Things that go Boom! Parts 5 and 6: Don't Step on Landmines

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JCab747
March 10, 2019 - 12:20am
Background: I've already submitted stories to Frontier Explorer magazine looking at grenades, which converts the Zebulon grenades into the Alpha Dawn system, plus gathering information about other grenades that were in Star Frontiersman, Frontier Explorer, and on this website.

Part 2 of the story looked at the Zebulon missiles, plus rockets -- both the Alpha Dawn rocket plus those from Tanks a lot! including the guided missile. 

This story is intended to build upon those earlier works. As yet, it is unfinished, but I would like any feedback or suggestions that anyone has.

Update: I am splitting the intended article into two pieces so it is more manageable. Part 2 should incorporate the information on more advanced detection methods, such as using ground penetrating radar, maybe even some sample minefields and minelaying/tending robots.
Joe Cabadas
Comments:

JCab747's picture
JCab747
June 6, 2019 - 1:34pm
I could change the name from charger to spider mine.

I also have an idea for "creeper mines," which move slower and have less of an explosive charge, but they are cheaper.

Then there are the "dishonor mines." These are a Yazarian development where clans would hang explosive bombs in trees to deny/discourage enemy warriors from rival clans from gaining a perch to launch an attack. They are dishonorable mines, because they are considered a sneaky tactic, but all of the clans adopted this technique. Modern-day Frontier "dishonor mines" might be called "Christmas tree" mines by humans or simply "dropper mines." They are set up in trees or high places and them bomb tresspassers below... or they can be a nasty surprise to a gliding Yazarian who lands on a tree branch. 
Joe Cabadas

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JCab747
June 6, 2019 - 1:38pm
Then, in keeping with a comment you made on another thread, there is the Sathar "fountain of death" mine that spits out a dozen sonic marble grenades or other explosives within a 3-5 meter radius. 

Another moving mine might be a burrower type, which stays underground, but changes position to get into the path of an oncoming person or vehicle. I guess we could call it the "mole mine." This could be another Sathar weapon.
Joe Cabadas

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JCab747
June 6, 2019 - 4:11pm

New Skill: Landmine Focused Skill

Thisis a specialized, Military PSA skill that permits a character without the demolition skill to set landmines and IEDs, provided the appropriate equipment, such as detonators, are available. This focused skill only costs 1 experience point for characters with the Military PSA – or 2 experience points for those who have a different PSA.

This is a one-level only military skill. It does not allow the character to disarm the mines or explosives. A character cannot buy more than one level, though the individual can use the experience points spent to learn this focused skill to earn demolitions.

The chance of success is one-half of either the character’s Logic or Intuition abilities plus 10 percent. If a demolition specialists tries to disarm a mine or IED set by someone with this skill, assume the setter’s skill level was zero (0).

Joe Cabadas

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JCab747
June 10, 2019 - 2:47pm
Costs of a simple anti-personnel minefield.

First some assumptions. 

Twilight 2000s rules call for 1d6 mines for every 1 meter x 5 meter area. So, in a Star Frontiers 5 meter square, that would be an average of 15 mines... But, we will say SF landmines are more advanced than TW2000's, so we could get away with 10 mines per 5 meter square.

A simple anti-personnel minefield would be 10 meters wide by 50 meters long. That is 500 square meters. If one is using the 5 meter per square common for the outdoor SF maps, a simple minefield is 2 squares wide by 10 squares long or a total of 20 squares.

there would be a total of 200 landmines in this field.

One would use the Zebs small mine kit: 20 Credits, 1 kg
Then 1 fragmentation grenade: 20 Credits and 0.5 kg (yes, I know grenades aren't supposed to have weight in SF, but that's ridiculous)
Then one pressure sensor (could also be a tripwire too): 35 Credits, 1 kg
Cost per mine: 75 Credits
Weight per mine: 2.5 kg

Total cost for a simple anti-personnel minefield: 2,400 Credits
Give a 20% cost reduction for buying in bulk. Revised cost: 1,920 Credits
Total weight: 500 kilograms.

Effectiveness: if using the TW2000 rules, which say a character has a 10% chance of setting off a mine per 5 meters traveled, then this minefield would only be 20% effective (it is only 2 squares wide).

So, maybe a revised figure would be a 20% chance of setting off a mine per 5 meters traveled?

Better sensors would improve the minefield's deadliness.

Also, someone purchasing all these mines might want more than one layer, and probably longer.


Joe Cabadas

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JCab747
June 22, 2019 - 3:55pm
I've been working on turning all this information into a story -- actually two stories -- for Frontier Explorer magazine. It was just getting too large to be published as one piece.


Joe Cabadas

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JCab747
June 23, 2019 - 10:44am
 The newest info follows:

Encountering Landmines

Many mines are buried, though it is possible that some might be laying openly on the ground. The rules below cover this prospect, but there are exceptions.

Detonation. A character walking through a minefield with tripwire or pressure plate sensors has a 10 percent cumulative chance of triggering a mine per 5 meters traveled through the minefield. For example, a character has walked 20 meters; he now has a 40 percent chance of triggering a mine.

In a party of several characters, unless they are following a marked trail and going single file, the referee should check for each one to see if they trigger a mine.

Ground vehicles have a 20 percent chance of triggering a pressure mine per 5 meter straveled. Note, hover vehicles will not set off pressure mines![1]

Mines with other types of sensors including proximity and motion detectors will havea higher chance of detecting a character or vehicle and detonate. For example, a vehicle traveling into a minefield that has magnetic sensors has a 50 percent cumulative chance of triggering a mine for every 5 meters traveled.

A character entering an area where a mine has a motion sensor has a 20 percent cumulative chance of setting it off for every 5 meters traveled; or a 50 percent chance if the mine is equipped with either a proximity or voice sensor.

Anti-Personnel or Anti-Vehicle Mines. Some mines are specifically designed for anti-vehicle use. They will not detonate when a character or size 0 vehicle is encountered. (See “Thingsthat go Boom! Part 3: Expanding the Demolition Skill” for more information about vehicle sizes).

Anti-vehicle mines will only detonate when a pressure of 160 kilograms or more is applied. [2] Characters can set an anti-vehicle mine for a specific size range. Hover vehicles will not set off pressure mines. For this reason, many anti-vehicle mines use magnetic or motion detectors.

Landmine Blast Areas. Unless otherwise stated, as per Zebulon’s Guide, landmines generally only have an immediate blast area. For example, if a character is using a mine kit to turn a Type II high explosive warhead into a landmine, it only has a blast radius of 14 meters. Ignore the secondary blast area that is supposed to extend out to 21 meters.

Landmine To-Hit Table

Sensor Level

IM

To-Hit

1

4

40%

2

5

50%

3

6

60%

4

7

70%

5

8

80%

Landmine To-Hit and Initiative Levels. When a landmine detonates, roll to-hit for all characters within the blast radius. The chance to hit is based upon the sophistication level ofthe weapon’s sensor cluster.

For example, most improvised explosive devices (IEDs) would be considered to be level 1 mines and would have a 40 percent chance to hit.

Most static mines do not need to roll for initiative; they just detonate. An exception would be if the character detects the mine during the same turn it would detonate. The character can then roll for initiative versus the mine to see if he can dive for cover, for example, before the weapon explodes.

Static mines are not affected by movement, size, or environmental conditions such as whether it is dusk or nighttime.

Moving mines such as the grasshopper, leapfrog, etc. have an initiative level based upon their sensor level. Always roll for initiative when it comes to these weapons. A moving mine is affected by the target’s movement modifiers, but it is not impacted by its own movement. The moving mine also ignores modifiers forthe target’s size and ignores environmental conditions such as for dusk or darkness.



[1] These rules are based on the ones found in Twilight 2000, a roleplaying game that was produced by Game Designers Workshop (GDW).

[2] Bonsor, Kevin. “How Landmines Work,” https://science.howstuffworks.com/landmine4.htm.


Joe Cabadas

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JCab747
June 23, 2019 - 10:54am

Landmine Sensors[1]

Landmine sensors act as the method to detect targets and detonate the grenade or warhead in the mine package. Thirteen types of mine sensor clusters are listed below.

Tripwire. The tripwire is a 3-meter-long, monofilament nylon cord or metal wire, which costs 1 Credit. Whenever a tug occurs on the cord, or the tension is released on the wire, it will trigger the landmine’s detonator. It is a level 1 sensor and is a fairly inexpensive.

Characters who are actively looking for such boobytrap wires receive a +10 percent bonus to their Intuition checks. A bright light or simple line laser – similar to a laser pointer but projects a visible laser beam – provides an additional +10 percent modifier to find tripwires. Line lasers cost 1 credit and are powered by a 1 SEU battery with 100 hours oflife.  

Pressure/Tripwire Sensor. This is a level 2 standard mine sensor. It is activated in one of two ways of triggering a mine – either by the pressure plate or if something activates a tripwire mechanism (tripwire sold separately).

The pressure/tripwire sensor is for landmines that are buried in the ground or under debris. If used as a tripwire, it has the same drawbacks as the basic tripwire sensor – characters receive a 10 percent bonus when actively searching for such devices and an additional 10 percent bonus if they supplement their search with a bright light or line laser.

When used with just the pressure plate, the sensor has a simple weight cell that relays analog weight levels back to the control unit, which could either have a computer chip or it could be mechanical. The control unit compares the detected weight against the sensitivity adjustment set during the setting of the charge.

It takes 5 turns to dig, bury, cover, perform a weight tare, calibrate the setting, and conceal a mine with this type of sensor. Any creature equaling or exceeding the weight setting will detonate the weapon. If desired, the mine’s detonation can be delayed 2 turns after the weight is released, in an attempt to attack a larger group being followed by a party’s scout who set it off.

Magnetic Sensor. Using magnets, this level 3 sensor triggers a mine when it detects large metal objects entering its immediate area.

Motion Sensor. Using multiple different technologies including detecting vibrations, sending out micro- and ultrasonic waves this sensor can measure reflections off of a moving object.

It can be calibrated to filter out repetitive motion (such as rotating satellite antennae) and can even have filters put in place to define minimum and maximum speeds and sizes of detected motion. When the propers ized object or creature moves at the proper speed, it will detonate the landmine.

It takes 2 turns to set and calibrate a filter array for a mine equipped with a motion sensor cluster.

Photon Sensor. This type of sensor is set to detect either light or lack thereof, depending on the presence or lack of light in the turn directly following the turn in which it is set.

For example, if it is dark when the mine is set, the sensor will detonate the explosive as soon as light becomes present. If it is light when the mine is set, it will detonate when darkness is detected.

This can be used as a booby trap: simply place in a dark room near the door, and when the door is opened and the light in the hallway pours in, the person opening the door will be surprised. It takes only one turn to set a mine equipped with a photon cluster.

Proximity Sensor. This level 4 sensor comes in one of two forms: electromagnetic proximity sensor or laser-eye sensor.

The electromagnetic sensor detects the presence of an electric field, either a bioelectric field generated by a living being or an activated defense screen – including a sonic screen that conceals the noises of an approaching intruder!

The laser-eye sensor has a beam projector and a receiver. The sensor wirelessly reports data safely back to the mine central processor through a simple radio frequency transmitter/receiver pair. The mine will detonate if it detects the light beam is broken or the signal is somehow interrupted. It takes 2 turns to properly set and calibrate a mine equipped with a proximity-sensor cluster.

Time Delay. Instead of a sensor, this cluster simply comes with a series of dials and buttons used to set a desired countdown. It can be set from 0 to 999 and can have hours, minutes, or seconds selected.

Once selected and the “Initiate” button is pressed, the countdown begins. When the time runs out, the mine detonates. It takes onlya single turn to set a mine equipped with a time delay delivery cluster.

Voice Recognition Cluster. One of the most advanced sensor clusters, it has a programmable logic controller that is set by simple voice commands. Although expensive, this cluster is destroyed by the mine’s detonation – as are all sensor clusters.

The character setting the mine simply speaks his command set to the mine. For example, a character can dictate: “Mine. Activate. Motion Sense. One meter movement size. Ten meter minimum movement rate. One hundred meter maximum movement rate. Initiate.”

The sensor cluster combines the operations of all other sensor types types. It is also possible to set up exclusion rules, such as identification of friend or foe (IFF transponders) to prevent allies from tripping the mine.

Voice recognition clusters are quite difficult to defuse because they require programming knowledge to identify how they’ve been set. It takes only a single turn to set a mine equipped with a voice recognition cluster.

Remote Control Unit. This is a simple plug-in addition to a normal mine sensor to permit a character to set off a mine byremote control. Each mine still requires a sensor cluster of some type, because that also has the detonator. The most basic type of remote controlled detonator is connected by a wire to a triggering device.

Several mines could be strung together to one central triggering device, which in turn could be connected to a landline or a radio receiver. That way, a character many kilometers away from the site can detonate the mine. The wire is sold in spools of 10, 50, or 100 meters, costing 1 Credit per meter in length. A spool of wire weighs 1 kilogram for each 10 meters of wire.

Ittakes two additional turns to set a mine that can be remote detonated.

Radio Beam Unit (Basic). Instead of using a wired remote control unit, a radio beam unit can receive a radio beam from a signaling device. This is aplug-in unit that must be used with another sensor cluster to work. The receiver has a 100 meter range.

RadioBeam Unit (Mid-Range). Similar to the basic model, the mid-range radio beam unit is sensitive enough to detect the detonation signal from up to 5 kilometers away.

Radio Beam Unit (Advanced). The advanced model can a ccept a signal from a radiophone, 500 kilometers away. Or, in space, it can receive a signal from a spaceship communication system from 100,000 kilometers away.

Radio Beam Signaling Devices. The basic signaling device for a radio beam unit only has a 100-meter range. Another option is a chronocom-based signaling device has a 5 kilometer range. The advanced signaling device has a 500k ilometer range.

Note, radio beams can be jammed, preventing the proper signal from going to the sensor.



[1] Moore, Larry. “Mine Kits,” Star Frontiersman, No. 5.

Joe Cabadas

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JCab747
June 23, 2019 - 5:27pm

Moving Mines

These are mines the move toward their targets to inflict damage. This category includes Bounding Mines (also known as the “Bouncing Betty”), plus the Grasshopper and Leapfrog mines from Zebulon’s Guide.

Some of these mines use a propelling charge – which is a small amount of explosive placed at the bottom of the weapon – so it can spring toward targets before the warhead detonates. 

 

Initiative. Because they move, roll for initiative when a moving mine attacks a character. The mine’s initiative level is based on its sensor level (please see the Landmine To-Hit Table). A character can attempt to dive for cover. It would be very difficult for a character to shoot a mine with a ranged weapon before the warhead explodes. 

If a referee permits this option, the character must win the initiative roll and then will only be able to get off one shot before the warhead explodes. The target would be considered moving Very Fast (-30 percent to-hit), The target is Small (-5 percent). And all other combat modifiers would apply including whether or not the character was surprised by the attack (-20 percent). The character would have to do 15 points of damage to disable a mine.


S-Mine. This is an obsolete, anti-infantry mine that was created by the Germans before World War II.  Nicknamed the “Bouncing Betty” by the Allies, it uses a mechanical pressure/tripwire sensor. When triggered, it will spring 1 meter into the air before detonating. It causes 6d10 points of fragmentation damage.

Grasshopper Mines. These weapons will fling themselves up to three meters straight up in the air before detonating, which can help them attack low flying or hovering targets. If it hits an obstacle on its way up, it will be deflected two meters in a random direction before detonating. Use the Area Effect Weapon Miss Diagram to determine a random direction.

The grasshoppers in Zebulon’s Guide only accept grenades as warheads, though a referee could design larger, anti-vehicle mines. Such a landmine would have a secondary blast area.

Leapfrog Mines. This landmine is made to jump up to 5 meters toward its target. If it misses, use the Grenade Bounce Chart to determine where it lands. The trigger system is usually a magnetic, motion, proximity or voice sensor cluster, as it must know which direction to leap toward the target.

Thel eapfrogs shown in Zebulon’s Guide only accept grenades as warheads. A referee could design larger, anti-vehicle mines. Such a landmine would have a secondary blast area.

Joe Cabadas

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JCab747
June 23, 2019 - 12:51pm

Damage to Characters and Vehicles

Buried fragmentation and similar mines will generally cause injuries to a character’s feet and legs, a robot’s lower half or the underside of a vehicle.

The type of damage that a landmine causes depends upon the type of warhead it has been equipped with. While most 20th and 21st century mines are the explosive/fragmentation type, Star Frontiers offers a variety of different munitions including stun, sonic, electrical discharge, incendiary, tangler, and other warheads that can cause either nonlethal or other types of injuries.

For fragmentation landmines, the explosion has similar effects of other blasts –such as causing knockdowns, fragmentation damage, and maybe even stunning. Much of this damage will normally hit one of the character’s legs (determine the leg randomly).

Moving mines – such as the grasshopper, which jumps up in the air, or the leapfrog, which leaps towards a target – will cause general damage to a character, robot or vehicle.

Consider any damage from a buried mine that is equal to one-fourth (25 percent) or more of the character’s Stamina points will hobble the individual, similar to impairment (see the Alpha Dawn combat rules for wounds). The character is reduced to one-half movement. Additionally, all of the character's attacks have a -10 percent penalty and the wounded person can fire only one shot per turn.

If the character’s STA score falls below half due to the landmine’s detonation, assume that the individual’s lower body has been badly injured. The person is gravely injured.

The character will only be able to crawl (one-fourth walking speed) if they make a current Strength check each turn. But, all of the gravely wounded person’s attacks, skill and ability checks (such as STR) are cut in half. Again, the character can only fire one shot per turn.

Defenses. As with any other type of damage, the type of armor the characters are wearing may help avoid or reduce damage from a landmine. For example, if a character is wearing a skeinsuit, it will absorb one-half of the damage from a fragmentation landmine, but not from a sonic or incendiary device. A sonic screen will shield a character from the effects of a sonic mine, but not from a foam weapon, etc.

If a character is wearing powered armor, mine damage will impact the suit’s legs.

Medical Treatment. Anesthetic drugs, which reduce pain, will cancel out the modifiers for impairment. For the gravely injured character, two doses of anesthetics are required. This will trim the penalty for skill and ability checks to a -10 percent penalty.

A dose of anesthetic lasts five hours.

When a gravely wounded character’s Stamina is restored above one-fourth, he will be considered impaired. Once an impaired character’s Stamina is restored to a 90 percent level, hewill no longer suffer impairment penalties.

For Dralasites. Just like how a Dralasite can absorb a “broken limb” and grow a new one, the character can absorb a mangled limb(s) and replace it/them. This will cut the movement penalties, but the Dralasite would still be impacted by the damage, such as loss of Stamina and penalties due to pain unless itreceives medical treatment.

Damage to Vehicles and Robots. Contact damage to a vehicles – from a static explosive landmine – roll on the vehicle damage table and ignore the “No Effect” result unless you are using the rules for structure points for vehicles. In that case, the explosion damages the structure.

Robots will receive damage to their legs or lower half. If the damage is equal to 25 percent of the robot’s stamina points, its movement will be reduced by half. If the damage is equal to 50 percent or more of its STA, the robot will be reduced to one-fourth speed. Repairs will negate these effects.

Damage to Characters Riding in Vehicles. Assume that a portion of the damage caused by an anti-vehicle mine will pass through to injure characters riding inside. To determine this damage, roll a 1d10 – separately for each character inside the vehicle. 

A result of 1-4 means the character takes no damage, a 5-6 means that the character will take 10 percent damage, a roll of 7-9 means the character takes 25 percent damage, while a roll of 10 means the character takes 50 percent damage.

Mine-Resistant Vehicles and Robots. Some armored vehicles and warbots may be specifically designed with a V-shaped body and armor to reduce the damaged caused by landmines exploding beneath them. This protection adds 50 percent of the cost of a robot body style or a base vehicle (without other modifications). Such protection will reduce damage to vehicles and robots by 75 percent while negating any pass-through damage to characters riding inside avehicle, or atop a warbot.

Electromagnetic Pulse Shielding. Electromagnetic Discharge (ED) warheads or other electromagnetic pulse (EMP) weapons can cause short-circuits that will shutdown robots, vehicles, computers and other electronics that have not been properly shielded. This shielding is not a power screen, but rather an extensive hardening of circuitry that is much more comprehensive than installing an electric shock implant.

If EMP shielding is included as part of a vehicle’s or robot’s initial construction, the cost is only an additional 50 percent of its base cost (or the body style in the case of robots with a 10 percent boost in weight). If this shielding is installed later, the modification is an added 90 percent of the vehicle’s base cost or 90 percent of a robot body style’s cost while increasing the body weight by 20 percent.

Effects: an anti-shock implant is only 10 percent effective against an ED or EMP weapon. A gauss screen is only 20 percent effective. EMP shielding is about 70 percent effective. It can be combined with an anti-shock implant and/or gauss screen to theoretically provide 100 percent shielding (an automatic hit by an EMP weapon will overcome any protection).

While most unshielded vehicles and robots will need extensive repairs if they suffer an EMP attack, those that have EMP shielding have a cumulative 5 percent chance per turn of “rebooting” and being able to resume operations. 

Joe Cabadas

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JCab747
June 23, 2019 - 5:33pm

Detecting Mines[1]

When entering an area with mines, characters without mine detection equipment shouldmake an Intuition check to notice the device(s). Characters with a demolitions skill and technical skills, such as detecting alarms and defenses, should make a skill check.

Since mines are normally concealed, those relying strictly on an Intuition check might receive penalties of -5 to -10 percent to notice and avoid a mine. Conditions that reduce visibility – such as smoke, fog, dusk, nighttime, rain, etc. – wil lalso impact a character’s efforts to discover mines, providing penalties ranging from -5 to -20 percent.

Characters can use tools – such as a knife or stick – to probe for mines, providing a 10 percent bonus, though it does risk triggering weapons that use motion and proximity detectors.

The other way characters detect a mine is when a hapless individual encounters one that explodes. Once the characters know they are in a minefield, they receive a +10 percent bonus for checking around.

Advanced detection equipment, such as the Demolitions-Computer Access Scanner (Demolitions-CAS), will help in detecting mines before they explode.

Demolitions-CAS. A Demolitions-Computer Access Scanner can check for explosives, bombs, or mines within a 10 meters radius and up to two meters deep.[2]Its detection equipment can look through all materials except federanium. It can indicate what type of explosive it is, what detonation devices areattached, and give suggestions on how to defuse it.

The Demolition-CAS provides a +20 percent bonus to characters with a Demolitions skill when they are trying to defuse an explosive.[3]



[1] These rules are based on Twilight 2000.

[2] This range has been increased from what was presented in Zebulon’s Guide, which only gave it a 2 meter detection radius.

[3] Adapted from Zebulon’s Guide.

Joe Cabadas

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JCab747
June 23, 2019 - 6:08pm

Marking and Removal[1] 

Once a minefield is discovered (either by detection as described above or by someone setting off a mine) characters who have successfully detected a mine can mark its location for removal. Only a demolition specialist – or a specialized robot– stands any chance of successfully deactivating a mine.

The ease of disarming a mine depends on its sensor type. A demolition specialist receives a +15 percent bonus for disabling a tripwire sensor or a +5 percent bonus for disarming mines with a time delay sensor. The character receives a normal skill check for deactivating mines with pressure, magnetic, and photonsensors.

The character has a -10 percent penalty when trying to disarm a mine with a proximity sensorand a -15 percent penalty for one with a voice sensor cluster. When the demolition specialist disables the primary sensor cluster, it will also incapacitates any remote controlled detonation devices.

Failure of the skill indicates that a mine has been accidentally detonated.

In a typical anti-personnel minefield, each 5-by-5 meter square will have an average of 10 mines. If supplemented by anti-vehicle mines, there will be an average of 2 anti-vehicle mines per square (these are in addition to the 10 anti-personnel mines).

Marking mines allows characters to crawl or walk through the minefield without hazard. Trotting through a marked minefield will require a Dexterity check. A character will receive a -10 percent penalty if they try to run through a marked minefield.

Marking a minefield does not reduce its hazard to vehicles.

Removing mines allows vehicles and personnel to move through the minefield without hazard. Paths marked or removed must be 1 meter wide for walking characters or 5 meters wide for vehicles.



[1] These rules are based on Twilight 2000.

Joe Cabadas

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JCab747
June 24, 2019 - 5:03pm
jedion357 wrote:
Also the name charger mine just doesn't have the cache of spider mine.

would sympathetic explosion of fellow spider mines be a possibility? if they are cluster taking out one means taking out others at the same time?

Perhaps a rule of if the damage that takes out the mine is an odd number then the mine explodes but even it just dies.

Starcraft had spider mines deployed by the Vulture cycles. that did something similar.
 

Ah, I got to thinking about this. The Sathar already have their spider robots. 

So, maybe I could call them "wolf mines"? Scorpion mines? A black widow mine?
Joe Cabadas

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jedion357
June 27, 2019 - 4:01am
JCab747 wrote:

Ground vehicles have a 20 percent chance of triggering a pressure mine per 5 meter straveled. Note, hover vehicles will not set off pressure mines![1]

Mines with other types of sensors including proximity and motion detectors will havea higher chance of detecting a character or vehicle and detonate. For example, a vehicle traveling into a minefield that has magnetic sensors has a 50 percent cumulative chance of triggering a mine for every 5 meters traveled.

A character entering an area where a mine has a motion sensor has a 20 percent cumulative chance of setting it off for every 5 meters traveled; or a 50 percent chance if the mine is equipped with either a proximity or voice sensor.

Anti-Personnel or Anti-Vehicle Mines. Some mines are specifically designed for anti-vehicle use. They will not detonate when a character or size 0 vehicle is encountered. (See “Thingsthat go Boom! Part 3: Expanding the Demolition Skill” for more information about vehicle sizes).

Anti-vehicle mines will only detonate when a pressure of 160 kilograms or more is applied. [2] Characters can set an anti-vehicle mine for a specific size range. Hover vehicles will not set off pressure mines. For this reason, many anti-vehicle mines use magnetic or motion detectors.




Hover vehicles do not dentonate mines? how much air pressure does it take to lift a hover vehicle? Is this enough to trigger a sensor or land mine? If so then the foot print of a hover vehicle- car and truck is bigger than the wheels of the ground vehicle and could be more likely to trigger mines.

The real question is, "is the air pressure of the hover vehicle, which must be substanstial for cars and trucks, enough to trigger sensor or jostle tripwires?"
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

JCab747's picture
JCab747
June 27, 2019 - 4:12am
jedion357 wrote:
JCab747 wrote:

Ground vehicles have a 20 percent chance of triggering a pressure mine per 5 meter straveled. Note, hover vehicles will not set off pressure mines![1]

Mines with other types of sensors including proximity and motion detectors will havea higher chance of detecting a character or vehicle and detonate. For example, a vehicle traveling into a minefield that has magnetic sensors has a 50 percent cumulative chance of triggering a mine for every 5 meters traveled.

A character entering an area where a mine has a motion sensor has a 20 percent cumulative chance of setting it off for every 5 meters traveled; or a 50 percent chance if the mine is equipped with either a proximity or voice sensor.

Anti-Personnel or Anti-Vehicle Mines. Some mines are specifically designed for anti-vehicle use. They will not detonate when a character or size 0 vehicle is encountered. (See “Thingsthat go Boom! Part 3: Expanding the Demolition Skill” for more information about vehicle sizes).

Anti-vehicle mines will only detonate when a pressure of 160 kilograms or more is applied. [2] Characters can set an anti-vehicle mine for a specific size range. Hover vehicles will not set off pressure mines. For this reason, many anti-vehicle mines use magnetic or motion detectors.




Hover vehicles do not dentonate mines? how much air pressure does it take to lift a hover vehicle? Is this enough to trigger a sensor or land mine? If so then the foot print of a hover vehicle- car and truck is bigger than the wheels of the ground vehicle and could be more likely to trigger mines.

The real question is, "is the air pressure of the hover vehicle, which must be substanstial for cars and trucks, enough to trigger sensor or jostle tripwires?"
 

There was an episode on Myth Busters where they showed that a hovercraft will not set off a traditional mine.

In fact, I have read stories about how the military has been worried that in the event of war with North Korea, that the NK army could use hover vehicles to cross the minefields to invade South Korea.

I'll see if I can find a story on that for you.
Joe Cabadas

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JCab747
June 27, 2019 - 4:19am
OK.

Things are a bit here and there on the subject.

One story: https://skeptics.stackexchange.com/questions/13785/do-hovercraft-trigger-minefields

Myth Busters video: https://www.youtube.com/watch?v=Q0UVNt3iNv8

From reddit: https://www.reddit.com/r/askscience/comments/ol09a/would_the_downward_pressure_of_a_military/

examples: 

Cutter John posted this, but I think it deserves to be the top level post:

It produces 350lb of lift force, but over a very wide area. It only applies 7 lb per square foot, or 0.05 psi. The human foot applies ~8psi, and tank ~15, and a truck ~25.It would be highly unlikely a mine would be set to be that sensitive. Just setting it would be highly dangerous, and virtually anything could set it off.

7 psi is half an atmosphere; not very much. Also, you should differentiate between antipersonnel and anti-tank mines. The former might not be well designed to damage a hovercraft (e.g. Google Bouncing Betty). The latter is probably designed to require a tank tread (or lots of metal close by) to set it off.

EDIT: For emphasis, assumed buried land mines are set off by pressure (P) over a certain threshold. A hovercraft requires a force (F) to keep it hovering, but spreads it over a large area (A). P=F/A, A is big and so P for a hovercraft is probably among some of the smallest pressures applied by almost any terrestrial vehicle.

 

 

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[–]FresnoRog 13 points 7 years ago 

Using the M14 landmine as an example of an anti-personnel pressure activated land mine, you can calculate the amount of pressure needed to detonate.

The pressure plate has a diameter of ~2 inches and requires a force of ~20 lbs to detonate. This translates to ~6 psi for the mine to detonate. Not the best source but all others agreed with the information and this made it the clearest visually.

The hovercraft model used in the film was an Osprey 5 which has an area of ~11 m2 and an operating weight of ~700kg. This translates to ~1400 lbs over 17,000 in2 which is ~0.08 psi.

The downward pressure required to lift the hovercraft is nearly two orders of magnitude less than is required to detonate a typical pressure activated anti-personnel mine.

The hovercraft wouldn't detonate the land mine.

 

Joe Cabadas

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JCab747
June 29, 2019 - 6:22pm
jedion357 wrote:
JCab747 wrote:

Ground vehicles have a 20 percent chance of triggering a pressure mine per 5 meter straveled. Note, hover vehicles will not set off pressure mines![1]

Mines with other types of sensors including proximity and motion detectors will havea higher chance of detecting a character or vehicle and detonate. For example, a vehicle traveling into a minefield that has magnetic sensors has a 50 percent cumulative chance of triggering a mine for every 5 meters traveled.

A character entering an area where a mine has a motion sensor has a 20 percent cumulative chance of setting it off for every 5 meters traveled; or a 50 percent chance if the mine is equipped with either a proximity or voice sensor.

Anti-Personnel or Anti-Vehicle Mines. Some mines are specifically designed for anti-vehicle use. They will not detonate when a character or size 0 vehicle is encountered. (See “Thingsthat go Boom! Part 3: Expanding the Demolition Skill” for more information about vehicle sizes).

Anti-vehicle mines will only detonate when a pressure of 160 kilograms or more is applied. [2] Characters can set an anti-vehicle mine for a specific size range. Hover vehicles will not set off pressure mines. For this reason, many anti-vehicle mines use magnetic or motion detectors.




Hover vehicles do not dentonate mines? how much air pressure does it take to lift a hover vehicle? Is this enough to trigger a sensor or land mine? If so then the foot print of a hover vehicle- car and truck is bigger than the wheels of the ground vehicle and could be more likely to trigger mines.

The real question is, "is the air pressure of the hover vehicle, which must be substanstial for cars and trucks, enough to trigger sensor or jostle tripwires?"
 

I addeed a better explanation to the story as to why I don't think hover vehicles would trigger a pressure landmine.

That being said, I am open to changing my mind. ... Hmm, a mind minefield... naw...

This could certainly be something for a later story.
Joe Cabadas

JCab747's picture
JCab747
June 30, 2019 - 4:00pm
These units are based on real life explosive containment vessels, so I know what the dimensions and weights should be.

Bomb Disposal Equipment

Over the years, the Core Four races developed a variety of equipment to carry and dispose of explosives. Some of this includes Explosion Containment Units (ECUs) that can be used to transport munitions or store suspicious objects.

Note, refer back to “Things that go Boom! Part 3:Expanding the Demolition Skill” for more information about TNT equivalent explosives. For example, Tornadium D-19 is four times as powerful as TNT, so a 250 gram charge is the equivalent of 1 kilogram of TNT.

Bomb Basket. The bomb basket is made up of non-fragmentation ballistic composite materials. Itc an be used as a safety ring, to minimize the impact of the fragmentation and sonic blasts. Each basket is mostly spherical shaped with a 1 meter diameter and has a fire-resistant, non-metallic holding net suspended inside. It is rated to it can deal with explosions resulting from 200 grams to 1.2 kilograms of TNT.[1]

This type of ECU is typically rendered useless if the explosion exceeds its maximum containment level

Bomb Basket Accessories. Bomb baskets can be outfitted with specialized energy screens – such as inertia or sonic projectors – that are designed to absorb damage coming from inside the field rather than from outside. The field generators cost the same as a normal defense screen and are typically powered by a 50 SEU beltpack or a 100 SEU backpack.

The Vidar Series. The Vidar and Ladon lines are made by Eversafe Enterprises; they represent of the ECUs available in the Frontier. Vidar ECUs have tiny vents to allow pressure to escape in the event of an explosion, so they will not contain a gas or foam warhead explosion.

Named after the Norse god of mythology that survived the apocalyptic Ragnarök, the Vidar Series of ECUs is rated to contain a blast up to a certain TNT equivalent weight. For example, the Vidar 3 is rated to handle an explosion up to 3 kilograms of TNT.

Explosions that exceed the container’s rating risk shattering it, allowing blast damage to leak out. The Vidar may be able to withstand explosions up to double their rating, but they are not guaranteed to do so.  Most Eversafe units can withstand multiple explosions and still be usable.

Vidar 0.03. This square-shaped unit is for transporting small, suspect electronics. It also provides a Demolition specialist a safe way to store and transport explosives and detonators/blasting caps. The container is 400 centimeters (cm) long and wide plus 115 cm deep. It weighs 12 kilograms.

Vidar 0.5. This ECU is often used by laboratories for transporting pyrotechnic chemicals or by police officers for storing small suspicious objects. It is 71 cm long, 81 cm wide and 61 cm deep with a 24-by-17 cm rectangular opening. It weighs 300 kilograms and is often set in place, set on heavy-duty casters, or mounted on a vehicle or robot.

Vidar 1. This style is often used at airports, spaceports or other major transportation terminals for security officers to store suspicious objects. It is 93 cm long, 57 cm high, and 53 cm wide while weighing 500 kilograms. It’s opening hatch is 50-by-20 cm.

Vidar 3. This containment vessel is designed to safely remove or store large suspect pieces of luggage. The Vidar 3 is ideal for spaceport and public safety applications. It is 177 cm long, 150 cm wide, 172 cm tall, and weighs 3,200 kilograms. Its hatch is 76-by-55 cm.

Vidar 10. This vessel often is used as an in-house storage locker for explosives and small caliber ammunition. The Vidar 10 also serves as a way to store large suspicious objects. It is 223 cm long, 216 cm wide, and 200 cm tall and weighs 5,000 kg. Its hatch is 95-by-50 cm.

Vidar 15. The Vidar 15 explosive containment vessel offers a convenient and cost-effective solution for an in-house storage location of explosives and small caliber ammunition. It can also be used to store large suspicious objects. It is 270 cm long, 315 cm tall, and 230 cm wide. It weighs 8,500 kg and has a hatch that is 95-by-50 cm.

Vidar 50. The Vidar 50 vessel offers a convenient and cost-effective solution for an in-house storage location of explosives and small caliber ammunition. Or it can store large suspicious objects. Its dimensions are 284 cm long, 386 cm tall, and 250 cm wide. The unit weighs 17,000 kg and its hatch is 110-by-60 cm.



[1] “With seven ‘baskets’, Bangalore police can now explode bombs safely,” DNA, https://www.dnaindia.com/bangalore/report-with-seven-baskets-bangalore-police-can-now-explode-bombs-safely-1428400


Joe Cabadas

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JCab747
July 15, 2019 - 7:18am

Army researchers building ‘smart’ landmines for future combat


Joe Cabadas