USMC ‘Secret’ Amtracs

A

AGRA

Guest
I’m searching for any information relating to three unsuccessful efforts to develop new amphibious landing craft for the US Marine Corps. In the 1950s there was a LVTP6 developed from the M59 APC that was trialed but never ordered into production. In the 1970s a LVA (Landing Vehicle, Assault) high water speed amtrac with a rotary engine and a backup low speed LVT (Landing Vehicle, Tracked) both with 25mm chainguns.

If anyone has any information or links about these projects please post them here.
 
Great! Here is all the information I have on these projects, apart from odd mentions in USMC papers about the need to fund the now EFV:

From War Machine 73 Modern Amphibious & Oversnow Vehicles
Published in 1985

LVTP6

In the early 1950s the Ordnance Division of FMC Corporation, which had produced 11,251 LVTs during World War II, built four prototypes of a full-tracked armoured amphibious troop carrier called the LVTPX2. This vehicle incorporated many automotive and suspension components of the M59 full-tracked armoured personnel carrier that the company was building for the US Army. The four prototypes were delivered to Camp Pendleton in February 1953, and each vehicle was put through 350 hours of endurance testing over all types of terrain and through heavy surf. These vehicles were then modified and further trials were car-red out in 1954, 1955 and 1956, after which the type was declared standard and given the type designation LVTP6. In the end, however, the LVTP6 never entered production. The LVTHX4 was the fire-support vehicle and fitted with a turret armed with a 105-mm (4.13-in) howitzer. The LVTAAX2 was fitted with the twin 40-mm turret of the M42 self-propelled anti-aircraft gun (also fitted to the previously-described LVTAAXI vehicle). A bolt-down 107-mm (4.2-in) mortar kit was also developed for the LVTP6, and projected versions included recovery, engineer and command vehicles.

LVA/LVT(X)

The LVTP7 series was to have been replaced by the Landing Vehicle Assault (LVA), and in 1976 the US Navy awarded conceptual design contracts to the Bell Aerospace Division of Textron Inc., to the FMC Corporation and to the Pacific Car and Foundry Company. The following year Curtiss-Wright was awarded a separate contract for the development of a stratified-charge rotary engine for the LVA. The original US Marine Corps requirement was for a vehicle with a water speed of between 40 and 64 km/h (25 and 40 mph), a land speed of between 64 and 88 km/h (40 and 55 mph), good operating range on both land and water, the ability to carry between 18 and 22 fully equipped troops, and the provision of a turret-mounted 25-mm cannon plus co-axial 7.62-mm (0.3-in) machine-gun. The idea was that two of the companies would be awarded further contracts which would eventually lead to the construction of full-scale mockups. But in 1979 the Landing Vehicle Assault was cancelled and contracts were subsequently awarded for the Landing Vehicle Tracked (Experimental), or LVT(X), to General Dynamics Land Systems Division, FMC and Bell Aerospace. As of late 1984 all three companies had submitted their proposals and two companies will probably be awarded contracts to build prototype vehicles, one of which will eventually be placed in production. All companies have proposed vehicles fitted with a two-man power-operated turret armed with at least a 25-mm cannon plus a co-axial 7.62-mm (0.3-in) machine-gun. The Bell and General Dynamics proposals also have two remote-controlled 7.62-mm. (0.3-in) machine-gun installations above the rear troop compartment; these have been fitted as the US Marine Corps expects that in future amphibious operations the US Marines will have to fight further inland than in the past. Although the LVT(X) will have improved mobility, firepower and armour protection over the current LVTP7 series, it will not have a dramatic increase in water speed: unless there is a considerable breakthrough in hull design (apart from the installation of hovercraft type skirts as proposed for the now defunct Landing Vehicle Assault) there is little scope for further development.
 
Source: F Crismon US Military Tracked vehicles Motorbooks 1992
Sorry about quality of pics Originals for these two vehicles not of FC's usual standard.
 

Attachments

  • LVT.gif
    LVT.gif
    490.1 KB · Views: 2,112
Two images, one of the troop carrier and another of the anti aircraft derivative .
 

Attachments

  • lvtp6_001.jpg
    lvtp6_001.jpg
    43.5 KB · Views: 1,781
  • lvtaax2_001.jpg
    lvtaax2_001.jpg
    46.5 KB · Views: 1,747
Not an 'AMTRAC', nonetheless another attempt at a high-speed amphibious landing craft.

The LVHX2 Hydrofoil Landing Craft.

Jon
 

Attachments

  • LVHX2_01.jpg
    LVHX2_01.jpg
    182.2 KB · Views: 1,660
  • LVHX2_02.jpg
    LVHX2_02.jpg
    146.9 KB · Views: 1,592
  • LVHX2_03.jpg
    LVHX2_03.jpg
    164.4 KB · Views: 323
I was wondering if this had anything to do with your LVT(X) inquiry?
All I can tell you is that it a modified M-113A2, with 25mm remote weapon station tailored for amphibious assault. ???

It looks very interesting and purposeful!


Regards
Pioneer
 

Attachments

  • An unknown modified M-113A2, with 25mm remote weapon station tailored for amphibious assault.jpg
    An unknown modified M-113A2, with 25mm remote weapon station tailored for amphibious assault.jpg
    15.2 KB · Views: 360
Pioneer said:
I was wondering if this had anything to do with your LVT(X) inquiry?
All I can tell you is that it a modified M-113A2, with 25mm remote weapon station tailored for amphibious assault. ???

That looks like the Italian add on mod to the M113 to make a surf crossing amphibious vehicle.

I very much doubt it is an LVT(X) because these were all clean skin designs for a high speed surf crossing amphibious vehicle.
 
Don't know, if it really is interesting, but before I forget about it:
In Aviation Week June 1960, there was an advert from the FMC Ordnance Division,
showing their range of APCs and derivatives. Attached are the cutouts with the
amphibious types:
 

Attachments

  • LVT-4.jpg
    LVT-4.jpg
    111.6 KB · Views: 387
  • LVT-3.jpg
    LVT-3.jpg
    124 KB · Views: 321
  • LVT-2.jpg
    LVT-2.jpg
    115.9 KB · Views: 291
  • LVT-1.jpg
    LVT-1.jpg
    89.2 KB · Views: 274
In later 1970's or early 1980's USMC come up an air cushion landing vehicle to replace old AAV-7A1, and seems like this vehicle go no further than art work.
 

Attachments

  • 1.jpg
    1.jpg
    89.5 KB · Views: 353
  • 2.jpg
    2.jpg
    59.9 KB · Views: 380
xiaofan said:
In later 1970's or early 1980's USMC come up an air cushion landing vehicle to replace old AAV-7A1, and seems like this vehicle go no further than art work.

It went further but no prototypes. This was the LVA project from the late 70s which was replaced by the LVT(X) which was replaced by the AAAV (aka EFV).

In 1961 planing began to replace the LVTP5. The new Amtrac was to be in service in 1966-67. The Marine Corps Development Centre (MCDC) conducted an Amphibious Vehicle Requirement (AVR) study that would influence Amtrac development to this date and on. The main issue to come from the AVR was a need for a high speed, long range amphibian for over the horizon to over the beach landings. Initially this was forseen as being an air cushion Amtrac. However the AVR pointed out such a vehicle was unlikely to be ready by 66-67 so an ‘interim’ conventional Amtrac was required. This was the LVTP7.The LVTP7 was developed to be much better ashore (no dual role tracks) than the LVTP5 and would compensate for any short sea range by being capable of high speed launch. This way the LSD, LPA, etc would come in close to shore and not need to slow down to become a target and launch the new Amtrac. The LVTP7 was to be armed with a 20mm gun but problems with the weapon lead to the 12.7mm M85 being substituted.

The LVA (Landing Vehicle, Assault) program began in 1973 was targeted as a high speed, long range Amtrac for over the horizon to over the beach landings. The requirement was for carriage of 18-22 dismounts or 6,000 lbs of cargo and for a speed of 35 knots in water and 55 mph on land. Armament was to be the 25mm automatic gun. Three alternative vehicles were considered: hovercraft, hydrofoil and planning hull. In 1976 development contracts were let to Bell Textron for the hovercraft pictured above which had fixed tracks and a rapidly inflated, deflated air bag and FMC for the planning hull with retractable tracks. The LVA was to be powered by two Curtiss Wankel motors each producing 1,500 hp. Plywood mockups of the two designs were built in 77 but in 78 the marines became concerned about the size (30-33’x11’x11’) and the cost. Development cost was estimated at an additional $330m and $1.4 billion to build. LVA was cancelled in early 1979 (about the same time of the year as EFV was cancelled).

To replace the LVTP7 and fill the gap of the LVA the marines proposed the LVT(X) and an enhanced version of high speed launch by LCAC. The LVT(X) was to be much better than the LVTP7 and armed with at least a 25mm automatic gun, add on anti tank missile system and a stabilised turret. Originally at least 17 dismounts were to be carried but later 13 man (LVTX13) and 21 man (LVTX21) configurations were studied. However the success of the LVTP7 product improvement program saw LVT(X) cancelled and the requirement deferred until the 2000s and the later EFV.
 
..."LVA was to be powered by two Curtiss Wankel motors each producing 1,500 hp..."

I remember various articles from as far back as the mid-late 1980s,
where there was discussion of the rotary engine to be used in the follow-on to the LVTP (when it was still called AAAV and not yet EFV).
The one that sticks out in my memory most was the SCORE, Stratified Charge Omnivorous Rotary Engine (omnivorous, that it could use multiple fuel types, like some military grade multi-fuel diesels can).

http://protonet.org/doc/rota_text_1986_ltr.pdf


I've always been curious why those engine types never really went very far, neither on the military side nor civilian sector (Mazda did feature a rotary/Wankel engine in one or two cars and pick up trucks).
As I uderstand it, there were issues with the seals between the triordal trochoid (triangular shaped but with bulged sides) and the "cylinder" wall,
that apparently haven't been sufficiently resolved to this day, as piston engines or turbines are still seen as the powerplant of choice.
 
DanielStarseer said:
I remember various articles from as far back as the mid-late 1980s,
where there was discussion of the rotary engine to be used in the follow-on to the LVTP (when it was still called AAAV and not yet EFV).

After the LVA program was cancelled in '79 the engine program was funded for a few more years.

DanielStarseer said:
As I uderstand it, there were issues with the seals between the triordal trochoid (triangular shaped but with bulged sides) and the "cylinder" wall,
that apparently haven't been sufficiently resolved to this day, as piston engines or turbines are still seen as the powerplant of choice.

Rotary's are used in quite a few UAVs where like the Mazda RX-7 they are noisy as F :-*k.
 
Straying a bit into the realm of speculation, I know, but the role of landing craft and armored vehicle seem so diametrically opposite, I wonder if any of the various Amtrac proposals over the years might have simply separated the two roles. It would seem a lot easier to design a normal armored vehicle and fit it with it's own surf-crossing personal landing craft controlled by the tank crew.

You could even imagine a setup where the landing craft portion has no engine of its own and power is provided by a take-off from the armored vehicle engine. If you're feeling goofy, you could make it a treadmill powered by the wheels or tracks (not really serious there).

Surely, given the very high profile of the USMC AAV, which increases their visibility and vulnerability on land, not to mention the high cost of a bespoke vehicle for the USMC alone, someone must have come up with concepts for individual, even disposable landing craft, left behind on the beach?
 
Mole said:
Surely, given the very high profile of the USMC AAV, which increases their visibility and vulnerability on land, not to mention the high cost of a bespoke vehicle for the USMC alone, someone must have come up with concepts for individual, even disposable landing craft, left behind on the beach?

Well the increased size of Amtracs has more to do with the increased internal carriage required by the USMC. LVTP7, LVA, LVT(X) and EFV are all required to have 2-3 times more under armour volume than contemporary non amphibious APCs/IFVs. Of course this increased volume helps with buoyancy but it also adds weight which requires more buoyancy and so on. But if you wanted to build a surf crossing vehicle with only 10-12 dismounts (or 6-8 dismounts and a two man turret) it would not be much bigger than Army APCs/IFVs. As seen in the LVTP6 compared to the M59 APC it was based on.

Mole said:
Straying a bit into the realm of speculation, I know, but the role of landing craft and armored vehicle seem so diametrically opposite, I wonder if any of the various Amtrac proposals over the years might have simply separated the two roles. It would seem a lot easier to design a normal armored vehicle and fit it with it's own surf-crossing personal landing craft controlled by the tank crew.

You could even imagine a setup where the landing craft portion has no engine of its own and power is provided by a take-off from the armored vehicle engine. If you're feeling goofy, you could make it a treadmill powered by the wheels or tracks (not really serious there).

You’ve just added a load of complexity and vulnerability for very little gain and then effectively make the amphibious capability a oncer. What happens in training? With all those discarded landing platforms on the beach. Also what happens when the Amtracs need to go back to sea to pick up the second wave?

The USMC has looked at a range of other options for Amtrac capability including using more conventional manned landing craft and regular Army spec APCs/IFVs. The big problem of this is it requires far more landing ships and significantly reduces the ability to simultaneously build up the landing force on land. Amtracs are there for a reason not just the whim of the Marine Corps.
 
xiaofan said:
I wondering what is after EFV.

The RFI was released about a month ago: the Amphibious Combat Vehicle (ACV). Basically the same requirement as the EFV but more leeway on the speed in water.

A number of requirements for the ACV were set out in the RFI, including:

• The ability to autonomously deliver a Marine infantry squad from an amphibious ship to shore a minimum distance of 12 nautical miles, at “a speed to enable the element of surprise in the buildup ashore.” The notice acknowledges that a high rate of speed “may prove to be unaffordable.”

• Protection against direct and indirect fire, mines and improvised explosive devices. The protection can be modular, “applied incrementally as the situation dictates.”

• Employ open architecture principles to rapidly integrate new technologies, and be reconfigurable to carry out alternative roles, including operation of heavy mortars or rockets, and logistic or medical evacuation missions.

• Be powerful enough to engage and destroy similar vehicles, provide direct fire support to dismounted infantry and maneuver with M1A1 Abrams main battle tanks.
The Marines want the vehicle to be configured in several variants, including as a squad maneuver/fighting vehicle, a command-and-control vehicle, and for recovery and maintenance.
 
Abraham Gubler said:
xiaofan said:
I wondering what is after EFV.

The RFI was released about a month ago: the Amphibious Combat Vehicle (ACV). Basically the same requirement as the EFV but more leeway on the speed in water.

A number of requirements for the ACV were set out in the RFI, including:

• The ability to autonomously deliver a Marine infantry squad from an amphibious ship to shore a minimum distance of 12 nautical miles, at “a speed to enable the element of surprise in the buildup ashore.” The notice acknowledges that a high rate of speed “may prove to be unaffordable.”

• Protection against direct and indirect fire, mines and improvised explosive devices. The protection can be modular, “applied incrementally as the situation dictates.”

• Employ open architecture principles to rapidly integrate new technologies, and be reconfigurable to carry out alternative roles, including operation of heavy mortars or rockets, and logistic or medical evacuation missions.

• Be powerful enough to engage and destroy similar vehicles, provide direct fire support to dismounted infantry and maneuver with M1A1 Abrams main battle tanks.
The Marines want the vehicle to be configured in several variants, including as a squad maneuver/fighting vehicle, a command-and-control vehicle, and for recovery and maintenance.

The new vehicle sound like ZBD 2000 family current serve in the Chinese army and Chinese Marine.

ZBD 2000 is available in four versions: 105mm gun-armed light tank, infantry fighting vehicle (IFV), command vehicle, and recovery and maintenance vehicle. These vehicle may not reached the travelling performance of the EFV, but they are able to achieve a high speed of travelling in the water and a reasonable speed on land over a long distance.
 

Attachments

  • 1.jpg
    1.jpg
    168.7 KB · Views: 647
  • 2.jpg
    2.jpg
    211.6 KB · Views: 571
  • 3.jpg
    3.jpg
    158 KB · Views: 556
xiaofan said:
The new vehicle sound like ZBD 2000 family current serve in the Chinese army and Chinese Marine.

I doubt it. The ZDB 2000 is a failed attempt at building a planning hull like the EFV. However because the Chinese Marines didn't have a preceeding Amtrac and to maintain the 'face' of the Party it was placed into production. Something bad is better than nothing.

Hopefully the ACV will be something like the Fast Track Amphibian. This turns the clock back to before the LVTP7 and uses a single mode of propulsion for sea and land except the tracks and hull are designed for water planning.

[flash=200,200]http://www.youtube.com/watch?v=tZTg9X13JvE[/flash]
 
Abraham Gubler said:
xiaofan said:
The new vehicle sound like ZBD 2000 family current serve in the Chinese army and Chinese Marine.

I doubt it. The ZDB 2000 is a failed attempt at building a planning hull like the EFV. However because the Chinese Marines didn't have a preceeding Amtrac and to maintain the 'face' of the Party it was placed into production. Something bad is better than nothing.

Hopefully the ACV will be something like the Fast Track Amphibian. This turns the clock back to before the LVTP7 and uses a single mode of propulsion for sea and land except the tracks and hull are designed for water planning.

ZDB 2000 is similar to the U.S. Expeditionary Fight Vehicle (EFV) in concept, both in the way of deployment and in design concept. It is may have yet reached the travelling performance of the EFV, and may not as advance as EFV did, but still it is faster than most if not all vehicle current in service, also it is simpler and cheaper to build.

Chinese Marines did have a preceeding Amtrac. Actually Chinese Marines did have two preceeding Amtrac, one is type-77, and other one is a modified variant of type-63 mort or less similar to Italian A.R.I.S. Arisgator.

For a long time Chinese Military leadership did not consider Chinese Marines as an offensive forces, and it has been under funded, this situation only start to change.
 
Neither the Type 63 or Type 77 have an amphibious capability to safely cross surf zones or approach the shore from anything other than a very short distance. They are only useable for seaward amphibious assault if you have a very high risk tolerance. That is you don’t mind lots of marines drowning in swamped vehicles and your mother ships being pounded by shore based artillery. By no means of the commonly accepted definition can such a vehicle be called an Amtrac. They and the PT76 they are copied from are river crossing amphibians not surf crossing amphibians.

The ZDB 2000 may be cheaper and easier to produce than the EFV but that is because it lacks the power to weight ratio to water plan. While it may be faster than other amphibians in water like the LVTP7 that is because it is burning far more fuel to achieve a marginal speed gain. For a vehicle designed to plan it is clearly a failure. But at least it offers the Chinese Marines a surf zone crossing vehicle with enough sea range that the landing craft deploying it isn’t a sitting duck to coast defences. That it is launched into production while the EFV is cancelled is simply a microcosm of the widely different quality standards of their armed forces and governance standards of their parent countries.
 
Abraham Gubler said:
Neither the Type 63 or Type 77 have an amphibious capability to safely cross surf zones or approach the shore from anything other than a very short distance. They are only useable for seaward amphibious assault if you have a very high risk tolerance. That is you don’t mind lots of marines drowning in swamped vehicles and your mother ships being pounded by shore based artillery. By no means of the commonly accepted definition can such a vehicle be called an Amtrac. They and the PT76 they are copied from are river crossing amphibians not surf crossing amphibians.

The ZDB 2000 may be cheaper and easier to produce than the EFV but that is because it lacks the power to weight ratio to water plan. While it may be faster than other amphibians in water like the LVTP7 that is because it is burning far more fuel to achieve a marginal speed gain. For a vehicle designed to plan it is clearly a failure. But at least it offers the Chinese Marines a surf zone crossing vehicle with enough sea range that the landing craft deploying it isn’t a sitting duck to coast defences. That it is launched into production while the EFV is cancelled is simply a microcosm of the widely different quality standards of their armed forces and governance standards of their parent countries.

During an interview the chief designer of the ZDB 2000 did mention the vehicle is similar to EFV in design concept, that is water plan, he also mention these vehicles is not full water plan, it is a kind of combination of water plan and hydrofoil (the board at the rear of vehicle acting as some kind of hydrofoil) .
 
What is Marine Personnel Carrier for? To replace LAV-25?
 

Attachments

  • MarinePersonnelCarrierDemonstrator.jpg
    MarinePersonnelCarrierDemonstrator.jpg
    75.5 KB · Views: 604
Marine Corps Systems Command says it's to complement the EFV (Basically, sounds like it fills out the numbers gap caused by EFV price escalation and procurement cuts). Not an LAV replacement, though that would be the logical next step, IMO.

An MPC company lifts an infantry battalion in conjunction with the infantry’s organic wheeled assets. Like the planned Expeditionary Fighting Vehicle (EFV), MPCs will be assigned to the Assault Amphibian Battalions of the Marine Division currently outfitted with Amphibious Assault Vehicles (AAVs). The reconstituted Assault Amphibian battalion would tentatively consist of one MPC company (nominally 88 vehicles) and three EFV companies (about 45 vehicles each).

The MPC family of vehicles will consist of a base vehicle and two supporting mission role variants. The MPC-Personnel will be the base vehicle, two of which carry and support a reinforced rifle squad of 17 Marines (one EFV would do the same). Each vehicle would carry 9-10 combat-equipped Marines and a two-man crew. This meets the need to transport more Marine infantrymen than the existing Light Armored Vehicle (LAV) or Humvee platforms while providing greater protection. The eight-wheeled LAV is not employed as an armored personnel carrier and usually carries a four-person Marine scout/reconnaissance team in addition to its crew. The MPC-Command will be equipped to serve as a mobile command-echelon/ fire-support coordination center for the infantry battalion headquarters. The MPC-Recovery will be the maintenance and recovery variant of the MPC.

Edit: forgot to add the link.
 
Hmm, the linked article, and the Wikipedia entry, don't say anything about this particular vehicle itself being amphibious.
 
TomS said:
The MPC? It's not.

Hmmm.... not quite correct.

It does have propellers.

MarinePersonnelCarrierDemonstrator4.jpg


To quote from the previously linked PEO Land Systems article: "The MPC will be designed to cross rivers and inland bodies of water in a Marine Air-Ground Task Force’s littoral operational area."
 
Looks awfully tall.
Anyone know whose vehicle design this is?

Myself, I'm a fan of IVECO's SuperAV 8x8.
Seems like a well-thought-out design compared to what American defense industry committees have been offering as "solutions" (in quotations because US defense contractors tend to create money traps moreso than fieldable, mostly-trouble-free vehicles).

http://www.military-today.com/apc/iveco_superav.htm
http://www.defense-update.com/products/s/superav8x8_290409.html
http://www.armyrecognition.com/italian_army_italy_wheeled_and_armoured_vehicle_uk/superav_apc_8x8_iveco_wheeled_armoured_vehicle_personnel_carrier_amphibious_italian_army_italy_tech.html


When looking to the fact that the USMC want so many people stuffed into it,
I wonder if, for their needs, it's time to step up to 10 wheels instead of 8, at least in the APC variants...


http://www.army-guide.com/eng/product959.html
(hard to locate decent pics of the 10x10 Piranha variants, sorry...)
 
xiaofan said:
During an interview the chief designer of the ZDB 2000 did mention the vehicle is similar to EFV in design concept, that is water plan, he also mention these vehicles is not full water plan, it is a kind of combination of water plan and hydrofoil (the board at the rear of vehicle acting as some kind of hydrofoil) .

That is a terrible excuse. If he had come to a defence trade show in the west all the journalists would have laughed at him. They design a planning hull but it does not have enough thrust to get over the hump and lift the hull out of water (or it is to heavy for the thrust it has) so he then claims that the rear plate acts like a hydrofoil! LOL the plate that is meant to help the vehicle plan is in no position to achieve a hyrdofoil effect. It may help hydrodynamics but certainly not to the effect of all the weight of it all. They would be better just to pull off all the planning plates and lowering gear and just sail it as the displacement hull that it is.
 
xiaofan said:
What is Marine Personnel Carrier for? To replace LAV-25?

Effectively to replace the MRAP and provide the Marines with more of an ashore mechanised capability.
 
Niiiiice!

Unfortunately,
I wasn't aware these 10-wheelers lacked propellors...or is that just one more option in the versatile Piranha family?
Or are they just getting too heavy to swim? I notice the USMC LAV family has them (Piranha I?), but Strykers avoided them (Piranha II? III?).

Don't recall seeing them on the latest Piranha V's either...just not enough market for swim capability anymore?
 
The number of wheels on the side of the 10x10 has little to do with gross vehicle weight (GVW) in comparison with later Piranhas/LAVs. The important thing is to realize which generation of Piranha/LAV this vehicle is. There have been five to date and each one changed the weight the axles can bear and the size of the hull. The 10x10 Piranha is a Gen 3 Piranha/LAV and has a lower maximum GVW than the 8x8 Gen 5 Piranha/LAV. Stryker started as a Gen 3 Piranha/LAV but is rightly now classified as Generation 4.

As to why there are no propellers or waterjets on some of these Piranhas/LAVs that is because they are too heavy to float so a propeller would not be of much benefit. Like all floating objects the ability to do is dependent on the relationship between weight and volume generally known as displacement. For a Gen 2 Piranha/LAV (LAV-25, ASLAV) the maximum weight that can be supported via water displacement of the hull is around 12.5 tonnes. So when you add extra armour to these vehicles they can’t float. The Gen 3 Piranha/LAV hull is a bit bigger than the Gen 2 one so can support more weight. But it tops out at around 15 tonnes. A Gen 3 Piranha/LAV heavier than that will not float.
 
http://www.defenseprocurementnews.com/2011/03/07/u-s-marine-corps-begins-efv-replacement-process/

Update – Clarified to correct that the Amphibious Combat Vehicle (ACV) is the EFV replacement vice the MPC. The MPC is to be used on land to move infantry around.

In its 2012 budget request the Obama Administration continued its plan to overhaul defense acquisition by proposing the cancellation of the new amphibious assault vehicle for the U.S.M.C. The Expeditionary Fighting Vehicle (EFV) program led by General Dynamics (GD) was over budget and behind schedule.

Part of the problems the program faced was that the requirements were for a well armored vehicle that could move fast in water and on land. The EFV was really a modern Infantry Fighting Vehicle (IFV) that also had to travel across several miles of ocean under fire at high speed. These kind of requirements often cause issues with development and the EFV was a fairly aggressive program to begin with.

Congress has not necessarily been receptive to the idea of ending the program as it would represent yet another big ticket item ended with resulting job losses and millions of dollars seemingly not invested well. They are the final decision makers and it will be interesting to see how the final budget falls out next year with the pressures of trying to reduce spending but also to keep programs going.

Of course the Marines still need a replacement for their Seventies vintage AAV-7 they are currently using which is optimized for delivery of troops to shore but not for use as an armored transport on a battlefield threatened by the IED and mine such as the Marines faced in Iraq and continue to do so in Afghanistan. Because of this need in mid-February the government released a series of Request for Information (RFI) to begin the process again of rebuilding their vehicle fleet.

The RFI cover the gamut of upgrading the existing AAV with more power, armor and weapons to replacing the wheeled LAV used for reconnaissance and troop transport to the new version of the EFV. This is currently called the Amphibious Combat Vehicle (ACV) and mirrors many of the requirements that the EFV was trying to meet although the Marine Corps now says that the ability to move quickly across the water may be too expensive to pursue.

Hopefully some of the money spent on developing the EFV may also have bought things that can be used by the ACV program to expedite its development and delivery while lowering its costs. The situation is similar to the Army and the end of their Future Combat Systems (FCS) vehicle program. There remains a need and the Army had to start the Ground Combat Vehicle (GCV) program to get replacement for the M2 Bradley IFV.

Unless the U.S. is willing to forgo a large portion of the U.S.M.C.’s mission a modern amphibious assault vehicle is going to need to be developed and built. Let’s hope the ACV has a better result then the EFV did.

http://defensetech.org/2011/03/01/amos-ill-be-able-to-drive-efv-replacement-within-four-years/#ixzz1FO7hRod1

Amos: I’ll Be Able To Drive EFV Replacement Within Four Years

Marine Corps Commandant Gen. James Amos today shed some much anticipated light on when the Corps could see a replacement for the cancelled Expeditionary Fighting Vehicle, telling lawmakers he expects to drive its replacement by the end of his tenure as commandant.

“There are two answers to that, one is as Commandant of the Marine Corps’s answer which is Before I leave leave office four years from now … we’ll have a program of record, we’ll have steel, there will be a vehicle and I’ll be able to drive it,” Amos said responding to lawmakers questions during a House Armed Services Committee hearing. “I’m trying to pressurize industry, I’m trying to pressurize the acquisition folks, I want the word to get out. If we followed the standard acquisition timeline, which in some cases got us to where we are today, it’ll be 2024.”

To avoid such a fate, the general said the Department of the Navy will be using a model similar to the one it used to quickly buy and field thousands of MRAPs during the height of the Iraq war.

“Something probably that resembles the sense of urgency that we had for the MRAP but probably a little bit more scheduled, and that’s what we’re going to do.”

Now that’s not saying that Amos will necessarily be driving the production model EFV replacement, dubbed the Amphibious Combat Vehicle, but it will will be some sort of early version ACV.

The EFV was cancelled earlier this year after it was predicted that its rising costs would swallow up waaay too much of the Marines’ procurement budgets. The craft was first conceived in the 1980s and has taken billions in development cash over the decade yet remained stuck in development purgatory.

It’s replacement will draw on the lessons learned from EFV development while using available technologies to field a 21st Century armored personnel carrier for the Corps, according to Amos.
 
Off-topic references to Piranha deleted.
 
I came across this image while cleaning out my desktop's HD last week. It looks like some sort of air defense variant of the LVTP-7, with vertically-launched SAMs. Any ideas as to what it is?
 

Attachments

  • amtrac-mis.jpg
    amtrac-mis.jpg
    21 KB · Views: 748

Similar threads

Back
Top Bottom