Anti-Tank Guided Missles

[Warmonger2005]

Ok so the next combat mission game is modern warfare. Therefore one weapon to be introduced will be ATGMs. I have a couple questions on how these will be handled in the game.

1) ATGMs have very long ranges but travel rather slowly compared to most weapons. It is quite possible for one to be still in flight at the end of the turn. Will the flight of this weapon e held and resolved on the next turn or will it arrive even after the time has run out like artillery?

2) Due to the slow speed of these weapons it is possible for an alert tank crew to take defensive actions if they spot the launch. These defensive measure could enclude some of the following:

Susppresion: Fire at the launcher site and try and disrupt or kill the soldier guiding the missle.

Move to cover: Simply move the target AFV out of sight of the launcher

Swerve: The tank could as a desperate measure speed up to maximum speed and swerve at the last moment to throw off the aim of the ATGM. This tactic was successfully used by the Isreali's during the war in 1973. I have read accounts of Isreali tanks returning from battle drapped with the guide line of missles which just missed the target.

My question is will defensive attempts like these be built in to the AI?

Warmonger

[c3k]

Warmonger,

Good points, especially about missiles in mid-flight at the end of a turn.

However, I'm curious about the swerve manuever. (I thought the Sagger-wire draping was more due to operator error or aiming at other tanks rather than vehicular vector changes.)

Some off-the-cuff calculations: 60 mph = 88 fps

Lets assume a tank is moving at 15 mph - a reasonable advance speed. That's 22 fps. Assume a generic ATGM moves at 600 mph (barely subsonic), which is 880 fps. At what range does the ATGM fire? Say, 1,000 yards; which is 3,000 feet. That's less than 3.5 seconds of flight time. In that 3.5 seconds, the tank can (assuming it will CHANGE it's velocity) get a delta V of 22 fps. That would change its EXPECTED location by 77 feet. ASSUMING it saw and reacted with zero inertia INSTANTLY upon ATGM firing. Give it some delay, 1 second, some inertia (assume an acceleration of 1/2 its velocity/second) and that distance drops. I get about 33 feet. If it's a GUIDED missile, that's approximately one vehicle length. Not much of a factor.

I'm sceptical of the suppression fire tactic.

Pick all the assumptions to shreds. If a NON-TARGETED unit tries to suppress the ATGM unit, I'm okay with it. Please don't tell me that every tank (or most, or a large proportion) will know it's being fired at, it can find the specific ATGM unit (ignore scores of Egyptian Sagger units) which has THAT tank targeted, can slew a weapon in that direction, range in and get rounds close enough to suppress... You see my sceptisism?

(Again, I'll grant if the target units outnumber the ATGM firing units it MAY be possible.)

We need some real analysis on this.

Regards,

Ken

[Midnight Warrior]

I think 600 mph is a bit fast.

For example go here and you will see that the maximum TOF for a TOW missile is 20 sec.

[Renaud]

When I was on M1's (late 87-91) we did do 'sagger drills' in which you speed up to 35-40mph and swerved in big arcs. The commander was supposed to lay the gun toward the puff-o'-smoke indicating the launch site while the gunner was in 3x power. The gunner would then acquire the target and start hosing it while the commander fired .50 in the general direction. (the loaders m240 was useless beyond 200 meters)

This all assumes you actually saw the launch signature, which is unlikely unless the crew is unbuttoned and looking in the direction of launch. Even then, unlikely.

All in all, we didn't kid ourselves about the chances of the sagger drill one day saving our bacon. More a tactic of desperation. We hoped the armor was up to the task. Which it largely turned out to be (from the front, mind you).

In training, a simulated OPFOR sagger which hits was assumed to KIA any M1 from any aspect. I always assumed this was done on the theory that overestimating the threat was the best course.

In reality, I don't think the original sagger could penetrate the frontal armor of the original M1, probably not even the side turret or hull. Unless it hits the drivers hatch, which is a narrow/small weak point, but very real. Or the turret top/engine deck/rear, all of which virtually anything can penetrate (20-40mm plain steel).

I wonder how BF will determine what weapon can penetrate what armor...much simpler in WWII where you have ample historical research, yet we still argued about the minutea for days on end. Modern weapons are often top secret, like the details of chobham armor, kinetic penetrators, advanced defense systems and systems to defeat those systems. It's bewilderingly complex and mostly unknown.

I for one won't expect some pie-in-the-sky realism. If its plausible, i'm good. Judgement calls will be part of the modelling here, much more so than even in armor/penetration modeling for a WWII era game.

[c3k]

Midnight Warrior,

Thanks. Not being snotty here, as I said those were off-cuff numbers. Using the SAME website, the maximum range for a TOW 2 is 3750 meters. The flight time to reach maximum range is 21 seconds. Let's do some math: 3750 meters x 39 inches/meter = 146,250 inches. That divided by 12 inches/foot = 12,187 feet. 12,187 feet/21 seconds = 580 feet per second.

So, my 880 fps is fast. BUT, is the TOW 2B booster/sustainer firing for the duration of flight? Or, does it glide the last bit? I don't know.

If I'm wrong on all counts, then the ATGM takes twice as long (being generous) to reach the tank. So, the tank can be up to two vehicle lengths away from the predicted impact point; of a GUIDED missile.

I think Renaud's training account is much more accurate.

Thanks,

Ken

[M1A1TC]

Yes, we always did Sagger Drills when I was still armor. Its a standard practice for a driver to be on a lookout for puffs of smoke indicating sagger launch, and then attempt do a zig-zag pattern

Hey Renaud, what unit were you in? I was in 3rd ID, 2-69 C Co in Ft Benning, GA, and 2nd ID, 1-72 C Co Camp Casey, South Korea

[ October 14, 2005, 08:01 PM: Message edited by: M1A1TankCommander ]

[Redcon-5]

I got to argee with Renuad. Even in the late 90's we still learned Sager drills in the M1's. Whether that was from experience in GW1 or just old habits die hard I cant say. But they seemed like so much BS we never thought it would save our lives.

However from the other side the Bradley Gunner's always complained that they had to hold a lock on the tank for 14 seconds before the Miles system woud call it a kill. In a small unit fight, say company team level, even odds that the Brad would be dead before the TOW hit. But that is just Miles and STIX lanes.

Is there a Brad Gunner out there that could say if this time limit was any realtion to real combat? (Of course no one probably had a stop watch going durring combat.)

[Warmonger2005]

Another aspect of ATGMs that I didn't know until I looked at the web site that Midnight Warrior found is that the velocity of the TOW ATGM drops during flight. The graph found at the site shows an initial velocity of 300m/sec but it slowly drops to 100m/sec at the missles max range. I always thought missle velocities remain around the same until the missle ran out of fuel.

Warmonger

[Renaud]

My impression from watching guys fire TOWs and vids of dragon and Saggers is that the old wire-guided first generation ATGMs were hard as heck to control. Especially dragons and saggers. Saggers had this silly little joystick which controlled the directional jets.

Javelins and such are nothing like those old ATGM's. For starters, they aren't wire guided. They are usually electo-optical or somesuch with fire and forget capability, target recognition, etc. I imagine the newest rusky ones are too. Not to mention top-attack.

I was with E Troop 2/3ACR (loader-driver, then a bit of gunnery, the usual progression). Then in 91 was a reserve tank commander (!) with a V Corp replacement battalion at Graf during Gulfwar. That was fun. Got a friend in Korea now, 1LT with mech infantry.

Hey redcon I remember that. I bet that 14 sec figure comes from 'average flight time at 3000 meters' or somesuch nonsense. Took some stones with the old M113 TOW, where you had to be standing up with the launcher. :eek: At least on the brad you can be hull down and it's a remote launcher/sight.

[SD Smack]

Ok guys I have a question...

How will the turns simulate ATGM fire. What I mean by this is if a ITV fires at a target a long distance away at 56 seconds left in the turn, will the missle still continue to fly after the turn is over? (like artillery in CMx1) Or will it stop in mid-flight as players plot there next moves? This could allow for the "sagger drill" to occur but in the long run I dont think it will matter.

just wondering

[YankeeDog]

IMHO, it's absoultely criticall that BFC solves the turn-end discontinuity thing for SM:SF in some way. ATGMs are probably the biggest single reason, but there's other stuff, too, like LGBs, that have a considerable number of seconds between release (or fire) time, and impact time.

Given the increasing number of guided weapons systems on the modern battlefield, it's just not going to work if, at second 60 of every turn, all units freeze while the remaining ordnance "en route" continues to fly on to target.

But I have faith that BFC realizes this. They were well aware that this was a problem in CMx1, and I'm sure it was high on their list to fix for CMx2.

Cheers,

YD

[Renaud]

Yawn. I don't see it as a show-stopper if some missiles need to be finished up at the end of a turn.

Sure, it would be nice if the missiles froze in flight at the end of the turn so we could look at them and say 'COOL' and for a wonderful sense of temporal continuity. But if I can see the frozen missile during orders phase, I can trace it's flight path and get a good idea of where it came from, knowledge that wouldn't be available in reality (the missile is a blur or dot at best). That's a big deal if we are talking about missiles with reduced or no launch signature such as javelin launched by grunts who need to remain undetected to live.

So optimally, you freeze all the missiles during orders phase, but they are invisible, or at best small directionless dots. FOW would apply to spotting launch signatures.

[Drusus]

The TOW is out of fuel after the first 300m. After that is uses the velocity (300 m/s) it gained during the first 300m to fly to its target.

[hellfish]

I spent about a year as an on-again, off-again Dragon gunner and, while I never fired live rounds, I did get a few turns in the simulator and, later on, I got some time with a TOW simulator. I remember that tracking a moving target was extraordinarily difficult, especially if it was maneuvering.

I also recall that the Dragon and the TOW only have limited course correction capability - meaning you can only adjust so much before you burn the thrusters out and you're SOL.

I've seen a lot of pH/pK probabilities for ATGMs, but I'm guessing that those are only for stationary targets (which are actually pretty easy to hit, IIRC). I wouldn't be at all suprised if the pH for a moving target was half that of a stationary target.

[Renaud]

So it can coast for over 3000 meters? Wow.

[Kurtz]

Originally posted by fytinghellfish:

I also recall that the Dragon and the TOW only have limited course correction capability - meaning you can only adjust so much before you burn the thrusters out and you're SOL.

Do these missiles have engines for manouvering? Don't they use fins and rudder for that?

I'm trained as an ATGM team leader (the Swedish BILL top-attack missile) and that missile don't have engines for manouvering, just for boosting the speed.

Although the BILL can kill a tank from all angles, firing againt the front is considered almost suicidal because the tank crew has most of its attention focused in that direction.

Treat your ATGM as every other AT-asset and fire against the flanks, preferably from position where not everyone can fire back at you.

The BILL use a small charge to propel the missile some distance away from the launcher vefore the missile's engine start. The engine burns for a few seconds (should I remember how long, 15 years later? ), after that the missile glides towards its target. Maximum velocity is something like 200-250 m/s which has slowed down to 65m/s at 2000 m.

[Salkin]

Originally posted by Kurtz:

</font><blockquote>quote:</font><hr />Originally posted by fytinghellfish:

I also recall that the Dragon and the TOW only have limited course correction capability - meaning you can only adjust so much before you burn the thrusters out and you're SOL.

Do these missiles have engines for manouvering? Don't they use fins and rudder for that?

I'm trained as an ATGM team leader (the Swedish BILL top-attack missile) and that missile don't have engines for manouvering, just for boosting the speed.

Although the BILL can kill a tank from all angles, firing againt the front is considered almost suicidal because the tank crew has most of its attention focused in that direction.

Treat your ATGM as every other AT-asset and fire against the flanks, preferably from position where not everyone can fire back at you.

The BILL use a small charge to propel the missile some distance away from the launcher vefore the missile's engine start. The engine burns for a few seconds (should I remember how long, 15 years later? ), after that the missile glides towards its target. Maximum velocity is something like 200-250 m/s which has slowed down to 65m/s at 2000 m. </font>

[Kurtz]

Hey Salkin, do you think we can find a loader around here? :cool:

The BILL is a top-attack missile, it flies about a meter above line-of-sight and has a warhead angled 30 degrees downward. There is a BILL 2 with two warheads pointed vertically, the first one removes reactive armour, the second strikes the same spot.

Both BILL and BILL 2 should be able to kill all existing tanks. The BILL 2 is probably a bit of a overkill right now.

I think the top-attack profile makes it more lethal than the LOS-attacking TOWs. The direction of the blast is downward, into the ammo compartment under the floor of Soviet-designed tanks. And the effectiveness of sloped frontal armour is reduced since it strikes at (or about) right angle to the armour. If it strikes the top armour, the angle doesn't really matter that much.

Compared to the TOW, the BILL is:

- lighter (35-40kg loaded; Sight: 5kg + thermal sight add-on 5kg, tripod: 10kg, missile in launch tube: 20kg)

- Top attack (but there are TOWs with top-attack)

- Shorter range (2000 m)

- Slower (11 s time of flight to 2000 m)

- Longer minimum range 150 m (65 m for the original TOW, didn't find any figure for newer models)

- Cost? Probably cheaper, but I can't say for sure.

TOW is mostly used from vehicles, but there is a tripod. Can't comment on how often it is used in the field. Doesn't look like something I would like to drag around the countryside. BILL is designed to be man-portable (but the ammo-bearer should carry 2 missiles :eek: )

pros & cons of top-attack:

- Hits the (comparatively) thin roof armour.

- Less useful against other targets, although BILL 2 can be set to direct-attack or over-fly attack.

- Makes hull-down less effective since the entire vehicle is "visible" when the missile flies over it.

BILL 2 info

[ October 15, 2005, 05:34 AM: Message edited by: Kurtz ]

[John D Salt]

Originally posted by Renaud:

My impression from watching guys fire TOWs and vids of dragon and Saggers is that the old wire-guided first generation ATGMs were hard as heck to control. Especially dragons and saggers. [snips]

Quite right -- and Sagger, being an MCLOS (Manual Command-to-LOS) missile, needs to be even slower than a SACLOS (Semi-Automatic Command-to-LOS) missile like Dragon or TOW, because the controller has to actively fly it by joystick, rather than just keep the aiming point on the target.

The early MCLOS ATGMs such as SS-10, SS-11, Swatter, Snapper, Sagger and all those were worst of the lot, as the MCLOS used acceleration control -- move the joystick left, missile goes left and keeps going left, so you need to give it a nudge right, missile keeps going right... you get the idea. The operator needs to correct continuously to hit even a stationary target. Vigilant and Swingfire, though still MCLOS systems, used velocity control, so you could make a correction, the missile would move to the new commanded bearing, and the autopilot would keep it there, so it was possible to hit a static target "hands off" if the last correction was a good one. I've only had a couple of simulator shots with Swingfire, but it seemed pretty straightforward to me, and an absolute doddle compared to the Blowpipe simulator (Blowpipe was a MANPAD missile -- acceleration control, fast missile, horrid little thumb-joystick for control, and a bloody great missile lurching off your shoulder just as you are trying to concentrate).

I believe that Swingfire must be one of the slowest guided missiles ever to enter service. The great advantage such systems had, lost with the move to SACLOS, was launcher separation, where the controller could be sited something like 50m away from the missile launcher, at the penalty of a slightly increased minimum range to gather the missile once fired.

All the best,

John.

[Kurtz]

In addition to what John said about early ATGMs it should be mentioned that they often have very long minimum range.

The Sagger has a minimum range of 500 meters! Try using that in urban areas!

Some German stuff from WW2 must of course be mentioned:

What about the Panzerabwehrrakete X-7 Rotkäppchen? And the Pz IVs used by Syria?

A question to the tankers out there:

How quickly can you fire at a detected target? Of course this depends partly on how much the turret have to be turned, but could you give an estimate if the target is "forward" or "to your side"?

On longer distances the time in flight of the tank's fire is another factor that ust be considered. The HE round may kill the ATGM crew after the misile has hit the tank.

[ October 15, 2005, 07:36 AM: Message edited by: Kurtz ]

[Salkin]

Good posts Kurtz.

We mostly worked with the BILL from Ambush positions . We prepared so that we would get flanking shots and then the plan was to get out of there as fast as possible. Did you also use the MTLB for transport Kurtz ?

//Salkin

[Sgt Joch]

According to soviet reports, the AT-3 SAGGER knocked 800 Israeli tanks (M-48s & M-60s) out of action for at least 24 hours in the Yom Kippur war, so they are a real threat, since Syria is supposed to have 3,000.

Having said that, they require a lot of training on the part of the operator, something the Syrian army is'nt strong on. The best troops will be equipped with the newer stuff, AT-14s and MILANs.

Also all the Syrian SAGGERs are at least 30 years old, we have no idea what conditions they are in or even how many can still fire.

I would be surprised if it's an effective weapon in CMSF.

[hellfish]

Originally posted by Kurtz:

</font><blockquote>quote:</font><hr />Originally posted by fytinghellfish:

I also recall that the Dragon and the TOW only have limited course correction capability - meaning you can only adjust so much before you burn the thrusters out and you're SOL.

Do these missiles have engines for manouvering? Don't they use fins and rudder for that?

</font>

[Battlefront.com]

Unlike the artillery rounds that complete their fall after the 60 second clock runs out, missiles and artillery will now "hang" until the turn starts up again. The missiles use real time tracking so there are no worries about gamey cheats where the guy stops the tank or what not to avoid being hit. The missile, if it is supposed to hit, will hit.

Steve

[Sirocco]

Originally posted by Battlefront.com:

The missiles use real time tracking so there are no worries about gamey cheats where the guy stops the tank or what not to avoid being hit.

Will we have to wait for CM:MATRIX for that?