"Amphibious Vehicles: How Practical?" Topic

Another topic mentioned "challenges" with amphibious vehicles such as the M113 and AAV.

Based on training/field experience just how practical would amphibious vehicle be under combat conditions?

From what I've read amphibious capabilities look impressive in defense contractor marketing videos but the reality appears to be very different. Some vehicles require extensive pre- and post-crossing conversion (eg crossing a river) while others that hawk on-the-fly transition between land and water seem to suffer serious flooding problems that might give a field commander pause.

Opinions/comments?

MB

The WW2 DUKW was a very practical amphibious vehicle. Some of them are still in operation some 60 years later:

londonducktours.co.uk

No solution will be perfect, but hopefully you're not trying to cross a river under fire. The strongest argument for amphib capability is that you don't have to have your maneuver units sit and wait for the engineers to move forward and build a bridge (which itself would be an artillery magnet).

Even having to pop out the trim vane or whatever is faster than waiting three or four hours for an engineer bridging company to build a Bailey or medium-girder bridge over a decent-sized river. Pontoon bridges still take time and are susceptible to river currents and battle damage.

Of course, crossing a river under fire, if you had to do it, would best be done by first suppressing the heck out of threat forces on the far shore using artillery and direct fire, than laying smoke over the entire area. As it is, if the enemy has had any time at all to prepare a defense, they'll have mined the shallows and riverbank on the far side, so you'd have to expect some casualties there anyway.

Until we have practical GEV or anti-grav tanks, we'll need to consider river-crossing options, and amphib designs are a key part of that. I say we keep 'em.

Javelin,

Your points are well taken and go to the heart of my question with respect to wargame scenarios.

Depending upon the games's level/scale it would seem reasonable that one would want a couple of "levels"of amphibious capability represented: a basic level that could be performed if the vehicle/unit is not under any adverse morale effects in game terms (ie the crew/support staff would need to dismount and undertake complex operations to prep the vehicle…not practical under fire.) And an advanced level that allows the vehicle to cross a water obstacle even when suffering the effects of enemy fire.

MB

During the Vietnam War, there was an incident where the Communists were attempting to force a crossing over a bridge. There was an M8 armored car (or the like) dug in on the opposite side of the bridge and was actually doing a fine job of holding off the attack. At some point, the armored car panicked and backed out of its position only to be immediately destroyed – which blocked the bridge.

Two PT-76s (which may have been what spooked the a/c) attempted to swim across in order to bypass the bridge. Two F-4 Phantoms which had been called in as air support made a low-level pass along the river and swamped the PT-76s because they left their hatches open.

Wyatt

I can't speak for the Marines, but I don't think the US Army has plans to do the type of direct amphibious river assaults that were seen in WWII. I may be completely wrong, but we never trained for that type of thing for the 3 years I was in a Divisional Cavalry Squadron in the 90's.

It is my opinion that air mobility, air power and the improvements in artillery would only leave an amphibious assault as a more desperate measure.

I think the amphibious capabilities of US armored vehicles are more Strategic than Tactical in a similar way to Airborne capability. In smaller level games I would leave that off of the table.

If I were in command and planning on taking a platoon across a river I would attempt to do it out of the prying eyes of the enemy or at least up/down river from the teeth of the enemy.

Ed G

Ed,

What about a game in which 1 stand = 1 platoon and you have about a reinforced battalion per side?

We play that scale a lot and with microarmor one can start beyond "engagement range" on a reasonable sized table (eg 5 x 8).

Would that fit your "strategic level" concept? (Maybe "operational" would be more apt.)

MB

I see where you're coming from, MB, and those sound like fine ideas.

If you treat a river as an obstacle, and then treat crossing it the same way you would breach an obstacle, then the principles of combat engineering would apply: SOSR -- Suppress, Obscure, Secure, Reduce. You'd have to put enough fire on the enemy on the far bank to suppress them, blanket the entire area in smoke, then get your leading forces across the river to secure a beach head. The "Reduce" step might include bridging.

In the six years I was in the Army, we never once tried to swim our M113's. And I certainly wouldn't try that while in contact with the enemy! Unless, of course, there was no other possibility.

I think that, for game purposes, amphib ops would become important if you needed to get your forces to the front and didn't have time or capacity for bridging to take place.

We ran some tracks (AAVP7s) up a river one night during an exercise. The opposition hadn't considered that to us it was a road instead of an obstacle, so we neatly bypassed the nasty ambush on the route to the bridge. The AAV is truly amphibious – I've taken it into 14 foot (4 meters and change) surf. I didn't notice any flooding problems, even when the cargo hatch popped open due to a careless crewman failing to lock it (420 gpm bilge pump capacity on two different power systems). It floats just fine. The downside is that it's slow (about 5 kts. – dolphins would swim figure 8s in front of the bow just to show off), loud, and not especially well-protected. In the water itself, the low freeboard forms a pretty good defilade against RPGs, most cannons (water is a *very* effective ballistic shield) and Saggers (uninsulated guide wires), but you show your belly climbing out. You also need to rather rapidly find a place to stop for about 15 seconds to reengage the fanshaft (the driver flips a switch), which can snap if it's done on the fly at high RPMs.

The LCAC trasport hovercraft requires vehicles to be undogged (the cables securing the vehicles to the deck have to be detached) by men standing upright on deck. This takes a few minutes.

Might be worth remembering that vehicles with amphibious capability are by their very nature relatively lightly armoured (otherwise they would not be able to float). They are reconnaissance or transport vehicles, not battle tanks.

Therefore, using them for a direct assault (amphibious or overland) is not likely to be ideal solution.

What the amphibious capabilities really give is operational mobility and flexibility.

They just don't make 'em like they used to:

YouTube link

Allen

Great video Allen, but it looks like you could poke a hole in it with a screwdriver. Hehe…did you see how light the hatch was.

MB, your right Operational is probably a better description and I am only refering to the light crap the Army has. Marine LAVs and AAVs may be MUCH better at this sort of thing. My real point is that you wouldn't do it in the face of an enemy unless it was a dire situation. Normally there are many other less risky alternatives…Normally.

Ed G.

Yes, I guess this is also all relative to need vs desire to avoid casualties.

Today we might consider going ashore or crossing a river under fire while in a lightly armored AAV mounting Mk 19s and 50 cals as "not being wise."

But in WWII we assaulted beaches in essentially open-topped plywood craft mounting little or no firepower.

And when I was a kid we lived in a shoe box in the middle of the road, we walked 10 miles to school across 6 foot deep snow drifts while being pursued by wolves, and we were thankful for the opportunity! None of this fancy modern stuff for us! :-D

MB

As I said on the other thread about AAVs, we swam M113s in the ROK in '84-'85. I think that Amphib AFVs are usefu. However, if used in a Forced Entry operation they become fairly easy targets. In a general movement to contact type op or just rapid movement across a sector, they have their uses. But the time to prep to swim vs. the time to find a crossing point like a ford or brigde, the later may be quicker … It is a good ability to have, I guess. I commanded an M113 Mech Co. '87-'89. We were deployed to (then West) Germany among other places and we never swam them … I believe the concept is in modern warfare, don't do what we saw at Omaha Beach and many USMC landings in the PTO. Frontal assaults even well supported by FA, Navy Gunfire, CAS, etc. are usually bloody affairs … so land where the enemy isn't … The same can be said about Air Assault Ops, landing in a Hot LZ, even if "preped", is very risky. I was a Rifle Plt Ldr and Bn Air Ops Officer in the 101, '80-'83 … Landing in Hot LZs was something we planned on not doing …

Legion 4,

Your last point about hot LZs is very interesting and similar to the beach landing issue with respect to tactical developments.

In WWII we did frontal beach assaults but it sounds like that's a thing of the past.

In Vietnam we did air assaults into hot LZs and lost plenty of people and machines doing so, but did it anyway (lots of very interesting memoirs from Vietnam era pilots available on that topic).

But today it really does seem that the assumption is such landings are too dangerous, perhaps one reason being the wider availability of more accurate RPGs which can take down any helo currently flying including the ungainly and rather large Osprey.

I suppose this topic could be move up one level conceptually to cover all forms of transport available to infantry while moving to contact: unarmored carriers such as trucks and humvees, APCs, IFVs, LCTs/AAVs/LCACs, helos, and now tilt-wings.

I think the Israeli experience in 2006 demonstrates just how dangerous it is for infantry even in AFVs to move against well concealed light infantry armed with long range AT weapons, let alone trying the same thing in something like an AAV!

MB

Have you seen footage of the Marines new Expeditionary Fighting Vehicle? link

Forget old-school AAV7 displacement hulls at 5 knots in the water, the EFV has 2 waterjets and a planing bow-plate. Drive into the water, deploy the amphib gear hydraulically (it includes track covers), and close on the beach at something like 25 knots.

They're not great for crossing a narrow river (no faster than an AAV7), but have similar firepower to a Bradley. For larger bodies of water or using rivers like a road, though… yeeee-hah!

But can it pull a jet-ski?

:-D

Yes, MajerBlundor, you got it correct. I served 10+ years as an active duty US Army Infantry Officer ('79-'90). I served in 1 Air Assault Inf Bn and 3 Mech Bns(all with M113s). Modern weapons lethality makes frontal assaults, landing in Hot LZ, etc., etc. much too costly in lives (and money !). Infantry does it's best work on the ground … hiding behind cover … and using their organic firepower and supporting assets, like FA, CAS, etc.(ie. combined arms) … and maneuvering utilizing cover and concealment to close with the enemy on the flanks to kill, capture and destroy enemy personal and equipment. It's in the manual …

PS … excuse my terrible spelling & typing …

Having spent the bulk of my time in the Guard in a mech division, I can say that I have only forded once up at Camp Roberts in No Cal. The Nacimiento was high that year. We took a a dollar thirteen across and had about 6 inches of freeboard. The Army is not planning on any D-Day type landings that I know of, but there are lots of little streams and the like to cross, Mech infantry gets no AVLBs. With the 113, you don't have to put up a flotation screen like on a Bradley or Sheridan.
Natokina.

In Europe much less kit is now amphibious but that may be due to the environment. Many of our rivers (only 20 m wide or less) have high vertical banks of clay. They are not passible by most tracked vehicals particularly when dumping water onto the ground. This makes them less valuable as there are not that many entry and egress points and in many cases not in the same point on a river. You would need to maintain/prepare and entry and egress point at which time much of the advantage is lost. The US manual on river crossing notes the number of tanks that can cross can be as low as 5 due to them dumping water onto the banks making impassible mud.

Amphibius assults like D-day spent large amounts of time surveying beaches to define which were sutable for vehicals to cross.

Who needs to pull a jet-ski, but 25mph is (barely) fast enough to pull a water-skier! Talk about a recruiter's dream!

Yes, in many cases if you did want to swim M113s, the engineers may have to prep the bank(s) as well. However, it's better to have the ability then not … The M113 was developed on lessons learned in WWII in the ETO and the Korean War mostly. Being able to cross bodies of water is an advantage. Many of the lessons however, had to be relearned though …

Do these look cool or what?

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Dan
TMP link

Ok, I can definitely see a use for those little toys as a scout platoon's wheels, CC.

One problem with just about any amphibious vehicle is that they are not particularly sneaky. That EFV I posted about? Loud, but it's really intended to perform the same job as a Sherman DD. The Marine LAVs have a pair of props on the stern, so they can wallow across rivers and lakes. They all make large wakes, even at 5 knots, never mind under the influence of high-power jet drives, and it's easy to detect a wake at long distances.