Modelling Explosives : TNT

[lensman]

Found this on Wikipedia:

Grams TNT Symbol Tons TNT Symbol Energy

gram of TNT g microton of TNT μT 4.184×103 J

 

at

http://en.wikipedia.org/wiki/TNT_equivalent

 

I looked in 5th ed. rev. pg. 487 one stick is listed at 5 d6, with a strange progression.

 

I need to find the charts someone did of expressions of d6 in J.

 

http://en.wikipedia.org/wiki/TNT_equivalent

1 foot-pounds = 1.35581795 joules

 

NOTE: I made the classic mistake and confused TNT for Dynamite. Dynamite uses nitroglycerin, not TNT.

 

I am trying to find data on Nitro, which as a compoinent in dynamite is approx. 40 to 60 %.

[Guest steamteck]

Re: Modelling Explosives : TNT

 

here you go.

I just don't remember were I got this but thanks to them. Step forward if you see this. Sorry I wish I could give credit

 

TNT equivalent

DC Energy Muzzle velocity Point 1 Hex Explosion Notes

1 32 J 25 ft-lbs - - 1/32 lbs

2 64 J 50 ft-lbs - - 1/16 lbs

3 125 J 100 ft-lbs - - 1/8 lbs

4 250 J 200 ft-lbs - - 1/4 lbs

5 500 J 400 ft-lbs - - 1/2 lbs

6 1 KJ 800 ft-lbs - 1/64 lbs 1 lbs

7 2 KJ 2 K ft-lbs - 1/32 lbs 2 lbs

8 4 KJ 3 K ft-lbs - 1/16 lbs 4 lbs

9 8 KJ 6 K ft-lbs - 1/8 lbs 8 lbs

10 16 KJ 13 K ft-lbs - 1/4 lbs 16 lbs

11 32 KJ 25 K ft-lbs - 1/2 lbs 32 lbs

12 64 KJ 50 K ft-lbs 1/64 lbs 1 lbs 64 lbs

13 125 KJ 100 K ft-lbs 1/32 lbs 2 lbs 125 lbs

14 250 KJ 200 K ft-lbs 1/16 lbs 4 lbs 250 lbs

15 500 K 400 K ft-lbs 1/8 lbs 8 lbs 500 lbs

16 1 MJ 800 K ft-lbs 1/4 lbs 16 lbs 1 Tn

17 2 MJ 2 M ft-lbs 1/2 lbs 32 lbs 2 Tn

18 4 MJ 3 M ft-lbs 1 lbs 64 lbs 4 Tn

19 8 MJ 6 M ft-lbs 2 lbs 125 lbs 8 Tn

20 16 MJ 13 M ft-lbs 4 lbs 250 lbs 16 Tn

24 250 MJ 200 M ft-lbs 64 lbs 4 Tn 250 Tn Minimum Yield Nuke

30 16 GJ 13 G ft-lbs 4 Tn 250 Tn 16 KTn Hiroshima/Nagasaki

33 125 GJ 100 G ft-lbs 32 Tn 2 KTn 125 KTn Median US Nuke

39 8 TJ 6 T ft-lbs 2 KTn 125 KTn 8 MTn Largest Current US Nuke

42 64 TJ 50 T ft-lbs 16 KTn 1 MTn 64 MTn Tsar Bomba (Largest Nuke ever made)

107 2E33 J 2E33 ft-lbs 500 Ytn 3E27 Tn 2E30 Tn Minimum needed to destroy Earth

124 3E38 J 2E38 ft-lbs 6E31 Tn 4E33 Tn 3E35 Tn Death Star

150 2E46 J 1E47 ft-lbs 4E39 Tn 3E41 Tn 2E43 Tn SuperNova

211 1E66 J 2E64 ft-lbs 8E57 Tn 1E60 Tn 3E60 Tn Big Bang

 

 

Methodology:

Starting Assumptions:

1- The average person could do 6DC damage max. (2DC + 4DC Haymaker)

2- The average person could lift 100kg 2 meters (or they could exert 200 kg meters of energy).

3- The average person cannot release all their lift strength in a punch (even a haymaker). So haymaker energy should be about 1/2 total lift.

4- 6 DC should thus be about 100 kg meters.

I then calculated the equivalent in other measuring systems, doubling the energy for each additional DC. As a sanity check I looked up the muzzle velocity of a half dozen common pistols and rifles and compared my calculated DCs to the values listed in FREd. They matched exactly. So I feel that my methods were validated.

Equivalent in TNT has three values. The first is if the explosion was focused and all the energy released is directly applied to a single point (ie no area effect advantage). The second is if the energy were contained within a 2m diameter sphere (ie 1 hex AE advantage +1/2). The last is if it is a normal explosion and the energy was allowed to disperse normally (ie explosion AE advantage +1/2).

[Force]

Re: Modelling Explosives : TNT

 

here you go.

I just don't remember were I got this but thanks to them. Step forward if you see this. Sorry I wish I could give credit

 

TNT equivalent

DC Energy Muzzle velocity Point 1 Hex Explosion Notes

1 32 J 25 ft-lbs - - 1/32 lbs

2 64 J 50 ft-lbs - - 1/16 lbs

3 125 J 100 ft-lbs - - 1/8 lbs

4 250 J 200 ft-lbs - - 1/4 lbs

5 500 J 400 ft-lbs - - 1/2 lbs

6 1 KJ 800 ft-lbs - 1/64 lbs 1 lbs

7 2 KJ 2 K ft-lbs - 1/32 lbs 2 lbs

8 4 KJ 3 K ft-lbs - 1/16 lbs 4 lbs

9 8 KJ 6 K ft-lbs - 1/8 lbs 8 lbs

10 16 KJ 13 K ft-lbs - 1/4 lbs 16 lbs

11 32 KJ 25 K ft-lbs - 1/2 lbs 32 lbs

12 64 KJ 50 K ft-lbs 1/64 lbs 1 lbs 64 lbs

13 125 KJ 100 K ft-lbs 1/32 lbs 2 lbs 125 lbs

14 250 KJ 200 K ft-lbs 1/16 lbs 4 lbs 250 lbs

15 500 K 400 K ft-lbs 1/8 lbs 8 lbs 500 lbs

16 1 MJ 800 K ft-lbs 1/4 lbs 16 lbs 1 Tn

17 2 MJ 2 M ft-lbs 1/2 lbs 32 lbs 2 Tn

18 4 MJ 3 M ft-lbs 1 lbs 64 lbs 4 Tn

19 8 MJ 6 M ft-lbs 2 lbs 125 lbs 8 Tn

20 16 MJ 13 M ft-lbs 4 lbs 250 lbs 16 Tn

24 250 MJ 200 M ft-lbs 64 lbs 4 Tn 250 Tn Minimum Yield Nuke

30 16 GJ 13 G ft-lbs 4 Tn 250 Tn 16 KTn Hiroshima/Nagasaki

33 125 GJ 100 G ft-lbs 32 Tn 2 KTn 125 KTn Median US Nuke

39 8 TJ 6 T ft-lbs 2 KTn 125 KTn 8 MTn Largest Current US Nuke

42 64 TJ 50 T ft-lbs 16 KTn 1 MTn 64 MTn Tsar Bomba (Largest Nuke ever made)

107 2E33 J 2E33 ft-lbs 500 Ytn 3E27 Tn 2E30 Tn Minimum needed to destroy Earth

124 3E38 J 2E38 ft-lbs 6E31 Tn 4E33 Tn 3E35 Tn Death Star

150 2E46 J 1E47 ft-lbs 4E39 Tn 3E41 Tn 2E43 Tn SuperNova

211 1E66 J 2E64 ft-lbs 8E57 Tn 1E60 Tn 3E60 Tn Big Bang

 

 

Methodology:

Starting Assumptions:

1- The average person could do 6DC damage max. (2DC + 4DC Haymaker)

2- The average person could lift 100kg 2 meters (or they could exert 200 kg meters of energy).

3- The average person cannot release all their lift strength in a punch (even a haymaker). So haymaker energy should be about 1/2 total lift.

4- 6 DC should thus be about 100 kg meters.

I then calculated the equivalent in other measuring systems, doubling the energy for each additional DC. As a sanity check I looked up the muzzle velocity of a half dozen common pistols and rifles and compared my calculated DCs to the values listed in FREd. They matched exactly. So I feel that my methods were validated.

Equivalent in TNT has three values. The first is if the explosion was focused and all the energy released is directly applied to a single point (ie no area effect advantage). The second is if the energy were contained within a 2m diameter sphere (ie 1 hex AE advantage +1/2). The last is if it is a normal explosion and the energy was allowed to disperse normally (ie explosion AE advantage +1/2).

 

I didn't understand a single bit of this.

 

Rep'ed anyways for the work you put in this.

[lensman]

Re: Modelling Explosives : TNT

 

Thanks Steamtek.

[Edsel]

Re: Modelling Explosives : TNT

 

I didn't understand a single bit of this.

 

Since the table formatting was lost when it was posted to the forums it is pretty much incomprehensible. It is a shame it looks like something I might like.

 

Steamteck, is it possible you could post an .rtf attachment or some other file with the formatting intact?

[Outsider]

Re: Modelling Explosives : TNT

 

As far as I can figure out, this is what it looks like with the formatting cleaned up a bit :

 

 

 

 

here you go.

I just don't remember were I got this but thanks to them. Step forward if you see this. Sorry I wish I could give credit

 

TNT equivalent

DC___Energy_____MV__________Point___1 Hex____Explosion_Notes

__1____32 J____25 _ ft-lbs______________________1/32 lbs

__2____64 J____50 _ ft-lbs______________________1/16 lbs

__3___125 J___100 _ ft-lbs______________________1/8 lbs

__4___250 J___200 _ ft-lbs______________________1/4 lbs

__5___500 J___400 _ ft-lbs______________________1/2 lbs

__6____1 KJ___800 _ ft-lbs____________1/64 lbs____1 lbs

__7____2 KJ_____2 K ft-lbs____________1/32 lbs____2 lbs

__8____4 KJ_____3 K ft-lbs____________1/16 lbs____4 lbs

__9____8 KJ_____6 K ft-lbs____________1/8 lbs_____8 lbs

_10___16 KJ____13 K ft-lbs____________1/4 lbs____16 lbs

_11___32 KJ____25 K ft-lbs____________1/2 lbs____32 lbs

_12___64 KJ____50 K ft-lbs___1/64 lbs__1 lbs______64 lbs

_13__125 KJ___100 K ft-lbs___1/32 lbs__2 lbs_____125 lbs

_14__250 KJ___200 K ft-lbs___1/16 lbs__4 lbs_____250 lbs

_15__500 KJ___400 K ft-lbs___1/8 lbs___8 lbs_____500 lbs

_16____1 MJ___800 K ft-lbs___1/4 lbs__16 lbs_______1 Tn

_17____2 MJ_____2 M ft-lbs___1/2 lbs__32 lbs______2 Tn

_18____4 MJ_____3 M ft-lbs___1 lbs____64 lbs______4 Tn

_19____8 MJ_____6 M ft-lbs___2 lbs___125 lbs______8 Tn

_20___16 MJ____13 M ft-lbs___4 lbs___250 lbs_____16 Tn

_24__250 MJ___200 M ft-lbs__64 lbs_____4 Tn____250 Tn_Minimum Yield Nuke

_30___16 GJ____13 G ft-lbs____4 Tn___250 Tn_____16 KTn Hiroshima/Nagasaki

_33__125 GJ___100 G ft-lbs__32 Tn______2 KTn___125 KTn_Median US Nuke

_39____8 TJ_____6 T ft-lbs___2 KTn___125 KTn_____8 MTn_Largest Current US Nuke

_42___64 TJ____50 T ft-lbs__16 KTn_____1 MTn___64 MTn_Tsar Bomba (Largest Nuke ever made)

107__2E33 J__2E33 ft-lbs___500 Ytn___3E27 Tn___2E30 Tn_Minimum needed to destroy Earth

124__3E38 J__2E38 ft-lbs__6E31 Tn____4E33 Tn___3E35 Tn_Death Star

150__2E46 J__1E47 ft-lbs__4E39 Tn____3E41 Tn___2E43 Tn_SuperNova

211__1E66 J__2E64 ft-lbs__8E57 Tn____1E60 Tn___3E60 Tn_Big Bang

 

 

Methodology:

Starting Assumptions:

1- The average person could do 6DC damage max. (2DC + 4DC Haymaker)

2- The average person could lift 100kg 2 meters (or they could exert 200 kg meters of energy).

3- The average person cannot release all their lift strength in a punch (even a haymaker). So haymaker energy should be about 1/2 total lift.

4- 6 DC should thus be about 100 kg meters.

I then calculated the equivalent in other measuring systems, doubling the energy for each additional DC. As a sanity check I looked up the muzzle velocity of a half dozen common pistols and rifles and compared my calculated DCs to the values listed in FREd. They matched exactly. So I feel that my methods were validated.

Equivalent in TNT has three values. The first is if the explosion was focused and all the energy released is directly applied to a single point (ie no area effect advantage). The second is if the energy were contained within a 2m diameter sphere (ie 1 hex AE advantage +1/2). The last is if it is a normal explosion and the energy was allowed to disperse normally (ie explosion AE advantage +1/2).

[gojira]

Re: Modelling Explosives : TNT

 

Good job Outsider. It still doesn't make much sense to me thought. What is MV? Is that supposed to be mass x velocity^2? And "Point" and "1 Hex" mean nothing at all to me. The Explosion Notes I guess is in TnT, although no unit other than weight is given.

 

Ditto on that formatted version, Steamteck. A post with CSV (comma separated values) would be better, since that could be imported into Excel.

[Edsel]

Re: Modelling Explosives : TNT

 

MV is the Muzzle Velocity in foot-pounds (ft-lbs). I guess if you were firing a projectile of energy equal to the TNT charge, this is the amount of velocity it would have at the point of leaving the barrel.

 

As for Point, 1 Hex and the other right-hand columns I am not sure either.

[Guest steamteck]

Re: Modelling Explosives : TNT

 

Ok lets try this again If I can figure out attachments There is another similar chart. This was originally done by Bartman

 

The j is energy in joules

 

 

 

Equivalent in TNT has three values. The first is if the explosion was focused and all the energy released is directly applied to a single POINT(ie no area effect advantage). The second is if the energy were contained within a 2m diameter sphere (ie 1 hex AE advantage +1/2). The last is if it is a normal explosion and the energy was allowed to disperse normally (ie explosion AE advantage +1/2).

[Guest steamteck]

Re: Modelling Explosives : TNT

 

Yes! Its attached there's also a chart for DC in kilowatts and Mega watts as well as some examples. Sorry for the confusion.

[Cancer]

Re: Modelling Explosives : TNT

 

Just guessing, but ... MV is actually the energy of the blast, but in English rather than metric units. 1 foot-pounds = 1.35581795 joules

[Guest steamteck]

Re: Modelling Explosives : TNT

 

MV is muzzle velocity. The attached file has explanations as well as a damage class to voltage chart.

[Rapier]

Re: Modelling Explosives : TNT

 

MV is the Muzzle Velocity in foot-pounds (ft-lbs). I guess if you were firing a projectile of energy equal to the TNT charge, this is the amount of velocity it would have at the point of leaving the barrel.

 

As for Point, 1 Hex and the other right-hand columns I am not sure either.

 

I would assume that point is the point pressure, 1 hex is the pressure over an entire hex and the rough equivalent of explosive TNT.

[SCUBA Hero]

Re: Modelling Explosives : TNT

 

I *think* I first saw this from Toadmaster, but not sure...

[Cancer]

Re: Modelling Explosives : TNT

 

MV is the Muzzle Velocity in foot-pounds (ft-lbs). I guess if you were firing a projectile of energy equal to the TNT charge, this is the amount of velocity it would have at the point of leaving the barrel.

 

As for Point, 1 Hex and the other right-hand columns I am not sure either.

 

MV is muzzle velocity. The attached file has explanations as well as a damage class to voltage chart.

 

OK, when two guys who are usually knowledgeable say the same thing, then I must be confused. So help the poor b*****d with the physics education: the column labeled MV throws me.

 

Velocity ought to be in ft/sec or m/sec or some such. The units given are foot-pounds, and foot-pounds is not a unit of velocity, it's a unit of energy. You can't turn energy in joules to a muzzle velocity (in m/sec or ft/sec) without specifying a projectile mass.

 

Further, the values in column MV are approximately proportional to the values in the "Energy" column, and the numbers in the "energy" column are proportional to the numbers in each of the last three columns, which makes sense if the energy release is just (heat of explosion of TNT) * (mass of TNT).

 

But it doesn't work with any assumption I can think of for projectile mass. If you take Edsel's assumption that the projectile mass is in one of the last three columns, then the velocity ought to be constant (if projectile mass = explosive mass).

 

So I'm pretty sure the "MV" column is just the energy yield expressed in English units. I'm not a gunbunny, but foot-pounds is what I've seen used in those discussions of cartridge energy release (given in foot-pounds for a given load, or foot-pounds per grain of powder in a load), bullet mass (specified in grains), and muzzle velocity (in fps).

[Jaxom]

Re: Modelling Explosives : TNT

 

I hesitate to point this out, but assumption 2 is fundamental to this conversion and has absolutely no bearing. The reason a human can lift 100 kilos 2 meters is that he's 2 meters tall. It's often done in a clean-and-jerk which is not a single movement and isn't going to yield meaningful measurements.

 

Maybe this should be done using shotput or something where you could argue a single motion and then get total energy output without any limitation on size of the human.

 

(To be explicit, compare a typical human to a bodybuilder with dwarfism. I get to claim 100kg and 2m but he gets to claim 150kg and 1 meter so he is less powerful?)

[Toadmaster]

Re: Modelling Explosives : TNT

 

I *think* I first saw this from Toadmaster' date=' but not sure...[/quote']

 

I have a similar chart but this isn't mine, the numbers are different and I don't have all the other stuff just DC & energy, no TNT, etc.

 

Personally these numbers are way low, mine starts at 100 Joules and each doubling adds another DC, so DC1 = 100 or less, DC2 = 100-200, DC3 = 200-400 etc. 99% accurate for pre 5th ed HERO and still pretty close in 5th except for a few weapons I strongly disagree with cough .45ACP bionic super duper ultra magnum cough

[Toadmaster]

Re: Modelling Explosives : TNT

 

Oh and I would assume the original creator of the chart either made a typo or misunderstood the difference between muzzle velocity and muzzle energy. The first column is muzzle energy in Joules, the second is muzzle energy in ft/lbs. Velocity is not listed although MV is the common abbreviation for muzzle velocity.

 

This chart is way off compared to what the wikipedia article says, 1 gram of TNT is 4184 joules, this chart would require 4 lbs of TNT for that force.

 

Someone did a lot of work but unfortunately it looks like it was poorly researched. Then again wikipedia isn't always 100% and 4184 joules for a gram of TNT sounds high.

[gojira]

Re: Modelling Explosives : TNT

 

I have a similar chart but this isn't mine, the numbers are different and I don't have all the other stuff just DC & energy, no TNT, etc.

 

Personally these numbers are way low, mine starts at 100 Joules and each doubling adds another DC, so DC1 = 100 or less, DC2 = 100-200, DC3 = 200-400 etc. 99% accurate for pre 5th ed HERO and still pretty close in 5th except for a few weapons I strongly disagree with cough .45ACP bionic super duper ultra magnum cough

 

Could you post yours? I'd like to compare.

 

Just a guess. This chart takes damage and gun damage, as specified in game, and works backwards, attempting to rationalize the result.

 

I'm also wondering if the Wikipedia value is a the theoretical upper limit, and this table gives practical useful energy. Not all of the energy in a cartridge goes into the MV of a bullet. Some gets dissipated as heat, kickback, sound, ejecting the cartridge (mechanical losses), etc. That would explain why the Wikipedia entry for J in TNT sounds higher than it out to be.

[theltemes]

Re: Modelling Explosives : TNT

 

As far as lifting mass goes, the FAA Human Factor Design Standard (HFDS) gives numbers for a 5th and 95th percentile lifting of weight to a height of 100cm. For males the values were 444.4 N and 931.0 N (average) and for females the values were 185.0 N and 443.0 N. If we assume the 50th percentile lies midway between the two extremes, the 100cm lifting strength for a STR 8 character is 687.7 N (male) or 314 N (female). Since the game mechanics don't differentiate between genders, let's go with the value of 687.7 N or 154.6 lb. So the work would be 688 N-m (70 kg-m) or 507 ft-lb.

 

The 4184 J per gram of TNT is a defined unit. Although you found it on Wikipedia, it is indeed correct.

 

The true destructive power of TNT is indeed its power (J/sec or Watts). TNT actually has a relatively low energy content per kilogram (4.184 MJ/kg). For comparison, the combustion of air-dried wood yields 15.5 MJ/kg, anthracite coal 31.4 MJ/kg, propane 50.3 MJ/kg. The advantage of TNT is that it doesn't need air to combust and the combustion rate is much higher.

[Jaxom]

Re: Modelling Explosives : TNT

 

Methodology:

Starting Assumptions:

1- The average person could do 6DC damage max. (2DC + 4DC Haymaker)

2- The average person could lift 100kg 2 meters (or they could exert 200 kg meters of energy).

3- The average person cannot release all their lift strength in a punch (even a haymaker). So haymaker energy should be about 1/2 total lift.

4- 6 DC should thus be about 100 kg meters.

 

These assumptions are a terrible place to start. What you are trying to determine is the energy in a Haymaker so find a better model for it. Try a shotput. I know I am an average male so I'll go out and throw something for you. Or go with vertical leap or something. There are a so many better ways of measuring the ability of the human body to do explosive work.

 

Heck, a quick google search on "average human vertical jump" produces a whole collection of scientific papers on this subject.

 

The point is that lifting requires an extrapolation like "we'll assume that some fraction of lifting can go into a punch" while a vertical jump is essentially the same set of mechanics as a kick (which is already modeled in HERO). The place you get uncertainty in this is in what you convert as real-world energy into a punch. Clean that up as much as you can and you'll get the most reliable starting point. I'd have to guess that differences in this approximation are why different versions of this spreadsheet vary the way they do.

[Toadmaster]

Re: Modelling Explosives : TNT

 

This is my chart, fairly simple except I like the mid level steps that some don't use (1/2 die and d6-1). I based it off the gun damage in 4th ed and earlier HERO books. It is based off of trial and error to find a good balance between accuracy and ease of use (rounded to a base of 100 since that is easy to calculate step to step vs an odd number like 104 or 93). Energy over that listed goes to the next catagory, so a bullet with 202J would be DC 4. If you don't like the d6-1 then you can ignore it and make that value apply to the 1/2, so DC5 would be 1.6KJ instead of 1.2KJ.

 

DC Damage Energy

1 1 pip 100J >

2 1/2d6 150J

2+ 1d6-1 200J

3 1d6 400J

4 1d6+1 800J

5 1 1/2d6 1.2KJ

5+ 2d6-1 1.6KJ

6 2d6 3.2KJ

7 2d6+1 6.4KJ

8 2 1/2d6 9.6KJ

8+ 3d6-1 12.8KJ

9 3d6 25 KJ

10 3d6+1 50KJ

11 3 1/2d6 75KJ

11+ 4d6-1 100KJ

12 4d6 200KJ

 

 

etc

[lensman]

Re: Modelling Explosives : TNT

 

Excellant. Thanks Toadmaster

[Guest steamteck]

Re: Modelling Explosives : TNT

 

Thanks,toadmaster

[Teflon Billy]

Re: Modelling Explosives : TNT

 

As far as lifting mass goes, the FAA Human Factor Design Standard (HFDS) gives numbers for a 5th and 95th percentile lifting of weight to a height of 100cm. For males the values were 444.4 N and 931.0 N (average) and for females the values were 185.0 N and 443.0 N. If we assume the 50th percentile lies midway between the two extremes, the 100cm lifting strength for a STR 10 character is 687.7 N (male) or 314 N (female). Since the game mechanics don't differentiate between genders, let's go with the value of 687.7 N or 154.6 lb. So the work would be 688 N-m (70 kg-m) or 507 ft-lb.

 

The 4184 J per gram of TNT is a defined unit. Although you found it on Wikipedia, it is indeed correct.

 

The true destructive power of TNT is indeed its power (J/sec or Watts). TNT actually has a relatively low energy content per kilogram (4.184 MJ/kg). For comparison, the combustion of air-dried wood yields 15.5 MJ/kg, anthracite coal 31.4 MJ/kg, propane 50.3 MJ/kg. The advantage of TNT is that it doesn't need air to combust and the combustion rate is much higher.

Your calculations are off because you equated average (mean) STR as 10, but the average (mean) populations strength in HERO 5E is STR 8.

 

TB