New safer explosive


#1

http://www.army.mil/-news/2010/11/15/48108-safer-explosive-tested–qualified-at-picatinny-named-a-time-best-invention-of-2010/index.html


#2

…“TNT will go off when dropped”??? From how high up? Orbital?? It was the STANDARD of insensitivity, having to sustain the shock of a .30-06 bullet impact. That’s why it is a component in Comp B, the standard filler for grenades and an assortment of rounds, to make the RDX less sensitive. I just LOVE newsies, they ALWAYS get things correct. NOT!!!


#3

Interesting article but insensitive HE has been around a long time. I seem to remember that the Navy led the way to reduce the vulnerability of their carriers. I don’t understand how this is different from what has been in bombs and warheads for years----or am I all screwed up?

Cheers,

Lew


#4

I played with explosives in the Navy for over 20 years. The statement of TNT going off by dropping is not true. The only way TNT will become unstable is if it gets very hot,exposed to air,for a very long time. The explosive will ooze an oily substance called “TNT exudate” It is not stable, a shock can set it off. Perhaps a drop onto a hard surface.
TNT can be detonated by the brisance of another explosive detonating close by.
I have witnessed projectiles that were never armed,or had defective fuzes.when fired, hit rock and shatter with no explosion happening.
The Navy has use a high explosive filler for many years called “Composition-B” It is very stable and quite powerful. I have fired many thousand of 5"/54 Anti-aircraft,Common and VTSD/NSD projectiles in anger. I have never seen or heard of any Composition-B projectiles exploding by anything other than a raging fire accident.
We had a Hot Gun where the projectile was stuck in the bore of the gun where it was so hot the paint on the barrel was burning. The projectile was so hot when we removed it it could not be touched by bare hands. The projectile was thrown overboard with nothing happening.
The Navy also uses a “safe” explosive in some torpedoes called " Torpex"


#5

The mentioned there that this one is more temperature insensitive compared to TNT.

The after a disasterous carrier incident during the Vietnam war the Navy used to coat it’s aircraft bombs with a special insulating material to extend the time till critical temperatures are reached when they are in a fire. These bombs have a very rough surface and are easy to be identified.

Having a temperature insensitive explosive is certainly a good thing. I’d be curious to see the critical temperatures of this new explosive vs TNT.

I also agree with bacarnal and Rapidrob.


#6

Your talking about the fire on the USS Forrestal. It was started when a deck tug parked a running APU ( auxiliary power unit,a small jet engine called a “puffer” ) exhaust onto a live rocket on a jets wing. It fired and struck other aircraft causing a chain reaction fire/explosions of ordnance.


#7

Very interesting, love that nickname “Zippo” given to USS Forrestal.
en.wikipedia.org/wiki/1967_USS_Forrestal_fire


#8

Recently saw vintage footage of S.Vietnamese soldiers unloading an ammo truck by rolling 155mm projectiles off the back of a Duece-n-a-half. I cringed. We were somewhat more particular in our ordnance handling habits, back in the day.


#9

Slick Rick, In 1966 my two hangers were directly across a taxiway from the parking ramp for VNAF A-1s at Bien Hoa. In the morning a flatbed with about 60 or 70 250# bombs use to drive slowly along the rows of A-1s and three or four guys on the back use their feet to push bombs off the back of the flatbed as it rolled along. The bombs landed on the concrete or each other and rolled around on the ramp. occasionally they did the same thing with 500# bombs and these bombs dated back to WWII. Never had an unplanned explosion (even one morning when I watched a VNAF armourer installing a nose fuse with a ballpeen hammer).

On the other hand, In 1965 the USAF blew up the B-57 flightline, apparently by mishandling a bomb-I don’t believe they ever really figured out what happened (en.wikipedia.org/wiki/Bien_Hoa_Air_Base). The fire spread through the fueled B-57s, many armed with bombs. Twenty six aircraft were destroyed (including quite a few A-1s on the same ramp discussed above, and one Navy F-8) and 27 airmen died.

Bottom line, even the very old bombs from WWII can stand a lot of rough handling but are very sensitive to a fire.

I also chased down the Insensitive High Explosives (IHE). There are a number of different types and are described as:

[quote]Insensitive munitions (IM) will only burn (rather than explode) when subjected to fast or slow heating, bullets, shrapnel, shaped charges or the detonation of another nearby munition. The term refers to warheads, bombs, rocket motors, although different countries’ armed forces may have their own definitions.

Three approaches are taken when designing insensitive munitions: Firstly, the high energy device can be protected and transported with an external protection of some kind. Some munition shipping containers are designed to provide a degree of protection and thermal insulation. Secondly, the chemistry of the high energy fill is chosen to provide a higher degree of stability, for example by using plastic bonded explosives. Lastly, the casings of high energy devices can be designed in such a way as to allow venting or some other form of pressure relief in a fire.[/quote]

The first use US use of IHE was in 1979 in nuclear weapons, so the concept isn’t new. The article is pretty shallow.

Cheers,

Lew


#10

Navy projectiles were not totally safe. During the Vietnam war several ships encountered “in-bore” explosions where the projectile detonated when the gun was fired.

USS Lowry (DD-770) in June 1969 had one in a forward 5"/38 mount which killed one sailor and injured eight others. USS Newport News had one in the center gun of Turret 2, (I don’t know how many casualties from that one, but they never repaired that gun, and used the turret with only two good guns. I believe there were also incidents with 5"54 guns and I believe one with a Rocket Assisted Projectile (RAP) round.

I vaguely recall the outcome being a decision to stop using one type of explosive in favor of another, but I do not recall which they decided were good or bad ones.


#11

The Newport News lost 20 killed and 36 injured in that explosion.


#12

Torpex dates back to WWII and while it is safer than TNT even the MK14 and MK16 torpedo warheads were retrofitted with one of the H compounds, probably in the 60’s. Some Torpex may have stayed around but I never saw any by the 1970’s. With the advent of the MK 46 (surface) and MK 48 (submarine) programs in the late 60’s and 70’s torpedo warheads were using a PBXN compound. Our training manuals referred to it as “a high-energy fuel” and it was extremly stable except to extreme shock, such as booster charges. Keep in mind that the intent of these explosives was to create gas bubbles and shock but neither torpedo used contact exploders.


#13

I was steaming with the USS Newport News Heavy cruiser while in Viet Nam. She was 1,000 yards off of our starboard side when Turret two,gun two had an in bore explosion. It was found the the projectile had the base detonating fuze seal installed upside down. When the gun fired, the shell had a low order detonaion in the bore of the gun blowing the barrel backwards which caused the breech block to cam open as it moved forward. The gas pressure and heat caused secondary ignition of the next several powder charges in the gun’s loading system to fill the turret with fire,extreme heat and poisonous gases. These gases went from the turret down into the berthing area behind the turret. Many men were killed below decks. My ship the Joseph Hewes rendered assistance. We later met her in Subic Bay,PI. I went over to show my respects to my fallen friends. I took a few photo’s without permission in case there was to be a cover up.
I lost 13 friends in the explosion. We all were in the same “A” school class from the Green House.
I don’t know about the 5"/38 projectiles.
I can provide photo’s of the damaged gun if you want.