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Re: Go Navy!

Posted: Thu Sep 15, 2016 9:01 pm
by ladajo
On the ship is really is like getting slapped by god.

Re: Go Navy!

Posted: Thu Sep 15, 2016 10:00 pm
by Tom Ligon
I've never personally been thru the tests. We had to have it done for a large slipring assembly we built for the Pegasus hydrofoil, back in the last millenium. I had to build the test harness, originally for lab testing, and the company did not want to spring for the proper mil spec connectors, about $400 each. So I made some up with home-made insulators and no screw on shells. But then they found out about the Slap of God, and told me that my connectors had better not let them down.

We lashed the things down with all sorts of lacing cord and it worked. The big aluminum frame built to hold the slipring assembly was crushed, but the kludge cables and the slipring did OK.

The "Slap of God" line made me grin. Here's a line from a story I published some years back, "Rendezvous at Angels Thirty." The protagonist has just finished his first hyper-realistic Mustang simulation using a future technology.

I pointed to my Mustang, parked across the hangar. “It is exactly like the real thing, in every respect I can tell. The gee forces, vibration, temperature, you even got the smell right. But Walkin’ Cane over there does not have real guns. I’ve flown simulators for decades, civilian and military. Most make a nice rat-a-tat-tat noise when you pull the trigger, and shake a little. But this one … incredible! I felt like a god! I felt like Thor hurling thunderbolts! It was frickin’ awesome!”

Re: Go Navy!

Posted: Sat Sep 17, 2016 2:30 am
by KitemanSA
paperburn1 wrote:I have been near some big bangs before but that would be incomprehensible to me. It looked like hatches bounced in that on vid.

I think the technical term is Big da da boom :lol:
And just think, that was probably ≤1/2 design level!
Check out MIL-SPEC MIL-S-901D.

Re: Go Navy!

Posted: Sat Sep 17, 2016 5:04 pm
by ladajo
To get a sense of what a ship can take, check out this vid. shot this year during RIMPAC, former ship of a buddy of mine.

Time 1:14 first hit, small weapon (not a Harpoon).

Time 3:09 showing more small hits, and a (probable Mk.82) 500lb bomb hit damage aft.

Time 7:14 Mk. 48 Heavy Weight Torp hit. Notice the whipping effect the length of the hull.

The Perry Class were built tough.

Here is an LPD getting shellacked for comparison.

Re: Go Navy!

Posted: Sat Sep 17, 2016 11:05 pm
by krenshala
darn, but that ship looks like it could at least limp home even after the heavy torp hit!

Re: Go Navy!

Posted: Sun Sep 18, 2016 8:05 pm
by Tom Ligon
krenshala wrote:darn, but that ship looks like it could at least limp home even after the heavy torp hit!
Read Last Stand of the Tin Can Sailors (Ladajo and I have). The accounts of the damage absorbed by a Fletcher-class destroyer and a Butler-class destroyer escort (Johnston and Roberts) during the Battle Off Samar. While both were sunk, the amount of damage each took, and continued not just to limp but to fight, was mind-numbing. This included hits from the largest battleship afloat, the Yamato.

Presumably the ships today are tougher.

A torpedo bow shot like the one shown, fired by one of the two ships above, took the bow clean off of a Japanese heavy cruiser in that battle. That an essentially unarmored frigate could handle such a blast is incredible.

Had there been a turret on the bow (there seems to have been a dummy structure there) the gun there would have been lost. Likewise, the buckled deck at the stern probably would have taken out the steering. The hits amidships look well positioned to damage the engine rooms. The Johnston took damage like this and more. It lost multiple guns but kept firing, could barely make way but kept doing so, and the rudder had to be activated by the skipper standing on the deck shouting commands to men manhandling the steering gear below the deck.

The Thatch, shown in the video, probably sank due to lack of a crew on board. In a battle, damage control might have saved it. I expect it was rigged with watertight compartment sealed, accounting for the time it took to sink. That it did sink after 12 hours suggests relatively small leaks, something one might well seal with an intrepid team of sailors. I notice a gun amidships seems undamaged, and little damage to the superstructure, so it is possible this tub could still direct fire. I don't know much about the missile arrangement on these, but it may have still had teeth.

Re: Go Navy!

Posted: Mon Sep 19, 2016 1:01 am
by ladajo
The mount forward was for the Mk.13 single rail missile launcher. They were removed from the Perry Class over the last decade or so in anticipation of decommissionings. The main battery was (none left now in the USN) a 76mm Oto Melari. That mount is very modular, however unmanned. There used to be manual directors mounted on top on the pilot house to allow direct control of the gun via servos/synchro circuits. Normally it was fired using radar tracks from either the Mk.92 CAS or STIR fire control antenna.
The damage Thach was shown to take would probably have resulted in a loss of propulsion. Not so much due to main engine damage, but the probably 500lb bomb hit aft of the hangers. Below that is AMR3, and the admin office complex, and at the bottom, the main line shaft passing from the MER (which is directly below the stack and the front ends of the helo hangers) to the wheel. If the shaft remained rollable (a possibility), then steering would have been at a minimum available in aft steering which is all the way astern. If the Mk.13 had remained installed, I doubt it would have been functional after the torp hit. Also lost would have been the APUs, and AC Mach, which is a major source of cooling for combat equipment. That said, there were other ways to cool. The midships hits seemed to be hitting around berthing spaces for the most part. There is a good chance that either or both of the SSDGs in AMR2 would have survived and remained functional. #1 SSDG was probably done, as was #4 which lives in AMR3. With two SSDGs you can do a lot. CIC looked fairly untouched, it is aft of and below the Pilot House. All of that said, the shock effect of the torp hit would have been significant in both equipment damage and personnel casualties. It literally is the Slap of God. Watch the video again and look for the longitudinal whipping from the slap. One sharp hit, and lots of resonant wiggle. While Perrys are really hard to sink, proven several times, that shock damage to gear and crew may have taken her out of the fight, for sure for a while. One does not really know until you try, which is one of the reasons we do shock testing, as well as Sinkexes. I served on two different Perrys in my time, and can tell you I always felt they were really strong and well built.
And I did really enjoy "Last Stand", as well as the following precursor "Neptune's Inferno". Another good read is Ian Toll's new work, "The Pacific Trilogy" which has "Pacific Crucible" and "The Conquering Tide" released so far.

Re: Go Navy!

Posted: Mon Sep 19, 2016 2:39 am
by Tom Ligon
Indeed! The Johnston was not struck by a torpedo, and it would have been bad news. It was believed to have been struck several times by main guns of battleships (IIRC), some of which went thru the lightly-armored ship without detonating. AP would have been designed to go off after hitting an armored deck and so the shells tended to not recognize a DD as n actual hit. Still, a 14" or 18" cannonball is not trivial to a destroyer.

The bow torpedo hit on the cruiser Kumano, believed to have been fired by Johnston, blew her bow off. The Kumano was out of action and later sank, and the cruiser that stopped to help her was effectively out of the fight as well. A torpedo can sink anything with a good hit, and DDs and DEs both carried them.

The sheer tonnage, number of guns, and size of guns in this engagement was totally lopsided in favor of the Japanese. I think I worked out that the American DDs and DEs attacking the Japanese fleet were taking on something like 24 times their mass in fighting enemy. Two DDs and one DE were lost. Three Japanese heavy cruisers were lost and the other three had their superstructures shredded by highly accurate fire from the tiny 5" pop guns of the tin cans. And then the Japanese turned tail and ran, a turn of events that baffled the outgunned Americans.

This was all done on sheer guts and audacity. The the Johnston, Hoel, and Roberts were all mangled beyond any hope of being effective fighting units. In any other circumstance they should have withdrawn. But they didn't. The surviving crewmembers did what damage control they could, got what could still run to run, jury-rigged human-powered steering, and fought to the bitter end, because there could be no retreat and there was nobody to replace them.

And they won. Commander Evans of the Johnston believed before that battle that destroyers could fight a lot harder than most people realized. He got to prove it. The Medal of Honor was posthumous.

Would this little frigate still have been able to fight in such a circumstance, with this kind of damage? A lot depends on the exact damage, of course. It is, of course, pretty unlikely that it would ever face a big gun battle fleet in a lopsided engagement in favor of the other side, especially with our modern Navy at its back. But I'd personally not want to piss off even the smallest of the US Navy ships carrying missiles. In this scenario, the first couple of hits were not fatal, although might kill propulsion. If the missile launcher were still operative, God help the other guy.

Ladajo, what do you think a modern destroyer or frigate could have done to Center Force? Not even a fair fight, I'm thinking, especially if you had a couple of teensy little nukes in the mix. The battleships might survive.

Re: Go Navy!

Posted: Mon Sep 19, 2016 4:07 pm
by ladajo
An FFG and Flt I/II DDGs both carry Harpoon, which is a big pop. So with OTH targeting (ESM or Helo), they could reach out and make holes while staying out of counter-battery range.
The irony isi that an FFG fired Harpoon from the Mk. 13, and thus was limited only to max magazine loadout. Nominally they would carry 8. DDGs carry Harpoon in the deck mounted canisters, which limits them to 8 (two four packs).
No modern ship carries Heavy Weight Torps, which in my mind is a massive mistake. The idea is that with air power in the mix, you would never get close enough to shoot them. I disagree, especially one the first volley. And modern HWTs have some legs.

Gunnery wise, there is no comparison. While a 76mm has no real punch weight, it can penetrate with some armor piercing, and it shoots at up to greater than 80 rounds/minute (which is the ring load, inner and outer as I recall). Once you shoot the ring, firing rate is pretty much limited to how fast you can drop new rounds into the ring.

Notice how stable the mount is on target, given the ship rolls.

CIWS, especially Block 1B is not fun for the receiving end, however it is range limited to up close and personal.

The second link shows 76mm with a higher rate of fire setting, and it also shows a CIWS burst of about 150 rounds.

The third link shows an updated 76mm mount, and more importantly the ring loader under the mount.

Re: Go Navy!

Posted: Mon Sep 19, 2016 4:27 pm
by ladajo
5 inch guns in the mix, are even more lethal. Especially when firing with the Optical Sighting and a Laser Range Finder (Can you say 5inch sniper rifle?) They typical fire up to 20 rounds per minute, depending on round mix types. Single type shoots faster than mixing.

A DDG has one mount, while a CG has two.

Then, if you add in Standard Missiles in surface mode to the mix, a legacy platform is going to be gutted probably before they get a ranging shot off. ... destroyers ... apon-15132

Re: Go Navy!

Posted: Thu May 11, 2017 9:37 pm
by paperburn1
At first I thought this was an article from the Onion.
This means a major retrofit ... -launchers
:!: :!: :!:

Re: Go Navy!

Posted: Thu May 11, 2017 11:19 pm
by ladajo
They won't do it. It may eventually surface again in the mix as a media, "Trump got it wrong". In this case Trump is speaking of what he knows not. EMALS is far superior to steam for many many many reasons. The least of which is cycle rates. Probably topping the list is that you can launch things with EMALS that you could NEVER launch with steam.


Re: Go Navy!

Posted: Sun May 14, 2017 8:50 am
by KitemanSA
IIRC, they CAN'T do it. All the pipe paths they held in reserve to install steam if EMALS didn't work have been released and used. They were getting close when I left.

Re: Go Navy!

Posted: Mon Aug 21, 2017 2:52 pm
by paperburn1

Re: Go Navy!

Posted: Mon Aug 21, 2017 4:17 pm
by Tom Ligon
paperburn1 wrote:ZAP BOOM pew! Pew! ... ge/139953/
As much fun as that sounds, Ladajo's TNT converter says their future capacity of 32 MJ is 6.928 kg of TNT.

Needs some work yet. But this could be an interesting way of plinking the LFT's rockets. ... joule&v=32