Breaching a ship

[whartung]

So, in another thread, the point of a hostile boarding of a ship came up.

What does it take to cut through an airlock and/or a bulkhead? How long does it take? Do they have specialized breaching charges? Laser Torches?

The scenario is a pirate attack. The goal is to prevent the target Free Trader from jumping. If they can prevent that, then they have all the time they need to ransack and take what they want from the ship.

Is there anything the crew can do to actually stop prepared, motivated attackers? Can shotguns and cutlasses defend against vacc suited marauders with grenades and explosives? How many Free Traders are deigned to be death traps to potential invaders?

If the pirates literally cut out the airlock hatch, that is where there once was an airlock hatch is now a hatch size hole, is that enough to disrupt the jump grid on the ship to prevent jump? Just how much disruption can the grid take? Perhaps rather than boarding the ship, they'll just blow holes in the grid to keep the ship from jumping and decompress the ship.

In Snapshot a breach is 1000 points of damage. In AHL, its 250 points of damage, and a satchel charge does (net) 25. So, that's 10 satchel charges to breach the hull. Lot of work.

 

[Dragoner]

Last game I ran the players entered through a hull breach, and damaged turret, both caused by battle damage. If the ship was fine, I'd have them roll a computer system hack, which I have also done, in that one ship can hack another. I mean though, looking at the damage repairs in Book 2, it's probably best to avoid combat, like dump cargo, or try to beat feet away from the other ship. Most of the movement work is figuring intercepts for that reason.

 

[AnotherDilbert]

How to prevent a ship from jumping:
1) Attack them within 100 D to make them hesitate to jump lest they misjump.
2) Damage the jump drive. Since that is a large part of the prize, that's problematical.
3) Get a larger ship within 100 lengths of the target ship.
4) Docking a small craft to the hull will prevent a J-1 ship from jumping.

Breach a hull:
There is presumably specialised equipment to do it (see Mongoose). I assume a ship's laser at close range will work a treat.

A breached airlock will not prevent a ship from jumping, but the airlock will be a decidedly unhealthy place to be during jump (see early JTAs news).

 

[McPerth]

Most of this will depend on the damage status of the target ship.

The breach may already be there, if damaged enough... Otherwise, sur there are such breach producing explosives, at least for military use.

As for the crew resisting, it will depend on their numbers, prepareness and working state of their ani-hijack programing. IIRC in MT:SOM it said usual defensive tactics could involve sudden gravity changes, just to give an example ,and those can be quite difficult to overcome even for people i nvacc suit (and even damage the vacc suit).

 

[McPerth]

Most of this will depend on the damage status of the target ship.

The breach may already be there, if damaged enough... Otherwise, sur there are such breach producing explosives, at least for military use.

As for the crew resisting, it will depend on their numbers, prepareness and working state of their ani-hijack programing. IIRC in MT:SOM it said usual defensive tactics could involve sudden gravity changes, just to give an example ,and those can be quite difficult to overcome even for people i nvacc suit (and even damage the vacc suit).

 

[Condottiere]

You have to cut the cord between the bridge and the jump drive.

Detonating a gravitational device close by increases the likelihood for a misjump, but tends to be rather expensive.

 

[Deldarius]

How much juice does a laser throw down? 80Mj? How much of that actually reaches the target and is enough to cut a hole in the armor/hull, 20Mj?

So say due to the efficiencies of placing the charges on the hull, would 5Mj worth of explosives be sufficient? Physically how much would one need at that point?

Most explosives seem to me more anti personnel in nature. I am likely missing something.

 

[AnotherDilbert]

In FFS a laser is something like 120 MJ (and up), consuming about 3.3 MW.

In CT/MT a laser consumes 250 MW, so comparatively about 10 GJ...

 

[McPerth]

would 5Mj worth of explosives be sufficient?

5 Mj is the about the equivalent to 1 kg of TNT explosion. I guess not enough for a man sized breach on the hull of a starship. Nonetheless there ae more powerful explosives, and may be directionally set, so I guess some equivalent to RL explosive cable to make such breaches would exist

In FFS a laser is something like 120 MJ (and up), consuming about 3.3 MW.

In CT/MT a laser consumes 250 MW, so comparatively about 10 GJ...

The key fact here is how much time may those weapons be focussed on the target... For every second, they will deliver their power (in wats) as joules. So, if you can focus a (MT/Striker) beam laser for a full second, it would deliver 250 Mj (the equivalent to 50 kg of TNT.

For pulse lasers, I understand they accumulate the energy for a single burst, so if each burst is worth a second of accumulated energy, it would deliver 250 Mj in the same point of the hull...

 

[Spinward Flow]

An airlock requires bulkheads for pressure integrity.
Hatches or iris valves would need to "match" bulkhead strength for damage resistance.
CT specifies that bulkheads require 1000 points of damage from energy weapon or explosive to create a man-sized breach a person can get through.

LBB8 Robots includes Laser Welders (Laser Rifle damage but limited to 5 meters range), as do some previous CT products as well.
In LBB1.81 the Laser Carbine is a 4D weapon for damage, while the Laser Rifle is 5D.
3.5*5=17.5 damage from 5D on average.
1000/17.5=57.14 ... call it 58 combat rounds.
LBB1.81 combat rounds are 15 seconds each.

So ... call it 15 minutes (more like 14.5 minutes, but some dice rolls might be low) or 60x 15 second combat rounds to cut through a hatch or an iris valve with a Laser Welder (or Laser Rifle).

If you need to breach an airlock (2 hatches/iris valves) sealed against you that could take 30 minutes with man portable laser weapons to cut through an airlock or 2 bulkheads to penetrate into the interior of a ship. Note that without a pressure seal with the ship sending the boarding party, the interior of the ship being cut into will get depressurized as the bulkheads are cut into.

Demolitions skill (and proper explosive charges for the task) could potentially be much MUCH faster.

 

[BlackBat242]

If the pirates literally cut out the airlock hatch, that is where there once was an airlock hatch is now a hatch size hole, is that enough to disrupt the jump grid on the ship to prevent jump? Just how much disruption can the grid take? Perhaps rather than boarding the ship, they'll just blow holes in the grid to keep the ship from jumping and decompress the ship.

If direct hits from anti-ship weapons simply degrade the jump number, then just blowing an airlock will NOT disable the Jump drive.

 

[whartung]

If direct hits from anti-ship weapons simply degrade the jump number, then just blowing an airlock will NOT disable the Jump drive.

That's not what I asked. I asked if the damage hull now with a man sized hole in it was enough to damage the integrity of the jump grid to which a jump would not be possible.

If you need to breach an airlock (2 hatches/iris valves) sealed against you that could take 30 minutes with man portable laser weapons to cut through an airlock or 2 bulkheads to penetrate into the interior of a ship. Note that without a pressure seal with the ship sending the boarding party, the interior of the ship being cut into will get depressurized as the bulkheads are cut into.

Demolitions skill (and proper explosive charges for the task) could potentially be much MUCH faster.

Yea, based on Snapshot and AHL, breaching a hatch is a Big Deal. I mean, 10 satchel charges? I recall a time back playing Squad Leader when some Finns on skis came up to a tank, tossed a satchel charge on it, and knocked it out.

I would think that breaching pirates might have some specialized breaching explosives, something akin to, albeit likely larger, to the armor car heist scene in "Heat".

 

[AnotherDilbert]

For pulse lasers, I understand they accumulate the energy for a single burst, so if each burst is worth a second of accumulated energy, it would deliver 250 Mj in the same point of the hull...

According to FFS all lasers are pulsed, the difference is how often / how long the pulses are. "Beam" lasers presumably have long pules and "pulse" lasers have short pulses.

Keeping a laser focussed on a single spot over hundreds of thousands kilometers, as both ships manoeuvre is probably impossible.

As all lasers to some extent sweeps over the target, "beam" lasers with longer pulses have better chance to hit, but "pulse" lasers with shorter, more concentrated pulses do more damage if they manage to hit.


P.S. Please, it's "MJ", not "Mj", at least if you refer to the SI unit joule.

 

[Condottiere]

If you get close enough, you can use a mining laser drill.

 

[coliver988]

and different versions also have breaching tubes which would be significantly faster as well as safer as I believe they create their own air lock. Until you leave.

 

[infojunky]

I just reset the Satchel Charge properly set to blow hatchs, valves and access plates in that they are the equivalent of a missile warhead.

As for laser cutters I figure use the max damage twice a round.

 

[Enoki]

Well, the first thing you have to answer is, how long is it between you detecting them and their starting to breech and board? That gives you your prep time. This could mean the crew is armed to resist and in vac suits along with having the ship secured and power off on many systems making access more difficult.

If the crew can do that, then you better be hauling a lot of breeching charges since every major hatch will be secured with no power. Worse, if the crew knows where you're trying to breech at they can--assuming they have the necessary stuff--prepare all sorts of horrid responses for you. Let's say they're better prepared, and the second you and your crew drop through the breech into the compartment of the ship they set off several claymore mine equivalents... Rolling in a grenade or two first won't prevent that from happening.
Of course, they could wait until you do that, then board, then toss a few of their own your way...

I'd think the first thing the pirates would want to do is make it so your ship can't maneuver by either damaging the engines, taking out fuel tanks, or something like that. Blast the bridge / cockpit area? Once they have the ship in a non-maneuvering position, they can start to board.

If you wanted a man-sized hole in the hull, using a linear shaped charge in the shape of a circle that would cut the hole in one shot is the way to go.

 

[whartung]

If the crew can do that, then you better be hauling a lot of breeching charges since every major hatch will be secured with no power. Worse, if the crew knows where you're trying to breech at they can--assuming they have the necessary stuff--prepare all sorts of horrid responses for you. Let's say they're better prepared, and the second you and your crew drop through the breech into the compartment of the ship they set off several claymore mine equivalents... Rolling in a grenade or two first won't prevent that from happening.

Do you think starports just accept as "OK" to have traders docking that are stocked with claymores, grenades, and other such things in their ship locker? Is a belt fed, shielded, light machine gun standard equipment on a Free Trader? Starports okey dokey with that too? An automatic grenade launcher? Those would make quick work of a breaching force.

Do traders perform vacc suit drills with passengers for when they depressurize while waiting for boarding?

 

[Spinward Flow]

Do you think starports just accept as "OK" to have traders docking that are stocked with claymores, grenades, and other such things in their ship locker?

Bolded for emphasis.
So long as the weapons don't leave the ship, the starport isn't going to have a problem ... absent a search warrant situation that requires Starport Authority to board the ship and conduct a search (and presumably, seizure) of contraband. If the starport doesn't need to search the ship, anything that stays aboard is of no concern to the starport.

 

[whartung]

Thats fine, just curious if you think that it's routine for a ship to have anti-personnel explosives bumping around in the locker next to the first aid kit.