Booby Traps & Area Denial: Claymores, Bouncing Betty, Spring-gun, Deadfall Traps, Electrified Floor, Motorised Blades, etc

nameless_survivor · 2019-01-02T17:39:44.339Z

Darkfirephoenix:

On a different note: I think those super wires aren’t also that far fetched given how there are already super alloy platings ingame and you can bet that the military would really like super thin and sharp wires for whatever (morally wrong) reasons

There would be TONS of applications for a material that is both ductile and has ultra high tensile strength, most of them would not be remotely military related. Springs would be one common example.

I suspect Kevin will not go for the super-science material thing. Creating a monomolecular wire is way beyond current technology, much less for a survivor building traps in a cave with a box of scraps. And that is what you would need for a static wire trap to be effective unless you are using thick wire or cable, and a truly enormous motor or weight. And I can think of better things to do with a bunch of superalloy plates than drawing it into wire or cables.

Darkfirephoenix · 2019-01-02T18:02:36.087Z

I never said that the survivor should be able to MAKE those wires, just find em.
Now a idea for a less complicated (thematically speaking) trap: A guillotine trap. Nothing more than a (sufficiently thick and heavy) sharpend plate of metal between two posts/walls (most likely a thing for the building menu) on rails (so it doesn’t wander off when it hits) and a motor to pull it back up after dropping.
Would be a REALLY nasty surprise in Labs like in the Resident Evil movies

kevin.granade · 2019-01-02T18:51:16.738Z

nameless_survivor:

The advantage of bouncing mines is not concealment, it is that they are designed to detonate at chest/head height,

If concealment isn’t an issue, you can just put your explosive on top of a stick jammed into the ground, so yes, the purpose is concealment.

nameless_survivor:

If you can craft fuses and regular landmines, you have the expertise to manufacture a bouncing one.

That is definitely an incorrect statement. Theres a big difference between crafting a working trigger, fuze and detonator and crafting a multi-stage fuze and launcher that will reliably detonate your payload at the correct height. Its not just a matter of knowledge but also precision.

Blade traps:

github.com

CleverRaven/Cataclysm-DDA/blob/25837b7fc0d4dd3e3d68b30b9a9538fe82c2be7c/data/json/traps.json#L208


    "name" : "spinning blade engine",
    "color" : "light_red",
    "symbol" : "_",
    "visibility" : 0,
    "avoidance" : 0,
    "difficulty" : 2,
    "action" : "none",
    "drops" : ["motor", "blade", "blade", "string_36"]
},
{
    "type" : "trap",
    "id": "tr_blade",
    "name" : "spinning blade",
    "color" : "cyan",
    "symbol" : "\\",
    "visibility" : 0,
    "avoidance" : 4,
    "difficulty" : 99,
    "action" : "blade"
},
{

github.com

CleverRaven/Cataclysm-DDA/blob/533f19141749c44b6c7c48c8a64423d3a29e9d0d/src/trapfunc.cpp#L402


        z->deal_damage( nullptr, bp_torso, damage_instance( DT_CUT, rng( 40 * shots, 60 * shots ) ) );
    }
    c->check_dead_state();
}


g->m.spawn_item( p, g->m.tr_at( p ).loadid == tr_shotgun_1 ? "shotgun_s" : "shotgun_d" );
g->m.spawn_item( p, "string_36" );
g->m.remove_trap( p );
}


void trapfunc::blade( Creature *c, const tripoint & )
{
if( c != nullptr ) {
    c->add_msg_player_or_npc( m_bad, _( "A blade swings out and hacks your torso!" ),
                              _( "A blade swings out and hacks <npcname>s torso!" ) );
    c->add_memorial_log( pgettext( "memorial_male", "Triggered a blade trap." ),
                         pgettext( "memorial_female", "Triggered a blade trap." ) );
    damage_instance d;
    d.add_damage( DT_BASH, 12 );
    d.add_damage( DT_CUT, 30 );
    c->deal_damage( nullptr, bp_torso, d );

nameless_survivor:

For my proposal I was thinking it would be a furniture item or construction. 3x3 area.

This is pretty much what already exists, and its rather iffy. For one thing, does it really have 1.5m or so blades? Thats huge. Along with that is the problem that it’s a perpetual motion machine, it doesnt consume fuel to keep operating. One tile worth of solar panels is not going to be sufficient to keep something like that in motion.

Electrocution
You need to do some more research on electrocution, I’m absolutely certain you’re wrong about an electric fence consuming no power at rest, and I’m pretty sure that the plates or grids arrangement you’re describing would not be lethal with any feasible current level since it would at best be unlikely to send current through the heart, since it would instead bridge between the legs.

wire trap
I’m sceptical of this too, slicing through a body with ordinary wire is going to take a huge amount of force, and most likely it’ll just push the victim back instead of cutting them. Though that did make me think of an interesting application. It’s fairly well understood that crowds moving toward a target tend to develop extreme stresses that can injure and even kill members of the crowd. Most research is aimed at minimising this effect, but with research a survivor may be able to construct a large scale trap that maximizes these forces and/or places passive hazards (blades, piano wire, etc) at its focal points to maim and kill zombie hordes as they pass through.

nameless_survivor · 2019-01-02T19:01:31.850Z

kevin.granade:

Electrocution
I’m pretty sure that the plates or grids arrangement you’re describing would not be lethal with any feasible current level since it would at best be unlikely to send current through the heart, since it would instead bridge between the legs. They start getting shocked and get stuck on the plate until they fry.

So are we trying to stop a zombie’s heart? Do they even have working organs?

I was thinking they did not and you would just want to put enough current through them to boil the blob cells inside it and just outright roast them, like that electric chair scene from The Green Mile. Any ground based system is going to have to go through the legs and feet.

kevin.granade:

, it doesnt consume fuel to keep operating. One tile worth of solar panels is not going to be sufficient to keep something like that in motion.

Well, you could run it off of storage batteries, or gasoline. If/when power grids get implemented, hook it up to that.

As for the length issue, there have historically been greatswords/bastard swords 1.6-1.8 meters long, so I don’t see length being an issue as long as the blade is made a bit thicker for durability, and the two blades are relatively balanced in terms of mass.

The more balanced they are the better as the motor bearings will last significantly longer, but a small rotating imbalance wouldn’t necessarily cause it to fail immediately, or require constant repair. From my experience (mechanical engineer here), I’ve seen chemical plants run high RPM pumps with small amounts of imbalance with little issue. It doesn’t have to be PERFECT, close can be good enough.

Litppunk · 2019-01-02T19:10:08.681Z

Electrocution
Fences would not, but I think an unfinished circuit completed by flesh as the fuse/switch would use no more power than whatever it cost to keep the batteries/capacitors for the trap charged. My concern would be how the trap would turn off again once it has a corpse melted between the plates.

Since what he’s talking about is basically an intentional short circuit as a trap Would mean either killing the batteries or having a relay in the circuit (minimal amount maintenance power required) probably a timer relay (slightly more power probably but almost still negligible)

…Brain rebooting
OH wait… no thats not right at all, It would have to be a pressure-plate based circuit to have minimal power maintenance when not in use… but everything else should be… still in line with what I was saying…I think… What happened to my brain just then?

nameless_survivor · 2019-01-02T19:22:09.854Z

Litppunk:

Since what he’s talking about is basically an intentional short circuit as a trap

Yep. Big time. I might have to look into how to reliably (and relatively safely) generate an arc flash as way of weaponizing electricity as well. They can kill/maim you if you are not careful, so I see no reason why it wouldn’t work on a zombie.

kevin.granade:

You need to do some more research on electrocution, I’m absolutely certain you’re wrong about an electric fence consuming no power at rest

Thinking about power consumption a bit more (forgive me, I’m a mechanical engineer, not electrical, and it has been years since I took Circuits 101 and Power Systems 301 back in college.), the low end of the step up transformer from the mains power supply would constantly be consuming power. The lack of a completed circuit on the output coil would just not allow any induced current to flow on that end. So yeah, you would be using power constantly unless you had an enormous freaking capacitor bank, or a pressure plate to turn the power on to the trap when something walked on it.

How to turn it off once whatever triggered it is dead is a good question. In terms of game mechanics, I was thinking any corpses on the plate would get set on fire by the constant heating by the electrical current and burn up. No more corpse to conduct electricity and complete the circuit. I would consider the fact that you now have fire blocking that square a bonus as the zombies will try to walk through it, and get both burned AND electrocuted.

kevin.granade · 2019-01-03T01:19:35.243Z

nameless_survivor:

I was thinking they did not and you would just want to put enough current through them to boil the blob cells inside it and just outright roast them

That’s why I said, “with any feasible current”. Yes that kind of thing is possible, but the power source you have behind it would be ridiculous. If you want a reasonable power source to be lethal, you need to bridge the heart and/or brain, and that requires something a lot more sophisticated than a set of static electrodes.

nameless_survivor:

Well, you could run it off of storage batteries, or gasoline. If/when power grids get implemented, hook it up to that.

You can make it work, I’m just saying you’re oversimplifying it at the moment, it needs a trigger and a finite power source in addition to the blades and motor.

nameless_survivor:

As for the length issue, there have historically been greatswords/bastard swords 1.6-1.8 meters long

You can certainly make a blade that long, but how’s it going to handle being mounted laterally for months? I feel like that’s stretching things quite a bit, and it would be reasonable to just have it occupy one tile instead.

Back to electrocution…
With the addition of a seperate trigger I think you could cut the at-rest power consumption a great deal. If you’re contemplating vaporizing the victim, you really need to dig into how much power consumption that would require, my guess is it’s not a reasonable number. A much more reasonable option IMO is to have it just immobolize or knockdown the target (you don’t generally get immobilization unless someone grabs an electrode and it forces their hand closed (extension muscles are smaller than gripping muscles)), and stop supplying current after either some amount of flow or some amount of time. That would AFAIK limit resource usage to something resembling an electric fence.

Melen · 2019-01-03T02:11:42.921Z

I don’t know that I even agree with the whole electrocution trap, but if you’re looking for a bridge to the heart/brain, then perhaps a simpler idea would be this - the electrified plate with a trellis type structure overhead - metal of course. From the trellis would be cables or chains dangling to, say, waist level. Basically the trellis-chain combo would complete the circuit from the electrified plate beneath and could even act as a lightning rod of sorts, carrying the current back into a capacitor for reuse. It’d be like some beaded curtain turned sinister.

Poragon · 2019-01-03T05:09:39.331Z

'ey, a more trap mechanics thread!
A lot of the discussion seems to be centered here around lethal traps though, and that leaves out what I think may be an untapped well of potential, disabling traps. While murdering the zeds is all fine and dandy, disabling traps have some pretty great potential in static defense.

The bear trap is a great example of this that’s already in game. You put down a few in a hallway, and you now know that hallway is secure(ish). The beartrap may not be lethal, but by securing that hallway you have lowered the chance of one of the more terrifying scenarios in CDDA; being attacked from multiple sides. This is particularly important when for some reason you find yourself tied to a location and can’t just flee from the situation.

I don’t really know much about real world traps so I dunno what would be effective in this sorta role, but random possibilities that are low tech and come to mind are;
Nets to entagle zombies and slow them down/prevent attacking for X turns
Putting blob globs to good use with sticky puddles
Bright flashes from some electronic or chemical device to stun/disorient creatures that can see

GrandpuhTy · 2019-01-03T10:41:21.624Z

I’d agree we need some more disabling traps. The only other one that I know of, since I really haven’t used traps apart from bear traps, is the trip wire.

I’d love to be able to rip out the camera flash from an eyebot and use it as an underbarrel flashlight that can blind things, I’ve seen 'em blind brutes before. Perhaps a directional vehicle light that any creature in the lit squares of it are blinded until out of it.

nameless_survivor · 2019-01-03T14:08:12.266Z

kevin.granade:

If you’re contemplating vaporizing the victim, you really need to dig into how much power consumption that would require, my guess is it’s not a reasonable number.

No, you misunderstand. I’m not suggesting that it would vaporize them, that would take a ridiculous amount of energy. The human body is mostly water, which has a pretty damn high specific heat. 4.184 kJ/kg*C. Just eyeballing that at 70 kg total mass, 60% of which is water, would suggest a 175 kilojoules of energy or so just to raise all the water a single degree.

What I’m suggesting is that the current would heat any metal on/inside them, as well as potentially set clothing on fire and turn them into a walking pyre. Then after they die, current in game fire/burning mechanics would make their corpse burn up… unless you plan on altering that at some point to make corpses harder to burn, because honestly a set of clothing and a flip lighter or molotov should not be able to burn up a corpse entirely.

Melen:

but if you’re looking for a bridge to the heart/brain, then perhaps a simpler idea would be this - the electrified plate with a trellis type structure overhead - metal of course. From the trellis would be cables or chains dangling to, say, waist level. Basically the trellis-chain combo would complete the circuit from the electrified plate beneath and could even act as a lightning rod of sorts,…

This might be possible. You would likely need to electroplate the chains or whatever with copper, but that is definitely doable. Though intermittent electrical contact between the chains and whatever is triggering the trap (from the creature thrashing around) might reduce its effectiveness somewhat.

I don’t think the bit about capacitors would work though, because once the capacitors are charged up current will no longer flow through them. Though that might be a good way of limiting power consumption and turning off/cycling the trap.

kevin.granade:

You can certainly make a blade that long, but how’s it going to handle being mounted laterally for months?

I was actually thinking this kind of trap would need some maintenance anyway, and not even from wear & tear on the blades from chopping up zombies. Even a perfectly balanced rotating mass is going to to eventually wear out the bearings on the motor, though it would take a while under nominal conditions (ie, not chopping up zombies). Strain on the system from the blades hitting zombie bodies, unwanted vibration from imbalance due to damage to the blades, etc is going to wear out the motor, bearings, shaft, and the motor/shaft coupling. Based on what I’ve seen in the field (again, mechanical engineer here) and for the purposes of gameplay balance without becoming excessively tedious, I’d say a having a blade trap last 2-3 months continuous running or 50-100 zombies would be a decent way of simulating the maintenance requirements.

A superior way of setting up a blade trap to cover a large enough area to be useful, while still having small blades would be to have multiple smaller rotating blades all connected to a central motor via belts, gears, or chains. Kind of like the bottom of a large riding lawnmower.
Riding%20lawnmower%20bottom

Litppunk · 2019-01-03T17:21:58.267Z

nameless_survivor:

What I’m suggesting is that the current would heat any metal on/inside them

If your trying to set them on fire with electricity, then I think what your after isn’t amount of power anymore than is required to produce sufficient arc through unknown amounts of clothing. Then there would have to be a chance/complete failure of trap based on targets potential flammability including clothing (is there boots for it to ark through? Socks? Are they wearing only leather? Are the bits of flammable clothing in positions that won’t be arced through

I can’t see any way that process would be capable of being efficient enough to be usable unless they are pre-doused with flammable liquid that would light on arc

nameless_survivor:

trellis type structure overhead

XD thats a fun doorway /window trap. + efficiency if it is rigged to adjust height of the trellis for head height of targets, but can’t think of any way/ setup it would be practical enough to save the energy by bothering with.

nameless_survivor:

Even a perfectly balanced rotating mass is going to to eventually wear out the bearings on the motor

Hmm, if it is known that its going to have that kind of range, with the tips seeing all/most of the action, then supporting angles could be welded on with the bearings being lower, and/or the blades themselves can only be held aloft by centripetal force. The spin is only needed when there is a target that needs to be chopped, so maintenance needs could be dropped further by having it activated by pressure plates, trip wires etc. Although depending on what is used, deactivating (reseting) the trap would be a thing, although that could just be part of the cleanup process since SOMETHING would need to be done about the bodies piling up anyways. Switching it back into standby while throwing the bodies on a cart would hardly be a hassle.

Could go with wall/ceiling mounted variant for head/chest height, although probably easier to just build it taller, other than vulnerability to crawler/ short monsters. Leg height would make crawler > kill crawler anyways, though with more wear & tear if they fall full on the spinning blade, especially heavier brutes and such.

Centripetal force blades would help with this, but if at leg height when spinning would necessitate a pit around the blade trap, which would also help with corpse buildup.

Lot of possibilities. Especially when we start thinking about some of the advanced lab grade stuff survivors come across sometimes.
Laser trip wires, Piston shovers, Romba style - body/item dozers, Bladed death traps, turrets on wheels stabilized portal dozer etc.

Back to simpler stuff, don’t think we have any spring loaded traps yet do we? Trip wire released Blades and such. Sapling powered nooses

nameless_survivor · 2019-01-03T17:52:57.758Z

Litppunk:

Hmm, if it is known that its going to have that kind of range, with the tips seeing all/most of the action, then supporting angles could be welded on with the bearings being lower, and/or the blades themselves can only be held aloft by centripetal force.

So, like a centrifugal governor? I mean, that would reduce the strain on the bearings when they are slowing down or starting up. But when its running full speed it wouldn’t make any difference.

en.wikipedia.org

Centrifugal governor

A centrifugal governor is a specific type of governor with a feedback system that controls the speed of an engine by regulating the amount of fuel (or working fluid) admitted, so as to maintain a near-constant speed. It uses the principle of proportional control. Centrifugal governors were invented by Christiaan Huygens and used to regulate the distance and pressure between millstones in windmills in the 17th century. In 1788, James Watt adapted one to control his steam engine where it regulates...

Litppunk · 2019-01-03T17:58:26.045Z

hmm. Basically. I was just thinking hinges on the base of the blades or something so the rotation held them up, but if the motors speed is kept from going to fast for the blades, then sure.

How difficult would it be for our survivor to add one to the spinning blade death machines? Would it be an upgrade? Or basically need to be built-in? Seems like it would depend on the motor/gear ratios on if its necessary/ would help or not.

nameless_survivor · 2019-01-03T18:01:29.199Z

Something else that might be cool would be a flamethrower “sprinkler” system. You could set up a bunch of regular garden sprinklers around your base, that have been modified with a pilot light and each fed from a fuel tank/pump and the system rigged to a remote control. Zombies horde shows up, and you turn on your sprinkler system, setting the area around your base on fire.

Litppunk · 2019-01-03T18:26:14.530Z

Long as you have fire-proof walls… does the game support this? Thought all buildings were flammable.
Torch pits. Gas mister plus igniter for max efficiency of liquid, optional metal spikes on bottom for further slowing of burn victim to keep it from leaving pit, or from getting as far after its on fire.

Actually gas misters could just be their own thing to combo with the terrain around them. With alt triggers for flame, be it time/amount sprayed or manual trigger.

nameless_survivor · 2019-01-03T18:39:08.853Z

I don’t think concrete or metal walls are. Besides, you could just clear the ground around your walls and set the sprinkler system so that flames will not reach your base.

Litppunk · 2019-01-03T19:00:10.730Z

Once you have it built yeah. Some might prioritize burning dead over safety water

nameless_survivor · 2019-01-03T19:13:58.012Z

No, I mean have the flamethrower sprinklers far enough away from your walls that flames physically cannot reach them, and clear ground all around your walls.

Personally, I like living in bunkers and they are already fireproof.

Litppunk · 2019-01-03T19:15:52.545Z

walking zombies on fire can get far, depending on the their hp/speed.