"Are swimming vehicles more or less vulnerable to fire?" Topic

When amphibious vehicles are in the act of swimming are they more or less vulnerable to direct fire or artillery fire? Presumably they are more visible. I don't think that water would offer any protection to direct fire. I would think that the loss of forward momentum from any kind of a hit would could lead to getting swamped. It would seem that direct fire would be more lethal, but what about artillery? Is water dense enough to set off a shell? Would a shell going off on the river bed be more or less lethal? How would water effect the blast and shrapnel? Do any rule sets actually cover this?

River crossing are considered only slightly less dangerous than amphibious landings.
Vehicles have no cover or concealment, they can't maneuver or take evasive action, most can't return fire (except for small arms) and even miss with a from enemy artillery can swamp and sink the vehicle. If the vehicle is equipped with external flotation (like the M163,) if those components can be even partial damaged it can send the vehicle to the bottom.

Harder to hit with direct fire, due to being "hull down" in the water.

Probably a "wash" (pun intended) for indirect HE fire – less shrapnel will hit, but the waves the impacts/explosions will make, assuming they go off at all on impact with the water, could help swamp the vehicles.

They're also moving a lot slower while swimming too.

Artillery shells certain to detonate. Water is incompressible and near-misses in naval combat consistently detonate.

Direct fire protection depends on the size and velocity of the round. 37mm AP is going to lose velocity fast; 115mm AP much less so. No idea what would happen with long rod penetrator, whether the narrow diameter would cause shatter, if the trajectory would be knocked completely off (fin stabilization providing much less force relatively when the fins are in air and the body is entering the water, what happens when the fins hit the water, etc.).

thanks, sort of what i was thinking. I'm thinking that you could use the same "to hit" number but make the damage one category worse

Smaller targets but still they are basically in the open …

We swam our M113s a few times. And again, they may be a smaller target, but still vulnerable.

One tactic would be to lay smoke to cover the river crossing. It will make them harder to hit. But the smoke obviously won't stop any rounds/incoming fire. And even a near miss say from a large FA round, e.g. 152mm could cause damage and you may sink.

Our sister Bn sunk an M113 in training … 3 died sadly … RIP soldiers. And again that was just practicing swimming across a river.

For gaming purposes you may want to put some sort of rule in there for just that type of event. E.g. In an old AH wargame "Panzer Leader", IIRC. In of the Normandy scenarios. You roll a 6 and your M4 DD sinks … But that was a beach assault not a river crossing, etc. However, either way it could happen …

Well my Cavalry Squadron swam a large lake at Fort Hood. Our company did not lose a track but the Squadron lost five tracks as a whole. Two M113, 1 M577 and two M551s. All vehicles had empty milk jugs attached that would float to Mark the spot for the recovery crews later in the day. Nobody was killed. More later.

My platoon had 6 M113, 1 M106, 3 M551, the HQ section had 1 M557 and 2 M113. So our company had 20 M113, 3 M106, 1 M557 and 9 M551. Add in the other companies and the Sqdn HQ M557s four and M113s and it was a massive exercise. It was observed by many special guests including foreign officers.
I posted on my Facebook page some of the photos from the swim. The hardest part was setting up and breaking down the swim kits for the M551. Floated with cargo top open and men visible.
More vulnerable? Yes to artillery and mortar fire. Waves from misses could swamp the driver.
First fire was a tough very low silhouette.
Returning fire with .50 cal HMG was difficult. TOWs impossible, M551, main gun no way. Covering fire with the smoke grenade launchers ok.

Yea, most swimming armor is really marginal at that.

About the only one I can think of that might be decent is the olde, Soviet/Russian, PT-76. Looks to be a quite large vehicle with minimal armor, so probably has decent flotation. From the videos I've seen of them, they've got a decent amount of freeboard – looks like more than most of the "swimming" class. They can even fire their main guns while swimming, albeit probably not very accurately, even if in glass-like seas/lakes/rivers.

We lost an AAV and a bunch of soldiers in SoCal in just the last couple of weeks due to a mistake, or mishap. A bunch of guys died, sadly, but a few survived.

We lost a lot more swimming Shermans in the assault on the Normandy beaches. I think the whole unit was wiped out as I seem to recall – not sure if they intended to land on Omaha, or not, but the conditions were rough (obviously too rough for that at the time).

Thanks for sharing those anecdotes, guys.

What year was that, Rudy? I'm curious about the TO&E for your unit(s).

For the 10 x vehicle platoon, I'm guessing 5 x M113s for the scout section – 2 x sections of 2 plus an HQ of 1 x M113. Then, 1 x more M113 to carry the infantry, and/or to act as the HQ vehicle for the whole unit. The one support M106 track, and of course, the obligatory three tank section also. Sound about right?

For the company, 2 x M113s in the HQ, along with 1 x M577?

I did not post it since I had posted it before. I did not want to bore Legion, wolfhag, and others.
The First Cavalry was part of the Division Restructuring tests for post Vietnam with a focus on Europe.
My Armored Cavalry platoon had a heavy support section of 3 x M551 Sheridans, in 1979-80 we replaced the Sheridans with M1 Abrams.then the term shifted to tank section. (12 with Plt Sgt)
One mortar track with a 4.2" mortar. (5)
One M113 with an infantry squad. (11)
One scout section with two M113 with dragons, motorcycle and a crew of three. Each scout track worked with a M901 TOW track with a crew of three. Some test exercises bumped each of these up to four in order to keep a driver in the track at all times. (12)
HQ section was me with one M113 and a crew of three. (3). LAWs but no dragoon. Often I had a stinger team attached or an artillery FO. For reforged one year we even had an Air Force Major riding with us to direct air assets. A few times we would have a MI CEWI or GSR M113 attached.
Not counting the attachments we had 43 men and 10 tracks. So it was one of the largest platoons of the 1970s and early 1980s
By mid-1980s the infantry squad was lost, sent to Mech company.
The vehicles of the DRS trials varied over time.
Initially the First Brigade had five tank platoons. The second Brigade had three tank platoons. The Third Brigade had four tank platoons which was actually the size recommended by the commission after the trials.
In the cavalry we actually had gun jeeps post Vietnamization era. In the scout section and my command section. We had M60 MGs and ground mounted TOWs in trailers. Those were crowded with three crew. We then went to M113 and M901 in about 1978. The Abrams came the next year.

Hi Rudy,

Thanks for the reply and info.

Weren't there 2 x scout sections with 2 x M113s each in the "platoon" (so large, always seemed more like a company to me)?

Those, plus the M113 Inf. Squad and the other M113 track as the HQ vehicle, for a total of six M113s like you listed above.

Sorry for being dense on this, but I think that's what I recall reading, and/or we discussed before. I'm working on my 1/144th TO&Es for this unit. Looks like I need to order another M113.

Also, when you got the M-1 tanks, didn't the quantity of those increase to 4, from the 3 x M551s (and/or the older M48 tanks)?

IIRC for the M60A1/A3, and/or the M-1 orgs, I think the TO&E was as follows, from memory, but not sure on timing:

Armd. Cav. Platoon:
4 x M60 or M-1 Tanks
5 x M113s (or 3 x M113s; and either 2 x M-150s w/TOW, or M901s)
1 x M106

So, no M-150s for your guys, eh, prior to the M901s?

Now being Manoeuvre Group authors and lovers of complex and interesting scenarios we have looked at a few interesting scenarios involving rivers.

First I should point out I live in the UK. Past experience of folk outside the UK is that they look at our rivers somewhat askance. They would tend to call it a Brook

I live close to the River Trent our third longest river (185 miles). It is about 50 yds or less wide and navigable by small boats such as an amphibious vehicles over much of its length. Having personally done some investigations, the banks in summer are in many places 5 ft. high. Viewed cross wise you need to be almost at the bank (within 15 yds.) to see down onto an amphibious vehicle. Therefore on straight stretches it's very hard to get a shot. Admittedly shooting down the river is easy but where it winds you can only observe very short stretches so it would take a lot of weapons to guard certain sections. The only issue with the Trent is that Entrance and Egress is difficult the essentially soil banks are too steep over much of its length, near vertical. Plus being soil quoting the US manual on river crossing it would probably only allow about 10 vehicles out of an unimproved crossing before it became impassably muddy.

However such rivers do lend themselves to interesting reconnaissance and low level combat and while amphibious troop carriers are of little use in numbers, as once improved a 50 yd. crossing is not worth an amphibious vehicle. Like Russian and many European countries and the UK amphibious recon vehicles are worth having.

So with repect to fire, it can be hull down, turret down or completely obscured. Clearly scenario design is critical in getting what you want but there are some interesting issues.

Hope this proves of interest

I did not post it since I had posted it before. I did not want to bore Legion, wolfhag,

No problem Rudy ! I like to hear about other Vets' experiences, etc. I'm old and can't remember all the the TO&Es anymore …

50 yds or less wide and navigable by small boats such as an amphibious vehicles over much of its length. Having personally done some investigations, the banks in summer are in many places 5 ft. high. Viewed cross wise you need to be almost at the bank (within 15 yds.) to see down onto an amphibious vehicle.

A narrow river is always easier to cross obviously. Whether in vehicles or rubber boats, i.e. RB-15 or Zodiac, been there done that. Even did beach insertions from off a coast in RB-15s.

You have to look at the weather conditions and in turn the speed and conditions of the river, stream, coast, etc. With AFVs you have to have strong enough shoulders and not too steep to allow a crossing, etc. Even if just fording. You need to determine if the bottom of the ford point is solid enough, etc. As well as look at the geology of the earth/soil to determine if it will be a muddy mess after a number of vehicles had crossed.

Being frequently attached to M60 MBT Bns. We'd have to recon a ford point at times for those monsters and out M113s. The MBTs can't swim obviously. We'd even prefer to ford our M113s vs. swimming. If it is shallow enough, had a solid bottom, etc.

Crossing any Linear Danger Area, e.g. a road or trail, stream or river, etc., can always be challenging. Whether on foot or in a vehicle. Take the proper precautions and get across/thru it a quickly as possible. But again, that is no surprise either.

If you could avoid swimming you probably would. But some times you may have no choice …

Also in US GI lingo a Brook … you could easily wade thru on foot or even in a vehicle. Which we did frequently with little to no difficulty. Of course you'd get your feet/legs wet if dismounted. And in certain weather conditions like an ROK winter you don't want to do that.

In places like Panama, in the jungle we were always crossing wet areas, e.g. swamps, streams and even shallow rivers on foot.

Legion4 my attempt at humor clearly failed. Most folk look at our rivers and look strange, our rivers are very small, some you can even wade across, but the Trent is a bit bigger than that. ;-).

Crossing a narrow body of water was different than crossing a wide body of water. That is one reason why our crossing of the huge lake with a squadron drew so much outside interest. Prior to that we had conducted platoon or company sized crossing of narrow waterways. Getting the M113s across was easier than the M551. In a combat environment, we never expected to deploy the swim kits due to shrapnel damage from artillery.
N regard to the M901, remember we had ground mounted TOWs and gun jeeps for so long, the we skipped other generations. One note some platoons replaced their M113 and M901 with TOw HUMVEE and dragon HUMVEE.
The term section and teams can be confusing and may have varied with units. Our TOE board which the vehicle status with crew assignments used the term Scout section as having four vehicles. Tactically these would be deployed in two vehicle team Dragon + TOE. Our platoon could be deployed up to 1 1/2 kilometers in mixed terrain. In open or desert terrain it was often even greater. A point defense assignment was the main instance when we could see each. I spent many of a hour driving between defensive positions and swerved like a drunk between positions when on the advance.
It is hard not to ignore the attachments to the TOE. The Electronic communication Warfare and Intelligence M113 was essential to Division G2 and Brigade S2. Just as important was the Ground Survelliance Radar track. The ADA Stinger or Red Eye track was key for local air cover.
Now while someone from Europe may have a different response but I never saw a M60 assigned to Armored Cavalry units. Only M1 and M551.
Oh yes if fielding a AC Squadron, do not forget Delta Troop. Having those Cobras at your back while withdrawing under fire was very reassuring.

Our scout handbook ensured that we reported a water features, width, depth, water current, composition and hardness of the bed, another traffic ability data point was the condition and how steep the banks were. If it was a specific water crossing point we would comment on the cover of the area.

Legion4 my attempt at humor clearly failed.

As has mine … 🤩

And Rudy +1