Armored Fighting Vehicles Version M5 (it is a tradition now)

[grimlock1]

Is that a direct consequence of the exothermic reaction of brewing up, or does removal of the protective paint layer cause this? I would have expected modern armour alloys to be stainless ....

As steels go, stainless is relatively weak. Even at lower loading levels, I have a high-carbon kitchen knife that holds an edge better than my stainless kitchen knives.

[chanman]

Is that a direct consequence of the exothermic reaction of brewing up, or does removal of the protective paint layer cause this? I would have expected modern armour alloys to be stainless ....

No for the same reason most steel applications aren't stainless (like cars, for instance). Stainless steel is both more expensive in materials costs (and possibly manufacturing), but more importantly, it might not be possible to get the desired material properties (hardness, ductility, etc.) in a stainless alloy.

[MoneyLovinOgre4Hire]

Stainless steel tends to be pretty brittle and prone to shattering under stress.  A lot of the fantasy swords sold in malls and comic book stores are made out of stainless steel and will snap under their own weight if actually removed from their scabbards.

[Daryk]

Snap under their own weight?  That sounds more than a bit incredible..  ???

[MoneyLovinOgre4Hire]

They're cheap, mass-produced garbage that was never intended to be anything other than a means of separating a nerd from his money.

[truetanker]

I can test that... I have held the He-Man sword... Heavy as hell and it wobbled a lot when test swing... Same with the Conan sword... Real swords are made with iron or steel... These are either shitty pewter covered chrome aka imitation stainless or some suspicious crafty shit...

TT

[Daryk]

I suppose, but that's a REALLY low bar...  8)

[Cannonshop]

Snap under their own weight?  That sounds more than a bit incredible..  ???

It may sound incredible, but it's not that far from the facts.  a lot of the 'Fantasy Swords' sold to mall-ninjas are made of cheap alloys, which were then not-heat-treated correctly *IF AT ALL.

They're like that, because tehy aren't being made to be USED.  The term "Wall-hanger" is accurate here.  The term 'cheap' can be understood to be 'just this side of the casting slag'.

Competently made blades are expensive, but it's pretty easy to make something that 'looks good' if it doesn't need to stand up to use.

[Daryk]

True, but you have to admit that "under their own weight" is an EXTREMELY low bar...  ^-^

[truetanker]

I have a demacus claymore that not only is she super sharp, I haven't the need to touch her up with a whetstone. But I also have a period Hand a Half that is fishy because I had to touch it up after an hour of swing. Balance was pretty good, but the blade was dull...

TT

[MoneyLovinOgre4Hire]

True, but you have to admit that "under their own weight" is an EXTREMELY low bar...  ^-^

From what I understand, it's usually the ones that have the elaborate patterns on the blades that are prone to that.  But just about any of them can be at risk because there's little if any quality control.

And to get back on subject, here's an M551 Sheridan with its problematic, unreliable 152mm gun-launcher (seriously, if you're going to call a weapon that, it really ought to launch guns).

[Failure16]

Ah, 3/11. I don't think I have ever seen a 551 that pristine before. Good Lord. The background looks Irwinish, or close enough, so is that some kind of a museum display (doubly so, since the Blackhorse hasn't had its 3rd Squadron activated since probably the 90s)?

Looking around for that image, I've seen that tank in more worn condition:

[BairdEC]

Would that Sheridan happen to be serial No. 1?  Back when it was 63 AR and 52 INF, we had No. 1 in the motor pool.  Supposedly, it was going to be fixed up and sent to the armor museum at Ft. Knox, but it didn't happen when I was stationed there.

[MoneyLovinOgre4Hire]

Ah, 3/11. I don't think I have ever seen a 551 that pristine before. Good Lord. The background looks Irwinish, or close enough, so is that some kind of a museum display (doubly so, since the Blackhorse hasn't had its 3rd Squadron activated since probably the 90s)?

Looking around for that image, I've seen that tank in more worn condition:

Yeah, both pics were taken at the same place: you can see the same vehicle in the left rear of it.  What is that thing, a bridge layer?

[truetanker]

What is that thing, a bridge layer?

Answer:
http://4.bp.blogspot.com/-ZvIRdCqYjSY/UTI28p1xC4I/AAAAAAAASAw/pDMX1qNmfPY/s1600/IMG_1025001.jpg
M74 Tank Recovery Vehicle

TT

[Natasha Kerensky]

Arresting images from today’s New York Times:

[I am Belch II]

Ah, 3/11. I don't think I have ever seen a 551 that pristine before. Good Lord. The background looks Irwinish, or close enough, so is that some kind of a museum display (doubly so, since the Blackhorse hasn't had its 3rd Squadron activated since probably the 90s)?

Looking around for that image, I've seen that tank in more worn condition:

I wonder gun/missile was ever fired hwile the Sheridan was floating because it was designed too.

[MoneyLovinOgre4Hire]

I don't recall hearing of any amphibious tanks that were actually capable of fighting while in the water.  Most of them tended to be fairly unstable and prone to flipping over, trying to fire the main gun would presumably exacerbate that significantly.

[mikecj]

Funny story.  I was doing ROTC Advanced Camp at Bragg and one of the 82nd's Sheridans came crashing out of the pines in front of my hole, took a hard turn and went around our position.  I'll never forget the recognition pattern (chevrons and dots) on it.  Fast forward 17 years and my battalion commander has a photo with the same markings- turned out he almost ran me over when he was the tank commander.  His platoon of the 3-73 Armor had been tasked out to the Camp.
He was fond of saying after meetings that he never should have told the driver to pivot left.  I've always paid more attention & effort when I'm digging in after that.

[glitterboy2098]

I wonder gun/missile was ever fired hwile the Sheridan was floating because it was designed too.

probably not, because in order to actually 'swim' it had to deploy canvas screens to boost its bouyancy, similar to the older DD sherman. and those blocked the gun's line of fire except for the highest elevation. and trying to fire it with those up would basically set the fabric on fire and cause the tank to sink.




the main reason it is considered amphibious is the fact it was designed with the swimming screens and duplex drive components as a standard, unlike previous swimming tanks, which had to be converted to such use and were thus in short supply when the swimming ability was needed. (especially as the Marine Corps tended to monopolize them, which meant the Army didn't really have that option for performing and supporting river crossings very often)

the M113 similarly was originally designed to be amphibious using deployable screens, though it used a design where the track motion provided the motive force in water. that ability was removed from the M113A2 and onward due to the added weight of all the additiona armor and systems that had been added to fix the survivability and reliability issues the original and M113A1 models had

[chanman]

I don't recall hearing of any amphibious tanks that were actually capable of fighting while in the water.  Most of them tended to be fairly unstable and prone to flipping over, trying to fire the main gun would presumably exacerbate that significantly.

The PLA's Type 05 amphibious AFVs have a 105mm version, with video of both it and the IFV version firing in the water here: https://www.youtube.com/watch?v=gdvtn3ELBrE

[Sabelkatten]

Note that they only fire the gun straight ahead. I suspect the only practical use for the firing capability is smoke or HE for general suppression.

IIRC the old Swedish IKV91 could, technically, fire when swimming. But I doubt anyone bothered, it was intended to cross rivers and small lakes not do naval invasions!

[MoneyLovinOgre4Hire]

Yeah, I caught that.  It also looks longer and wider than a Sheridan.

[kato]

I don't recall hearing of any amphibious tanks that were actually capable of fighting while in the water.

Rostec claimed that the Sprut SDM1 was supposed to be able to fire while afloat (with very limited traverse across the bow arc), and was planning to start a test series in the Black Sea late last year.

Not that the first afloat firing trials from 2020 looked like that'd be all that successful in really hitting anything:


The German WW2 Schwimmpanzer II - 52 built, never issued - could fire its main gun perfectly fine while afloat. Mostly because the design took a complete Panzer II, wrapped it in a full boat hull about five times the size - and the main gun was 20mm.

[Daryk]

Yeah, the shockwaves from firing that close to the water couldn't have done anything good for accuracy...  8)

[I am Belch II]

That is some blast form that cannon on that tank

[grimlock1]

Yeah, the shockwaves from firing that close to the water couldn't have done anything good for accuracy...  8)

I suppose a modern gun stabilizer would have the range of travel to account for pitching and rolling of the water.

[BATTLEMASTER]

It's my understanding that the gun on the Sheridan had some real kick to it when firing shells.  The other issue I think had to do with the caseless ammunition not completely clearing the breach, which caused the crew to suffocate or immolate, or something like that.  I think they did eventually fix that otherwise the tanks wouldn't have been used in Desert Storm/Shield.

I think a longer-barreled variant of that gun was used on the MBT-70 prototype.

[Garrand]

It's my understanding that the gun on the Sheridan had some real kick to it when firing shells.  The other issue I think had to do with the caseless ammunition not completely clearing the breach, which caused the crew to suffocate or immolate, or something like that.  I think they did eventually fix that otherwise the tanks wouldn't have been used in Desert Storm/Shield.

I think a longer-barreled variant of that gun was used on the MBT-70 prototype.

The problem with the M551 was that the caseless ammo would not always be totally consumed, so there would be burning embers still in the barrel when the next round was loaded. This increased the chances of a cook off, either prematurely firing the round, or actually causing an explosion before the breech was closed. This was resolved later by a CBSS (Closed Bore Scavenger System), that pushed compressed air through the barrel to clear it before loading. Many modern tanks, including the M1A1, have this system.

Another issue was that the rounds tended to absorb moisture from the air. This was especially an issue in Vietnam, where the air was often hot & humid. This caused the rounds to warp & deform, sometimes to the point where they cannot be chambered anymore. One resolution was to wrap them in plastic, to be removed immediately before firing. I don't know if the ammo was further refined at a later date.

The gun was probably a little too powerful for the hull. When firing often the first pair, or even the first two pair, of road wheels would lose contact with the ground.

The MBT-70 indeed did have a similar gun, longer barreled though. The M60A2 as well. Though those were quickly withdrawn from service, about the same time as the M551 was withdrawn from service (save as an Airborne Assault Vehicle & VisMODS).

There were attempts to remedy the armament issue, to keep the M551 relevant (the actual vehicle itself was pretty good; just that the main gun was very problematic). This included fitting the turret with the 76mm high velocity cannon from the M41 Walker Bulldog, as well as attempts to fit a 90mm cannon. None of these solutions were used, & the vehicle was withdrawn anyway.

Damon.

[CVB]

There are also some photos of an XM274 ARES 75mm caseless automatic gun in an unmanned turret atop an M551. Not sure if this was a pure testbed for the gun or someone actually tried to build an operational AFV.