18C's and Wannabes, Name This Item
 

What is this item, specifically, and why is it a very nasty little bugger?

TR

Just a wannabe here, but it looks like an unexploded mortar round or an RPG projo. Upon closer inspection, looks quite a lot like an RPG projo. I suspect that it has been photoshopped to eliminate markings and make this interesting.

Doubt its a RPG, lacks the "stick" out of the back end. Doubt that its a mortar as it lacks the fins. I am guessing an Artillery shell. What is interesting, and probably why it makes it a nasty lil' SOB is the flat nose. Most artillery shell heads I have seen have the pointed fuse for a nose. So, if there is no fuse, what is it's purpose? Is this a chemical warhead?

Could it be an RPG, already fired, and therefore very sensetive right now? The propellent has already burned and that's why we can't see a "stick" at the rear? The propellent and warhead can be separated.

If the warhead can be detatched from the rear stick, it could be an RPG-7, although it doesn't have those indentations running down its nose.

It is NOT an RPG.

TR

Looks a lot like a rifle grenade but am leaning towards a 60mm mortar shell. Too small for an 81 IIRC. I'm ignoring the fact that the fins are missing because it is conceivable that they broke off on impact.

Need to blow up the image.

Sub-munition

The 60mm mortar shells don't have such a long middle, according to the pictures on FAS.

Solid, your right.

I'll go with a M31 rifle grenade. When I'm wrong, nobody dies.

With its fins knocked off, I'd agree.

Or removed?

That is not the M31 Rifle Grenade as the back element, the silver portion, is the incorrect proportions. I ammend my initial thought regarding chemical, as it lacks the lifting plugs that are prevelant upon such warheads. The clue is in the initial question by TR Now to determine what he means by it. Sub-munitions?

I'm seeing the silver part as the firing pin section. It's color says HE.

Looks like a LAW Warhead.

First guess (I may have several):

Willy-Peter round from 60MM mortar

Ladies and gentlemen, we have a winnah!! Good eye, ktek!

Now why is it a nasty item for UXO disposal?

TR

Not even close. 60mm WP round has a longer body with a more cylindrical shape and is usually painted light green. Dark Green with Yellow markings is almost always an HE item.

TR

Is it because it is a HEAT round, and could go flying some distance if blown in place? Or is the impact fuse that sensitive?

Quit fishing and deliver the rest of your answer.

TR

LOL, if I knew for sure I wouldnt be fishing. I was just a regular Leg, no demo expert, and that lecture in basic on the LAW fuse was 19 years ago. :D

Once again, just a civ, but doesn't a HEAT round generate a jet of plasma in the direction it is pointed when it goes off?

That is correct about the "Jet of Plasma", but more importantly, How does it work?? That is, what sets it off, how, when, and what other precautions need to be taken when this type of Dudd is encountered ??

Take care.
Martin

Rocket. The rocket is a percussion-ignited, fin-stabilized, fixed munition. It is attached by the igniter to the inside of the launcher. The rocket consists of a 66-mm HEAT warhead, a point-initiating, base-detonating fuze, and a rocket motor. Six spring-loaded fins are attached to the rear of the rocket motor. These fins are folded forward along the motor when the rocket is in the launcher. When ignited, the propellant in the rocket motor burns completely, producing gasses about 1,400F(760C). The gas pressure pushes the rocket toward the target and exits to the rear of the launcher as the backblast.

-Caliber .................. 66 mm
-Length ................... 50.8 cm (20 inches)
-Weight.................... 1.8 kg (2.2 pounds)
-Muzzle Velocity........... 144.8 mps (475 fps)
-Minimum Range (Combat).... 10 meters (33 feet)
"-Minimum Arming Range...... 10 meters (33 feet)"
-Maximum Range............. 1,000 meters (3,300 feet)
Maximum Effective Ranges
-Stationary Target ...... 200 meters (660 feet)
-Moving Target........... 165 meters (541 feet)

TS

Bingo.

What sort of fuse does it have?

FYI, a HEAT round should be less dangerous to the surrounding area than a conventional HE round, so the charge or its configuration is not the issue.

TR

I believe it has a base-detonating fuze located in the rocket's closure section.

Solid

Once again, Pure civilian speculation, but if what Solid says is true, and the fuse is supposed to be in the tail section, that would mean that the fuse is probably damaged. Making it unpredictable at best.

What Solid mentioned is the wrong part of the fuze data.

I asked about the fuze, not the detonator.

Damage to the tail is irrelevant.

TR

Percussion?

and it is teeter-tottered nose toward the ground being somewhat significant?

No.

No.

I take it that we are about at the end here, and I have defeated the knowledge base of this august body of budding demolition experts?

TR

How it works...

Upon impact, the nose cone crushes; the impact sensor activates the fuze. The ogive crush switch activates the electric detonator. The booster detonates, initiating the main charge.

Not exactly sure why this makes it so tricky for the EOD guys?

Damn, sorry for misleading you guys.

It is the warhead for the older 66mm LAW rocket. It uses a piezo-electric crystal in the nose that crushes and generates a spark of electricity that detonates a base detonating fuze at the rear center of the warhead (as do all HEAT shaped charges). I have no idea why the rocket motor (a tube about 10 inches long, with fins) is not present.

If the nose has impacted and partially collapsed, you can get a bellville-spring effect. (Think of that annoying popping of the bottom of a beer can, in-out, pop-pop). Except, if the nose cap pops inward and the crystal is crushed - detonation. There is supposed to be a graze element (set back armed under the push of launch) that detonates the warhead upon sudden de-acceleration, it obviously did't function, but may be cocked or half cocked and at risk of being jarred free.

In extreme cases, I've heard of the mere cooling of a shadow on the warhead causing uneven cooling of a sun-soaked fuze, freeing a firing pin that then slammed home.

finally, someone who knows WTF is going on. Whew! I thought you Pro fellas were gonna leave this to us Civs to work out. That could have been interesting:D

Thank you, CSB.

BINGO!!

Well done, CSB, though as an SF guy, I am not surprised that you knew that.

It has a "a point-initiating, base-detonating fuze" (almost all HEAT rounds are base detonated, that is how they function).

As you noted, after firing, the piezo electric crystal fuze in the nose can sit and do nothing for a long time, and then detonate for the most minor of reasons, like a small movement, such as a clearing charge being placed on it, or even a shadow causing the fuze to cool and contract enough to generate the current to detonate it.

That is why it is important to only fire LAWs at hard targets (armored, not thin skinned) and do a thorough police call of the area after shooting, if you are clearing the range.

It is an electric/electronic device, IIRC, there is no firing pin in the warhead that I am aware of.

TR

If desired, I can post a picture of how it happened, but will answer no questions from non-SF guys about the specifics.

TR

So, TR what would you recommend doing about such a thing? Back off and shoot it with a .50? Throw rocks at it till it goes BOOM?

TR, any pictures would be much appreciated, even without an SF commentary.

Thank you,

Solid

The other thing to worry about is Static Electricity and all of the above other concerns. Piezos are very reliable when they hit something Solid , as TR said, but once "Armed", and damaged they are unpredictable at best. A .50 shot may set it off, but if you don't know what you are doing, don't even think about approaching it and definitely do not get anywhere in front of it, I've seen "Plasma Balls and Jets" in action and it would not be pretty. I won't go into any detailed diposal in here.

Take care.
Martin

You could shoot it with a de-arming gun to scatter it, but I would VERY CAREFULLY place a clearing charge or better yet, one of the EOD mini-shaped charges on top of it.

Here is the rest of it. Remember, no questions.

TR