HEAT round has two settings? What for?

Cap'n Jack

Cap'n Jack

Final Approach
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Cap'n Jack
I was visiting customers and one of them had unusual door stops. The pointy end could be rotated to one of two settings. What do the settings mean?

Air and Ground?

Air doesn't make sense unless the tank is shooting at a helicopter, maybe. I'm pretty sure a helicopter is difficult to aim at unless they are just hovering in one spot.

JAK_1162 by Jack Silver, on Flickr

JAK_1161 by Jack Silver, on Flickr
 
Armor-piercing vs. Contact (ground) fusing?

Ron Wanttaja
 
google HEAT-MP-T brought up a link to a pdf describing the new(-ish) round.

Apparently it has an air-burst mode vs ground mode.

"....The M830A1 uses a discarding sabot with sub-caliber warhead and a multifunction fuzing system. Its unique airburst capability is quickly selectable by the tank crewman."
 
Proximity fuse setting for use against helicopters and softer targets…Prox fuses are great unless it’s raining…but thats for another discussion…cool door stop though, I would like one.
 
Why the hell would a tank engage a helicopter with the main gun? That is what the coax is for.
 
Sac Arrow said:
Why the hell would a tank engage a helicopter with the main gun? That is what the coax is for.
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Makes perfect sense to me. I also prefer to kill a fly with a cinder block instead of a lousy fly swatter.
 
Spring Ford said:
Page 12 (printed), 14/56 (pdf counter) of link has a article about this round. Air mode is proximity fuzed and intended primarily for use against helicopters.

https://www.benning.army.mil/Armor/eARMOR/content/issues/1994/MAY_JUN/ArmorMayJune1994web.pdf
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Thanks much, answers it well.

What's the battery situation, for that proximity fuse? Do they have to drop a couple of AAs in before deployment, is there a way to test battery capacity without disassembly, etc. Seems like the round would need a "freshness date" on it, to tell you when a trip to Costco is needed to get new batteries.

I'm assuming surplus supplies of these are being used by people with blue and yellow flags on their uniforms right now...what assures them the batteries aren't flat?

Ron Wanttaja
 
Cap'n Jack said:
I was visiting customers and one of them had unusual door stops. The pointy end could be rotated to one of two settings. What do the settings mean?

Air and Ground?

Air doesn't make sense unless the tank is shooting at a helicopter, maybe. I'm pretty sure a helicopter is difficult to aim at unless they are just hovering in one spot.

JAK_1162 by Jack Silver, on Flickr

JAK_1161 by Jack Silver, on Flickr
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I dunno. What I do know is, that's a customer you probably don't want to pizz off.
 
wanttaja said:
What's the battery situation, for that proximity fuse?
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Dunno about the new ones, but the original ones had a vial full of electrolyte that would break when the round was fired, flowing into the cell and energizing the fuze circuitry.
 
Wish I knew some tankers from back in the day. As I remember, the early production Abrams had the standard 105 mm rifled tank gun, and were all retrofitted with the 120 mm smoothbore Bofors guns by the mid 80's. They were also very fast. I -think- that later production tanks were equipped with speed limiters to keep suspension components from breaking. The quoted speed of the M1 is 45 mph. I know for a fact they were faster than that. A lot faster.
 
My company supported the first Gunnery of M-1’s Germany as they ARTEP’ed he first battalion fielded. We traded AH-1 Cobra rides for M1 rides…This was prior to the governor and there was no doubt it could well exceed 50mph. These tanks were so new crews removed their boots and slipped into tennis shoes inside the tank to keep them spotless. I got my ride in socks. Original M1 had the same gun as the M60 but the fire control computer and stability stuff made it much better shooting on the move. We figured out fast that they also could give us accurate weather. All this happened at range 301 at Graf…
 
Warlock said:
My company supported the first Gunnery of M-1’s Germany as they ARTEP’ed he first battalion fielded. We traded AH-1 Cobra rides for M1 rides…This was prior to the governor and there was no doubt it could well exceed 50mph. These tanks were so new crews removed their boots and slipped into tennis shoes inside the tank to keep them spotless. I got my ride in socks. Original M1 had the same gun as the M60 but the fire control computer and stability stuff made it much better shooting on the move. We figured out fast that they also could give us accurate weather. All this happened at range 301 at Graf…
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Right, as I understand the gun was the same as the M60's but the round itself fed information in to the fire control computer and it took in to account barrel deflection (thermal, etc.) They were designed as first shot weapons.

We had M2 Bradleys. I never played gunner much but I have fired a couple TOW's and lots of 25mm. The 25mm was a sweet shooter. But it wasn't a tank. The whole point of an IFV is to sort of keep up with tanks and get Infantry to the fight in relative safety plus offer some fire support against wheeled vehicles and lightly armored IFV's, eg. BMP's and BTR's. The TOW could take out a tank, but it was at best a flanking, or a rear shot. If you had to face off with a tank, you'd lose. The TOW is a wire guided missile, and you had to keep the tracker trained on the target until impact, and it took several seconds for the missile to travel downrange. If a tank detected that you fired, you were likely dead meat.

I had been told that the (ungoverned) M1's could reach 70 mph on a flat road. That seems high, but they definitely could exceed 50 and I've seen them just fly across fields at unreal speeds.

Been there at Graf. Many times.
 
Bob Noel said:
google HEAT-MP-T brought up a link to a pdf describing the new(-ish) round.

Apparently it has an air-burst mode vs ground mode.

"....The M830A1 uses a discarding sabot with sub-caliber warhead and a multifunction fuzing system. Its unique airburst capability is quickly selectable by the tank crewman."
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Thanks!
Sac Arrow said:
Why the hell would a tank engage a helicopter with the main gun? That is what the coax is for.
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I didn't think the main gun could target a helicopter unless it was just hovering, but I've no knowledge on the subject either. I guess A=air and G=ground after all!
 
A family friend was a tank driver mid 90s. He said 70mph also.
 
That TOW missile 23 seconds to wire cut at 3750 meters…a long time to keep the reticle on the target and improved for us by the Israelis. With running fire in a desert environment you could launch the TOW at 4500 meters and fly it for 18-20 seconds above the target and make the break at impact just less than 3750… and right at ZSU range…AH -64 and Hellfire made it much less personal…
 
Sac Arrow said:
Why the hell would a tank engage a helicopter with the main gun? That is what the coax is for.
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I've never been in a tank. But they used to make the cannons for them just up the river at Watervliet. At one time, M1 main gun was one of the most accurate direct fire weapons in the world. Some of the folks at the arsenal got to go along to some of the shooting competitions between the different NATO armies. If they can see a stationary target or moving vehicle, more or less they can hit it. Higher velocity and lower spread than a .50 cal. Also back in the old days, a low hover right off the ground, popping up to engage, was supposed to be a helicopter anti-armor missile tactic. To keep below radar and be less visible overall...and I think not just the TOW were wire guided, but other army's too. The 120mm round is several times faster than a TOW.

So if you're an enemy helicopter hovering just off the deck, and you're within range, a proximity fused main round from an M1 would seem like a credible threat. I think the theory was to then force the helicopters to go higher and to keep moving, where they could be engaged by stingers and aircraft. But that's just a guess of a theory.

It's a great doorstop.
 
The air burst allows the warhead to explode over objects in bunkers.

It's pretty hard to hide from something exploding ten feet above your head. Boom!
 
Albany Tom said:
I've never been in a tank. But they used to make the cannons for them just up the river at Watervliet.
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I don't know if they still give tours, but that place is amazing to see.
 
Albany Tom said:
I've never been in a tank. But they used to make the cannons for them just up the river at Watervliet. At one time, M1 main gun was one of the most accurate direct fire weapons in the world. Some of the folks at the arsenal got to go along to some of the shooting competitions between the different NATO armies. If they can see a stationary target or moving vehicle, more or less they can hit it. Higher velocity and lower spread than a .50 cal. Also back in the old days, a low hover right off the ground, popping up to engage, was supposed to be a helicopter anti-armor missile tactic. To keep below radar and be less visible overall...and I think not just the TOW were wire guided, but other army's too. The 120mm round is several times faster than a TOW.

So if you're an enemy helicopter hovering just off the deck, and you're within range, a proximity fused main round from an M1 would seem like a credible threat. I think the theory was to then force the helicopters to go higher and to keep moving, where they could be engaged by stingers and aircraft. But that's just a guess of a theory.

It's a great doorstop.
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Just to be clear, I never would have considered engaging a helicopter with a TOW and it was not in any training scenario. At least at the time. The 25 mm though, would be able to shred a helicopter pretty quickly. HE rounds for soft targets like wheels and helicopters, and AP rounds for light armor like IFVs. The 25 mm AP rounds were also sabots, so high velocity but obviously much lower kinetic energy than a tank round.
 
Warlock said:
AH -64 and Hellfire made it much less personal…
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And a HELLFIRE (yes, it’s an acronym) fired off a Predator is even less personal.

Or try the JAGM version with a LOAL capability and take on a non-LOS target.
 
IK04 said:
The air burst allows the warhead to explode over objects in bunkers.

It's pretty hard to hide from something exploding ten feet above your head. Boom!
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How does one set the fuse to go off over the bunker? I'd understand if it were an artillery round where the round is generally ballistic and a proximity fuse detects the ground. But tank rounds have a flat trajectory, correct? That means they fly over and past the bunker?
 
Cap'n Jack said:
How does one set the fuse to go off over the bunker? I'd understand if it were an artillery round where the round is generally ballistic and a proximity fuse detects the ground. But tank rounds have a flat trajectory, correct? That means they fly over and past the bunker?
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Use of the wall in space theory, many modern munition coming out of some systems can be fused based on a fire control computer laser range and environmental factors hitting an imaginary wall and exploding…Hydra 70 rockets are a good example…
 
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Sac Arrow said:
Just to be clear, I never would have considered engaging a helicopter with a TOW and it was not in any training scenario. At least at the time. The 25 mm though, would be able to shred a helicopter pretty quickly. HE rounds for soft targets like wheels and helicopters, and AP rounds for light armor like IFVs. The 25 mm AP rounds were also sabots, so high velocity but obviously much lower kinetic energy than a tank round.
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I actually meant the other way around...I probably phrased it poorly, late night typing. A helicopter trying to launch a TOW or other wire guided missile against an M1 with a 120mm proximity round. Completely outside my area to even evaluate, and I'd suspect it would take incredible timing and maybe luck for the M1 crew to react that quickly...but in theory, the 120mm has a lot less flight time than the TOW. I'm sure it's all public knowledge now, but when the 120mm came out, the muzzle velocity was eyebrow raising for all of the people used to rifled guns.
 
Albany Tom said:
I actually meant the other way around...I probably phrased it poorly, late night typing. A helicopter trying to launch a TOW or other wire guided missile against an M1 with a 120mm proximity round. Completely outside my area to even evaluate, and I'd suspect it would take incredible timing and maybe luck for the M1 crew to react that quickly...but in theory, the 120mm has a lot less flight time than the TOW. I'm sure it's all public knowledge now, but when the 120mm came out, the muzzle velocity was eyebrow raising for all of the people used to rifled guns.
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Helicopters have been used to launch TOWs before, but they still have the same limitation that ground fired units have - they have to be stationary, as in very still. The tank crew wouldn't necessarily need a proximity fused round, and they would have on the order of 10-20 seconds to react depending on the range.

If they have a round loaded, and they are already facing the launcher, then the tank would likely win if the launch was detected in time, even if they were firing a standard kinetic sabot round. TOW shots are flanking or rear shots. In a faceoff situation with a tank, the TOW gunner is in a very bad place.

maxresdefault.jpg

This is a picture of a Bradley firing a TOW. When deployed, the launcher unit elevates and depresses with the main gun. You can get an idea of the limit that the barrel can be depressed, so it's going to be unlikely to find a suitable berm that is able to hide the vehicle with only the launcher sticking out. Standard practice for using the main gun (and that goes for tanks too) is to come up out of a berm, take a shot, or a series of shots with the 25 mm, and back out until the next target is ready for engagement. But you can't do that with the TOW, you have to have at least the turret exposed, and probably the hull too, until impact.
 
Launching a TOW from a helicopter you could manuver sideways as long as the TSU can see the target…also a test we did late in the game of TOW and AH-1s showed we could also launch in running fire up to 120kts as long as we were oriented toward the target. During training to support operation Enduring Freedom we even tried to fire them at night under self illumination using 2.75 inch rockets…the TOW was daytime only but the idea was for it to hit like an area weapon on an oil rig or tank farm…that failed miserably with or without NVG’s…
 
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The Bradley had a pretty sophisticated passive IR night vision sight. The sights were common for the 25mm, coax and TOW. In fact, it was in some cases easier to see targets and follow tracer rounds during the day using night sights. The Dragon (baby TOW, man portable ATWGM) also had a passive IR night tracker unit, which was fairly useless since it weighed fifty pounds and had a form factor that didn't allow it to be easily carried. Cryogenic cooling was achieved through pressurized gas bottles, giving about ten minutes of use per bottle.
 
Did Dragon have any practical value? It always seemed like a last ditch sort of thing to me, but I know that things that seem obvious to a lay person are really way more complicated.
 
Albany Tom said:
Did Dragon have any practical value? It always seemed like a last ditch sort of thing to me, but I know that things that seem obvious to a lay person are really way more complicated.
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I think so. It was a light Infantry weapon, and it was truly man portable unlike a ground tripod TOW mount which has to be transported by some type of vehicle. I would consider it more of a weapon of opportunity. It wasn't that much larger or heavier than a LAW, but it had a much greater range and was much more capable. A dismount team or other light Infantry unit camped out in the hills could potentially blast the bejesus out of a BMP or stop or disable a T72 if they had one handy. And by the way, ground troops bearing anti-tank weapons are the second biggest threat to tanks, next to other tanks. This is why Infantry, armor, and artillery have sort of a rock scissors paper type of relationship.

Being a light Infantry weapon, the Dragon's relevance was more in a European or jungle type theater, and not in desert warfare, where ground troops are not going to be very far from armor, and armored transports bearing heavier weapons. These days, there are more compact and more capable portable anti-tank weapons. The TOW and the Dragon came out about the same time. The Dragon was phased out in the 90's, and the TOW is still in service.
 
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Javelin the Dragon replacement fixed many of the issues…added a seeker head and has proven very effective in Beta testing in Ukraine…LAW was always that last desperate act in my book.
 
Warlock said:
Javelin the Dragon replacement fixed many of the issues…added a seeker head and has proven very effective in Beta testing in Ukraine…LAW was always that last desperate act in my book.
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Yeah that is a tough one. The LAW was definitely an underperformer. It wasn't quite like the Russian RPG, as in it was designed to poke small holes in light targets but not be an area weapon. We trained with LAWs in basic, but they were never an issue weapon in either of my TOD units. We never really had an equivalent to an RPG. The closest we had was the 40mm grenade launched from the M203, or the later automatic 40mm Mk 19 grenade launchers.
 
wanttaja said:
What's the battery situation, for that proximity fuse?
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This just drifted by on twitter regarding GMLRS (I think it is) rocket batteries —

"The guidance system is powered by a lithium thermal battery. The electrolyte is solid so the battery won't deteriorate in storage. Just before launch, pyrotechnics inside the battery melt the electrolyte. The battery then provides electricity like a normal (but hot) battery."
FYxiGk2WYAENqD-


https://twitter.com/kenshirriff/status/1552723519087198208
 
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