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Re: LRASM sensor production 2017

Unread postPosted: 28 Jan 2021, 06:41
by element1loop
mmm wrote:What is the "shock speed" mind if I ask? I assume it doesn't mean detonation velocity, even going from TNT to HMX don't produce that much difference. I'm sure warhead's gotten better over the years, especially in insensitive munition department, just nothing I see suggest that much more energetic. Then again I don't claim to be the expert, I'd welcome the source.

The amount of explosive used for Cole bombing is about comparable to up to 1000lb warhead, given not all warhead mass is explosive.

Enough slights thanks, this is a discussion.

The shock-speed is the sustained propagation speed of a shock wave through an explosive material. The shock results in detonation behind the shock front as it propagates. It governs the rate the material can release the chemical energy it has available. A faster shock-wave equates to a faster energy release, and a sharper impulse transient, when the shockwave interacts with surrounding materials, like a frag-tamper, or bulkhead. More impulse force is delivered in a shorter period of time. Very fast shocks produce strong sharp disruptive shattering impulses. Lower-explosives produce more gradual energy rise and a tendency to shove/push/deform objects more than shatter them or completely blow them open.

Aluminium is much more ductile than steel, which is to say even ductile forms of steel are likewise much more brittle than aluminium. So USS Stark being an aluminum upper structure with a steel hull, was much more prone to deformation above deck, to absorb a medium shock speed impulse than the steel hull would be, which is more prone to shattering, cracking, ripping and blowing open.

Source examples of the practical difference were already given above, i.e. the NSM detonation above of a very fast explosive, compared to a SINKEX Harpoon strike which has a moderate speed explosive. Those are quite a bit better than dry text to make the point.

USS Stark’s damage, a ripped open steel hull, but a mostly deformed aluminum structures above it (488 lb warhead):

NSM's smaller very fast shock speed warhead produces damage on another level (276 lb warhead):

There's no comparison in damage level between a medium explosive, and a smaller amount of a fast high-energy explosive. A fast explosive detonating inside a steel ship is going the destroy it.

Explosive warhead designs have not remained about the same energy release with time. The warhead of an SDBI (36 lb of AFX 757 fast explosive) is described in effects as equivalent to a Mk-82 500 lb LGB (192 lb of low to medium speed explosives mixed). Explosions are chemical energy release, every explosive material has its own shock speed, plus different atoms and different molecular bonds between them, Completely different energy release as a result as the energy comes from the bonds that change configuration. No explosives produce the same energy release level.

Newer insensitive munitions warheads are using faster explosives for sharper more shattering impulses to break things apart, combined with a higher energy release per pound, to then 'blow' them apart. Blowing as in a fast wind. A higher pressure transient and higher temperature is produced to make that faster wind. Compression produces heat. Shorten the pressure's rise-time with a faster explosive that releases more gas (and its wind) sooner, and the explosion will be hotter, it will incinerate more of what is available to be burned, and will blow things apart with more energy. Faster more penetrating frag from smaller warheads.

Re: LRASM sensor production 2017

Unread postPosted: 28 Jan 2021, 08:48
by hornetfinn
mmm wrote:It's a good question to ask under what circumstance the new generation of IIR anti ship missile can fail. AIM-9x was widely assumed to be infallible to flare in the enthusiast circle, not least to Syrian SU-22 in a very high Pk shot, only then theories started to come out. SRBOC does include infrared flare as is, hard to say how the success rate is compared to better tested aircrafts. Reminds me of the story DDG laying carbon fiber smoke screen(although as I understand it was for radio frequency), as if back to WW2. May not be that outlandish afterall, all you can assume these day is that technology monopoly won't last forever.

That AIM-9X launch against Syrian Su-22 most likely failed for some other reasons than being seduced by flares. The Super Hornet pilot said that he lost the sight of the missile right after he launched it. If it was countered by flares, it would've guided towards the Su-22 and went after flares only when it got close to it. The SH pilot would've been able to observe the missile flight and know if it missed or hit. It was not some high-G HOBS missile shot after all. Basically most likely reason is missile malfunction of some kind because of defect or maintenance error. There is always the possibility that missile fail for some reason or another. Anti-ship missiles have been very reliable in combat though.

Re: LRASM sensor production 2017

Unread postPosted: 28 Jan 2021, 10:27
by spazsinbad
I guess the story about the Shornet shooting down the Su-22 will continue to be retold incorrectly for ever and a day. The Super Hornet flew past the Su-22 warning it by ejecting flares. The Su-22 took no notice so the Super Hornet fired a malfunctioning SideWinder. Yes they disappear almost instantaneously if they malfunction, especially if they go wide out of the usual field of vision expected. So then the AIM-120 was used as per SOP to shoot down the oblivious it seems Su-22.

Su-22 Shoot Down 4 USN Pilots Explain TAILHOOK 2017 Excerpt [7min 12sec]

At 4min 28sec 'MOB' [Shornet pilot shooter] says "execute a HEAD BUTT" (flypast ejecting flares) & calling on GUARD. He does this THREE times with no result then the Su-22 drops ordnance so 'MOB' SHOOTS BAD AIM-9X etc.

Su-22 Shoot Down 4 USN Pilots Explain ALL at TAILHOOK 2017 [47min 27sec]

Re: LRASM sensor production 2017

Unread postPosted: 28 Jan 2021, 12:59
by spazsinbad
.MP3 sound only excerpt of LCDR 'Mob' Tremel describing 3 WARNING FLARE / Guard Passes (Head Butt) then Shoot Down.

Re: LRASM sensor production 2017

Unread postPosted: 28 Jan 2021, 13:15
by spazsinbad
Su-22 Shoot Down LCDR 'Mob' Tremel Explains Warnings at TAILHOOK 2017 [same as .MP3 file]

Re: LRASM sensor production 2017

Unread postPosted: 03 May 2021, 13:51
by spazsinbad
US Navy Issues Details on New Offensive Anti-Surface Warfare (OASuW) Increment 2
03 May 2021 Xavier Vavasseur

"Naval Air Systems Command (NAVAIR) issued the latest details about an upcoming competition for the U.S. Navy's next anti-ship missile known as the Offensive Anti-Surface Warfare (OASuW) Increment 2.

A notice published on 30 April 2021 on reads: ... f3900/view
The Naval Air Systems Command (NAVAIR), Program Executive Office for Unmanned Aviation and Strike Weapons (PEO (U&W)), Precision Strike Weapons Program Office (PMA-201) announces its intention to design, develop and procure a carrier aircraft-based offensive strike weapon. The Department of the Navy is developing the Offensive Anti-Surface Warfare Increment 2 (OASuW Inc 2) based on recently completed OASuW analysis activities. OASuW Inc 2 is envisioned to be a long-range, carrier-based, strike fighter aircraft-launched weapon system providing ASuW capabilities. The program is part of the Navy’s Long Range Fires investment approach to meet objectives of the National Defense Strategy. As a key component of this strategy, OASuW Inc 2 will address advanced threats from engagement distances allowing the Navy to operate in, and control, contested battle space in littoral waters and anti-access/area denial (A2/AD) environments....

...The notice published on 30 April 2021 adds:
The Navy has begun fielding OASuW Increment 1. However, threat capability continues to advance and additional range and warfare capability and capacity is required to address the more demanding threat environment. The Next Generation Land Attack Weapon Analysis of Alternatives helped better define part of the battlespace, but was primarily focused on land threats. Further analysis was completed to determine the potential alternatives to address ship-based threats and constitutes the primary focus area for OASuW Inc 2. However, land strike does have value to the Government, albeit less important than ASuW, and is an area that the Government also wishes to characterize potential weapon performance.

The Government expects the acquisition to follow a competitive, phased approach with initial activities focusing on system concepts, model-based systems engineering, preliminary design and technology development and technology integration efforts. Successful offerors may have the opportunity to continue with detailed design, production activities and technology insertion efforts as part of future contracting efforts.

Requirements (Unclassified)
• Operational range: Long Range
• Target peer combatant ships
• Launched from carrier-based strike aircraft"

Photo: "F-35 fighter fitted with two LRASM. Lockheed Martin image." ... Martin.jpg

Source: ... crement-2/