History of the T-62

[Stuart Galbraith]

 

Only what I remember seeing in weapons and tactics of the Soviet Army, which had a similar table to that which you saw above, which I believe was from the TRADOC report on the T62.

 

Bear in mind, the US Army and the Israelis did test the hell out of it. They did know what made it tick, so I dont think the comments should be dismissed out of hand.

 

 

Why the disparity? Well the 105 was a rifle, and the 115mm was a smoothbore. The latter inevitably translates into better penetration, as we saw in the Rheinmetall 120mm. But you need a first rate fire laser rangefinder, stab and fire control to get the range out of it, and T62 for the most part didnt have these things. Id be curious though to see if the variants equipped with Laser rangefinder did any better though.

 

 

But where is it ever stated that the 115mm gun itself was inaccurate at long range? There's certainly nothing in TRADOC reports that says this, and nothing in FM71-2 either.

 

There's a huge difference between the technical capabilities of the gun and ammunition and the accuracy of the tank as a whole. These two things shouldn't be confused.

 

As for rifled vs smoothbore... The APFSDS rounds fired from the 115mm U-5TS of the T-62 had significantly lower dispersion than the APDS rounds fired from the 100mm U-8TS of the T-62A at 2,000 meters.

 

 

You know, Im going to take back most of what I say, and shows the difficulty of relying on memory. Or Maybe, just my memory.

 

This is page 136 of the 1988 edition of Weapons and tactics of the soviet army

 

''U5Ts accuracy reportedly deteriorates in sustained combat due to the effects of a hot barrel on the shells, or fouling due to incomplete combustion for the chamber.''

....

'' Despite this, the Israeli's are reportedly satisfied with the U-5TS and consider it capable of first round kills up to 4000m range''.

 

Which is completely contrary to what I remember. I remember them saying it was superior to the 105mm at short range. But perhaps what they were saying was 'particularly at short range'. ?

 

That said, there is a chart here showing performance of HVAPFSDS with a tank equipped with a laser rangefinder, and it shows a 43 percent chance of a hit at a target at 2000 metres. Its apparent the laser is much more accurate than the Stadia (first round for a stadia it gives 27 percent, 51 for second). Which is not shabby, and agrees with what you say, but im not sure how that correlates with first round kills at 4000m though.

[Stuart Galbraith]

 

 

stadiametric rangefinder is not that bad

 

 

Challenger 1/Chieftain with stadiametric for example

 

https://tankandafvnews.com/wo-194-2946-a-technical-assessment-of-the-t-55/

 

this report IIRC have some info about stadiametric on T-55

 

all this articles about "T-62/other soviet tank inaccurate" do you have any firing tables for 115mm or reports to prove that ?

 

 

Only what I remember seeing in weapons and tactics of the Soviet Army, which had a similar table to that which you saw above, which I believe was from the TRADOC report on the T62.

 

Bear in mind, the US Army and the Israelis did test the hell out of it. They did know what made it tick, so I dont think the comments should be dismissed out of hand.

 

 

Why the disparity? Well the 105 was a rifle, and the 115mm was a smoothbore. The latter inevitably translates into better penetration, as we saw in the Rheinmetall 120mm. But you need a first rate fire laser rangefinder, stab and fire control to get the range out of it, and T62 for the most part didnt have these things. Id be curious though to see if the variants equipped with Laser rangefinder did any better though.

 

Just an ex-sailor trying to remember, but the more or less average firing range distance NATO and Warsaw Pact tanks were expected to meet each other in Germany was about 1K to 1.5 K?

 

 

In Southern Germany, the USAEUR sector, yes. But it was a lot more open in the North, you are looking something like 2000-3000 metres in places.

[Interlinked]

 

You know, Im going to take back most of what I say, and shows the difficulty of relying on memory. Or Maybe, just my memory.

 

This is page 136 of the 1988 edition of Weapons and tactics of the soviet army

 

''U5Ts accuracy reportedly deteriorates in sustained combat due to the effects of a hot barrel on the shells, or fouling due to incomplete combustion for the chamber.''

....

'' Despite this, the Israeli's are reportedly satisfied with the U-5TS and consider it capable of first round kills up to 4000m range''.

 

Which is completely contrary to what I remember. I remember them saying it was superior to the 105mm at short range. But perhaps what they were saying was 'particularly at short range'. ?

 

That said, there is a chart here showing performance of HVAPFSDS with a tank equipped with a laser rangefinder, and it shows a 43 percent chance of a hit at a target at 2000 metres. Its apparent the laser is much more accurate than the Stadia (first round for a stadia it gives 27 percent, 51 for second). Which is not shabby, and agrees with what you say, but im not sure how that correlates with first round kills at 4000m though.

 

 

That chart sounds interesting. Could you post it here?

[Stuart Galbraith]

Sure.

 

Ammunition Shot at Target Rangefinder Target 500m 1000m 1500m 2000 2500 3000

 

BR5 AVAPFSDS 1st Stadia Static 98% 79% 50% 27% 14% 8%

BR5 AVAPFSDS 2nd Stadia Static 98% 84% 66% 51% 40% 32%

BR5 AVAPFSDS 1st Laser Static 98% 86% 60% 43% 20% 10%

BR5 AVAPFSDS 1st Stadia Moving 94% 75% 33% 19% 8% Nil

BK-4M HEAT 1st Stadia Static 89% 69% 33% 11% 3% 3%

BK-4M HEAT 1st Stadia Moving 75% 30% 5% Nil Nil Nil

 

Im not sure where they got this from, I had thought this might be from TRADOC. There is also a listing for 105mm rounds, and the APDS round it lists is not much different in performance from that listed for the 115mm APFSDS round with laser rangefinder.

[RETAC21]

It's from TRADOC derived from testing of ex-Syrian and Egyptian hardware provided by Israel

[Ken Estes]

Measuring stadia lines when I was a midshipman training on a destroyer in the Med was one thing, but I think as a gunner or TC on a tank under fire, I'd much prefer an optical or laser rangefinder, just for comfort.

[GARGEAN]

Measuring stadia lines when I was a midshipman training on a destroyer in the Med was one thing, but I think as a gunner or TC on a tank under fire, I'd much prefer an optical or laser rangefinder, just for comfort.

I think one would prefer cannon with better ballistics. Measuring short ranges is not even necessity and measuring long ones is pain in such situation with optical too. LRF is very different matter tho.

[DB]

Well, the nature of the ammunition may dominate the velocity issue, so at what point does HEAT need ranging, or HESH/HEP

[DKTanker]

Well, the nature of the ammunition may dominate the velocity issue, so at what point does HEAT need ranging, or HESH/HEP

Speaking only for M456 and M830 HEAT, beyond 1000 meters or so knowing the range becomes crucial for a 1st round hit. HESH/HEP, 800 meters was about the limit. Obviously I can't speak for the Russian equivalents, but for HEAT ammunition I should think it would generally be the same. They use HE, not HEP, so that might actually be better than their HEAT.

[Hakka]

Speaking only for M456 and M830 HEAT, beyond 1000 meters or so knowing the range becomes crucial for a 1st round hit. HESH/HEP, 800 meters was about the limit. Obviously I can't speak for the Russian equivalents, but for HEAT ammunition I should think it would generally be the same. They use HE, not HEP, so that might actually be better than their HEAT.

Yeah it's the same for the Soviet tanks. For the T-62, the maximum effective range of the HEAT round was 950 meters (50% probability of hit). Original 115mm HE-Frag rounds were ballistically matched with the HEAT rounds according to Interlinked's blog.

Edited July 30, 2019 by Hakka

[methos]

Relevant:

 

Trajectories and flight time of AP, HVAP, APDS, HEAT and HESH/HEP to a distance of 2,000 m.

 

Spread/hit offset of HESH/HEP, HEAT and APDS rounds to a distance of 2,000 m with a 10 m/s cross wind.

[Interlinked]

Kurzgesagt: using HESH is a real challenge for the gunner

[KV7]

Why did the HESH round have such low velocity ? I thought it would weigh less than the HE round as a result of not having the thick steel casing.

Edited July 30, 2019 by KV7

[Stefan Kotsch]

The shell body must be very thin for the squeezing effect. This prohibits excessive acceleration on firing. So the initial velocity must be relatively low.

Edited July 30, 2019 by Stefan Kotsch

[Ken Estes]

Kurzgesagt: using HESH is a real challenge for the gunner

No kidding. Estimating/measuring range and leading the target is bad enough, but for the natural drift of the round to the right, requiring its own reticle - also range based - made it a chore that few US gunners wanted to entertain. And then there were stowage issues if I remember correctly, equivalent to WP.

[Interlinked]

The shell body must be very thin for the squeezing effect. This prohibits excessive acceleration on firing. So the initial velocity must be relatively low.

 

It's not just that, but studies (or at least, the one study I read some time ago) showed that the effectiveness of the squashing effect using typical explosive compounds depends quite strongly on the impact velocity. Too fast (>600-700 m/s, IIRC), and the compound basically disintegrates on impact and only a fraction of the weight of explosives get detonated. The end result is almost no effect on the target. Too slow (<300-400 m/s, IIRC), and the squashed putty does not spread out at an optimal manner and the thickness of armour that can be defeated will decline by some amount.

[Panzermann]

And still Stuart will sing the praises of HESH despite all its drawbacks. IMHO today just using KE, HEAT and a programmable fused multipurpose HE-FRAG with a hardened tip are better for todays targets, because HESH is easily blocked with spaced armour.

---

 

Kurzgesagt: using HESH is a real challenge for the gunner

No kidding. Estimating/measuring range and leading the target is bad enough, but for the natural drift of the round to the right, requiring its own reticle - also range based - made it a chore that few US gunners wanted to entertain. And then there were stowage issues if I remember correctly, equivalent to WP.

 

Not surprsing, both WP and HESH have a lot of dangerous filler and thin walls.

[Chris Werb]

If you want to try out stadia ranging yourself, Steel Beasts does a great job of simulating it in various vehicles, including the T-55. I am guessing that the new realistically undulating terrain will make it even more realistic as you will often not be able to see the entire height of the vehicle.

[DB]

I hope they start paying you for all this shameless promotion

 

I think at this point everyone realises that HESH is relegated to being an available HE round of questionable value in a "real" war. <Werb>A bit like aircraft carriers.</Werb>

[DKTanker]

Not surprsing, both WP and HESH have a lot of dangerous filler and thin walls.

That's not the problem, the problem is that WP has a relatively low melting point, 111F or 44C. So what can happen is that a WP round stowed in a horizontal position might be subjected to temperatures in excess of the WP melting point. Not a big problem if the round is fired while the WP is in a liquid state. However, should the temperature fall below 111F, the once liquid WP, which was seeking its own level, will solidify with the WP to one side of the projectile interior. I'm sure you can imagine just how unstable the flight of that round would be. Stowing the rounds upright means the WP will always be symmetrically balanced around the interior circumference of the projectile.

 

While Composition B (HEP/HESH) has a higher melting point, one which wouldn't be achieved in the hottest of deserts, the concern is that that the explosive could become plastic enough to flow. Again, seeking its own level. And again making accurate fire impossible.

[Interlinked]

If you want to try out stadia ranging yourself, Steel Beasts does a great job of simulating it in various vehicles, including the T-55. I am guessing that the new realistically undulating terrain will make it even more realistic as you will often not be able to see the entire height of the vehicle.

 

Speaking of SB, I'm reminded of the appallingly slow reload speed in the T-62. I hope that gets changed soon.

[GARGEAN]

And still Stuart will sing the praises of HESH despite all its drawbacks. IMHO today just using KE, HEAT and a programmable fused multipurpose HE-FRAG with a hardened tip are better for todays targets, because HESH is easily blocked with spaced armour.

 

Even HEAT is barely practical. MPHE-FRAG and APFSDS is essentially all you need.

[Stuart Galbraith]

And still Stuart will sing the praises of HESH despite all its drawbacks. IMHO today just using KE, HEAT and a programmable fused multipurpose HE-FRAG with a hardened tip are better for todays targets, because HESH is easily blocked with spaced armour.

 

 

---

 

Kurzgesagt: using HESH is a real challenge for the gunner

No kidding. Estimating/measuring range and leading the target is bad enough, but for the natural drift of the round to the right, requiring its own reticle - also range based - made it a chore that few US gunners wanted to entertain. And then there were stowage issues if I remember correctly, equivalent to WP.

 

Not surprsing, both WP and HESH have a lot of dangerous filler and thin walls.

 

Now that is misrepresenting my position. Yes, HESH is obsolescent. My contention is, its not obsolescent enough to justify replacing the L30. It still works well at its primary mission of knocking holes in walls or killing soldiers, or very lightly armoured vehicles.

 

If we really wanted a more sophisticated round, we could easily replace FV432 mortar vehicles with a turret mounted 120mm mortar system. But we dont.

[Panzermann]

No, HESH is obsolete. It is not really good anymore against armoured vehicles and sucks against buildings. Just replace it with a programmable HE. Is there even a supplier for HESH left?

 

 

Replacing the L30 is not really in the budget, because that would mean completely rebuilding the turret for the then most probably chosen 120 mm smoothbore with its fixed ammunition.

[bojan]

 

While Composition B (HEP/HESH) has a higher melting point, one which wouldn't be achieved in the hottest of deserts, the concern is that that the explosive could become plastic enough to flow. Again, seeking its own level. And again making accurate fire impossible.

 

Some HESH warheads also have front part inert, made of paraffin wax or bitumen, which both have pretty low melting point.