Walls/doors/hatches/Iris valves

[Jak Nazryth]

A couple of games ago one of my players used breaching charges to blow open door and hatches on a ship they had infiltrated. They were not sneaking, the ship was in lock down, and the military character was using his "set of lock picks" to attain access into engineering and bridge sections etc..
The breaching charges had a listed amount of damage 3 or 4 dice.... but I couldn't find any information in the core book about the toughness of typical ship walls, doors, hatches, iris valves, etc...
Does anyone know if this is covered anywhere in the Mongoose rules? If not, are there any other rule systems that might list these items?

Tomorrow the group may board a space hulk and instead of winging it like last time, I would like to have a good idea of how much damage it takes to blow through a typical internal bulkhead, or hatch, or iris valve etc..

I know that 1 point of ship armor = 50 points of "normal/player scale" armor, but that's about all I have to go on. I'm not sure how much damage a non-armored ship will take to blow through/cut through the hull itself... but mostly I'm interested in the internals.
Thanks for any help.

 

[ShawnDriscoll]

The referee gets to decide such things.

 

[tolcreator]

It'd be pretty lame if these things in the box labelled "Breaching charges" could not, in fact, breach things. I wouldn't even roll dice.

 

[dragoner]

The original, and only one I know, is Supplement 7, Traders and Gunboats, Classic Traveller, pages 5 thru 7. Typically bulkheads have 1000pts to breach, and partition walls 100pts.

 

[phavoc]

I second what Dragoner said. I would treat internal armored bulkheads the same as hull plating (i.e. if you have a fusion/plasma weapon you can eventually bludgeon your way through, forget about anything else).

But that's why they have doors! Much easier to get through. Though I would say that if you put armored bulkheads around a section that access INTO the section should be treated the same. What's the point of having a vault if you put a screen door on it?

 

[BrianSmaller]

As a GM unless there was a plot reason for the charge not to work as expected I would say "door breached".

 

[Condottiere]

 

[simonh]

It'd be pretty lame if these things in the box labelled "Breaching charges" could not, in fact, breach things. I wouldn't even roll dice.

This. You're using a thing to do what it was designed to do. I could see an argument for requiring a skill roll, but it should be a fairly easy one.

Using weapons or tools not designed for the purpose is a different issue though. For that, it might be useful to have a baseline idea of the damage or armour factor of a bulkhead or hull, but then it gets a bit messy. Penetrating a wall and blowing a hole in it large enough to walk through are two very different things. Some wepaons will be good for the first case, and next to useless at the other.

Simon Hibbs

 

[CosmicGamer]

For consideration in your analysis

A weapon actually designed to fire on a ship is the 26mm Orbital Defense Cannon from the CSC page 124. It's damage is 20d6 Ultimate-AP. That is 100pts of AP for 2 pts against ships.

This assumes points of AP are divided by 50 like damage is.

Most ships that have armor have 4 points or more. 2pts of ship AP would tear through a light fighter though.

Unlike the example in Book 1 Mercenary where the # of damage dice is divided by 50 then ship damage is rolled as per normal, I'd roll for damage then divide by 50 or else this gun would never score a hit on even an unarmored ship unless using a battery of at least 3.

Which brings up group fire from Book 1 Mercenary. Would the AP ability of group fire be additive? With one of the guns above giving 100AP, would two together give 150?

Yes, a "breaching" charge is designed to breach and should be able to do so (when the proper amount is properly applied to the proper structure). However, a breaching charge for putting a hole in the concrete wall of a building may not do much to an armored vehicle let alone an armored ship. So the cheapo 100Cr. TL8 breaching charge on page 161 of the CSC is not getting through the hull of a ship. Or is it?

Task from page 54 of the core rules under explosives:
Planting a breaching charge: Education, 10–60 seconds, Average
(+0). The damage from the explosive is multiplied by the Effect.

Multiplied by effect! So a 4d6 breaching charge with an average damage roll and an effect of 4 on the explosives task would do over 50 points of damage and score a hit on a ship with no armor.

Probably not important in this example but a point for debate, do you think the AP effect of the charge can be multiplied by the effect of the explosives task?

If you do enough damage from a explosive breaching charge to score a hit on a ship do you roll for a single hit as if attacking a ship? What if you don't roll Armor or Hull but turret? With normal ship damage in combat you can damage internal systems and not damage the overall integrity of the armor or hull. Point being, you may need to do 50 points of damage to score a "hit" on a ship, but do you need the same to punch a small hole in the hull (relative to ships overall size) between the structural elements?

Note that if one were to get a breaching charge or weapon specifically designed for a ships hull and not vehicles or other ground operations, it would not be penalized with the divide damage by 50 for ground force weaponry vs a ship.

Not aware of ship specific breaching charges in the books but of note is the breaching tube in high guard and many other books. Perhaps because typical explosives are ineffective for breaching armored ships? The breaching tube has a ring of plasma torches. The backpack TL9 plasma cutting gear says it can "cut through most materials, though cutting through hull armour requires a very long time to create a breach."

Note that the amount of damage done by the torches is not given.

For the ships interior:
The ships outer hull is designed with inner structural supports. Very sound verses damage from the outside coming inward onto these supports. What about damage from the inside blowing outward?

I'd think most interior bulkheads and hatches will likely not have the same structural supports as the ships hull. Interior bulkheads need not undergo the stresses of landing in a variety of atmospheres, meteorite and space debris impacts, or other criteria such as the ships outer hull is.

For the typical ship, hull armor is on the hull, not the interior decks, bulkheads, and so on.

Perhaps there is an adventure somewhere that covers this?

 

[Jak Nazryth]

I don't want to get too complex, but I also don't think an inexpensive 100 cr breaching charge would defeat any high tech, high strength door. Every ship of the line would tremble in terror.
No, to me any normal door on an office building, or locked stateroom door on a ship will easily have the latch or other locking mechanism blown apart, and the door will lurch open from the blast from a breaching charge listed in CSC. I didn't bother with a standard hatch my player was using his charges on. But when he placed a charge on an iris valve to get into the engineering compartment, that's when I had to think. I know iris valves traditionally have been used on internal bulkheads as well as exterior entries on Traveller ships for decades. Since a breaching charge works by blowing a chunk in the door where it is secured to the door frame, a normal door will simply be slammed against the wall. But how to you cause an iris valve to open using a breaching charge? And since damage is listed as 4d6, that implied you do damage to what ever you're placing the charge on. That's why I started looking for "hit point" information on materials. If Mongoose lists damage done by a charge, you would need to know how much toughness a typical door has, strengthen door, bank vault door, concrete wall, etc.. I think there me some information in GURPS traveller, or simply GURPS basic rules might cover the toughness of materials. I don't want to get too complicated with this question, but I also don't want a low tech 100 credit explosive device defeating every door my players encounter. Remember the scene from X-MEN 2 (x-men united). At the installation at lake in Canada, Professor X was in the second Cerebro and a group of mercs secured a 5-point breaching charge to the door. The door was so thick and strong, the charge only left black smudges. That's what I see as entry hatches into ships. Bonded superdense hatch will be very tough, and a 100 credit low tech charge should not be able to breach it, just because is says "breaching charge" on the box. To me that is lame.

 

[Reynard]

"I'd think most interior bulkheads and hatches will likely not have the same structural supports as the ships hull. Interior bulkheads need not undergo the stresses of landing in a variety of atmospheres, meteorite and space debris impacts, or other criteria such as the ships outer hull is."

I can see the Core Book kept Boarding simple as with most things but you would figure at least Mercenary would give structure values for ship interiors and groundside structures.

Checking Snapshot, interior walls are listed as being broken to walk through after taking 100 points damage from energy or explosives. Doors can be broken down on a successful Strength check. Bulkheads and decks can be 'holed' with 100 points (allows pressure equalization) from energy weapons or explosives or breached to pass through from 1000 points. These are the Structure within a starship. In some ways, I'd say using examples in Mongoose, a point of ship structure is 50 points personal level structure so the numbers are 50 and 5. Multiple points of Structure represents the size of a ship not greater toughness. Hatches are as tough as bulkhead.

Ah, iris valves. I'm guessing here translating Classic to Mongoose. If fully closed, they can be forced open with a Difficult Check. Use either Str DM or Dex DM and a -3 if in a Vacc Suit. 1-6 minutes. If a strong metal object is placed in the valve before fully closing, it takes 10-60 seconds to open. Gunfire or explosives only make the valve close tighter, one step up on the difficulty level per attempt.

 

[phavoc]

The term "breaching charge" is a bit too generalized for what is being asked here.

A better way to deal with this, and to stay somewhat within the rules AND make it reasonable to deal with the various things you want to breach, is to give the standard breaching charge a DP amount, and each wall/hull/door type a damage resistance number.

So, for example, you want to blast through the corridor into the next room. The wall has a DR rating of 10. Each breaching charge can inflict 2pts of damage. The general rule of thumb should be if you don't exceed the DR rating you inflict a single point of damage to the object, and once you have inflicted enough overall damage you can consider it breached (if you wanna get more technical you could require X times damage to make it large enough for a person to get through, but that would be up to the ref). This allows for things like gunfire or whatever to brute force through something - IF you are willing to expend the time and effort. Most things can eventually be cut/blasted/bashed through (but use your own common sense here - a spoon might never get through that scout's hull plating...but if they had a spork, well, all bets are off!).

Doors and such work more or less the same. Maybe you are blasting a hole through it, or maybe you are blasting the opening mechanisms/hinges and forcing it open that way. Too much detail is a burden here, so keep it simple, just keep it universal.

Something like this allows you to scale up or down without having to do too much math. If you want to reflect things like armoring (say a vault, armory or even reinforced bulkheads) simply attach a X multiplier. So the regular wall that took 10 pts of damage now has 100 pts of DR. If you have enough time a man-portable energy weapon will probably be able to penetrate even starship armor. It just might require a LOT of turns. Even many kinetic energy weapons could be used, though you may want to have a cut-off and say anything less than this damage is simply unable to penetrate and therefore cannot damage/breach. Charges, however, are designed specifically for this sort of thing so I think it's ok to give them more leeway. It also makes it somewhat easier to keep track of things (you need 20 charges to get through this door, 5 for this wall, 200 through this armored bulkhead). Making up a table would probably not be a bad idea and provides quick reference. It would also allow you to create new types of charges, say with different TL of explosives, for quick reference and consistency.