Thoughts and prayers: 15th MEU AAV sinks...

I'm sorry for the loss, you would think that there would be time to at least get everyone safe for the float and wait for pickup...
The troop compartment of the AAV is cramped and has only a few doors and hatches.
The inside is also very dark.
Getting from the troop compartment to the troop commander's hatch or to the turret hatch is even more cramped.
Those (armored) doors and hatches are very heavy.
Some require two people to lift.
While floating, the rear ramp and the ramp door are impossible to open.
When the AAV sank and if it pitched and/or rolled even slightly, then those inside would quickly become disoriented, making their escape even more difficult.
 
The troop compartment of the AAV is cramped and has only a few doors and hatches.
The inside is also very dark.
Getting from the troop compartment to the troop commander's hatch or to the turret hatch is even more cramped.
Those (armored) doors and hatches are very heavy.
Some require two people to lift.
While floating, the rear ramp and the ramp door are impossible to open.
When the AAV sank and if it pitched and/or rolled even slightly, then those inside would quickly become disoriented, making their escape even more difficult.

I was thinking about this today.

I'm not a marine and I've never ridden in an AAV, but I spent a lot of time in APCs and none of them was easy to get a lot of people out of quickly without opening that rear ramp. Horrifying to think about it sinking.
 
Turns out they were from B Co., 1/4.
Searching has been suspended and recovery operations have begun.
Another guard relief has been posted to the streets of heaven's scenes.
Semper Fidelis!
 
A sailor and seven Marines are presumed dead:
  • Pfc. Bryan J. Baltierra, 19, of Corona, California
  • Lance Cpl. Marco A. Barranco, 21, of Montebello, California
  • Pfc. Evan A. Bath, 19, of Oak Creek, Wisconsin, a rifleman
  • US Navy Hospitalman Christopher Gnem, 22, of Stockton, California
  • Pfc. Jack Ryan Ostrovsky, 21, of Bend, Oregon, a rifleman
  • Cpl. Wesley A. Rodd, 23, of Harris, Texas, a rifleman
  • Lance Cpl. Chase D. Sweetwood, 19, of Portland, Oregon, a rifleman
  • Cpl. Cesar A. Villanueva, 21, of Riverside, California, a rifleman
 
Marine AAV Hit Rough Seas, Rapidly Took on Water Before Sinking

The three Marine Corps amphibious assault vehicles that left a training beach on a California island last week took the normal preparatory steps before entering the water, the service's top general said this week.

But they hit rough seas after passing the surf zone on their way back to the amphibious transport dock Somerset from San Clemente Island, leaving one AAV filling with more water than it could pump out, Commandant Gen. David Berger said on Monday. Nine of the 16 troops inside that vehicle were killed in the accident that left the AAV on the seafloor.

"Eventually that trac sank," Berger said, referring to the amphibious tracked vehicle, colloquially known as an amtrac. "The other amtrac converged on it and pulled some of the Marines out of the water. And they had safety boats in the water as well, which pulled some Marines out of the water."
 
Marines find human remains, vehicle that sunk in California training accident

The Marines Corps has found the amphibious assault vehicle (AAV) that sank off the coast of Southern California last week, killing nine service members, the service said Tuesday.

The 15th Marine Expeditionary Unit (MEU), I Marine Expeditionary Force (MEF) and the Makin Island Amphibious Ready Group found the AAV on Monday, according to a I MEF news release.

The Navy’s Undersea Rescue Command also found human remains on board by using an underwater remotely operated video system from a merchant ship, the release added.


https://thehill.com/policy/defense/...cle-that-sunk-in-california-training-accident
https://thehill.com/policy/defense/...cle-that-sunk-in-california-training-accident
 

I would be curious to see the specific reason for relief. The ground based services tend to be a little bit more disciplined than the Navy with their relieve everyone for a hangnail mantra.

I suspect a systematic training or maintenance program issue that affected the battalion as a whole. Much of that would be business as usual in every other battalion out there. 999 times out of 1000 it works as we have limited time, we have to train, and we can mitigate most risk. Once you get over 999?

I've been involved with training fatalities. It sucks-really f***ing bad.
 
I would be curious to see the specific reason for relief. The ground based services tend to be a little bit more disciplined than the Navy with their relieve everyone for a hangnail mantra.

I suspect a systematic training or maintenance program issue that affected the battalion as a whole. Much of that would be business as usual in every other battalion out there. 999 times out of 1000 it works as we have limited time, we have to train, and we can mitigate most risk. Once you get over 999?

I've been involved with training fatalities. It sucks-really f***ing bad.

I have too. Operational fatalities too. The training ones left me more shaken.

"Information was not immediately available on Regner's next assignment.."

I've got a guess or two, and they involve terminal leave. Might not have been his fault, but he's still accountable.
 
With regard to the seaworthiness of a Marine AAV (of which I was a crewman/crew chief) it is extremely sea worthy, until it is not and then it is just a matter of seconds before they go down.

They have two hydraulic and two electric bilge pumps which do a good job of clearing random water that comes in open hatches and leaky seals but if there is a catastrophic hull breach there is little hope for anyone not already riding at either the drivers, troop commanders, or weapons turret hatches.

One vulnerability is the positioning of final drive units in the hull. Unlike a tank where the engine and final drives are in the rear and protect from impact during operation, in an amtrac the engine is in the front beneath the plenum and final drive units are bolted into either side of the hull turning the drive sprockets at the front of the track.

One of my biggest fears was always the potential of striking the ship's ramp while coming onboard in high seas. You had to time the swells and make a rapid final approach into the welldeck when the ramp was fully submerged as you and the ship both rode the swells. If you got it wrong and struck the ship's ramp on a high swell you could potential pierce the hull or rip the final drive from the hull and that will leave about a 2 foot diameter hole in your hull and there is nothing that will stop that tractor from going to the bottom. I was not there but this happened in Subic Bay once, there were no grunts onboard and the crew were in hatches so they got out. This danger was more of a thing coming onto an LST with its shallower draft and smaller well deck than it was on a LPD, LSD.

But also you could always damage the seal on a final drive while ashore and not realize it until on your way back to the ship.

Another vulnerability is the tractors ramp, which along with a personnel hatch built into it, has an emergency disconnect handle that essentially unpins the entire ramp from its hinges and lets it fall away.
When the tractor splashes off the back of a navy ship it submerges just a little for a few seconds till buoyancy settles and it is not at all uncommon for some seawater to come leaking in the large troop hatches which make up the roof of the troop compartment. Now if you are a grunt crammed into the dark troop compartment of a vehicle accelerating off the back of a ship and bouncing into the ocean you might be a little nervous when water starts to splash in.
It was in fact standard operating procedure to position one of the crewman in the jump seat near the rear hatch holding a 16 inch wrench with orders to brain anyone who tried to touch that ramp while we were underway.

I have no idea why these poor fellows went down but when you take a 25-ton vehicle off the back of a ship into the ocean miles from shore there are inherent risks.

🐯
 
I’m shocked at the tolerance for laxity in watertight integrity. I get the impression after reading a handful of articles about the investigation that mechanical failures were just shrugged off, with little importance to seals, closures, and fittings.
 
I’m shocked at the tolerance for laxity in watertight integrity. I get the impression after reading a handful of articles about the investigation that mechanical failures were just shrugged off, with little importance to seals, closures, and fittings.

I'm not in that service, but I wouldn't be surprised if it is a vehicle vs vessel mentality combined with the standard just make it happen attitude which is prevalent in the two ground services and only comes out in the open after an accident.
 
Training fatallities suck for sure. I was attatched to the Third Marine Division, MP Co., on Okinawa, in 1970, after the Corps., pulled us, "the Third Marine Division", out of Nam, and sent us all to Oki. C.I.D. came to me one day and said they needed a NCO, me, to go out to the mortar range. The Corps. was in the process of pulling out of Viet Nam completely, but had not yet ended, sending troops to FMF WEST PAC, so troops were piling up in Okinawa, to be reasigned all over the place. The troops needed something to do, so they were practicing being Marines. To that end, the mortar range was pretty active, with training. One of these troops, got a round lodged in a mortar tube. A boot 2nd Lt. was in charge, along with a Gunnery Sgt.. As you would expect, the Gunny took charge of dislodging the stuck round. The Lt., reported to me, that the Gunny had been banging the tube on the ground, in a attempt to free the round, which was correct procedure, but when the round dislodged, the gunny's face/head, was partially in the way of the tube. The round took off about half of the Gunny's head. When I got there, the Marines were standing in formation, at attention. The 2nd Lt. was also at attention, covered with brain matter, on his field jacket and snivelling. The Gunny, sadly was dead. It was my responsibillity to document what I could and to recover as much of the Gunny as I could. To this day I can't get the picture of a piece of his skull, on the edge of a cliff, rocking a bit, in the high breeze, on the edge of the cliff, or the shocked look, on what was left of his face. I got the Gunny into my jeep and headed for sick bay, where I had to go through his persoal belongings/wallet. In the wallet was a picture of his wife and three beautul children. He was of retirement age, or very close to it. Such a needless death. I never had the honor of meeting the Gunny, but he'll be with me and not forgotten for the rest of my life. The tragedy and loss, in this thread, brings the Gunny, back to my thoughts. A Corpsman and seven Marines lost. The pain that this loss will bring so many people, saddnes me greatly. R.I.P. Brothers.
 
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The large photo below is of an AAV disembarking a ship. In the cropped photo I have added a couple of arrows that point out the front and rear plenum grates.

When on land engine cooling is accomplished by air being drawn across a very large radiator by a fan. The plenum system is like a cooling tower, airflow enters through the front grate on the deck into a duct, it is then drawn through the radiator, and forced out another duct to the rear grate on the deck.

Before entering the water the water jets are activated and the hydraulic system raises plenums covers against the underside of those grates that you see, this prevents water from entering the engine compartment. This naturally also cuts off the air flow to the radiator, and so at the same time the plenum is closed the engine coolant is diverted to a contact cooler in the bottom of the hull where engine cooling is accomplished by sinking the heat through the hull to the ocean water.

According to the article it was a seal around the "plenum" that allowed water to enter, honestly I am not sure if they are talking about the plenum cover itself or the plenum door (unit containing the front plenum which can be raised to access engine).

In the photos here (unrelated to the accident) I can tell the plenums are closed by zooming in and looking for the indicators, capped rods that are pushed up by the plenums (we called them mushrooms). Driving into the ocean without closing the plenums (check those mushrooms) is an immediate catastrophic failure.

The thing about the headlight leaking would on its own have been minor.

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🐯
 
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