Things are bad in Marine budget land and if my guessing is correct, its gonna get worse (by that I mean the F-35's maintenance costs will be so extreme that for the lifetime of the plane we won't be able to buy new armor).
If my beliefs are correct then we must do something about the AAV.
Unless the brainiacs at BAE or General Dynamics (not including Lockheed because I don't know if they would even bid on redesign work for an existing armored vehicle) can take the existing design and improve the hydrodynamics while increasing IED protection then we've got to work with what we've got.
I've covered what needs to be done with regards to firepower, protection and over ground mobility. But what about water speed? It seems like we've almost given up on making the legacy vehicle faster in the water. I'm not sure we're doing the Marine-thing by giving up on it that easily (I'm not saying die in a ditch to get it done, but a little out of the box stuff is clearly called for).
That's when my World of Tanks research on Japanese tanks of WW2 comes into play.
Ya see World of Tanks is having a 3x experience weekend and I'm playing some of my lower tier tanks...and to HUGE success. My computer is the same with the same mediocre graphics card and processing speed so what gives? Poor play on the part of other players or is it the fact that I'm getting kills on TONS of Japanese tanks. A quick google search brought me to this beauty that I've talked about in historical terms before...the Type 2 Kai-Ma. An amphibious tank used during WW2.
So what does this have to do with the AAV? Well check out the pic below....
Yeah. A flotation device. Quite honestly a ships bow. It was disposable upon landing but most crews kept them in place because they acted as a type of spaced armor.
So. Can we use some type of "outboard motor" that can be discarded (and later recovered) upon landing to improve the speed of the AAV? Even if its just some type of pack that houses additional motors in some type of sponson at the back of the vehicle like the type used on some barges, could we get a useful boost in water speed?
I guess what I'm really talking about is taking the example of the extra fuel sponsons on the M-113 and using it to mount extra fuel and thrusters for higher water speed.
It might be goofy but somethings got to give.
Sol, have you ever seen how the jet system works in the current aav? The longitudinal and lateral system and the transmission are huge reasons the aav looses power in the water.
ReplyDeletei've seen it but never understood the why behind you saying that the vehicle has enough power but that the transmission can't handle the load to make it faster.
Deletefrom the sounds of things that makes this a engineering/mechanical issue more than anything else.
if thats the case then why can't we get this done?
Im sure if the "want" was put into it that the system could be improved.
Deletewith the EFV you had more of a direct source of power from the engine to the water jets, instead of from the Engine-Tranny-Laterals-Longitudinals.
Be fair, the AAV was designed in the 70s. Water jets and electric motors were not mature tech then. If you went to electric motors, that solves a lot of problems and energy losses with mechanical transmission in one shot, and the flexibility of wiring to go anywhere you want without taking up space and weight for a huge arse drive shaft is a big boost.
DeleteIn fact if you wanted AAV-redux, there are a lot of things you can improve off the shelf now.
1) Steel/composite frame instead of aluminium.
2) Stabilized RWS turret to allow weapons use while swimming.
3) Electric motors
MrT also has a point in that the AAV is a displacement hull, displacement hulls have a fixed max speed in water that they can travel in proportion to the vehicle length I think. Wiki up displacement hull maximum speed. To get better speed you need to change the hull after you hit the max speed limit.
The Thread suggests that you could argue physics into submission.
DeleteAs the 3-Billion duper-tech EFV-project proved, you certainly can not - even if the money were there.
AAV-7's through-the-water-speed is pretty much locked-in by virtue of laws of physics limiting the velocity of such a 'lump in the water' to at best 7 kts.
There is just no way out of this.
No point in hopping up and down on this.
No magic tricks.
Dreaming won't get you there...
And that is before fuel-consumption to go 'faster' kills the whole cute thinking - as (again) in EFV.
At any rate, speed-through-the-water of any APC won't address the challenge, that to pull away from shore-defenses, the ARG/MEU is moving well Over The Horizon (OTH) to OTH-70-80 and beyond.
From less than half that distance, even the super-high-tech go-fast EFV was out of fuel by the time it got to the beach !!
Then what ??
This is clearly deficient thinking.
In anything but a happily 'permissive' environment that allows the SARG/MEU right off the beach, any wheeled and tracked MEU-combat-vehicles will be delivered via high-speed (30-40kts) air-cushion and medium-speed (20kts) heavy-lift displacement Connectors.
And lots of them.
From OTH-80 and well beyond.
I have often thought of just such a contraption (the Jap boat bow) but in my thoughts it could be more like a jet ski. Use the treads from the aav on treadmills to turn water jets to get up on plane. Hell the thing could even carry its own fuel for extended range. Several problems solved here; water drag, power loss, OTH range etc, etc. Like the Jap design it would have to jettisoned at the beach but think of how baddass it would be!
ReplyDeleteOn water speed in almost impossible to improve more power will not do much just dig a bigger hole and make the craft more prone to swamping. AAV is a displacment boat like a barge but with bad hydrodynamics more power(2x 3x or even 4x times more) will just dig a hole in the back and make craft try climb its bow wave but speed would increase marginally (talking about 10%-15% increase) ,more could be gained by cleaning the hull up with hydraulic suspension that could lift the tacks so that they would be flush with the hull but you would be still in 10-20% more speed so nothing dramatic as more is impossible to achieve without having a planing hull and huge engine like the canceled EFV
ReplyDeleteBe careful there ... you're almost into Mike 'Amphibgavins' Sparks territory :)
ReplyDeleteOn a more serious note, why keep with the transmission - replace the mechanically driven waterjet with electrical thrusters (similar to those on yachts - replace all the 'thruster' transmission with a big generator and some wires.
the advantage are probably more power, 360 thrust vectoring for improved maneuverability, more space inside due to lack of transmission drive shafts. As the wire can easily go anywhere, who says the waterjet should still be tucked in by the tracks, could be as suggested in pods on the back.
When not in the water, the generator can be used for other things.
I see others have the same idea - electric thrusters instead of mechanical and agree on the max speed of displacement hulls.
DeleteHowever, I think there was a video (on this site?) of Aussie? AAVs coming aboard their ship - the thing I noticed was as the AAVs pitched in the swell the jets came out of the water losing power
So while the hull may have a max speed due to it's design, does it hit that speed in anything but calm water, especially as the jets spend so much time pumping air?
So 'retractable outboard style' electric thruster pods on the back allowing the 'prop' to be lower in the water may not result in an increase in 'theoretical' max speed but in the real world it may allow the AAV to maintain a higher speed that it currently does.
It's not a Sparky thing, it's a 'Italian Marines (San Marco Battalion) built them and use them' thing. See http://www.army-guide.com/eng/product1007.html
DeleteSame company built a bolt on conversion for the M548 cargo vehicle.
What you need is a Top Gear style "Toyboata" solution...
ReplyDeletehttps://www.youtube.com/watch?v=nl3bsL7Nbnk&t=41s
You are going to have to tow or transport the AAV to the line of departure with a boat that can utilize it's planing hull then again a planing hull probably would not make a good tug, so it's a fast LCAC that has the ability of using a well deck to drop the AmTracs there.
ReplyDeleteThe Amtrac that can use high speed while afloat is not the best APC/AIFV while above the high water mark. Similar is the AmTrac that is a dog in the water while being a shit hot APC/AIFV.
Pick a job and concentrate on that mission.
The amphibious transport should be armored, semi submersable and fast in the water and only operate well during the wet part of the landing.
Trade water speed for underwater operation.
No range above the seawall, the APC/IFV is a dedicated fighting battle taxi the amphibious vehicle is a dedicated landing track.
I do not believe tech at this time can mate them into one all purpose vehicle.
Go for smaller vehicles in quantity, carry six men each the lander has high speed and can crawl up the beach, One man crew GPS guided.
ReplyDeleteUsed only as a lander with limited high water mark and beyond capabilities, kinda like an armored Schwimmwagen.