles is not translated over into Mass Drivers somehow, or in some way have Mass Drivers have an advantage in planetary bombardment, why spend 40 Million credits and 50 tons of space when 2 tons and 2 Million Credits lets you launch 6 missiles that do more damage. Each missile attack would cost you 150 000 credits, but to get the 5DD damage you would need 5 hits from a Mass Driver, so you are only spending an extra 50 000 credits. So saving the 38 million credits pays for 760 missile salvos.

 

[AnotherDilbert]

If you hit with 1 missile you do 1DD damage, if you hit with 2 missiles you do 1DD × 2, if you hit with 3 missiles you do 1DD × 3, right?

If you hit with 1 bay you do 1 × 1DD, if you hit with 2 bays you do 2 × 1DD, if you hit with 3 bays you do 3 × 1DD, right?

Yes, a single missile does as much damage as a bay, but is far easier to defend against.


Let's take a simple target in space, say a space station with armour 0, a single PD Battery and an EW modifier of +10.

If a missile salvo is launched against target from Long Range it will loose about 2D + 5 + 10 - 8 ≈ 14 missiles each round to EW for four rounds flight time, so 56 missiles. The PD Battery kills an additional 3D ≈ about 10 missiles. Totally 4 × 14 + 10 = 66 missiles have been rendered harmless. So to hit with a single missile (on average) we have launch 67 missiles. If we used 6 small bays and launched 72 missiles, about 6 missiles would remain of the salvo by impact. On average we would get an Effect of 2D + 1 + 3 + 5 - 8 ≈ 8, so damage is 1DD × 6 ≈ 210 damage for an ammo cost of 72 × kCr300 / 12 = MCr 1.8

If six ortillery bays attacks, they will hit on about 2D + 5 + 3 ≈ always. Damage would be 6 × 1DD ≈ 210 damage for an ammo cost of 6 × kCr20 = MCr 0.12.

This is a contrived example, but it illustrates that missiles are effective in large salvoes, but not very effective in small salvoes, at least against defended targets.

 

[Condottiere]

You probably have to compare it to a railgun spinal mount, the ammunition costs the same, but you have an increase in range and damage.

 

[PsiTraveller]

what modifiers on each attack are you using Another Dilbert? I'm having a slow morning and am not following the +1 +3 +5 . If 6 missiles get through the defensive wall it would be 2D +6 for the attack roll - 8 for the Effect number

And for the mass driver attack what are you using as your modifiers? What is giving you a +5 +3?

 

[AnotherDilbert]

what modifiers on each attack are you using Another Dilbert? I'm having a slow morning and am not following the +1 +3 +5 . If 6 missiles get through the defensive wall it would be 2D +6 for the attack roll - 8 for the Effect number

And for the mass driver attack what are you using as your modifiers? What is giving you a +5 +3?

Missile: 2D + 1[Smart] + 3[Launch Solution software] + 5[#ofMissiles, should be 6] - 8 ≈ 8

Bay: 2D + 5[gunner] + 3[Adv Fire Control software] => hit

 

[PsiTraveller]

Torpedoes can use the Launch software as well, does it stack with Advanced fire control I wonder?

And thanks for explaining the numbers, I had not even looked at software as a means of getting better results, too focused on the pg 162 mention of not using the Gunner skill.

Do Torpedoes get to use the Gunner skill and not missiles? or is it both?

 

[AnotherDilbert]

Torpedoes are a type of missile, so use the same rules as missiles, so cannot benefit from gunnery skill.

Fire Control software assists a gunner in an attack roll, so cannot be used with missiles or torpedoes.

Launch Solution software benefits missile and torpedo salvoes, but nothing else.

Ergo, an attack can use a DM from either Fire Control or Launch Solution, but not both.

 

[wbnc]

Or the low tech version of ortillery a few cargo containers loaded with iron projectiles the size of a railroad spike dumped out of a cargo ship as it comes in for a landing...the ship is not going at orbital velocities so the spikes won't burn up...but they will be moving at near supersonic speeds when they hit.

 

[PsiTraveller]

Crowbars from space! perfect for taking out TL 7 Tank divisions in Footfall by Larry Niven and Jerry Pournelle! Not surprising since Pournelle developed the Project Thor idea in the 1950's. The railway spikes might be like the lazy dog bomb from the vietnam war.

https://en.wikipedia.org/wiki/Kinetic_bombardment

Make the darts out of hull metal and they will not burn up when you dump them out from orbit. You could fit thousands of a shipping container. You could tenderize a large area of a city. 10 000 items hitting with the force of a grenade.

Or fire them out with a gatling type railgun a la The Expanse and strafe a surface.

 

[wbnc]

Crowbars from space! perfect for taking out TL 7 Tank divisions in Footfall by Larry Niven and Jerry Pournelle! Not surprising since Pournelle developed the Project Thor idea in the 1950's. The railway spikes might be like the lazy dog bomb from the vietnam war.

https://en.wikipedia.org/wiki/Kinetic_bombardment

Make the darts out of hull metal and they will not burn up when you dump them out from orbit. You could fit thousands of a shipping container. You could tenderize a large area of a city. 10 000 items hitting with the force of a grenade.

Or fire them out with a gatling type railgun a la The Expanse and strafe a surface.

The advantage of just dumping the out the cargo hatch is that your ship looks unarmed and loaded with a load of harmless metal if someone runs a densitometer scan.perfec for covert first strike or unconventional warfare attacks. An old two hundred ton cargo ship becomes a city/base buster.

 

[Spenser]

No idea how this would work out cost-wise, but in the book "Agent of the Imperium" Marc Miller goes into this in fair detail: the capital ships that are designated "siege engines" head out to the planetoid belt and harvest NiFe rocks, shape them correctly, attach thrusters and guidance systems to them, and just send them towards the planet to be scrubbed.

This sounds much cheaper and practical than having dedicated facilities and ammo.

 

[Annatar Giftbringer]

Rocks are NOT ‘free’, citizen.

Firstly, you must manoeuvre the Emperor’s naval vessel within the asteroid belt, almost assuredly sustaining damage to the Emperor’s ship’s paint from micrometeoroids, while expending the Emperor’s fuel.

Then the Tech Priests must inspect the rock in question to ascertain its worthiness to do the Emperor’s bidding. Should it pass muster, the Emperor’s Servitors must use the Emperor’s auto-scrapers and melta-cutters to prepare the potential ordinance for movement. Finally, the Tech Priests finished, the Emperor’s officers may begin manoeuvring the Emperor’s warship to abut the asteroid at the prepared face (expending yet more of the Emperor’s fuel), and then begin boosting the stone towards the offensive planet.

After a few days of expending a prodigious amount of the Emperor’s fuel to accelerate the asteroid into an orbit more fitting to the Emperor’s desires, the Emperor’s ship may then return to the planet via superluminous warp travel and await the arrival of the stone, still many weeks (or months) away.

After twiddling away the Emperor’s time and eating the Emperor’s food in the wasteful pursuit of making sure that the Emperor’s enemies do not launch a deflection mission, they may finally watch the ordinance impact the planet (assuming that the Emperor’s ship does not need to attempt any last-minute course correction upon the rock, using yet more of the Emperor’s fuel).


Given a typical (class Bravo-CVII) system, we have the following:

Two months, O&M, Titan class warship: 4.2 Million Imperials

Two months, rations, crew of same: 0.2 MI

Two months, Tech Priest pastor: 1.7 MI

Two months, Servitor parish: 0.3 MI

Paint, Titan class warship: 2.5 MI

Dihydrogen peroxide fuel: 0.9 MI

Total: 9.8 MI


Contrasted with the following:

5 warheads, magna-melta: 2.5 MI

One day, O&M, Titan class warship: 0.3 MI

One day, rations, crew of same: 0.0 MI

Dihydrogen peroxide fuel: 0.1 MI

Total: 2.9 MI


Given the same result with under one third of the cost, the Emperor will have saved a massive amount of His most sacred money and almost a full month of time, during which His warship may be bombarding an entirely different planet.

The Emperor, through this – His Office of Imperial Outlays – hereby orders you to attend one (1) week of therapeutic accountancy training/penance. Please report to Areicon IV, Imperial City, Administratum Building CXXI, Room 1456, where you are to sit in the BLUE chair.


For the Emperor,

Bursarius Tenathis,

Purser Level XI,

Imperial Office of Outlays.

 

[Condottiere]

Th Empire of Man is terribly inefficient.

 

[locarno24]

True, but the principle is sound. An M-drive and a lump of crystalliron can duplicate a dinosaur-killer quite happily at a comparatively low cost in time and effort - once you're already deploying a warship into a hostile system where you're expecting it to be shot at, a medium sized smallcraft used as an expendable asset isn't exactly a major cost.

 

[Condottiere]

Drake used to call them fireships.