Thursday, August 4, 2016

Revisiting Pen and Armor values for Team Yaakav

As I have been digging into the literature on the Lebanon war, I've come across some new information that made me want to rethink the conclusions and assumptions I made when I first made my unit cards for the various tanks on both sides.

Armor Penetrations

I came across a really revealing passage in "Operation Peace for Galilee" by Richard Gabriel.

"The Merkava's special armor also proved itself.  The Israelis have a data base of tank-armor protection against which they assess the performance of their M-60 and Centurion tanks and the enemy's T-62's.  The Israeli analysis showed that, under fire, there is a 61 percent probability that a round striking a tank will penetrate.  For the Merkava, the rate at which rounds striking it penetrated was 41 percent.  In addition, there is a 30 percent probability that a penetrating round will also penetrate the crew compartment; in the Merkava, it was 13 percent.  Its special armor and the placement of the engine in the front makes it almost invulnerable from the front.  No known tank round can penetrate the front glacis to the crew's compartment.  IDF data also show that in 31 percent of tank hits the tank will catch fire; by comparison, the Merkava caught fire only 15 percent of the times it was hit.  The data show that of tanks lit afire, 85 percent to 90 percent are completely destroyed.  In Lebanon, no Merkava was lost as a consequence of being set aflame."

I'm going to use this as my basis along with set armor values from Team Yankee for determining Pen and Armor values for the other tanks.  But first, I need look at penetration values.

I'm using a couple sites for armor penetration values.
1. Tankograd - https://thesovietarmourblog.blogspot.com/  This is a very well researched site with everything referenced.  There is a page for T-62 and T-72 (plus BMPs and other Soviet armor.
2.  World of Tanks post -  http://forum.worldoftanks.eu/index.php?/topic/128208-modern-gun-penetration-values/  The references used on this page are a broken link but the values they have match those for those on the Tankograd site.
3.  Steel Beasts - http://www.steelbeasts.com/sbwiki/index.php?title=Ammunition_Data  The data on this site has a lot higher penetration that other sites but it has some interesting notes about the different rounds.  I'm using the notes not the penetration values.

Ammo for T-62

Here are the possible rounds the Syrians could of used in 1982 in their T-62's:

BM-6 - used in Yom Kippur War, 1973.  280mm penetration at 0 degrees and 1000m* (Tankograd).  246mm at 2000m (World of Tanks)

BM-21 - 330mm penetration at 0 degrees and 1000m (Tankograd)

BM-6 Round
 
Ammo for T-72


BM-9 - 245mm penetration at 0 degrees and 2000m (Tankograd). The original APFSDS round for the 125mm gun.  It was sent out with the T-72 Urals.  According to Steelbeasts website, this was the round probably used by Syrians in 1982.

BM-15 - 310mm penetration at 0 degrees and 2000m (Tankograd).  This is the next better round that Syrians could of had.

BM-15 Round

Ammo for T-55

BM-8 - 238mm penetration at 2000m; 257mm at 1000m (worldoftanks site).  SteelBeasts assumes Middle East countries used this until mid-80s.

BM-25 - 296mm penetration at 2000m; 320mm at 1000m (worldoftanks site)

APDS Round for T-55
 Ammo for Israeli 105mm

After Sultan Yacoub, the Syrians found a new round in the tanks they captured; the M111 "Hetz" round.  You can read all about it at ((http://www.israelmilitary.net/showthread.php?t=679).  Gabriel says this about it in "Operation Peace for Galilee":

"In addition, the Israelis have developed a new round for the 105mm gun, an armor-piercing, fin-stablized, discarding-sabot hypershot round.  This Hetz, or arrow round, can reach and penetrate tank targets at a range exceeding 5,500 meters.  This means that the Israeli tank's ability to engage in combat at a range of the larger Soviet T-62 and T-72 gun."

M111 "Hetz" - 310 mm at 2000m (worldoftanks site also collaborated at http://echo501.tripod.com/Military/105ammo.htm )

The previous round was the L52 round used during Yom Kippur war, 240mm penetration at 2000m.


M111 round on left

Gun Summary

I'm going with the more likely rounds used during this war.  The BM-6 round for T-62, BM-9 round for T-72 and BM-8 round for T-55.  At 2000m, the penetrations are 246mm, 245mm and 238mm, respectively.  Very similar.  The Israeli Hetz round was found in captured tanks so I'll use that as the standard Israeli round.  It has 310mm penetration - markedly better than the older Soviet rounds.

Armor Values

I wanted to keep the standard so kept the T-72 armor from Team Yankee and gave the Merkava 1 the same armor as the US M1 Abrams.  Looking at the armor values in my A Fist Full of TOWs 3 book, that was acceptable.  I then used the Israeli penetration statistics to back out what the penetration should be for the Soviet guns.  The Merkava was penetrated 40% of the time.  I thought I could round that down to 33% due to the very low chance of crew compartment penetration.  With this in mind, I set the Soviet penetration values as 20 (for all guns since the penetration values were very close), two above the the Merkava's front armor.  At normal range, this will give the Soviet tanks a 1 in 6 chance of taking out the tank from the front (something that was shown to be very difficult).  I set the Remount value to 2+ due to the very low chance of crew compartment penetration and being set aflame.  Also, due to the advanced armor, I gave the Merkava I the BDD rule against HEAT weapons.  Wiki says the Merkava didn't get composite armor like Chobham until the 3rd version.

Looks like this Merkava fell off one of the mountain roads


With the Soviet guns at Pen 20, I needed to set the M-60 armor to fit the penetration probability of 60%.  I chose a front armor of 16 as that would allow the tank to be penetrated 50% of the time at normal range and the additional 1 in 6 chance of bailing.  The remount was set to 3+ since the crew compartment penetration was about twice of the Merkava.  Since the M-48 armor was slightly thinner than the M-60, the front armor value of the M-48 was set to 15.  That would give the M-48 a 1 in 6 chance of bouncing an incoming shot which seemed about right.

The Israelis tanks, with their Hetz ammo, have one better penetration than the Soviet rounds, Pen of 21.  I kept with Team Yankee front armor of 16 for the T-72.  The T-62 had 5-10% more armor than a T-55.  Since the guns are the same penetration, I wanted some difference between the tanks, so I figure the T-62 will have one better armor than the T-55.  The T-62 Tankograd website has the following on it's armor (https://thesovietarmourblog.blogspot.com/2015/12/t-62.html),

"Like the T-55 before it, the hull of the T-62 was essentially immune to American 90mm APBC at ranges exceeding 1000 m. However, due to the lack of any improvements to the armouring scheme meant that the T-62 had absolutely no chance of surviving the new British 105mm L7 cannon and its APDS ammunition any closer than 2000 m, even in a hull-down position."

Not looking good.  So, I gave the T-62 a front armor of 15.  Against the Israeli Pen of 21, the T-62s only chance of survival is rolling a 6 and then it's more than likely bailed.  The T-55 with a front armor of 14 doesn't even get that.  It's only hope is getting hit at long range.  The armor values of the T-62 and T-55 might be a bit high compared to the more heavily armored T-72 when the game is based on a D6 you can't have very big differences between armor and pen before absolute blow outs occur.  I think these odds of saving make sense. My FFT3 book has the M-60 with one higher armor than the T-62 also but, again using a D6 that limits the range you have to work.

T-55 from Syrian 85 (Mech.) Brigade, hit on the Beiruit-Alei road

 Updated Unit Cards

Here is a link to my updated unit cards.  They are in Microsoft PowerPoint - link

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*An interesting tidbit from Tankograd:

"It be remembered that the Soviet standard for certifying armour piercing projectiles is a V80, or 80%, referring to the expected consistency of achieving full armour perforation given a certain projectile velocity. In formulas, V80 must replace V50 (50% armour perforation). For example, if a certain projectile has to penetrate 500mm of steel, then at least 80% of all projectiles of that type must achieve that standard. This is very different from the NATO standard of only 50%. Soviet standards were not only stricter, but the steel they used for targets was of a greater hardness than NATO targets. In reality, the given penetration data does not correspond to the actual achievable penetration of these shells."

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