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pittspilot
October 19, 2004, 03:31 PM
I am led to understand that a Protection level 2 vest can withstand Medium Level energy strikes of 33 Jules or 34.3 ft lbf. The overtest condition is 50 J or 36.9 ft lbf

So my question is whether a 125 lb woman wielding a knife could overcome this level of armor?

Thanks in advance.

Darkangel
October 19, 2004, 04:02 PM
Dude, from what I understand Body Armor is not the best at defeating a knife attack. The right knife and a determined person might spell a big problem for you. You might want to consider other tactics.
IMHO

Arc Angel
October 19, 2004, 05:14 PM
:) My turn! The short answer is, 'No!' Unless, of course, she hits the center, 'trauma plate'. :eek:

CarlosDJackal
October 19, 2004, 05:47 PM
Only if you have the stab resistant stuff.

Normal body armor does well with bullets because the amount of energy spikes upon impact and then rapidly dispates. Therefore the energy delivered is quickly disipated. The relatively large cross-section of a bullet also makes it easier to distribute the energy.

A knife's point has a much smaller cross-section which means the energy is concentrated in a much smaller area. This prevents optimal distribution and allows that energy to get between the woven fabrics. Also, when a knife is thrust, the energy is continuously delivered because of the momentum created by the deliverer's arm and body (which is again concentrated at the point).

I hope this helps.

Double Naught Spy
October 19, 2004, 06:18 PM
Level II is a ballistic rating, not a puncture rating. There is combo ballistic and stab resistent armor, but it tends to be heavier than either regular ballistic armor or stab resistent armor.

Derius_T
December 1, 2004, 10:25 AM
IMHO if you find yourself in the situatiion that you are facing a determined, well-trained knife fighter, even with a gun you can die before you clear your holster.

Personaly, IF I have a chance to see the knife and am lucky enough to get my weapon clear, I will yell out for them to drop the knife as loud as I can (if there is time) and if he advances to within lethal range with no intention of stopping, double tap him in the chest and call your lawyer, then 911. :D

DT Guy
December 1, 2004, 10:40 PM
Depends heavily on:

*The configuration of the knife-something with a point is (obviously) going to penetrate easier/farther than something with a blunt tip, like a tanto.

*The level of determination of the lady-125# of 'absolutely gonna' killyerass' can be about 124# too much..

*Most importantly, though, may very well be how the vest is supported. A vest on a very solid backing is penetrated much easier than a vest that has some 'give' to it.


Stab a few vests-there are plenty of old ones around, sometimes for the asking-and see for yourself.

Larry

CobrayCommando
December 1, 2004, 11:14 PM
I don't think a knife can penetrate titanium plate, so maybe get yourself side, front and back form fitting titanium plates. And groin.

For the groin 2 inch thick titanium plate with reactive armor on top! :D

pbass
December 1, 2004, 11:22 PM
You can peruse the NIJ Stab Resistance Standard (http://www.nlectc.org/pdffiles/0115.00.pdf) if you want, but a corrections officer I know puts no faith in this stuff, just in huge numbers of huge guys throwing everything they have at one inmate with any sharp, pointy object, because anything can and will happen. Hopefully you already have a skeptical view of the effectiveness of handgun-round resistant vests. You already know that you don't want to get hit nearer than three inches from the edge of any panel, that even wearing a vest, most of your frontal area is still unprotected, and so on. OK, take that uncertainty to the umpteenth power with stab-resistant armor.

IZinterrogator
December 2, 2004, 03:11 AM
Avoiding a situation where that could happen is better than depending on a vest. The vest won't cover the femoral or carotid arteries. Slashes to the arms while you block will also drain you really quick.

I had a friend who had a similar question. I recommended marraige counseling. :D

Chiram2003
December 2, 2004, 05:06 AM
Okay, sensible questions. Are you considering a vest for patrol duty (police) or guard duty (prison guard)? I ask because at most prisons (atleast I sure hope so!) you aren't going to need a ballistic vest simply because the inmates aren't allowed firearms. In this case, you should look into a concealable stab vest. If you're looking primarily for a ballistic vest, it's going to resist bullet puncture, but a knife will go through it. Consider the following. How does a sewing needle get through fabric? It seperates the filaments of the fabric to that it can penetrate and loop with the thread.

That being said, there *IS* a ballistic/spike vest on the market. Galls (I know, they're expensive, but what can you do?) has a Double Threat Vest. Ballistic II/Spike III ratings. You're going to be looking at $750 BEFORE a trauma plate. While trauma plates aren't very expensive, it's a consideration that must be made. Ballistic trauma plates will run you anywhere from $17 to $93 from Galls.

All that being said, do you want to front the money for this vest? Is this something you will be wearing every day or just on the off occasion? Yes, body armor is expensive, but can YOU be replaced?

Double Naught Spy
December 2, 2004, 07:14 AM
So my question is whether a 125 lb woman wielding a knife could overcome this level of armor?

I am still trying to figure out the relevance of the woman's weight here, as if weight determines strength somehow.

While a vest may be able to stop X amount of ft lbs of energy, that is only part of the story. That energy must be captured by the fibers. Pointed implements allow the implement to get between the fibers and hence the fibers have trouble stopping the implement. So, a person with a blunt butter knife probably won't penetrate a ballastic vest when thrust by a person, but ice picks, pointy knives, etc. could be.

IMHO if you find yourself in the situatiion that you are facing a determined, well-trained knife fighter, even with a gun you can die before you clear your holster.

Interesting quote. Not very enlightening and maybe not accurate, but interesting. The sort of rule of thumb is that a person with a knife who is within 7 yards can close the distance and stab a person in 1.5 seconds, sometimes less, and 1.5 seconds is faster than the speed most people can draw their firearms, police from secured holsters or CCW people from concealed locations. This isn't necessarily a well-trained or particularly determined adversary. Of course, the draw time can be shortened if the intended victim perceives a threat and is prepped by doing things like already having a hand on the gun to be drawn.

As a clarification, a well-trained and determined person overcome a person carrying a gun in a whole manner of circumstances and with a variety of weapons. There is nothing particularly special about knives other than they can penetrate typical ballistic soft armor. A well trained and determined person could overcome a gun carry with something as common as a rock, golf club, baseball bat, stun gun, etc. etc. etc. The smarter well trained and determined folks will simply strike without warning.

Derius_T
December 2, 2004, 10:06 AM
Double Naught Spy : "Interesting quote. Not very enlightening and maybe not accurate, but interesting."

Well, I appriciate your interest, but the fact that its not accurate? I am talking about a trained knife fighter, who can kill your average, and even your trained, gun carrier faster than you can draw and fire. 1 quick, accurate swipe from a knife and you'll bleed out before you realize what just happened.
I speak from the experience of having been trained in these areas, and having seen the exact same scenario acted out in numerous defense and combat classes. I've even heard several instructors say things like " A guy pulls a knife on you and holds it like THIS.....shoot him now....because you can be dead before you can clear your holster....."

So if these experiences and advice from qualified instructors doesn't make my statement accurate..... :confused:


As to the guy looking for a decent stab proof vest, you could always invest in a really good, closely woven chain mail shirt. :D

nbk2000
December 2, 2004, 05:22 PM
...at most prisons (atleast I sure hope so!) you aren't going to need a ballistic vest simply because the inmates aren't allowed firearms.

I'm not aware of any prison that allows the inmates to have knives and spikes, but they have them anyways, as well as firearms if the inmate is willing to pay the price or is inventive enough.

claude783
December 3, 2004, 10:23 AM
In the Cold Steel Videos, Lynn Thompson, shows a knife attack, in which the blade is brough in a downward arc, ending up on the top of the shoulder, the intent is to go through the sub-clavical artery. There isn't any armour there, only straps to hold the vest on!

A well trained, determined woman, would be able to defeat your body armour.

Hell, even in THE BOOK OF 5 RINGS. Written late 1500's early 1600's, (wrong spelling: Matamoro Miyushi) mentions that even body armour can be defeated because there will always be weak spots such as the knee, elbows, ankle, places which require movement, and thereby weakening the ability of the armour to protect!

Phil306
December 3, 2004, 02:01 PM
I believe everyone else answered your question for you: simply, YES.

In so far as your level protection, why would you want to wear a Level II? If your going to wear body armor, for what ever reason, ESPECIALLY if your a police officer, get yourself Threat Level IIIA. It doesn't cost that much more and I always say: What is YOUR life worth?

Finally, go to http://www.tacticalforums.com. There is a whole MESS of information about body armor. Be careful as to what type of materials you purchase in your body armor also...Some aint what it says and can get you hurt.

By the way, I live a heck of a lot closer to Berkeley the you do :barf:

Thin The Herd

stevelyn
December 5, 2004, 10:39 PM
About three years ago another officer and I had the opportunity to informally test the stab resistance of top of the line IIIA ballistic panels.
The result was my tanto blade S&W Special Tactical went through with little effort. I used quick overhand short stabs and even tried pressing the tip against the material and then pushing it through. The other officer's Benchmade Mel Pardue was just as effective w/ it's blade configuration. I probably don't need to tell you that broadhead tipped arrows and crossbow bolts will whistle through them like they're not even there.
We did find that the material was extremely slash resistant. A person doing slashes only would probably tire themselves out long before they ever drew blood.
However you need to remember the weave used in body armor fabric differs between stab resistant and bullet resistant. The materials used are usually the same. The weave in ballistic panels is designed to absorb bullet energy and disspate it outwardly taking away it's penetrative ability.
Fabric used for stab resistant panels is woven in a manner that binds and ties up the point of a sharp instrument impeding penetrative ability and requiring more force to be needed to penetrate.
That's why a ballistic vest gives little or no stab protection and stab resistant panels give no ballistic protection. Which is the main reason combo vests are much heavier and thicker. They have to put in layers of panel material with both weaves.