KV1 restoration complete rebuild

Wow didn't know that but I had heard many of the units that had to train for scaling the cliffs had numerous accidents. Like guys getting hurt from slipping and then hitting the rocky cliff face some losing their footing or grip and falling to their death. And yes the long delays probably got troops antsy and they drilled them more than they had thought they would need to just to keep them from going stir crazy and keep them focused for the attack which they expected to be really bad. We were really fortunate that the Germans really thought we would land else where and had shirted most of their defense if they had had known the real target it might have been a different story as to how the landings went and if hitlers officers weren't afraid to tell him what was going on and the reserves were sent in as soon as the assault started who knows what would have happened. To lose a war because of a temper tantrum like really. Was her a man or a kid, plus if his staff was that afraid of him then even they knew he was unstable.

 

I think the Marines were pulling your leg about the cranes, though there are semi-regular incidents with the AAV actual sinkings are rare, each has four bilge pumps, each pump capable of removing 400 gallons of water a minute.

The AAV/LVTP-7 is actually a very good vehicle and has been in service for 50 years now (introduced 1972). It was, as you noted, built by FMC (Food Machinery Corporation), the same company that built the original LVT's (LVT-1, -2, -(A)1, -(A)2, -(A4), -(A)5, -4 of WWII). The only exception was the LVT-3 which debuted at Okinawa it was built by Ingersoll division of Borg-Warner and Graham-Paige Motor Corp.

The problem with the AAV-7 is its age, the Marine Corps operational tempo and other, more pressing areas for the Marine Corps funding. Over the last couple of decades, they've cut personnel, which means fewer operational battalions, to have the money to modernize or acquire new equipment, which increases operational tempo and reduces dwell time where extensive maintenance and training should be conducted. Then they'll get additional funding and get to add back cut assets, and parts and time to get the personnel and equipment back to training and maintenance levels that they want. One of the most recent cuts is the disbanding of the tank battalions which have been an intrinsic part of their structure since the 1930's. Marine tanks fought on Guadalcanal, the tanks of the defense battalions supported US Army units in the Central Solomons because the Army infantry divisions there had no intrinsic armor at the time, the first US Navy LSD (Landing Ship Dock) USS Ashland LSD-01, landed the first medium tanks in the Pacific at Tarawa. Then were present in every other Pacific land assault. Marine M-26 tanks with the 1st Provisional Brigade met and defeated the North Korean juggernaut at Pusan, dominating the T34/85. The iconic pictures of M-48's in Vietnam, and every conflict up to now. During the brutal fighting around Sangin in Afghanistan in 2010, the Marine Corps deployed tanks (the first US deployment of tanks to Afghanistan) and they were quite effective.
Then you have time. Every time Congress or DOD decides they'll add some feel-good training, some actual useful training gets sidelined or skipped. One of the issues in the Catalina incident was lack of underwater egress training, I'm sure that time block was re-purposed to fulfill a required instruction period into "being more sensitive to non-binary gender identities" or "recognizing and avoiding microaggression's", this in a service that specializes in macro-aggression and violence of action.

Riding in an Amtrac is an experience, unless they were recently deadlined and underwent Sustainment Level Maintenance or were recently returned from Depot Level Maintenance, they leak around the hatch gaskets. Water, swirling around the floor mixed with diesel/oil residue, then diesel fumes from being "buttoned up", makes some people sick and they puke which adds to the stuff swirling around in the floor, making more people sick. Then when you splash out of the well deck you can feel it going down, then you bob back up. It is a relief when they open the TC's/Drivers hatches allowing fresh air in.

AAVs Launched & Recovered By USS Rushmore - YouTube

We lost one in the Med when we were on a float once. Only one of the 4 pumps was working when it was splashed, and the hatch gaskets had not been replaced in forever, but the one working bilge pump was keeping up and the operational requirement forced it to be used. On the way to the beach the engine quit, and it went dead in the water and broached, got side on to the waves. We were supposed to have Navy LARC-V's LARC-V - Wikipedia as safety vessels but they had all been deadlined (stuff breaks during a 6th month float), so they sent a "Mike" boat to get the Marines off and tow the track back to the ship. They got all but two of the Marines off when a wave lifted the "Mike" boat and the ramp came down on top of the track, killing the Marine exiting one of the top hatches and causing a large volume of water to enter the open hatches. With the additional volume of water entering the trac, it started sinking rapidly and went down like a rock. One Marine was still inside but he managed to egress, swam to the surface and was picked up. Apparently, in the recent Catalina loss, the ships safety boats were down and not available, so they used two LVT's to act as safety vessels, not an optimal solution.

Now LCAC's can get you to the beach quickly, 40+ knots carrying 60 tons of men and equipment, but they lack some of the AAV's tactical advantages. The AAV can act as an APC if the unit is Mech'd up and allow for rapid advance with troops protected from small arms and fragmentation or the troops can dismount and the AAV can provide support with its 40mm and .50 cal.

This video shows how 2/5 (2d Battalion 5th Marines) was mech'ed up for the Iraq invasion, an infantry battalion, married to tanks and tracs. The video footage used was from an ABC news reporter that embedded with Fox 2/5.
Sacrifice - YouTube
Note the combat power rolling down that highway!

This video is of 3/1 in Operation Phantom Fury, the Battle of Fallujah, if you look closely, you'll see tracks a number of times. They brough ammo and supply forward to the Marines, supplied direct fire support and evacuated the wounded.
Operation Phantom Fury - YouTube

The AAV's first potential replacement the LVA, landing vehicle assault started development in 1974. It never got very far and was rolled into the development of the EFV in 1988, its development progressed far enough to have a contract awarded in 1996 for General Dynamics Land Systems. It never lived up to its hype and despite being in development for decades it never had all its problems worked out and was cancelled in 2011. It is interesting that another program the Pentagon and Secretary of Defense tried to get the Marine Corps to cancel at the time was the MV-22 Osprey. The Air Force was particularly skeptical of the MV-22 and pushed to have it cancelled. Funny how once the Marine Corps worked out the bugs the Air Force was quick to adopt them. Japan, India, Indonesia and Israel now operate them as well.
The ACV (Amphibious Combat Vehicle) has started entering service. It is a wheeled vehicle which reduces maintenance hours and costs over a tracked vehicle, but it has problems as well and is currently not allowed to swim, so the venerable AAV-7 will need to soldier on for a while longer.
So, don't accept all of China's hype at face value. We have greater experience in modern amphibious warfare going back to the 1930's and can carry this most complicated of operations out, routinely. If we can't get all the bugs worked out despite our greater experience, institutional experience, knowledge and industrial expertise, I doubt they've got their bugs worked out.

 

I took that ride in NROTC summer training in 1975, off the stern ramp of an LST. It was a one-time experience for midshipmen, and now that you mention it, I don't recall any egress training or briefing.

 

Yep, splashing in an Amtrac is an experience not soon forgotten. I don't recall us getting egress training either until years later, I think that is something that was adopted due to accidents. I know they also have the egress training for aircraft now and we had a hard water landing in a CH-46 years before I went through egress training for aircraft.