Tuesday, May 19, 2020

Ultra-Tech Ultra Quickie: Frag Out!

Quick update to get my creative ball rolling again.

In GURPS 4th edition an explosives fragmentation damage has been tied to the diameter of the warhead that carries it, that is the warheads diameter (in millimeters)/20. Now this works good enough in most cases but some warheads are designed to create an enhanced or heavier fragmentation effect. Below I cover two warhead options to get more fragmentation bang for your buck. See this post for even more Ultra-Tech warhead options.

High Explosive Enhanced Fragmentation Warhead (HEEF) (TL 9) 
This warhead uses either a thicker or denser case to create an enhanced fragmentation effect with greater penetration and wounding potential. Due to the stronger case, the warheads blast effect is reduced.

 Blast effect damage is figured as the square root (warhead weight)×19.8. Divide the product by 3.5 to get dice of damage. Damage is crushing explosive.

 Fragmentation damage is figured  as Warhead Diameter (in millimeters)/12 in dice of damage. Damage is cutting fragmentation damage.

Add +1 per die to the crushing explosive damage at TL10-12. This warhead is only available for 15mm or larger. Double normal cost.

HEEF projectiles, with the exception of hand grenades, that are built at TL 9 or higher can incorporate a programmable fuse that can be set for either impact or, if the target is at least 40 yards away or farther, for proximity detonation  see Ultra-Tech pg. 154. Grenades and satchel charges with HEEF warheads inflict the damage shown below. When set for impact detonation,guns and launchers with HEEF warheads inflict their normal piercing damage with a (0.5) armor divisor, plus a follow-up attack causing the damage shown below.

HEEF Table
Warhead           Damage
15mm              1d-2 cr ex [1d+1]
18.5mm           1d-1 cr ex [1d+2]
25mm              1d cr ex    [2d]
30mm              1d+1 cr ex [2d+2]
40mm              2d cr ex     [3d+1]
64mm              4d cr ex     [5d+1]
100mm            8d cr ex     [8d+1]      
130mm            12d cr ex  [11d-1]
160mm            8d×2 cr ex [6d×2]
400mm            4d×16 cr ex [5d×7]



Continuous Rod Warhead (TL 9) 
This is a special type of High Explosive Enhanced Fragmentation Warhead. A Continuous Rod Warhead surrounds the explosives with a bundle of metal rectangular  rods welded to one another at the top and bottom in an alternating pattern.

When the warhead goes off, the bundle of rods are propelled outward in an expanding ring, unfolding like a circular accordion gate.This effect not only greatly increases the warheads lethality against thin skinned targets, though it is less effective against thicker skinned or armored targets. Up until the ring finally breaks apart it is far more likely to hit targets within its effective range  then standard fragments (with hit probability dropping at a rate of 1/R rather than 1/R2 as for conventional fragments).

Even after the ring breaks the rods are still dangerous and have the hit probability of a normal fragmentation warhead.

While effective, Continuous Rod Warheads are more complicated and expensive to build then normal fragmentation warheads. They are also more effective with larger warheads (the first production warhead was the early TL 7 710mm RIM-8 Talos with a 30 yard effective range!).

A Continuous Rod Warhead has similar effects to a High Explosive Enhanced Fragmentation Warhead only the fragments have an armor divisor of (0.5) and fragmentation has both  a primary and a secondary threat range. In the primary threat range the chance of scoring a hit is increased.

The fragments still hit with a skill of 15 but penalties do to range to the target are ignored. Primary threat range is fragment dice of damage × 0.5 yards.

 In the secondary threat range use the normal fragmentation rules with the exception that you trace the range from the end of the primary threat range when figuring range penalties- not the center of the blast.

Blast effect damage is figured as the square root (warhead weight)×19.8. Divide the product by 3.5 to get dice of damage. Damage is crushing explosive.

Fragmentation damage is figured  as Warhead Diameter (in millimeters)/12 in dice of damage. Damage is cutting fragmentation damage with a (0.5) armor divisor.

Add +1 per die to the crushing explosive damage at TL10-12. This warhead is only available for mm 64mm or larger. Five times normal cost.


Continuous Rod projectiles are always set for proximity detonation- see Ultra-Tech pg. 154.


Continuous Rod Warhead Table
Warhead         Damage                      Effective/Secondary
64mm              4d cr ex     [5d+1]        3 yrd./26 yrd.
100mm            8d cr ex     [8d+1]        4 yrd./41 yrd.            
130mm            12d cr ex  [11d-1]        5 yrd./54 yrd.
160mm            8d×2 cr ex [6d×2]        6 yrd./60 yrd.
400mm            4d×16 cr ex [5d×7]      18 yrd./175 yrd.
        

10 comments:

  1. This may be a syncronicity, because recently I was complaining about damage calculated solely from diameter... again)
    Also worth to note that according to requirements XM1166 40mm grenade needs to defeat Level III armor with its fragmentation. Which would be about 24-25 DR.

    Actually I got slightly better grasp on bleeding-edge armor/arms developments in last months. Speaking of armor, I even bring someting on the forum.
    http://forums.sjgames.com/showthread.php?t=167894
    And this is without touching things like M5 fiber...

    Speaking of arms... well, turns out that UltraTech APEP must be made of so-called "liquid tungsten", that have uranium-like "sharpening" deformation when penetrating. But here is also Stakalloy, improved DU. https://patents.google.com/patent/US6726876B1/en
    I could see a polycrystalline diamond-tipped or Nitinol-tipped liquid metal penetrator
    having considerable merit.
    A combination of initial penetrator hardness and sectional density.
    But wait... according to various patents, it is possible to increase muzzle velocity by improving bullet aerodynamics and different method of holding projectile.
    https://patents.google.com/patent/EP3569972A1/en
    So, without taking things to extreme, it would be safe to assume that TL9 version of.308 rifle would got .300 WinMag ballistics too. For example.

    And then there is metastable kind or reactive materials, to make things sparkier.
    https://patents.google.com/patent/US8230789B1/en
    > ```Some MIC composites have demonstrated energy values up to 10 kcal per gram, a level exceeding that of Tri-Nitro Toluene (TNT) by more than a factor of 10. ```
    Just imagine all aforementioned in one package...

    And then there is thing like this.
    https://patents.google.com/patent/US6393991B1

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    Replies
    1. Yeah, the diameter/20 does works good for light fragments but not all warheads and bombs.

      What I did was pretty much take the cr ex damage an HE warhead of a given caliber as a base then take the cr ex damage of an APEX warhead, take the difference in damage between them, find the cube root of that and multiple the fragmentation damage it. This worked out to roughly the same as warhead diameter/12. Based on this you can trade blast effect for even greater fragmentation damage but increasing fragmentation damage by the cube root of how much your reduced blast damage. Of course sooner or later you are going to have to increase the overall weight of the warhead to account for the thicker liner.

      Of course this is still a simplification. Fragmentation damage should also scale with TL as more powerful explosives will produce higher velocity fragments to a point (the blast velocity of an explosive does have an upper limit. However it is 100% understandably why this left out of RAW. You would have to look up not only the type of explosives that are used in a weapon that you are stating up but also find what it's blast velocity was! And these are not always easy to find.

      Yep, APEP is liquid tungsten. Bulk amorphous tungsten falls under that category. Though I still feels that the early installment weirdness of the (3) armor divisor should be replaced with a damage modifier of 1.7 and a(2) armor divisor.

      Bullets with better ballistic coefficients are defiantly possible at TL9 (in a way that would not impact price that is) though I'm skeptical that it would increase velocity enough warrant a full point of damage increase except for some edge cases. At lest for your average bullet. More expensive super low drag bullets might be able to justify a point or so increase in damage.

      MIC concept reminds me of this http://forums.sjgames.com/showpost.php?p=1511845&postcount=2 Also while I have no doubt that an REF of 10 is possible... once stabilizer agents are added that number will probably be brought down a bit. TL 9 explosives assume warhead filler that's as stable or more stable then C4 with a REF of 4 so that sounds about right though if you want to use the assumed REF of 10, the plasma warheads on page 158 of Ultra-Tech have an REF of 10. Otherwise multiply TL9 warhead explosive damage by 1.58.

      The K-Charge is something I haven't come across before so I need to look into it though from what I gleamed going over patent is that it's a HEAT round that trades some if it's armor penetration for better after armor effect. I'll also have to think about how to handle that in GURPS.

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    2. Personally I think that (3) divisor was better because it's represent actual better penetraion without increasing overall basic damage.

      As for extreme end, somebody suggested to “tracking” the projectile with constantly high pressure of the powder gases in the bore" which reminds me of a certain Gerald Bull project... and basically giving you ETC gunts without ETC.
      https://patents.google.com/patent/RU191143U1/en

      Solid explosive also reminds me of this.
      https://patents.google.com/patent/US6679960B2


      K-charge goes even further. I already came across some papers claiming that is possible that 90% of liner can be thrown in penetrating jet. So with much more mass and even higher velocity, by maintaining jet coherency, and maintaining tail coherency it would penetrate more and be less disruptive by composite armor. Here they also use it to reduce weight of charge overall.
      But K-charge also got different modes. So it can be fuzed to function as HEAT. EFP or cluster os smaller EFPs.

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    3. "Personally I think that (3) divisor was better because it's represent actual better penetraion without increasing overall basic damage. "

      That does work if you want to keep the lethality of bullets in check. The reason why I use the 1.7 times damage increase is that it tracks with how bullet damage works in GURPS. All things being equal, a denser bullet will have a higher basic damage.

      "As for extreme end, somebody suggested to “tracking” the projectile with constantly high pressure of the powder gases in the bore" which reminds me of a certain Gerald Bull project... and basically giving you ETC gunts without ETC."

      Which in turn reminds me of the squeeze bore principle.
      https://www.historicalfirearms.info/post/137711773393/colt-salvo-squeeze-bore-in-1961-russell-robinson

      "K-charge goes even further. I already came across some papers claiming that is possible that 90% of liner can be thrown in penetrating jet. So with much more mass and even higher velocity, by maintaining jet coherency, and maintaining tail coherency it would penetrate more and be less disruptive by composite armor. Here they also use it to reduce weight of charge overall.
      But K-charge also got different modes. So it can be fuzed to function as HEAT. EFP or cluster os smaller EFPs."

      I'm always a bit suspect of wonder weapons that do it all, not that they can't work but they always have some draw back somewhere. That being said, for works of fiction and RPG's, they're all about the what if so they might be worth a crack even if as an Infinite Worlds what if round.

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    4. Oh, squeeze bores are made minor comeback too.
      https://techlinkcenter.org/news/us-army-researchers-are-turning-it-up-to-11-to-make-hypervelocity-firearms/

      Well, I usually follow such a guideline: if similar studies were done in other countries, if major company were involved in research and if somebody of inventors did actual tests - this may work with high possibility.
      If all that we got is pure theoretical babble form single individual... well, that's worse. Altough minor chance is still here)

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    5. Ive done some noodlings in the past on trying work out squeeze bores in GURPS terms trying to update the weapons from Going Faster's New interpretations for GURPS Ogre to 4th ed

      http://www.goingfaster.com/ogre/gurpsogre.html

      Sadly I think my work was lost when my old laptop died.

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    6. Oh, Going Faster! I suppose it's a small world after all...

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    7. His write up on Terminator plasma weapons are on point as well :D

      Ok, let's see just how small of a world it is if you get this:

      Have you embraced your lord and ammo barer, Gun Jesus?

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    8. Gun Jesus, whose secular name was Ian McCollum?) Then yes.

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    9. Welp.... it seems we are basically the same person lol.

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